Re: [PATCH 3/3] drm/connector: Deprecate split for BT.2020 in drm_colorspace enum
On Wed, 15 Feb 2023 at 20:54, Harry Wentland wrote: > On 2/15/23 06:46, Daniel Stone wrote: > > On Tue, 14 Feb 2023 at 16:57, Harry Wentland wrote: > >> On 2/14/23 10:49, Sebastian Wick wrote: > >> From what I've seen recently I am inclined to favor an incremental > >> approach more. The reason is that any API, or portion thereof, is > >> useless unless it's enabled full stack. When it isn't it becomes > >> dead code quickly, or never really works because we overlooked > >> one thing. The colorspace debacle shows how even something as > >> simple as extra enum values in KMS APIs shouldn't be added unless > >> someone in a canonical upstream project actually uses them. I > >> would argue that such a canonical upstream project actually has > >> to be a production environment and not something like Weston. > > > > Just to chime in as well that it is a real production environment; > > it's probably actually shipped the most of any compositor by a long > > way. It doesn't have much place on the desktop, but it does live in > > planes, trains, automobiles, digital signage, kiosks, STBs/TVs, and > > about a billion other places you might not have expected. > > > > Understood. > > Curious if there's a list of some concrete examples. If I was allowed to name them, I'd definitely be doing a much better job of promoting it ... but if you've bought a car in the last 7-8 years, it's much more likely than not that its console display is using Weston. Probably about 50% odds that you've flown on a plane whose IFE is driven by Weston. You've definitely walked past a lot of digital signage advertisements and display walls which are driven by Weston. There are a huge number of consumer products (and other modes of transport, would you believe?) that are too, but I can't name them because it gets too specific. The cars are probably using a 10+ year old (and frankly awful) SoC. The display walls are probably using a 6ish-year-old SoC with notoriously poor memory bandwidth. Or TVs trying to make 4K UIs fly on an ancient (pre-unified-shader) GPU. The hits go on. We do ship things on nice and capable new hardware as well, but keeping old hardware working with new software stacks is non-negotiable for us, and we have to bend over backwards to make that happen. > >> We should look at this from a use-case angle, similar to what > >> the gamescope guys are doing. Small steps, like: > >> 1) Add HDR10 output (PQ, BT.2020) to the display > >> 2) Add ability to do sRGB linear blending > >> 3) Add ability to do sRGB and PQ linear blending > >> 4) Post-blending 3D LUT > >> 5) Pre-blending 3D LUT > >> > >> At each stage the whole stack needs to work together in production. > > > > Personally, I do think at this stage we probably have enough of an > > understanding to be able to work with an intermediate solution. We > > just need to think hard about what that intermediate solution is - > > making sure that we don't end up in the same tangle of impossible > > semantics like the old 'broadcast RGB' / colorspace / HDR properties > > which were never thought through - so that it is something we can > > build on rather than something we have to work around. But it would be > > really good to make HDR10/HDR10+ media and HDR games work on HDR > > displays, yeah. > > I have a feeling we'll make some progress here this year. I definitely > think the whole HDR/Colour work is on the right track in Weston and > Wayland which will hopefully give us a good base to work with over > many years. Yep! Coming to the point you were making in the other mail - Weston was traditionally used as _the_ enablement vehicle for KMS, because we cared about using the depth of hardware much more than anyone else (e.g. being years ahead on planes), and the vendor who wanted to enable it either wanted to enable Weston specifically or just didn't have an open userspace stack for it. The other compositors couldn't be that vehicle, either because they were more focused on desktop UI, or they could just afford to throw the GPU at it and suck up the occasional frame hitch / thermal burn / etc. I like to think we had a reputation for being pretty thoughtful and careful with our review as well, and didn't give it lightly to misguided ideas which caused long-term problems. But we've got a greater diversity in userspace these days, and that's no bad thing. If the best vehicle to demonstrate HDR GPU rendering is gamescope, then use gamescope as that vehicle. We'll be there if we can, and if it makes sense for us, but it's not a requirement. Cheers, Daniel
Re: [PATCH 3/3] drm/connector: Deprecate split for BT.2020 in drm_colorspace enum
On 2/15/23 06:46, Daniel Stone wrote: > Hi, > > On Tue, 14 Feb 2023 at 16:57, Harry Wentland wrote: >> On 2/14/23 10:49, Sebastian Wick wrote: >> From what I've seen recently I am inclined to favor an incremental >> approach more. The reason is that any API, or portion thereof, is >> useless unless it's enabled full stack. When it isn't it becomes >> dead code quickly, or never really works because we overlooked >> one thing. The colorspace debacle shows how even something as >> simple as extra enum values in KMS APIs shouldn't be added unless >> someone in a canonical upstream project actually uses them. I >> would argue that such a canonical upstream project actually has >> to be a production environment and not something like Weston. > > Just to chime in as well that it is a real production environment; > it's probably actually shipped the most of any compositor by a long > way. It doesn't have much place on the desktop, but it does live in > planes, trains, automobiles, digital signage, kiosks, STBs/TVs, and > about a billion other places you might not have expected. > Understood. Curious if there's a list of some concrete examples. > Probably the main factor that joins all these together - apart from > not having much desktop-style click-and-drag reconfigurable UI - is > that we need to use the hardware pipeline as efficiently as possible, > because either we don't have the memory bandwidth to burn like > desktops, or we need to minimise it for power/thermal reasons. > I think we're very much aligned here. > Given that, we don't really want to paint ourselves into a corner with > incremental solutions that mean we can't do fully efficient things > later. We're also somewhat undermanned, and we've been using our > effort to try to make sure that the full solution - including full > colour-managed pathways for things like movie and TV post-prod > composition, design, etc - is possible at some point through the full > Wayland ecosystem at some point. The X11 experience was so horribly > botched that it wasn't really possible without a complete professional > setup, and that's something I personally don't want to see. However > ... Agreed. > >> I could see us getting to a fully new color pipeline API but >> the only way to do that is with a development model that supports >> it. While upstream needs to be our ultimate goal, a good way >> to bring in new APIs and ensure a full-stack implementation is >> to develop them in a downstream production kernel, alongside >> userspace that makes use of it. Once the implementation is >> proven in the downstream repos it can then go upstream. This >> brings new challenges, though, as things don't get wide >> testing and get out of sync with upstream quickly. The >> alternative is the incremental approach. >> >> We should look at this from a use-case angle, similar to what >> the gamescope guys are doing. Small steps, like: >> 1) Add HDR10 output (PQ, BT.2020) to the display >> 2) Add ability to do sRGB linear blending >> 3) Add ability to do sRGB and PQ linear blending >> 4) Post-blending 3D LUT >> 5) Pre-blending 3D LUT >> >> At each stage the whole stack needs to work together in production. > > Personally, I do think at this stage we probably have enough of an > understanding to be able to work with an intermediate solution. We > just need to think hard about what that intermediate solution is - > making sure that we don't end up in the same tangle of impossible > semantics like the old 'broadcast RGB' / colorspace / HDR properties > which were never thought through - so that it is something we can > build on rather than something we have to work around. But it would be > really good to make HDR10/HDR10+ media and HDR games work on HDR > displays, yeah. > I have a feeling we'll make some progress here this year. I definitely think the whole HDR/Colour work is on the right track in Weston and Wayland which will hopefully give us a good base to work with over many years. Harry > Cheers, > Daniel
Re: [PATCH 3/3] drm/connector: Deprecate split for BT.2020 in drm_colorspace enum
On 2/15/23 04:40, Pekka Paalanen wrote: > On Tue, 14 Feb 2023 15:04:52 -0500 > Harry Wentland wrote: > >> On 2/14/23 14:45, Sebastian Wick wrote: >>> On Tue, Feb 14, 2023 at 5:57 PM Harry Wentland >>> wrote: On 2/14/23 10:49, Sebastian Wick wrote: > On Fri, Feb 3, 2023 at 5:00 PM Ville Syrjälä > wrote: >> >> On Fri, Feb 03, 2023 at 10:24:52AM -0500, Harry Wentland wrote: >>> >>> >>> On 2/3/23 10:19, Ville Syrjälä wrote: On Fri, Feb 03, 2023 at 09:39:42AM -0500, Harry Wentland wrote: > > > On 2/3/23 07:59, Sebastian Wick wrote: >> On Fri, Feb 3, 2023 at 11:40 AM Ville Syrjälä >> wrote: >>> >>> On Fri, Feb 03, 2023 at 02:07:44AM +, Joshua Ashton wrote: Userspace has no way of controlling or knowing the pixel encoding currently, so there is no way for it to ever get the right values here. >>> >>> That applies to a lot of the other values as well (they are >>> explicitly RGB or YCC). The idea was that this property sets the >>> infoframe/MSA/SDP value exactly, and other properties should be >>> added to for use userspace to control the pixel encoding/colorspace >>> conversion(if desired, or userspace just makes sure to >>> directly feed in correct kind of data). >> >> I'm all for getting userspace control over pixel encoding but even >> then the kernel always knows which pixel encoding is selected and >> which InfoFrame has to be sent. Is there a reason why userspace would >> want to control the variant explicitly to the wrong value? >> > > I've asked this before but haven't seen an answer: Is there an > existing > upstream userspace project that makes use of this property (other than > what Joshua is working on in gamescope right now)? That would help us > understand the intent better. The intent was to control the infoframe colorimetry bits, nothing more. No idea what real userspace there was, if any. > > I don't think giving userspace explicit control over the exact > infoframe > values is the right thing to do. Only userspace knows what kind of data it's stuffing into the pixels (and/or how it configures the csc units/etc.) to generate them. >>> >>> Yes, but userspace doesn't control or know whether we drive >>> RGB or YCbCr on the wire. In fact, in some cases our driver >>> needs to fallback to YCbCr420 for bandwidth reasons. There >>> is currently no way for userspace to know that and I don't >>> think it makes sense. >> >> People want that control as well for whatever reason. We've >> been asked to allow YCbCr 4:4:4 output many times. > > I don't really think it's a question of if we want it but rather how > we get there. Harry is completely right that if we would make the > subsampling controllable by user space instead of the kernel handling > it magically, user space which does not adapt to the new control won't > be able to light up some modes which worked before. > Thanks for continuing this discussion and touching on the model of how we get to where we want to go. > This is obviously a problem and not one we can easily fix. We would > need a new cap for user space to signal "I know that I can control > bpc, subsampling and compression to lower the bandwidth and light up > modes which otherwise fail". That cap would also remove all the > properties which require kernel magic to work (that's also what I > proposed for my KMS color pipeline API). > > We all want to expose more of the scanout capability and give user > space more control but I don't think an incremental approach works > here and we would all do better if we accept that the current API > requires kernel magic to work and has a few implicit assumptions baked > in. > > With all that being said, I think the right decision here is to > > 1. Ignore subsampling for now > 2. Let the kernel select YCC or RGB on the cable > 3. Let the kernel figure out the conversion between RGB and YCC based > on the color space selected > 4. Let the kernel send the correct infoframe based on the selected > color space and cable encoding > 5. Only expose color spaces for which the kernel can do the conversion > and send the infoframe I agree. We don't want to break or change existing behavior (that is used by userspace) and this will get us far without breaking things. > 6. Work on the new API which is hidden behind a cap > > Hi, > > I agree on all that, too. > > I assume you
Re: [PATCH 3/3] drm/connector: Deprecate split for BT.2020 in drm_colorspace enum
Hi, On Tue, 14 Feb 2023 at 16:57, Harry Wentland wrote: > On 2/14/23 10:49, Sebastian Wick wrote: > From what I've seen recently I am inclined to favor an incremental > approach more. The reason is that any API, or portion thereof, is > useless unless it's enabled full stack. When it isn't it becomes > dead code quickly, or never really works because we overlooked > one thing. The colorspace debacle shows how even something as > simple as extra enum values in KMS APIs shouldn't be added unless > someone in a canonical upstream project actually uses them. I > would argue that such a canonical upstream project actually has > to be a production environment and not something like Weston. Just to chime in as well that it is a real production environment; it's probably actually shipped the most of any compositor by a long way. It doesn't have much place on the desktop, but it does live in planes, trains, automobiles, digital signage, kiosks, STBs/TVs, and about a billion other places you might not have expected. Probably the main factor that joins all these together - apart from not having much desktop-style click-and-drag reconfigurable UI - is that we need to use the hardware pipeline as efficiently as possible, because either we don't have the memory bandwidth to burn like desktops, or we need to minimise it for power/thermal reasons. Given that, we don't really want to paint ourselves into a corner with incremental solutions that mean we can't do fully efficient things later. We're also somewhat undermanned, and we've been using our effort to try to make sure that the full solution - including full colour-managed pathways for things like movie and TV post-prod composition, design, etc - is possible at some point through the full Wayland ecosystem at some point. The X11 experience was so horribly botched that it wasn't really possible without a complete professional setup, and that's something I personally don't want to see. However ... > I could see us getting to a fully new color pipeline API but > the only way to do that is with a development model that supports > it. While upstream needs to be our ultimate goal, a good way > to bring in new APIs and ensure a full-stack implementation is > to develop them in a downstream production kernel, alongside > userspace that makes use of it. Once the implementation is > proven in the downstream repos it can then go upstream. This > brings new challenges, though, as things don't get wide > testing and get out of sync with upstream quickly. The > alternative is the incremental approach. > > We should look at this from a use-case angle, similar to what > the gamescope guys are doing. Small steps, like: > 1) Add HDR10 output (PQ, BT.2020) to the display > 2) Add ability to do sRGB linear blending > 3) Add ability to do sRGB and PQ linear blending > 4) Post-blending 3D LUT > 5) Pre-blending 3D LUT > > At each stage the whole stack needs to work together in production. Personally, I do think at this stage we probably have enough of an understanding to be able to work with an intermediate solution. We just need to think hard about what that intermediate solution is - making sure that we don't end up in the same tangle of impossible semantics like the old 'broadcast RGB' / colorspace / HDR properties which were never thought through - so that it is something we can build on rather than something we have to work around. But it would be really good to make HDR10/HDR10+ media and HDR games work on HDR displays, yeah. Cheers, Daniel
Re: [PATCH 3/3] drm/connector: Deprecate split for BT.2020 in drm_colorspace enum
On Wed, Feb 15, 2023 at 12:01:25PM +0200, Pekka Paalanen wrote: > On Tue, 14 Feb 2023 22:10:35 +0200 > Ville Syrjälä wrote: > > > On Tue, Feb 14, 2023 at 08:45:00PM +0100, Sebastian Wick wrote: > > ... > > > > We also have to figure out how a user space which doesn't > > > know about the new property behaves when another client has set that > > > property. If any property which currently might change the pixel > > > values is used, we can't expose the entire color pipeline because the > > > kernel might have to use some element in it to achieve its magic > > > conversion. So essentially you already have this hard device between > > > "old" and "new" and you can't use the new stuff incrementally. > > > > That problem exists with any new property. Old userspace and new > > userspace may interact badly enought that nothing works right. > > In that sense I think these props might even be pretty mundane > > as the worst you might get from setting the infoframe wrong is > > perhaps wrong colors on your display. > > > > To solve that particular problem there has been talk (for years) > > about some kind of "reset all" knob to make sure everything is > > at a safe default value. I have a feeling there was even some > > kind of semi-real proposal in recent times, but maybe I imgained > > it? > > I've been talking about that too, but I think it all collapsed into > "let's just fix all KMS apps to always set all KMS properties" which > results in patches like > https://gitlab.freedesktop.org/wayland/weston/-/merge_requests/952 That requires some knowledge about the property in question to pick the value. I think for some prop types (enums at least) we could guarantee that the first value is always the safe default, but for eg. range properties there is no way to know. So doing that fully blind is not possible atm. I guess one option might be to include a "reset value" in the props somehow, and just have everyclient set all unknown props to that. But there are of course other options too (reset flag to atomic ioctl, etc.). > > It does not seem to be a serious enough problem for anyone to put in > the work. And why would it be, when you can easily fix it in your own > project like that Weston example. The Weston example is not even > representative, because I did it before I saw any real problems. > > Other musings have been in the direction that maybe logind (since it > opens DRM devices for you) should save the full KMS state on the very > first open after a reboot, and then KMS applications can ask logind > what the boot-up state was. This is a variation of "save all KMS state > from the moment you launch, and use that as the base if you ever let > something else touch KMS in between". > > You also never see the problem to begin with, if you never let > something else touch KMS in between, so that already makes the problem > rare outside of the tiny set of compositor developers. Yeah, it's a pretty rare problem so not much interest I guess. -- Ville Syrjälä Intel
Re: [PATCH 3/3] drm/connector: Deprecate split for BT.2020 in drm_colorspace enum
On Tue, 14 Feb 2023 22:10:35 +0200 Ville Syrjälä wrote: > On Tue, Feb 14, 2023 at 08:45:00PM +0100, Sebastian Wick wrote: ... > > We also have to figure out how a user space which doesn't > > know about the new property behaves when another client has set that > > property. If any property which currently might change the pixel > > values is used, we can't expose the entire color pipeline because the > > kernel might have to use some element in it to achieve its magic > > conversion. So essentially you already have this hard device between > > "old" and "new" and you can't use the new stuff incrementally. > > That problem exists with any new property. Old userspace and new > userspace may interact badly enought that nothing works right. > In that sense I think these props might even be pretty mundane > as the worst you might get from setting the infoframe wrong is > perhaps wrong colors on your display. > > To solve that particular problem there has been talk (for years) > about some kind of "reset all" knob to make sure everything is > at a safe default value. I have a feeling there was even some > kind of semi-real proposal in recent times, but maybe I imgained > it? I've been talking about that too, but I think it all collapsed into "let's just fix all KMS apps to always set all KMS properties" which results in patches like https://gitlab.freedesktop.org/wayland/weston/-/merge_requests/952 It does not seem to be a serious enough problem for anyone to put in the work. And why would it be, when you can easily fix it in your own project like that Weston example. The Weston example is not even representative, because I did it before I saw any real problems. Other musings have been in the direction that maybe logind (since it opens DRM devices for you) should save the full KMS state on the very first open after a reboot, and then KMS applications can ask logind what the boot-up state was. This is a variation of "save all KMS state from the moment you launch, and use that as the base if you ever let something else touch KMS in between". You also never see the problem to begin with, if you never let something else touch KMS in between, so that already makes the problem rare outside of the tiny set of compositor developers. Thanks, pq pgpfoMV7xRYzP.pgp Description: OpenPGP digital signature
Re: [PATCH 3/3] drm/connector: Deprecate split for BT.2020 in drm_colorspace enum
On Tue, 14 Feb 2023 15:04:52 -0500 Harry Wentland wrote: > On 2/14/23 14:45, Sebastian Wick wrote: > > On Tue, Feb 14, 2023 at 5:57 PM Harry Wentland > > wrote: > >> > >> > >> > >> On 2/14/23 10:49, Sebastian Wick wrote: > >>> On Fri, Feb 3, 2023 at 5:00 PM Ville Syrjälä > >>> wrote: > > On Fri, Feb 03, 2023 at 10:24:52AM -0500, Harry Wentland wrote: > > > > > > On 2/3/23 10:19, Ville Syrjälä wrote: > >> On Fri, Feb 03, 2023 at 09:39:42AM -0500, Harry Wentland wrote: > >>> > >>> > >>> On 2/3/23 07:59, Sebastian Wick wrote: > On Fri, Feb 3, 2023 at 11:40 AM Ville Syrjälä > wrote: > > > > On Fri, Feb 03, 2023 at 02:07:44AM +, Joshua Ashton wrote: > >> Userspace has no way of controlling or knowing the pixel encoding > >> currently, so there is no way for it to ever get the right values > >> here. > > > > That applies to a lot of the other values as well (they are > > explicitly RGB or YCC). The idea was that this property sets the > > infoframe/MSA/SDP value exactly, and other properties should be > > added to for use userspace to control the pixel encoding/colorspace > > conversion(if desired, or userspace just makes sure to > > directly feed in correct kind of data). > > I'm all for getting userspace control over pixel encoding but even > then the kernel always knows which pixel encoding is selected and > which InfoFrame has to be sent. Is there a reason why userspace would > want to control the variant explicitly to the wrong value? > > >>> > >>> I've asked this before but haven't seen an answer: Is there an > >>> existing > >>> upstream userspace project that makes use of this property (other than > >>> what Joshua is working on in gamescope right now)? That would help us > >>> understand the intent better. > >> > >> The intent was to control the infoframe colorimetry bits, > >> nothing more. No idea what real userspace there was, if any. > >> > >>> > >>> I don't think giving userspace explicit control over the exact > >>> infoframe > >>> values is the right thing to do. > >> > >> Only userspace knows what kind of data it's stuffing into > >> the pixels (and/or how it configures the csc units/etc.) to > >> generate them. > >> > > > > Yes, but userspace doesn't control or know whether we drive > > RGB or YCbCr on the wire. In fact, in some cases our driver > > needs to fallback to YCbCr420 for bandwidth reasons. There > > is currently no way for userspace to know that and I don't > > think it makes sense. > > People want that control as well for whatever reason. We've > been asked to allow YCbCr 4:4:4 output many times. > >>> > >>> I don't really think it's a question of if we want it but rather how > >>> we get there. Harry is completely right that if we would make the > >>> subsampling controllable by user space instead of the kernel handling > >>> it magically, user space which does not adapt to the new control won't > >>> be able to light up some modes which worked before. > >>> > >> > >> Thanks for continuing this discussion and touching on the model of how > >> we get to where we want to go. > >> > >>> This is obviously a problem and not one we can easily fix. We would > >>> need a new cap for user space to signal "I know that I can control > >>> bpc, subsampling and compression to lower the bandwidth and light up > >>> modes which otherwise fail". That cap would also remove all the > >>> properties which require kernel magic to work (that's also what I > >>> proposed for my KMS color pipeline API). > >>> > >>> We all want to expose more of the scanout capability and give user > >>> space more control but I don't think an incremental approach works > >>> here and we would all do better if we accept that the current API > >>> requires kernel magic to work and has a few implicit assumptions baked > >>> in. > >>> > >>> With all that being said, I think the right decision here is to > >>> > >>> 1. Ignore subsampling for now > >>> 2. Let the kernel select YCC or RGB on the cable > >>> 3. Let the kernel figure out the conversion between RGB and YCC based > >>> on the color space selected > >>> 4. Let the kernel send the correct infoframe based on the selected > >>> color space and cable encoding > >>> 5. Only expose color spaces for which the kernel can do the conversion > >>> and send the infoframe > >> > >> I agree. We don't want to break or change existing behavior (that is > >> used by userspace) and this will get us far without breaking things. > >> > >>> 6. Work on the new API which is hidden behind a cap Hi, I agree on all that, too. > >>> > >> > >> I assume you mean something like > >>
Re: [PATCH 3/3] drm/connector: Deprecate split for BT.2020 in drm_colorspace enum
On Tue, Feb 14, 2023 at 10:18:49PM +0100, Sebastian Wick wrote: > On Tue, Feb 14, 2023 at 9:10 PM Ville Syrjälä > wrote: > > > > On Tue, Feb 14, 2023 at 08:45:00PM +0100, Sebastian Wick wrote: > > > On Tue, Feb 14, 2023 at 5:57 PM Harry Wentland > > > wrote: > > > > > > > > > > > > > > > > On 2/14/23 10:49, Sebastian Wick wrote: > > > > > On Fri, Feb 3, 2023 at 5:00 PM Ville Syrjälä > > > > > wrote: > > > > >> > > > > >> On Fri, Feb 03, 2023 at 10:24:52AM -0500, Harry Wentland wrote: > > > > >>> > > > > >>> > > > > >>> On 2/3/23 10:19, Ville Syrjälä wrote: > > > > On Fri, Feb 03, 2023 at 09:39:42AM -0500, Harry Wentland wrote: > > > > > > > > > > > > > > > On 2/3/23 07:59, Sebastian Wick wrote: > > > > >> On Fri, Feb 3, 2023 at 11:40 AM Ville Syrjälä > > > > >> wrote: > > > > >>> > > > > >>> On Fri, Feb 03, 2023 at 02:07:44AM +, Joshua Ashton wrote: > > > > Userspace has no way of controlling or knowing the pixel > > > > encoding > > > > currently, so there is no way for it to ever get the right > > > > values here. > > > > >>> > > > > >>> That applies to a lot of the other values as well (they are > > > > >>> explicitly RGB or YCC). The idea was that this property sets the > > > > >>> infoframe/MSA/SDP value exactly, and other properties should be > > > > >>> added to for use userspace to control the pixel > > > > >>> encoding/colorspace > > > > >>> conversion(if desired, or userspace just makes sure to > > > > >>> directly feed in correct kind of data). > > > > >> > > > > >> I'm all for getting userspace control over pixel encoding but > > > > >> even > > > > >> then the kernel always knows which pixel encoding is selected and > > > > >> which InfoFrame has to be sent. Is there a reason why userspace > > > > >> would > > > > >> want to control the variant explicitly to the wrong value? > > > > >> > > > > > > > > > > I've asked this before but haven't seen an answer: Is there an > > > > > existing > > > > > upstream userspace project that makes use of this property (other > > > > > than > > > > > what Joshua is working on in gamescope right now)? That would > > > > > help us > > > > > understand the intent better. > > > > > > > > The intent was to control the infoframe colorimetry bits, > > > > nothing more. No idea what real userspace there was, if any. > > > > > > > > > > > > > > I don't think giving userspace explicit control over the exact > > > > > infoframe > > > > > values is the right thing to do. > > > > > > > > Only userspace knows what kind of data it's stuffing into > > > > the pixels (and/or how it configures the csc units/etc.) to > > > > generate them. > > > > > > > > >>> > > > > >>> Yes, but userspace doesn't control or know whether we drive > > > > >>> RGB or YCbCr on the wire. In fact, in some cases our driver > > > > >>> needs to fallback to YCbCr420 for bandwidth reasons. There > > > > >>> is currently no way for userspace to know that and I don't > > > > >>> think it makes sense. > > > > >> > > > > >> People want that control as well for whatever reason. We've > > > > >> been asked to allow YCbCr 4:4:4 output many times. > > > > > > > > > > I don't really think it's a question of if we want it but rather how > > > > > we get there. Harry is completely right that if we would make the > > > > > subsampling controllable by user space instead of the kernel handling > > > > > it magically, user space which does not adapt to the new control won't > > > > > be able to light up some modes which worked before. > > > > > > > > > > > > > Thanks for continuing this discussion and touching on the model of how > > > > we get to where we want to go. > > > > > > > > > This is obviously a problem and not one we can easily fix. We would > > > > > need a new cap for user space to signal "I know that I can control > > > > > bpc, subsampling and compression to lower the bandwidth and light up > > > > > modes which otherwise fail". That cap would also remove all the > > > > > properties which require kernel magic to work (that's also what I > > > > > proposed for my KMS color pipeline API). > > > > > > > > > > We all want to expose more of the scanout capability and give user > > > > > space more control but I don't think an incremental approach works > > > > > here and we would all do better if we accept that the current API > > > > > requires kernel magic to work and has a few implicit assumptions baked > > > > > in. > > > > > > > > > > With all that being said, I think the right decision here is to > > > > > > > > > > 1. Ignore subsampling for now > > > > > 2. Let the kernel select YCC or RGB on the cable > > > > > 3. Let the kernel figure out the conversion between RGB and YCC based > > > > > on the color space selected > > > > > 4. Let the kernel send the
Re: [PATCH 3/3] drm/connector: Deprecate split for BT.2020 in drm_colorspace enum
On Tue, Feb 14, 2023 at 9:10 PM Ville Syrjälä wrote: > > On Tue, Feb 14, 2023 at 08:45:00PM +0100, Sebastian Wick wrote: > > On Tue, Feb 14, 2023 at 5:57 PM Harry Wentland > > wrote: > > > > > > > > > > > > On 2/14/23 10:49, Sebastian Wick wrote: > > > > On Fri, Feb 3, 2023 at 5:00 PM Ville Syrjälä > > > > wrote: > > > >> > > > >> On Fri, Feb 03, 2023 at 10:24:52AM -0500, Harry Wentland wrote: > > > >>> > > > >>> > > > >>> On 2/3/23 10:19, Ville Syrjälä wrote: > > > On Fri, Feb 03, 2023 at 09:39:42AM -0500, Harry Wentland wrote: > > > > > > > > > > > > On 2/3/23 07:59, Sebastian Wick wrote: > > > >> On Fri, Feb 3, 2023 at 11:40 AM Ville Syrjälä > > > >> wrote: > > > >>> > > > >>> On Fri, Feb 03, 2023 at 02:07:44AM +, Joshua Ashton wrote: > > > Userspace has no way of controlling or knowing the pixel encoding > > > currently, so there is no way for it to ever get the right > > > values here. > > > >>> > > > >>> That applies to a lot of the other values as well (they are > > > >>> explicitly RGB or YCC). The idea was that this property sets the > > > >>> infoframe/MSA/SDP value exactly, and other properties should be > > > >>> added to for use userspace to control the pixel > > > >>> encoding/colorspace > > > >>> conversion(if desired, or userspace just makes sure to > > > >>> directly feed in correct kind of data). > > > >> > > > >> I'm all for getting userspace control over pixel encoding but even > > > >> then the kernel always knows which pixel encoding is selected and > > > >> which InfoFrame has to be sent. Is there a reason why userspace > > > >> would > > > >> want to control the variant explicitly to the wrong value? > > > >> > > > > > > > > I've asked this before but haven't seen an answer: Is there an > > > > existing > > > > upstream userspace project that makes use of this property (other > > > > than > > > > what Joshua is working on in gamescope right now)? That would help > > > > us > > > > understand the intent better. > > > > > > The intent was to control the infoframe colorimetry bits, > > > nothing more. No idea what real userspace there was, if any. > > > > > > > > > > > I don't think giving userspace explicit control over the exact > > > > infoframe > > > > values is the right thing to do. > > > > > > Only userspace knows what kind of data it's stuffing into > > > the pixels (and/or how it configures the csc units/etc.) to > > > generate them. > > > > > > >>> > > > >>> Yes, but userspace doesn't control or know whether we drive > > > >>> RGB or YCbCr on the wire. In fact, in some cases our driver > > > >>> needs to fallback to YCbCr420 for bandwidth reasons. There > > > >>> is currently no way for userspace to know that and I don't > > > >>> think it makes sense. > > > >> > > > >> People want that control as well for whatever reason. We've > > > >> been asked to allow YCbCr 4:4:4 output many times. > > > > > > > > I don't really think it's a question of if we want it but rather how > > > > we get there. Harry is completely right that if we would make the > > > > subsampling controllable by user space instead of the kernel handling > > > > it magically, user space which does not adapt to the new control won't > > > > be able to light up some modes which worked before. > > > > > > > > > > Thanks for continuing this discussion and touching on the model of how > > > we get to where we want to go. > > > > > > > This is obviously a problem and not one we can easily fix. We would > > > > need a new cap for user space to signal "I know that I can control > > > > bpc, subsampling and compression to lower the bandwidth and light up > > > > modes which otherwise fail". That cap would also remove all the > > > > properties which require kernel magic to work (that's also what I > > > > proposed for my KMS color pipeline API). > > > > > > > > We all want to expose more of the scanout capability and give user > > > > space more control but I don't think an incremental approach works > > > > here and we would all do better if we accept that the current API > > > > requires kernel magic to work and has a few implicit assumptions baked > > > > in. > > > > > > > > With all that being said, I think the right decision here is to > > > > > > > > 1. Ignore subsampling for now > > > > 2. Let the kernel select YCC or RGB on the cable > > > > 3. Let the kernel figure out the conversion between RGB and YCC based > > > > on the color space selected > > > > 4. Let the kernel send the correct infoframe based on the selected > > > > color space and cable encoding > > > > 5. Only expose color spaces for which the kernel can do the conversion > > > > and send the infoframe > > > > > > I agree. We don't want to break or change existing behavior (that is > > > used by userspace) and this will
Re: [PATCH 3/3] drm/connector: Deprecate split for BT.2020 in drm_colorspace enum
On Tue, Feb 14, 2023 at 08:45:00PM +0100, Sebastian Wick wrote: > On Tue, Feb 14, 2023 at 5:57 PM Harry Wentland wrote: > > > > > > > > On 2/14/23 10:49, Sebastian Wick wrote: > > > On Fri, Feb 3, 2023 at 5:00 PM Ville Syrjälä > > > wrote: > > >> > > >> On Fri, Feb 03, 2023 at 10:24:52AM -0500, Harry Wentland wrote: > > >>> > > >>> > > >>> On 2/3/23 10:19, Ville Syrjälä wrote: > > On Fri, Feb 03, 2023 at 09:39:42AM -0500, Harry Wentland wrote: > > > > > > > > > On 2/3/23 07:59, Sebastian Wick wrote: > > >> On Fri, Feb 3, 2023 at 11:40 AM Ville Syrjälä > > >> wrote: > > >>> > > >>> On Fri, Feb 03, 2023 at 02:07:44AM +, Joshua Ashton wrote: > > Userspace has no way of controlling or knowing the pixel encoding > > currently, so there is no way for it to ever get the right values > > here. > > >>> > > >>> That applies to a lot of the other values as well (they are > > >>> explicitly RGB or YCC). The idea was that this property sets the > > >>> infoframe/MSA/SDP value exactly, and other properties should be > > >>> added to for use userspace to control the pixel encoding/colorspace > > >>> conversion(if desired, or userspace just makes sure to > > >>> directly feed in correct kind of data). > > >> > > >> I'm all for getting userspace control over pixel encoding but even > > >> then the kernel always knows which pixel encoding is selected and > > >> which InfoFrame has to be sent. Is there a reason why userspace would > > >> want to control the variant explicitly to the wrong value? > > >> > > > > > > I've asked this before but haven't seen an answer: Is there an > > > existing > > > upstream userspace project that makes use of this property (other than > > > what Joshua is working on in gamescope right now)? That would help us > > > understand the intent better. > > > > The intent was to control the infoframe colorimetry bits, > > nothing more. No idea what real userspace there was, if any. > > > > > > > > I don't think giving userspace explicit control over the exact > > > infoframe > > > values is the right thing to do. > > > > Only userspace knows what kind of data it's stuffing into > > the pixels (and/or how it configures the csc units/etc.) to > > generate them. > > > > >>> > > >>> Yes, but userspace doesn't control or know whether we drive > > >>> RGB or YCbCr on the wire. In fact, in some cases our driver > > >>> needs to fallback to YCbCr420 for bandwidth reasons. There > > >>> is currently no way for userspace to know that and I don't > > >>> think it makes sense. > > >> > > >> People want that control as well for whatever reason. We've > > >> been asked to allow YCbCr 4:4:4 output many times. > > > > > > I don't really think it's a question of if we want it but rather how > > > we get there. Harry is completely right that if we would make the > > > subsampling controllable by user space instead of the kernel handling > > > it magically, user space which does not adapt to the new control won't > > > be able to light up some modes which worked before. > > > > > > > Thanks for continuing this discussion and touching on the model of how > > we get to where we want to go. > > > > > This is obviously a problem and not one we can easily fix. We would > > > need a new cap for user space to signal "I know that I can control > > > bpc, subsampling and compression to lower the bandwidth and light up > > > modes which otherwise fail". That cap would also remove all the > > > properties which require kernel magic to work (that's also what I > > > proposed for my KMS color pipeline API). > > > > > > We all want to expose more of the scanout capability and give user > > > space more control but I don't think an incremental approach works > > > here and we would all do better if we accept that the current API > > > requires kernel magic to work and has a few implicit assumptions baked > > > in. > > > > > > With all that being said, I think the right decision here is to > > > > > > 1. Ignore subsampling for now > > > 2. Let the kernel select YCC or RGB on the cable > > > 3. Let the kernel figure out the conversion between RGB and YCC based > > > on the color space selected > > > 4. Let the kernel send the correct infoframe based on the selected > > > color space and cable encoding > > > 5. Only expose color spaces for which the kernel can do the conversion > > > and send the infoframe > > > > I agree. We don't want to break or change existing behavior (that is > > used by userspace) and this will get us far without breaking things. > > > > > 6. Work on the new API which is hidden behind a cap > > > > > > > I assume you mean something like > > https://gitlab.freedesktop.org/pq/color-and-hdr/-/issues/11 > > Something like that, yes. The main point being a cap which removes a > lot of properties and sets new
Re: [PATCH 3/3] drm/connector: Deprecate split for BT.2020 in drm_colorspace enum
On 2/14/23 14:45, Sebastian Wick wrote: On Tue, Feb 14, 2023 at 5:57 PM Harry Wentland wrote: On 2/14/23 10:49, Sebastian Wick wrote: On Fri, Feb 3, 2023 at 5:00 PM Ville Syrjälä wrote: On Fri, Feb 03, 2023 at 10:24:52AM -0500, Harry Wentland wrote: On 2/3/23 10:19, Ville Syrjälä wrote: On Fri, Feb 03, 2023 at 09:39:42AM -0500, Harry Wentland wrote: On 2/3/23 07:59, Sebastian Wick wrote: On Fri, Feb 3, 2023 at 11:40 AM Ville Syrjälä wrote: On Fri, Feb 03, 2023 at 02:07:44AM +, Joshua Ashton wrote: Userspace has no way of controlling or knowing the pixel encoding currently, so there is no way for it to ever get the right values here. That applies to a lot of the other values as well (they are explicitly RGB or YCC). The idea was that this property sets the infoframe/MSA/SDP value exactly, and other properties should be added to for use userspace to control the pixel encoding/colorspace conversion(if desired, or userspace just makes sure to directly feed in correct kind of data). I'm all for getting userspace control over pixel encoding but even then the kernel always knows which pixel encoding is selected and which InfoFrame has to be sent. Is there a reason why userspace would want to control the variant explicitly to the wrong value? I've asked this before but haven't seen an answer: Is there an existing upstream userspace project that makes use of this property (other than what Joshua is working on in gamescope right now)? That would help us understand the intent better. The intent was to control the infoframe colorimetry bits, nothing more. No idea what real userspace there was, if any. I don't think giving userspace explicit control over the exact infoframe values is the right thing to do. Only userspace knows what kind of data it's stuffing into the pixels (and/or how it configures the csc units/etc.) to generate them. Yes, but userspace doesn't control or know whether we drive RGB or YCbCr on the wire. In fact, in some cases our driver needs to fallback to YCbCr420 for bandwidth reasons. There is currently no way for userspace to know that and I don't think it makes sense. People want that control as well for whatever reason. We've been asked to allow YCbCr 4:4:4 output many times. I don't really think it's a question of if we want it but rather how we get there. Harry is completely right that if we would make the subsampling controllable by user space instead of the kernel handling it magically, user space which does not adapt to the new control won't be able to light up some modes which worked before. Thanks for continuing this discussion and touching on the model of how we get to where we want to go. This is obviously a problem and not one we can easily fix. We would need a new cap for user space to signal "I know that I can control bpc, subsampling and compression to lower the bandwidth and light up modes which otherwise fail". That cap would also remove all the properties which require kernel magic to work (that's also what I proposed for my KMS color pipeline API). We all want to expose more of the scanout capability and give user space more control but I don't think an incremental approach works here and we would all do better if we accept that the current API requires kernel magic to work and has a few implicit assumptions baked in. With all that being said, I think the right decision here is to 1. Ignore subsampling for now 2. Let the kernel select YCC or RGB on the cable 3. Let the kernel figure out the conversion between RGB and YCC based on the color space selected 4. Let the kernel send the correct infoframe based on the selected color space and cable encoding 5. Only expose color spaces for which the kernel can do the conversion and send the infoframe I agree. We don't want to break or change existing behavior (that is used by userspace) and this will get us far without breaking things. 6. Work on the new API which is hidden behind a cap I assume you mean something like https://gitlab.freedesktop.org/pq/color-and-hdr/-/issues/11 Something like that, yes. The main point being a cap which removes a lot of properties and sets new expectations between user space and kernel. The actual API is not that important. Above you say that you don't think an incremental approach works here. Can you elaborate? Backwards compatibility is really hard. If we add another property to control e.g. the color range infoframe which doesn't magically convert colors, we now have to define how it interacts with the existing property. We also have to figure out how a user space which doesn't know about the new property behaves when another client has set that property. If any property which currently might change the pixel values is used, we can't expose the entire color pipeline because the kernel might have to use some element in it to achieve its magic conversion. So essentially you already have this hard device between "old" and "new" and
Re: [PATCH 3/3] drm/connector: Deprecate split for BT.2020 in drm_colorspace enum
On Tue, Feb 14, 2023 at 5:57 PM Harry Wentland wrote: > > > > On 2/14/23 10:49, Sebastian Wick wrote: > > On Fri, Feb 3, 2023 at 5:00 PM Ville Syrjälä > > wrote: > >> > >> On Fri, Feb 03, 2023 at 10:24:52AM -0500, Harry Wentland wrote: > >>> > >>> > >>> On 2/3/23 10:19, Ville Syrjälä wrote: > On Fri, Feb 03, 2023 at 09:39:42AM -0500, Harry Wentland wrote: > > > > > > On 2/3/23 07:59, Sebastian Wick wrote: > >> On Fri, Feb 3, 2023 at 11:40 AM Ville Syrjälä > >> wrote: > >>> > >>> On Fri, Feb 03, 2023 at 02:07:44AM +, Joshua Ashton wrote: > Userspace has no way of controlling or knowing the pixel encoding > currently, so there is no way for it to ever get the right values > here. > >>> > >>> That applies to a lot of the other values as well (they are > >>> explicitly RGB or YCC). The idea was that this property sets the > >>> infoframe/MSA/SDP value exactly, and other properties should be > >>> added to for use userspace to control the pixel encoding/colorspace > >>> conversion(if desired, or userspace just makes sure to > >>> directly feed in correct kind of data). > >> > >> I'm all for getting userspace control over pixel encoding but even > >> then the kernel always knows which pixel encoding is selected and > >> which InfoFrame has to be sent. Is there a reason why userspace would > >> want to control the variant explicitly to the wrong value? > >> > > > > I've asked this before but haven't seen an answer: Is there an existing > > upstream userspace project that makes use of this property (other than > > what Joshua is working on in gamescope right now)? That would help us > > understand the intent better. > > The intent was to control the infoframe colorimetry bits, > nothing more. No idea what real userspace there was, if any. > > > > > I don't think giving userspace explicit control over the exact infoframe > > values is the right thing to do. > > Only userspace knows what kind of data it's stuffing into > the pixels (and/or how it configures the csc units/etc.) to > generate them. > > >>> > >>> Yes, but userspace doesn't control or know whether we drive > >>> RGB or YCbCr on the wire. In fact, in some cases our driver > >>> needs to fallback to YCbCr420 for bandwidth reasons. There > >>> is currently no way for userspace to know that and I don't > >>> think it makes sense. > >> > >> People want that control as well for whatever reason. We've > >> been asked to allow YCbCr 4:4:4 output many times. > > > > I don't really think it's a question of if we want it but rather how > > we get there. Harry is completely right that if we would make the > > subsampling controllable by user space instead of the kernel handling > > it magically, user space which does not adapt to the new control won't > > be able to light up some modes which worked before. > > > > Thanks for continuing this discussion and touching on the model of how > we get to where we want to go. > > > This is obviously a problem and not one we can easily fix. We would > > need a new cap for user space to signal "I know that I can control > > bpc, subsampling and compression to lower the bandwidth and light up > > modes which otherwise fail". That cap would also remove all the > > properties which require kernel magic to work (that's also what I > > proposed for my KMS color pipeline API). > > > > We all want to expose more of the scanout capability and give user > > space more control but I don't think an incremental approach works > > here and we would all do better if we accept that the current API > > requires kernel magic to work and has a few implicit assumptions baked > > in. > > > > With all that being said, I think the right decision here is to > > > > 1. Ignore subsampling for now > > 2. Let the kernel select YCC or RGB on the cable > > 3. Let the kernel figure out the conversion between RGB and YCC based > > on the color space selected > > 4. Let the kernel send the correct infoframe based on the selected > > color space and cable encoding > > 5. Only expose color spaces for which the kernel can do the conversion > > and send the infoframe > > I agree. We don't want to break or change existing behavior (that is > used by userspace) and this will get us far without breaking things. > > > 6. Work on the new API which is hidden behind a cap > > > > I assume you mean something like > https://gitlab.freedesktop.org/pq/color-and-hdr/-/issues/11 Something like that, yes. The main point being a cap which removes a lot of properties and sets new expectations between user space and kernel. The actual API is not that important. > Above you say that you don't think an incremental approach works > here. Can you elaborate? Backwards compatibility is really hard. If we add another property to control e.g. the color range infoframe which doesn't
Re: [PATCH 3/3] drm/connector: Deprecate split for BT.2020 in drm_colorspace enum
On 2/14/23 10:49, Sebastian Wick wrote: > On Fri, Feb 3, 2023 at 5:00 PM Ville Syrjälä > wrote: >> >> On Fri, Feb 03, 2023 at 10:24:52AM -0500, Harry Wentland wrote: >>> >>> >>> On 2/3/23 10:19, Ville Syrjälä wrote: On Fri, Feb 03, 2023 at 09:39:42AM -0500, Harry Wentland wrote: > > > On 2/3/23 07:59, Sebastian Wick wrote: >> On Fri, Feb 3, 2023 at 11:40 AM Ville Syrjälä >> wrote: >>> >>> On Fri, Feb 03, 2023 at 02:07:44AM +, Joshua Ashton wrote: Userspace has no way of controlling or knowing the pixel encoding currently, so there is no way for it to ever get the right values here. >>> >>> That applies to a lot of the other values as well (they are >>> explicitly RGB or YCC). The idea was that this property sets the >>> infoframe/MSA/SDP value exactly, and other properties should be >>> added to for use userspace to control the pixel encoding/colorspace >>> conversion(if desired, or userspace just makes sure to >>> directly feed in correct kind of data). >> >> I'm all for getting userspace control over pixel encoding but even >> then the kernel always knows which pixel encoding is selected and >> which InfoFrame has to be sent. Is there a reason why userspace would >> want to control the variant explicitly to the wrong value? >> > > I've asked this before but haven't seen an answer: Is there an existing > upstream userspace project that makes use of this property (other than > what Joshua is working on in gamescope right now)? That would help us > understand the intent better. The intent was to control the infoframe colorimetry bits, nothing more. No idea what real userspace there was, if any. > > I don't think giving userspace explicit control over the exact infoframe > values is the right thing to do. Only userspace knows what kind of data it's stuffing into the pixels (and/or how it configures the csc units/etc.) to generate them. >>> >>> Yes, but userspace doesn't control or know whether we drive >>> RGB or YCbCr on the wire. In fact, in some cases our driver >>> needs to fallback to YCbCr420 for bandwidth reasons. There >>> is currently no way for userspace to know that and I don't >>> think it makes sense. >> >> People want that control as well for whatever reason. We've >> been asked to allow YCbCr 4:4:4 output many times. > > I don't really think it's a question of if we want it but rather how > we get there. Harry is completely right that if we would make the > subsampling controllable by user space instead of the kernel handling > it magically, user space which does not adapt to the new control won't > be able to light up some modes which worked before. > Thanks for continuing this discussion and touching on the model of how we get to where we want to go. > This is obviously a problem and not one we can easily fix. We would > need a new cap for user space to signal "I know that I can control > bpc, subsampling and compression to lower the bandwidth and light up > modes which otherwise fail". That cap would also remove all the > properties which require kernel magic to work (that's also what I > proposed for my KMS color pipeline API). > > We all want to expose more of the scanout capability and give user > space more control but I don't think an incremental approach works > here and we would all do better if we accept that the current API > requires kernel magic to work and has a few implicit assumptions baked > in. > > With all that being said, I think the right decision here is to > > 1. Ignore subsampling for now > 2. Let the kernel select YCC or RGB on the cable > 3. Let the kernel figure out the conversion between RGB and YCC based > on the color space selected > 4. Let the kernel send the correct infoframe based on the selected > color space and cable encoding > 5. Only expose color spaces for which the kernel can do the conversion > and send the infoframe I agree. We don't want to break or change existing behavior (that is used by userspace) and this will get us far without breaking things. > 6. Work on the new API which is hidden behind a cap > I assume you mean something like https://gitlab.freedesktop.org/pq/color-and-hdr/-/issues/11 Above you say that you don't think an incremental approach works here. Can you elaborate? >From what I've seen recently I am inclined to favor an incremental approach more. The reason is that any API, or portion thereof, is useless unless it's enabled full stack. When it isn't it becomes dead code quickly, or never really works because we overlooked one thing. The colorspace debacle shows how even something as simple as extra enum values in KMS APIs shouldn't be added unless someone in a canonical upstream project actually uses them. I would argue that such a canonical upstream project actually has to be a production environment and not something like
Re: [PATCH 3/3] drm/connector: Deprecate split for BT.2020 in drm_colorspace enum
On Fri, Feb 3, 2023 at 5:00 PM Ville Syrjälä wrote: > > On Fri, Feb 03, 2023 at 10:24:52AM -0500, Harry Wentland wrote: > > > > > > On 2/3/23 10:19, Ville Syrjälä wrote: > > > On Fri, Feb 03, 2023 at 09:39:42AM -0500, Harry Wentland wrote: > > >> > > >> > > >> On 2/3/23 07:59, Sebastian Wick wrote: > > >>> On Fri, Feb 3, 2023 at 11:40 AM Ville Syrjälä > > >>> wrote: > > > > On Fri, Feb 03, 2023 at 02:07:44AM +, Joshua Ashton wrote: > > > Userspace has no way of controlling or knowing the pixel encoding > > > currently, so there is no way for it to ever get the right values > > > here. > > > > That applies to a lot of the other values as well (they are > > explicitly RGB or YCC). The idea was that this property sets the > > infoframe/MSA/SDP value exactly, and other properties should be > > added to for use userspace to control the pixel encoding/colorspace > > conversion(if desired, or userspace just makes sure to > > directly feed in correct kind of data). > > >>> > > >>> I'm all for getting userspace control over pixel encoding but even > > >>> then the kernel always knows which pixel encoding is selected and > > >>> which InfoFrame has to be sent. Is there a reason why userspace would > > >>> want to control the variant explicitly to the wrong value? > > >>> > > >> > > >> I've asked this before but haven't seen an answer: Is there an existing > > >> upstream userspace project that makes use of this property (other than > > >> what Joshua is working on in gamescope right now)? That would help us > > >> understand the intent better. > > > > > > The intent was to control the infoframe colorimetry bits, > > > nothing more. No idea what real userspace there was, if any. > > > > > >> > > >> I don't think giving userspace explicit control over the exact infoframe > > >> values is the right thing to do. > > > > > > Only userspace knows what kind of data it's stuffing into > > > the pixels (and/or how it configures the csc units/etc.) to > > > generate them. > > > > > > > Yes, but userspace doesn't control or know whether we drive > > RGB or YCbCr on the wire. In fact, in some cases our driver > > needs to fallback to YCbCr420 for bandwidth reasons. There > > is currently no way for userspace to know that and I don't > > think it makes sense. > > People want that control as well for whatever reason. We've > been asked to allow YCbCr 4:4:4 output many times. I don't really think it's a question of if we want it but rather how we get there. Harry is completely right that if we would make the subsampling controllable by user space instead of the kernel handling it magically, user space which does not adapt to the new control won't be able to light up some modes which worked before. This is obviously a problem and not one we can easily fix. We would need a new cap for user space to signal "I know that I can control bpc, subsampling and compression to lower the bandwidth and light up modes which otherwise fail". That cap would also remove all the properties which require kernel magic to work (that's also what I proposed for my KMS color pipeline API). We all want to expose more of the scanout capability and give user space more control but I don't think an incremental approach works here and we would all do better if we accept that the current API requires kernel magic to work and has a few implicit assumptions baked in. With all that being said, I think the right decision here is to 1. Ignore subsampling for now 2. Let the kernel select YCC or RGB on the cable 3. Let the kernel figure out the conversion between RGB and YCC based on the color space selected 4. Let the kernel send the correct infoframe based on the selected color space and cable encoding 5. Only expose color spaces for which the kernel can do the conversion and send the infoframe 6. Work on the new API which is hidden behind a cap > The automagic 4:2:0 fallback I think is rather fundementally > incompatible with fancy color management. How would we even > know whether to use eg. BT.2020 vs. BT.709 matrix? In i915 > that stuff is just always BT.709 limited range, no questions > asked. > > So I think if userspace wants real color management it's > going to have to set up the whole pipeline. And for that > we need at least one new property to control the RGB->YCbCr > conversion (or to explicitly avoid it). > > And given that the proposed patch just swept all the > non-BT.2020 issues under the rug makes me think no > one has actually come up with any kind of consistent > plan for anything else really. > > > > > Userspace needs full control of framebuffer pixel formats, > > as well as control over DEGAMMA, GAMMA, CTM color operations. > > It also needs to be able to select whether to drive the panel > > as sRGB or BT.2020/PQ but it doesn't make sense for it to > > control the pixel encoding on the wire (RGB vs YCbCr). > > > > > I really don't want a repeat of the disaster of the > > >
Re: [PATCH 3/3] drm/connector: Deprecate split for BT.2020 in drm_colorspace enum
On Friday, February 10th, 2023 at 10:37, Pekka Paalanen wrote: > On Thu, 09 Feb 2023 17:03:19 + > Simon Ser cont...@emersion.fr wrote: > > > On Thursday, February 9th, 2023 at 17:38, Joshua Ashton jos...@froggi.es > > wrote: > > > > > > I mean, the strings are the uAPI, not the integers, right? > > > > > > Both are uAPI these days. > > > > Yes. The integers are uAPI, if you change them you'll break libliftoff > > users. There is an old thread discussing this somewhere. The tl;dr was > > that there is no use-case for exposing the same string with a different > > integer, so no good reason to justify the substantial complexity of > > handling this case. > > Funny, I remember exactly the opposite. There was a bacxk-and-forth on this topic. > This case would have been multiple different strings with the same > integer, anyway. That would be fine. As long as the meaning of an integer doesn't change across planes, it's all fine. > But no matter. If a uAPI header or documentation has exposed the > integers, then there is no taking that back. uAPI headers/docs don't expose the integers for this property. Nevertheless, one cannot break user-space. > This won't be a problem for enums that have no meaningful string names, > like enums where the integer names a blob that describes what the value > means, and enums where the integer is an index into an array of > descriptions exposed as a blob. This would be pretty tricky to handle.
Re: [PATCH 3/3] drm/connector: Deprecate split for BT.2020 in drm_colorspace enum
On Thu, 09 Feb 2023 17:03:19 + Simon Ser wrote: > On Thursday, February 9th, 2023 at 17:38, Joshua Ashton > wrote: > > > > I mean, the strings are the uAPI, not the integers, right? > > > > Both are uAPI these days. > > Yes. The integers are uAPI, if you change them you'll break libliftoff > users. There is an old thread discussing this somewhere. The tl;dr was > that there is no use-case for exposing the same string with a different > integer, so no good reason to justify the substantial complexity of > handling this case. Funny, I remember exactly the opposite. This case would have been multiple different strings with the same integer, anyway. But no matter. If a uAPI header or documentation has exposed the integers, then there is no taking that back. This won't be a problem for enums that have no meaningful string names, like enums where the integer names a blob that describes what the value means, and enums where the integer is an index into an array of descriptions exposed as a blob. Thanks, pq pgpiWGYsDVieU.pgp Description: OpenPGP digital signature
Re: [PATCH 3/3] drm/connector: Deprecate split for BT.2020 in drm_colorspace enum
On Thu, Feb 09, 2023 at 05:03:19PM +, Simon Ser wrote: > On Thursday, February 9th, 2023 at 17:38, Joshua Ashton > wrote: > > > > I mean, the strings are the uAPI, not the integers, right? > > > > Both are uAPI these days. > > Yes. The integers are uAPI, if you change them you'll break libliftoff > users. There is an old thread discussing this somewhere. The tl;dr was > that there is no use-case for exposing the same string with a different > integer, so no good reason to justify the substantial complexity of > handling this case. If people actually depend on that we should probably have tests to make sure no one breaks it by accident. -- Ville Syrjälä Intel
Re: [PATCH 3/3] drm/connector: Deprecate split for BT.2020 in drm_colorspace enum
On Thursday, February 9th, 2023 at 17:38, Joshua Ashton wrote: > > I mean, the strings are the uAPI, not the integers, right? > > Both are uAPI these days. Yes. The integers are uAPI, if you change them you'll break libliftoff users. There is an old thread discussing this somewhere. The tl;dr was that there is no use-case for exposing the same string with a different integer, so no good reason to justify the substantial complexity of handling this case.
Re: [PATCH 3/3] drm/connector: Deprecate split for BT.2020 in drm_colorspace enum
On 2/8/23 09:30, Pekka Paalanen wrote:
On Fri, 3 Feb 2023 02:07:44 +
Joshua Ashton wrote:
Userspace has no way of controlling or knowing the pixel encoding
currently, so there is no way for it to ever get the right values here.
When we do add pixel_encoding control from userspace,we can pick the
right value for the colorimetry packet based on the
pixel_encoding + the colorspace.
Let's deprecate these values, and have one BT.2020 colorspace entry
that userspace can use.
Note: _CYCC was effectively 'removed' by this change, but that was not
possible to be taken advantage of anyway, as there is currently no
pixel_encoding control so it would not be possible to output
linear YCbCr.
Signed-off-by: Joshua Ashton
Cc: Pekka Paalanen
Cc: Sebastian Wick
Cc: vitaly.pros...@amd.com
Cc: Uma Shankar
Cc: Ville Syrjälä
Cc: Joshua Ashton
Cc: dri-de...@lists.freedesktop.org
Cc: amd-gfx@lists.freedesktop.org
---
drivers/gpu/drm/display/drm_hdmi_helper.c | 9 -
drivers/gpu/drm/drm_connector.c | 12 ++--
drivers/gpu/drm/i915/display/intel_dp.c | 20 +---
include/drm/drm_connector.h | 19 ++-
4 files changed, 29 insertions(+), 31 deletions(-)
diff --git a/drivers/gpu/drm/display/drm_hdmi_helper.c
b/drivers/gpu/drm/display/drm_hdmi_helper.c
index 0264abe55278..c85860600395 100644
--- a/drivers/gpu/drm/display/drm_hdmi_helper.c
+++ b/drivers/gpu/drm/display/drm_hdmi_helper.c
@@ -99,8 +99,7 @@ EXPORT_SYMBOL(drm_hdmi_infoframe_set_hdr_metadata);
#define HDMI_COLORIMETRY_OPYCC_601(C(3) | EC(3) | ACE(0))
#define HDMI_COLORIMETRY_OPRGB(C(3) | EC(4) | ACE(0))
#define HDMI_COLORIMETRY_BT2020_CYCC (C(3) | EC(5) | ACE(0))
-#define HDMI_COLORIMETRY_BT2020_RGB(C(3) | EC(6) | ACE(0))
-#define HDMI_COLORIMETRY_BT2020_YCC(C(3) | EC(6) | ACE(0))
+#define HDMI_COLORIMETRY_BT2020(C(3) | EC(6) | ACE(0))
#define HDMI_COLORIMETRY_DCI_P3_RGB_D65 (C(3) | EC(7) | ACE(0))
#define HDMI_COLORIMETRY_DCI_P3_RGB_THEATER (C(3) | EC(7) | ACE(1))
@@ -113,9 +112,9 @@ static const u32 hdmi_colorimetry_val[] = {
[DRM_MODE_COLORIMETRY_SYCC_601] = HDMI_COLORIMETRY_SYCC_601,
[DRM_MODE_COLORIMETRY_OPYCC_601] = HDMI_COLORIMETRY_OPYCC_601,
[DRM_MODE_COLORIMETRY_OPRGB] = HDMI_COLORIMETRY_OPRGB,
- [DRM_MODE_COLORIMETRY_BT2020_CYCC] = HDMI_COLORIMETRY_BT2020_CYCC,
- [DRM_MODE_COLORIMETRY_BT2020_RGB] = HDMI_COLORIMETRY_BT2020_RGB,
- [DRM_MODE_COLORIMETRY_BT2020_YCC] = HDMI_COLORIMETRY_BT2020_YCC,
+ [DRM_MODE_COLORIMETRY_BT2020_DEPRECATED_1] = HDMI_COLORIMETRY_BT2020,
+ [DRM_MODE_COLORIMETRY_BT2020_DEPRECATED_2] = HDMI_COLORIMETRY_BT2020,
+ [DRM_MODE_COLORIMETRY_BT2020] = HDMI_COLORIMETRY_BT2020,
};
#undef C
diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c
index 61c29ce74b03..58699ab15a6a 100644
--- a/drivers/gpu/drm/drm_connector.c
+++ b/drivers/gpu/drm/drm_connector.c
@@ -1029,11 +1029,11 @@ static const struct drm_prop_enum_list
hdmi_colorspaces[] = {
/* Colorimetry based on IEC 61966-2-5 */
{ DRM_MODE_COLORIMETRY_OPRGB, "opRGB" },
/* Colorimetry based on ITU-R BT.2020 */
- { DRM_MODE_COLORIMETRY_BT2020_CYCC, "BT2020_CYCC" },
+ { DRM_MODE_COLORIMETRY_BT2020_DEPRECATED_1, "BT2020_DEPRECATED_1" },
/* Colorimetry based on ITU-R BT.2020 */
- { DRM_MODE_COLORIMETRY_BT2020_RGB, "BT2020_RGB" },
+ { DRM_MODE_COLORIMETRY_BT2020_DEPRECATED_2, "BT2020_DEPRECATED_2" },
/* Colorimetry based on ITU-R BT.2020 */
- { DRM_MODE_COLORIMETRY_BT2020_YCC, "BT2020_YCC" },
+ { DRM_MODE_COLORIMETRY_BT2020, "BT2020" },
/* Added as part of Additional Colorimetry Extension in 861.G */
{ DRM_MODE_COLORIMETRY_DCI_P3_RGB_D65, "DCI-P3_RGB_D65" },
{ DRM_MODE_COLORIMETRY_DCI_P3_RGB_THEATER, "DCI-P3_RGB_Theater" },
@@ -1054,7 +1054,7 @@ static const struct drm_prop_enum_list dp_colorspaces[] =
{
/* Colorimetry based on SMPTE RP 431-2 */
{ DRM_MODE_COLORIMETRY_DCI_P3_RGB_D65, "DCI-P3_RGB_D65" },
/* Colorimetry based on ITU-R BT.2020 */
- { DRM_MODE_COLORIMETRY_BT2020_RGB, "BT2020_RGB" },
+ { DRM_MODE_COLORIMETRY_BT2020, "BT2020" },
{ DRM_MODE_COLORIMETRY_BT601_YCC, "BT601_YCC" },
{ DRM_MODE_COLORIMETRY_BT709_YCC, "BT709_YCC" },
/* Standard Definition Colorimetry based on IEC 61966-2-4 */
@@ -1066,9 +1066,9 @@ static const struct drm_prop_enum_list dp_colorspaces[] =
{
/* Colorimetry based on IEC 61966-2-5 [33] */
{ DRM_MODE_COLORIMETRY_OPYCC_601, "opYCC_601" },
/* Colorimetry based on ITU-R BT.2020 */
- { DRM_MODE_COLORIMETRY_BT2020_CYCC, "BT2020_CYCC" },
+ { DRM_MODE_COLORIMETRY_BT2020_DEPRECATED_1, "BT2020_DEPRECATED_1" },
/* Colorimetry based on ITU-R BT.2020 */
- {
Re: [PATCH 3/3] drm/connector: Deprecate split for BT.2020 in drm_colorspace enum
On Wed, 8 Feb 2023 16:49:31 +0200 Ville Syrjälä wrote: > On Wed, Feb 08, 2023 at 11:18:42AM +0200, Pekka Paalanen wrote: > > On Fri, 3 Feb 2023 16:02:51 +0200 > > Ville Syrjälä wrote: > > > > > On Fri, Feb 03, 2023 at 02:52:50PM +0100, Sebastian Wick wrote: > > > > On Fri, Feb 3, 2023 at 2:35 PM Ville Syrjälä > > > > wrote: > > > > > > > > > > On Fri, Feb 03, 2023 at 01:59:07PM +0100, Sebastian Wick wrote: > > > > > > On Fri, Feb 3, 2023 at 11:40 AM Ville Syrjälä > > > > > > wrote: > > > > > > > > > > > > > > On Fri, Feb 03, 2023 at 02:07:44AM +, Joshua Ashton wrote: > > > > > > > > Userspace has no way of controlling or knowing the pixel > > > > > > > > encoding > > > > > > > > currently, so there is no way for it to ever get the right > > > > > > > > values here. > > > > > > > > > > > > > > That applies to a lot of the other values as well (they are > > > > > > > explicitly RGB or YCC). The idea was that this property sets the > > > > > > > infoframe/MSA/SDP value exactly, and other properties should be > > > > > > > added to for use userspace to control the pixel > > > > > > > encoding/colorspace > > > > > > > conversion(if desired, or userspace just makes sure to > > > > > > > directly feed in correct kind of data). > > > > > > > > > > > > I'm all for getting userspace control over pixel encoding but even > > > > > > then the kernel always knows which pixel encoding is selected and > > > > > > which InfoFrame has to be sent. Is there a reason why userspace > > > > > > would > > > > > > want to control the variant explicitly to the wrong value? > > > > > > > > > > What do you mean wrong value? Userspace sets it based on what > > > > > kind of data it has generated (or asked the display hardware > > > > > to generate if/when we get explicit control over that part). > > > > > > > > Wrong in the sense of sending the YCC variant when the pixel encoding > > > > is RGB for example. > > > > > > > > Maybe I'm missing something here but my assumption is that the kernel > > > > always has to know the pixel encoding anyway. The color pipeline also > > > > assumes that the pixel values are RGB. User space might be able to > > > > generate YCC content but for subsampling etc the pixel encoding still > > > > has to be explicitly set. > > > > > > The kernel doesn't really know much atm. In theory you can just > > > configure the thing to do a straight passthough and put anything you > > > want into your pixels. > > > > But it's impossible to use a YCbCr framebuffer and have that *not* > > converted to RGB for the KMS color pipeline even if userspace wanted it > > to be strictly pass-through, only to be converted again to YCbCr for > > the cable, is it not? > > > > Even more so with 4:2:0. > > > > How could it be possible to stop the driver from doing those two > > YUV-to-RGB and RGB-to-YCbCr conversions at the beginning and at the end > > of the KMS color pipeline? > > You can stop the conversion at the start of the pipeline by > using a "RGB" framebuffer. At the end of the pipe it's not > possible with the current props. But there is no such thing as a 4:2:0 sub-sampled RGB framebuffer to be abused for YUV content. It would be possible for some kind of xYUV 4:4:4 content though, but then the pipeline wouldn't work. Joshua had the excellent point that disabling the conversion at the end of the pipeline is not possible for a non-RGB output signal, period. The KMS color pipeline is defined in terms of RGB channels, that's the only(?) way alpha-blending could work, and the LUT-like elements cannot handle negative values. On one hand I very much agree that the definition of "Broadcast RGB" property was a mistake by combining pixel operations with infoframe settings. OTOH, since the pipeline end conversion is today chosen by the driver, then the KMS color pipeline output must be known to the driver so that the driver can pick the right conversion. That's what "Broadcast RGB" did: it assumed the pipeline produces full range values, so that it is able to insert the right conversion and the right infoframe data. It rules out possible use cases, but the infoframe matches. As for the pipe-end RGB-to-YCbCr conversion, the situation is partly similar. There is the assumption that the pipeline produces RGB model values. However, this assumption is likely never going to change, because the pipeline is inherently RGB, always. A better question is, does it need other assumptions as well? Quantization range? RGB (electrical encoding) transfer function? Most RGB-to-YCbCr conversions are just a matrix applied to the electrical RGB values, but not all. Particularly the constant luminance encoding requires optical, not electrical, RGB values, and it also needs the transfer function since it emits electrical values. I haven't looked if e.g. BT.2100 has more cases making the RGB-to-something conversion complex. Even having a doubt about that really does point towards
Re: [PATCH 3/3] drm/connector: Deprecate split for BT.2020 in drm_colorspace enum
On Wed, Feb 08, 2023 at 11:18:42AM +0200, Pekka Paalanen wrote: > On Fri, 3 Feb 2023 16:02:51 +0200 > Ville Syrjälä wrote: > > > On Fri, Feb 03, 2023 at 02:52:50PM +0100, Sebastian Wick wrote: > > > On Fri, Feb 3, 2023 at 2:35 PM Ville Syrjälä > > > wrote: > > > > > > > > On Fri, Feb 03, 2023 at 01:59:07PM +0100, Sebastian Wick wrote: > > > > > On Fri, Feb 3, 2023 at 11:40 AM Ville Syrjälä > > > > > wrote: > > > > > > > > > > > > On Fri, Feb 03, 2023 at 02:07:44AM +, Joshua Ashton wrote: > > > > > > > Userspace has no way of controlling or knowing the pixel encoding > > > > > > > currently, so there is no way for it to ever get the right values > > > > > > > here. > > > > > > > > > > > > That applies to a lot of the other values as well (they are > > > > > > explicitly RGB or YCC). The idea was that this property sets the > > > > > > infoframe/MSA/SDP value exactly, and other properties should be > > > > > > added to for use userspace to control the pixel encoding/colorspace > > > > > > conversion(if desired, or userspace just makes sure to > > > > > > directly feed in correct kind of data). > > > > > > > > > > I'm all for getting userspace control over pixel encoding but even > > > > > then the kernel always knows which pixel encoding is selected and > > > > > which InfoFrame has to be sent. Is there a reason why userspace would > > > > > want to control the variant explicitly to the wrong value? > > > > > > > > What do you mean wrong value? Userspace sets it based on what > > > > kind of data it has generated (or asked the display hardware > > > > to generate if/when we get explicit control over that part). > > > > > > Wrong in the sense of sending the YCC variant when the pixel encoding > > > is RGB for example. > > > > > > Maybe I'm missing something here but my assumption is that the kernel > > > always has to know the pixel encoding anyway. The color pipeline also > > > assumes that the pixel values are RGB. User space might be able to > > > generate YCC content but for subsampling etc the pixel encoding still > > > has to be explicitly set. > > > > The kernel doesn't really know much atm. In theory you can just > > configure the thing to do a straight passthough and put anything you > > want into your pixels. > > But it's impossible to use a YCbCr framebuffer and have that *not* > converted to RGB for the KMS color pipeline even if userspace wanted it > to be strictly pass-through, only to be converted again to YCbCr for > the cable, is it not? > > Even more so with 4:2:0. > > How could it be possible to stop the driver from doing those two > YUV-to-RGB and RGB-to-YCbCr conversions at the beginning and at the end > of the KMS color pipeline? You can stop the conversion at the start of the pipeline by using a "RGB" framebuffer. At the end of the pipe it's not possible with the current props. -- Ville Syrjälä Intel
Re: [PATCH 3/3] drm/connector: Deprecate split for BT.2020 in drm_colorspace enum
On Mon, 6 Feb 2023 12:16:28 -0500 Harry Wentland wrote: > On 2/6/23 04:47, Ville Syrjälä wrote: > > On Sat, Feb 04, 2023 at 06:09:45AM +, Joshua Ashton wrote: > >> > >> > >> On 2/3/23 19:34, Ville Syrjälä wrote: > >>> On Fri, Feb 03, 2023 at 09:25:38PM +0200, Ville Syrjälä wrote: > On Fri, Feb 03, 2023 at 08:56:55PM +0200, Ville Syrjälä wrote: > > On Fri, Feb 03, 2023 at 01:28:20PM -0500, Harry Wentland wrote: > >> > >> > >> On 2/3/23 11:00, Ville Syrjälä wrote: > >>> On Fri, Feb 03, 2023 at 10:24:52AM -0500, Harry Wentland wrote: > > > On 2/3/23 10:19, Ville Syrjälä wrote: > > On Fri, Feb 03, 2023 at 09:39:42AM -0500, Harry Wentland wrote: > >> > >> > >> On 2/3/23 07:59, Sebastian Wick wrote: > >>> On Fri, Feb 3, 2023 at 11:40 AM Ville Syrjälä > >>> wrote: > > On Fri, Feb 03, 2023 at 02:07:44AM +, Joshua Ashton wrote: > > Userspace has no way of controlling or knowing the pixel > > encoding > > currently, so there is no way for it to ever get the right > > values here. > > That applies to a lot of the other values as well (they are > explicitly RGB or YCC). The idea was that this property sets the > infoframe/MSA/SDP value exactly, and other properties should be > added to for use userspace to control the pixel > encoding/colorspace > conversion(if desired, or userspace just makes sure to > directly feed in correct kind of data). > >>> > >>> I'm all for getting userspace control over pixel encoding but even > >>> then the kernel always knows which pixel encoding is selected and > >>> which InfoFrame has to be sent. Is there a reason why userspace > >>> would > >>> want to control the variant explicitly to the wrong value? > >>> > >> > >> I've asked this before but haven't seen an answer: Is there an > >> existing > >> upstream userspace project that makes use of this property (other > >> than > >> what Joshua is working on in gamescope right now)? That would help > >> us > >> understand the intent better. > > > > The intent was to control the infoframe colorimetry bits, > > nothing more. No idea what real userspace there was, if any. > >> > >> Controlling the infoframe alone isn't useful at all unless you can > >> guarantee the wire encoding, which we cannot do. > >> > > > >> > >> I don't think giving userspace explicit control over the exact > >> infoframe > >> values is the right thing to do. > >> > >> +1 > >> > > > > Only userspace knows what kind of data it's stuffing into > > the pixels (and/or how it configures the csc units/etc.) to > > generate them. > > > > Yes, but userspace doesn't control or know whether we drive > RGB or YCbCr on the wire. In fact, in some cases our driver > needs to fallback to YCbCr420 for bandwidth reasons. There > is currently no way for userspace to know that and I don't > think it makes sense. > >>> > >>> People want that control as well for whatever reason. We've > >>> been asked to allow YCbCr 4:4:4 output many times. > >>> > >>> The automagic 4:2:0 fallback I think is rather fundementally > >>> incompatible with fancy color management. How would we even > >>> know whether to use eg. BT.2020 vs. BT.709 matrix? In i915 > >>> that stuff is just always BT.709 limited range, no questions > >>> asked. > >> > >> That's what the Colorspace property *should* be determining here. > >> That's what we have it set up to do in SteamOS/my tree right now. > >> > >>> > >> > >> We use what we're telling the display, i.e., the value in the > >> colorspace property. That way we know whether to use a BT.2020 > >> or BT.709 matrix. > > > > And given how these things have gone in the past I think > > that is likey to bite someone at in the future. Also not > > what this property was meant to do nor does on any other > > driver AFAIK. > > > >> I don't see how it's fundamentally incompatible with fancy > >> color management stuff. > >> > >> If we start forbidding drivers from falling back to YCbCr > >> (whether 4:4:4 or 4:2:0) we will break existing behavior on > >> amdgpu and will see bug reports. > > > > The compositors could deal with that if/when they start doing > > the full color management stuff. The current stuff only really > > works when the kernel is allowed to do whatever it wants. > > > >> > >>> So I think if userspace
Re: [PATCH 3/3] drm/connector: Deprecate split for BT.2020 in drm_colorspace enum
On Fri, 3 Feb 2023 14:33:46 -0500 Harry Wentland wrote: > On 2/3/23 14:25, Ville Syrjälä wrote: > > On Fri, Feb 03, 2023 at 08:56:55PM +0200, Ville Syrjälä wrote: > >> On Fri, Feb 03, 2023 at 01:28:20PM -0500, Harry Wentland wrote: > >>> > >>> > >>> On 2/3/23 11:00, Ville Syrjälä wrote: > On Fri, Feb 03, 2023 at 10:24:52AM -0500, Harry Wentland wrote: > > > > > > On 2/3/23 10:19, Ville Syrjälä wrote: > >> On Fri, Feb 03, 2023 at 09:39:42AM -0500, Harry Wentland wrote: > >>> > >>> > >>> On 2/3/23 07:59, Sebastian Wick wrote: > On Fri, Feb 3, 2023 at 11:40 AM Ville Syrjälä > wrote: > > > > On Fri, Feb 03, 2023 at 02:07:44AM +, Joshua Ashton wrote: > >> Userspace has no way of controlling or knowing the pixel encoding > >> currently, so there is no way for it to ever get the right values > >> here. > > > > That applies to a lot of the other values as well (they are > > explicitly RGB or YCC). The idea was that this property sets the > > infoframe/MSA/SDP value exactly, and other properties should be > > added to for use userspace to control the pixel encoding/colorspace > > conversion(if desired, or userspace just makes sure to > > directly feed in correct kind of data). > > I'm all for getting userspace control over pixel encoding but even > then the kernel always knows which pixel encoding is selected and > which InfoFrame has to be sent. Is there a reason why userspace would > want to control the variant explicitly to the wrong value? > > >>> > >>> I've asked this before but haven't seen an answer: Is there an > >>> existing > >>> upstream userspace project that makes use of this property (other than > >>> what Joshua is working on in gamescope right now)? That would help us > >>> understand the intent better. > >> > >> The intent was to control the infoframe colorimetry bits, > >> nothing more. No idea what real userspace there was, if any. > >> > >>> > >>> I don't think giving userspace explicit control over the exact > >>> infoframe > >>> values is the right thing to do. > >> > >> Only userspace knows what kind of data it's stuffing into > >> the pixels (and/or how it configures the csc units/etc.) to > >> generate them. > >> > > > > Yes, but userspace doesn't control or know whether we drive > > RGB or YCbCr on the wire. In fact, in some cases our driver > > needs to fallback to YCbCr420 for bandwidth reasons. There > > is currently no way for userspace to know that and I don't > > think it makes sense. > > People want that control as well for whatever reason. We've > been asked to allow YCbCr 4:4:4 output many times. > > The automagic 4:2:0 fallback I think is rather fundementally > incompatible with fancy color management. How would we even > know whether to use eg. BT.2020 vs. BT.709 matrix? In i915 > that stuff is just always BT.709 limited range, no questions > asked. > > >>> > >>> We use what we're telling the display, i.e., the value in the > >>> colorspace property. That way we know whether to use a BT.2020 > >>> or BT.709 matrix. > >> > >> And given how these things have gone in the past I think > >> that is likey to bite someone at in the future. Also not > >> what this property was meant to do nor does on any other > >> driver AFAIK. > >> > >>> I don't see how it's fundamentally incompatible with fancy > >>> color management stuff. > >>> > >>> If we start forbidding drivers from falling back to YCbCr > >>> (whether 4:4:4 or 4:2:0) we will break existing behavior on > >>> amdgpu and will see bug reports. > >> > >> The compositors could deal with that if/when they start doing > >> the full color management stuff. The current stuff only really > >> works when the kernel is allowed to do whatever it wants. > >> > >>> > So I think if userspace wants real color management it's > going to have to set up the whole pipeline. And for that > we need at least one new property to control the RGB->YCbCr > conversion (or to explicitly avoid it). > > And given that the proposed patch just swept all the > non-BT.2020 issues under the rug makes me think no > one has actually come up with any kind of consistent > plan for anything else really. > > >>> > >>> Does anyone actually use the non-BT.2020 colorspace stuff? > >> > >> No idea if anyone is using any of it. It's a bit hard to do > >> right now outside the full passthrough case since we have no > >> properties to control how the hardware will convert stuff. > >> > >> Anyways, sounds like what you're basically proposing is > >> getting rid of this property and starting from scratch. > > > > Hmm. I
Re: [PATCH 3/3] drm/connector: Deprecate split for BT.2020 in drm_colorspace enum
On Fri, 3 Feb 2023 02:07:44 +
Joshua Ashton wrote:
> Userspace has no way of controlling or knowing the pixel encoding
> currently, so there is no way for it to ever get the right values here.
>
> When we do add pixel_encoding control from userspace,we can pick the
> right value for the colorimetry packet based on the
> pixel_encoding + the colorspace.
>
> Let's deprecate these values, and have one BT.2020 colorspace entry
> that userspace can use.
>
> Note: _CYCC was effectively 'removed' by this change, but that was not
> possible to be taken advantage of anyway, as there is currently no
> pixel_encoding control so it would not be possible to output
> linear YCbCr.
>
> Signed-off-by: Joshua Ashton
>
> Cc: Pekka Paalanen
> Cc: Sebastian Wick
> Cc: vitaly.pros...@amd.com
> Cc: Uma Shankar
> Cc: Ville Syrjälä
> Cc: Joshua Ashton
> Cc: dri-de...@lists.freedesktop.org
> Cc: amd-gfx@lists.freedesktop.org
> ---
> drivers/gpu/drm/display/drm_hdmi_helper.c | 9 -
> drivers/gpu/drm/drm_connector.c | 12 ++--
> drivers/gpu/drm/i915/display/intel_dp.c | 20 +---
> include/drm/drm_connector.h | 19 ++-
> 4 files changed, 29 insertions(+), 31 deletions(-)
>
> diff --git a/drivers/gpu/drm/display/drm_hdmi_helper.c
> b/drivers/gpu/drm/display/drm_hdmi_helper.c
> index 0264abe55278..c85860600395 100644
> --- a/drivers/gpu/drm/display/drm_hdmi_helper.c
> +++ b/drivers/gpu/drm/display/drm_hdmi_helper.c
> @@ -99,8 +99,7 @@ EXPORT_SYMBOL(drm_hdmi_infoframe_set_hdr_metadata);
> #define HDMI_COLORIMETRY_OPYCC_601 (C(3) | EC(3) | ACE(0))
> #define HDMI_COLORIMETRY_OPRGB (C(3) | EC(4) | ACE(0))
> #define HDMI_COLORIMETRY_BT2020_CYCC (C(3) | EC(5) | ACE(0))
> -#define HDMI_COLORIMETRY_BT2020_RGB (C(3) | EC(6) | ACE(0))
> -#define HDMI_COLORIMETRY_BT2020_YCC (C(3) | EC(6) | ACE(0))
> +#define HDMI_COLORIMETRY_BT2020 (C(3) | EC(6) | ACE(0))
> #define HDMI_COLORIMETRY_DCI_P3_RGB_D65 (C(3) | EC(7) | ACE(0))
> #define HDMI_COLORIMETRY_DCI_P3_RGB_THEATER (C(3) | EC(7) | ACE(1))
>
> @@ -113,9 +112,9 @@ static const u32 hdmi_colorimetry_val[] = {
> [DRM_MODE_COLORIMETRY_SYCC_601] = HDMI_COLORIMETRY_SYCC_601,
> [DRM_MODE_COLORIMETRY_OPYCC_601] = HDMI_COLORIMETRY_OPYCC_601,
> [DRM_MODE_COLORIMETRY_OPRGB] = HDMI_COLORIMETRY_OPRGB,
> - [DRM_MODE_COLORIMETRY_BT2020_CYCC] = HDMI_COLORIMETRY_BT2020_CYCC,
> - [DRM_MODE_COLORIMETRY_BT2020_RGB] = HDMI_COLORIMETRY_BT2020_RGB,
> - [DRM_MODE_COLORIMETRY_BT2020_YCC] = HDMI_COLORIMETRY_BT2020_YCC,
> + [DRM_MODE_COLORIMETRY_BT2020_DEPRECATED_1] = HDMI_COLORIMETRY_BT2020,
> + [DRM_MODE_COLORIMETRY_BT2020_DEPRECATED_2] = HDMI_COLORIMETRY_BT2020,
> + [DRM_MODE_COLORIMETRY_BT2020] = HDMI_COLORIMETRY_BT2020,
> };
>
> #undef C
> diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c
> index 61c29ce74b03..58699ab15a6a 100644
> --- a/drivers/gpu/drm/drm_connector.c
> +++ b/drivers/gpu/drm/drm_connector.c
> @@ -1029,11 +1029,11 @@ static const struct drm_prop_enum_list
> hdmi_colorspaces[] = {
> /* Colorimetry based on IEC 61966-2-5 */
> { DRM_MODE_COLORIMETRY_OPRGB, "opRGB" },
> /* Colorimetry based on ITU-R BT.2020 */
> - { DRM_MODE_COLORIMETRY_BT2020_CYCC, "BT2020_CYCC" },
> + { DRM_MODE_COLORIMETRY_BT2020_DEPRECATED_1, "BT2020_DEPRECATED_1" },
> /* Colorimetry based on ITU-R BT.2020 */
> - { DRM_MODE_COLORIMETRY_BT2020_RGB, "BT2020_RGB" },
> + { DRM_MODE_COLORIMETRY_BT2020_DEPRECATED_2, "BT2020_DEPRECATED_2" },
> /* Colorimetry based on ITU-R BT.2020 */
> - { DRM_MODE_COLORIMETRY_BT2020_YCC, "BT2020_YCC" },
> + { DRM_MODE_COLORIMETRY_BT2020, "BT2020" },
> /* Added as part of Additional Colorimetry Extension in 861.G */
> { DRM_MODE_COLORIMETRY_DCI_P3_RGB_D65, "DCI-P3_RGB_D65" },
> { DRM_MODE_COLORIMETRY_DCI_P3_RGB_THEATER, "DCI-P3_RGB_Theater" },
> @@ -1054,7 +1054,7 @@ static const struct drm_prop_enum_list dp_colorspaces[]
> = {
> /* Colorimetry based on SMPTE RP 431-2 */
> { DRM_MODE_COLORIMETRY_DCI_P3_RGB_D65, "DCI-P3_RGB_D65" },
> /* Colorimetry based on ITU-R BT.2020 */
> - { DRM_MODE_COLORIMETRY_BT2020_RGB, "BT2020_RGB" },
> + { DRM_MODE_COLORIMETRY_BT2020, "BT2020" },
> { DRM_MODE_COLORIMETRY_BT601_YCC, "BT601_YCC" },
> { DRM_MODE_COLORIMETRY_BT709_YCC, "BT709_YCC" },
> /* Standard Definition Colorimetry based on IEC 61966-2-4 */
> @@ -1066,9 +1066,9 @@ static const struct drm_prop_enum_list dp_colorspaces[]
> = {
> /* Colorimetry based on IEC 61966-2-5 [33] */
> { DRM_MODE_COLORIMETRY_OPYCC_601, "opYCC_601" },
> /* Colorimetry based on ITU-R BT.2020 */
> - { DRM_MODE_COLORIMETRY_BT2020_CYCC, "BT2020_CYCC" },
> + { DRM_MODE_COLORIMETRY_BT2020_DEPRECATED_1, "BT2020_DEPRECATED_1" },
> /*
Re: [PATCH 3/3] drm/connector: Deprecate split for BT.2020 in drm_colorspace enum
On Fri, 3 Feb 2023 20:56:55 +0200 Ville Syrjälä wrote: > Anyways, sounds like what you're basically proposing is > getting rid of this property and starting from scratch. I would be happy with that (throwing "Colorspace" out and defining something new). Then we can start with enum values we care and know about. Thanks, pq pgpNyNicMbsuM.pgp Description: OpenPGP digital signature
Re: [PATCH 3/3] drm/connector: Deprecate split for BT.2020 in drm_colorspace enum
On Fri, 3 Feb 2023 18:00:44 +0200 Ville Syrjälä wrote: > On Fri, Feb 03, 2023 at 10:24:52AM -0500, Harry Wentland wrote: > > > > > > On 2/3/23 10:19, Ville Syrjälä wrote: > > > On Fri, Feb 03, 2023 at 09:39:42AM -0500, Harry Wentland wrote: > > >> > > >> > > >> On 2/3/23 07:59, Sebastian Wick wrote: > > >>> On Fri, Feb 3, 2023 at 11:40 AM Ville Syrjälä > > >>> wrote: > > > > On Fri, Feb 03, 2023 at 02:07:44AM +, Joshua Ashton wrote: > > > Userspace has no way of controlling or knowing the pixel encoding > > > currently, so there is no way for it to ever get the right values > > > here. > > > > That applies to a lot of the other values as well (they are > > explicitly RGB or YCC). The idea was that this property sets the > > infoframe/MSA/SDP value exactly, and other properties should be > > added to for use userspace to control the pixel encoding/colorspace > > conversion(if desired, or userspace just makes sure to > > directly feed in correct kind of data). > > >>> > > >>> I'm all for getting userspace control over pixel encoding but even > > >>> then the kernel always knows which pixel encoding is selected and > > >>> which InfoFrame has to be sent. Is there a reason why userspace would > > >>> want to control the variant explicitly to the wrong value? > > >>> > > >> > > >> I've asked this before but haven't seen an answer: Is there an existing > > >> upstream userspace project that makes use of this property (other than > > >> what Joshua is working on in gamescope right now)? That would help us > > >> understand the intent better. > > > > > > The intent was to control the infoframe colorimetry bits, > > > nothing more. No idea what real userspace there was, if any. > > > > > >> > > >> I don't think giving userspace explicit control over the exact infoframe > > >> values is the right thing to do. > > > > > > Only userspace knows what kind of data it's stuffing into > > > the pixels (and/or how it configures the csc units/etc.) to > > > generate them. > > > > > > > Yes, but userspace doesn't control or know whether we drive > > RGB or YCbCr on the wire. In fact, in some cases our driver > > needs to fallback to YCbCr420 for bandwidth reasons. There > > is currently no way for userspace to know that and I don't > > think it makes sense. > > People want that control as well for whatever reason. We've > been asked to allow YCbCr 4:4:4 output many times. > > The automagic 4:2:0 fallback I think is rather fundementally > incompatible with fancy color management. How would we even > know whether to use eg. BT.2020 vs. BT.709 matrix? In i915 > that stuff is just always BT.709 limited range, no questions > asked. The difference between 4:4:4 and 4:2:0 is purely the sub-sampling. It has absolutely no implication to colorimetry nor MatrixCoefficients at all. Thanks, pq pgprYHeBRUNlQ.pgp Description: OpenPGP digital signature
Re: [PATCH 3/3] drm/connector: Deprecate split for BT.2020 in drm_colorspace enum
On Fri, 3 Feb 2023 16:02:51 +0200 Ville Syrjälä wrote: > On Fri, Feb 03, 2023 at 02:52:50PM +0100, Sebastian Wick wrote: > > On Fri, Feb 3, 2023 at 2:35 PM Ville Syrjälä > > wrote: > > > > > > On Fri, Feb 03, 2023 at 01:59:07PM +0100, Sebastian Wick wrote: > > > > On Fri, Feb 3, 2023 at 11:40 AM Ville Syrjälä > > > > wrote: > > > > > > > > > > On Fri, Feb 03, 2023 at 02:07:44AM +, Joshua Ashton wrote: > > > > > > Userspace has no way of controlling or knowing the pixel encoding > > > > > > currently, so there is no way for it to ever get the right values > > > > > > here. > > > > > > > > > > That applies to a lot of the other values as well (they are > > > > > explicitly RGB or YCC). The idea was that this property sets the > > > > > infoframe/MSA/SDP value exactly, and other properties should be > > > > > added to for use userspace to control the pixel encoding/colorspace > > > > > conversion(if desired, or userspace just makes sure to > > > > > directly feed in correct kind of data). > > > > > > > > I'm all for getting userspace control over pixel encoding but even > > > > then the kernel always knows which pixel encoding is selected and > > > > which InfoFrame has to be sent. Is there a reason why userspace would > > > > want to control the variant explicitly to the wrong value? > > > > > > What do you mean wrong value? Userspace sets it based on what > > > kind of data it has generated (or asked the display hardware > > > to generate if/when we get explicit control over that part). > > > > Wrong in the sense of sending the YCC variant when the pixel encoding > > is RGB for example. > > > > Maybe I'm missing something here but my assumption is that the kernel > > always has to know the pixel encoding anyway. The color pipeline also > > assumes that the pixel values are RGB. User space might be able to > > generate YCC content but for subsampling etc the pixel encoding still > > has to be explicitly set. > > The kernel doesn't really know much atm. In theory you can just > configure the thing to do a straight passthough and put anything you > want into your pixels. But it's impossible to use a YCbCr framebuffer and have that *not* converted to RGB for the KMS color pipeline even if userspace wanted it to be strictly pass-through, only to be converted again to YCbCr for the cable, is it not? Even more so with 4:2:0. How could it be possible to stop the driver from doing those two YUV-to-RGB and RGB-to-YCbCr conversions at the beginning and at the end of the KMS color pipeline? From uAPI point of view: "Colorspace" currently defines (or does it? see my patch 2 review) the colorimetry and the color model encoding. If a driver chooses the cable encoding independently, the "Colorspace" color model encoding is often wrong. If we have another KMS property to choose the cable encoding, then it is possible to still set "Colorspace" to disagree with the actual cable encoding. What's the use of that possibility to configure things wrong? Thanks, pq > > > > > So with the kernel always knowing exactly what pixel encoding is sent, > > why do we need those variants? I just don't see why this is necessary. > > > > > > > > -- > > > Ville Syrjälä > > > Intel > > > > pgpWh1fOGS_Au.pgp Description: OpenPGP digital signature
Re: [PATCH 3/3] drm/connector: Deprecate split for BT.2020 in drm_colorspace enum
On 2/6/23 04:47, Ville Syrjälä wrote: > On Sat, Feb 04, 2023 at 06:09:45AM +, Joshua Ashton wrote: >> >> >> On 2/3/23 19:34, Ville Syrjälä wrote: >>> On Fri, Feb 03, 2023 at 09:25:38PM +0200, Ville Syrjälä wrote: On Fri, Feb 03, 2023 at 08:56:55PM +0200, Ville Syrjälä wrote: > On Fri, Feb 03, 2023 at 01:28:20PM -0500, Harry Wentland wrote: >> >> >> On 2/3/23 11:00, Ville Syrjälä wrote: >>> On Fri, Feb 03, 2023 at 10:24:52AM -0500, Harry Wentland wrote: On 2/3/23 10:19, Ville Syrjälä wrote: > On Fri, Feb 03, 2023 at 09:39:42AM -0500, Harry Wentland wrote: >> >> >> On 2/3/23 07:59, Sebastian Wick wrote: >>> On Fri, Feb 3, 2023 at 11:40 AM Ville Syrjälä >>> wrote: On Fri, Feb 03, 2023 at 02:07:44AM +, Joshua Ashton wrote: > Userspace has no way of controlling or knowing the pixel encoding > currently, so there is no way for it to ever get the right values > here. That applies to a lot of the other values as well (they are explicitly RGB or YCC). The idea was that this property sets the infoframe/MSA/SDP value exactly, and other properties should be added to for use userspace to control the pixel encoding/colorspace conversion(if desired, or userspace just makes sure to directly feed in correct kind of data). >>> >>> I'm all for getting userspace control over pixel encoding but even >>> then the kernel always knows which pixel encoding is selected and >>> which InfoFrame has to be sent. Is there a reason why userspace >>> would >>> want to control the variant explicitly to the wrong value? >>> >> >> I've asked this before but haven't seen an answer: Is there an >> existing >> upstream userspace project that makes use of this property (other >> than >> what Joshua is working on in gamescope right now)? That would help us >> understand the intent better. > > The intent was to control the infoframe colorimetry bits, > nothing more. No idea what real userspace there was, if any. >> >> Controlling the infoframe alone isn't useful at all unless you can >> guarantee the wire encoding, which we cannot do. >> > >> >> I don't think giving userspace explicit control over the exact >> infoframe >> values is the right thing to do. >> >> +1 >> > > Only userspace knows what kind of data it's stuffing into > the pixels (and/or how it configures the csc units/etc.) to > generate them. > Yes, but userspace doesn't control or know whether we drive RGB or YCbCr on the wire. In fact, in some cases our driver needs to fallback to YCbCr420 for bandwidth reasons. There is currently no way for userspace to know that and I don't think it makes sense. >>> >>> People want that control as well for whatever reason. We've >>> been asked to allow YCbCr 4:4:4 output many times. >>> >>> The automagic 4:2:0 fallback I think is rather fundementally >>> incompatible with fancy color management. How would we even >>> know whether to use eg. BT.2020 vs. BT.709 matrix? In i915 >>> that stuff is just always BT.709 limited range, no questions >>> asked. >> >> That's what the Colorspace property *should* be determining here. >> That's what we have it set up to do in SteamOS/my tree right now. >> >>> >> >> We use what we're telling the display, i.e., the value in the >> colorspace property. That way we know whether to use a BT.2020 >> or BT.709 matrix. > > And given how these things have gone in the past I think > that is likey to bite someone at in the future. Also not > what this property was meant to do nor does on any other > driver AFAIK. > >> I don't see how it's fundamentally incompatible with fancy >> color management stuff. >> >> If we start forbidding drivers from falling back to YCbCr >> (whether 4:4:4 or 4:2:0) we will break existing behavior on >> amdgpu and will see bug reports. > > The compositors could deal with that if/when they start doing > the full color management stuff. The current stuff only really > works when the kernel is allowed to do whatever it wants. > >> >>> So I think if userspace wants real color management it's >>> going to have to set up the whole pipeline. And for that >>> we need at least one new property to control the RGB->YCbCr >>> conversion (or to explicitly avoid it). >> >> I mentioned this in my commit description, we absolutely should offer >> fine control here eventually. >> >> I don't think we need to solve that problem here though.
Re: [PATCH 3/3] drm/connector: Deprecate split for BT.2020 in drm_colorspace enum
On Sat, Feb 04, 2023 at 06:09:45AM +, Joshua Ashton wrote: > > > On 2/3/23 19:34, Ville Syrjälä wrote: > > On Fri, Feb 03, 2023 at 09:25:38PM +0200, Ville Syrjälä wrote: > >> On Fri, Feb 03, 2023 at 08:56:55PM +0200, Ville Syrjälä wrote: > >>> On Fri, Feb 03, 2023 at 01:28:20PM -0500, Harry Wentland wrote: > > > On 2/3/23 11:00, Ville Syrjälä wrote: > > On Fri, Feb 03, 2023 at 10:24:52AM -0500, Harry Wentland wrote: > >> > >> > >> On 2/3/23 10:19, Ville Syrjälä wrote: > >>> On Fri, Feb 03, 2023 at 09:39:42AM -0500, Harry Wentland wrote: > > > On 2/3/23 07:59, Sebastian Wick wrote: > > On Fri, Feb 3, 2023 at 11:40 AM Ville Syrjälä > > wrote: > >> > >> On Fri, Feb 03, 2023 at 02:07:44AM +, Joshua Ashton wrote: > >>> Userspace has no way of controlling or knowing the pixel encoding > >>> currently, so there is no way for it to ever get the right values > >>> here. > >> > >> That applies to a lot of the other values as well (they are > >> explicitly RGB or YCC). The idea was that this property sets the > >> infoframe/MSA/SDP value exactly, and other properties should be > >> added to for use userspace to control the pixel encoding/colorspace > >> conversion(if desired, or userspace just makes sure to > >> directly feed in correct kind of data). > > > > I'm all for getting userspace control over pixel encoding but even > > then the kernel always knows which pixel encoding is selected and > > which InfoFrame has to be sent. Is there a reason why userspace > > would > > want to control the variant explicitly to the wrong value? > > > > I've asked this before but haven't seen an answer: Is there an > existing > upstream userspace project that makes use of this property (other > than > what Joshua is working on in gamescope right now)? That would help us > understand the intent better. > >>> > >>> The intent was to control the infoframe colorimetry bits, > >>> nothing more. No idea what real userspace there was, if any. > > Controlling the infoframe alone isn't useful at all unless you can > guarantee the wire encoding, which we cannot do. > > >>> > > I don't think giving userspace explicit control over the exact > infoframe > values is the right thing to do. > > +1 > > >>> > >>> Only userspace knows what kind of data it's stuffing into > >>> the pixels (and/or how it configures the csc units/etc.) to > >>> generate them. > >>> > >> > >> Yes, but userspace doesn't control or know whether we drive > >> RGB or YCbCr on the wire. In fact, in some cases our driver > >> needs to fallback to YCbCr420 for bandwidth reasons. There > >> is currently no way for userspace to know that and I don't > >> think it makes sense. > > > > People want that control as well for whatever reason. We've > > been asked to allow YCbCr 4:4:4 output many times. > > > > The automagic 4:2:0 fallback I think is rather fundementally > > incompatible with fancy color management. How would we even > > know whether to use eg. BT.2020 vs. BT.709 matrix? In i915 > > that stuff is just always BT.709 limited range, no questions > > asked. > > That's what the Colorspace property *should* be determining here. > That's what we have it set up to do in SteamOS/my tree right now. > > > > > We use what we're telling the display, i.e., the value in the > colorspace property. That way we know whether to use a BT.2020 > or BT.709 matrix. > >>> > >>> And given how these things have gone in the past I think > >>> that is likey to bite someone at in the future. Also not > >>> what this property was meant to do nor does on any other > >>> driver AFAIK. > >>> > I don't see how it's fundamentally incompatible with fancy > color management stuff. > > If we start forbidding drivers from falling back to YCbCr > (whether 4:4:4 or 4:2:0) we will break existing behavior on > amdgpu and will see bug reports. > >>> > >>> The compositors could deal with that if/when they start doing > >>> the full color management stuff. The current stuff only really > >>> works when the kernel is allowed to do whatever it wants. > >>> > > > So I think if userspace wants real color management it's > > going to have to set up the whole pipeline. And for that > > we need at least one new property to control the RGB->YCbCr > > conversion (or to explicitly avoid it). > > I mentioned this in my commit description, we absolutely should offer > fine control here eventually. > > I don't think we need to solve that problem here though. > > > > > And given that the proposed patch
Re: [PATCH 3/3] drm/connector: Deprecate split for BT.2020 in drm_colorspace enum
Hi Joshua, Thank you for the patch! Perhaps something to improve: [auto build test WARNING on drm-misc/drm-misc-next] [also build test WARNING on drm/drm-next drm-intel/for-linux-next drm-intel/for-linux-next-fixes linus/master v6.2-rc6 next-20230203] [If your patch is applied to the wrong git tree, kindly drop us a note. And when submitting patch, we suggest to use '--base' as documented in https://git-scm.com/docs/git-format-patch#_base_tree_information] url: https://github.com/intel-lab-lkp/linux/commits/Joshua-Ashton/drm-connector-Add-enum-documentation-to-drm_colorspace/20230203-100927 base: git://anongit.freedesktop.org/drm/drm-misc drm-misc-next patch link: https://lore.kernel.org/r/20230203020744.30745-3-joshua%40froggi.es patch subject: [PATCH 3/3] drm/connector: Deprecate split for BT.2020 in drm_colorspace enum reproduce: # https://github.com/intel-lab-lkp/linux/commit/14174503e23d2174ba6089fb4090778513cd202b git remote add linux-review https://github.com/intel-lab-lkp/linux git fetch --no-tags linux-review Joshua-Ashton/drm-connector-Add-enum-documentation-to-drm_colorspace/20230203-100927 git checkout 14174503e23d2174ba6089fb4090778513cd202b make menuconfig # enable CONFIG_COMPILE_TEST, CONFIG_WARN_MISSING_DOCUMENTS, CONFIG_WARN_ABI_ERRORS make htmldocs If you fix the issue, kindly add following tag where applicable | Reported-by: kernel test robot All warnings (new ones prefixed by >>): >> Documentation/gpu/drm-kms:417: ./include/drm/drm_connector.h:479: WARNING: >> Definition list ends without a blank line; unexpected unindent. -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests
Re: [PATCH 3/3] drm/connector: Deprecate split for BT.2020 in drm_colorspace enum
On 2/3/23 19:34, Ville Syrjälä wrote: On Fri, Feb 03, 2023 at 09:25:38PM +0200, Ville Syrjälä wrote: On Fri, Feb 03, 2023 at 08:56:55PM +0200, Ville Syrjälä wrote: On Fri, Feb 03, 2023 at 01:28:20PM -0500, Harry Wentland wrote: On 2/3/23 11:00, Ville Syrjälä wrote: On Fri, Feb 03, 2023 at 10:24:52AM -0500, Harry Wentland wrote: On 2/3/23 10:19, Ville Syrjälä wrote: On Fri, Feb 03, 2023 at 09:39:42AM -0500, Harry Wentland wrote: On 2/3/23 07:59, Sebastian Wick wrote: On Fri, Feb 3, 2023 at 11:40 AM Ville Syrjälä wrote: On Fri, Feb 03, 2023 at 02:07:44AM +, Joshua Ashton wrote: Userspace has no way of controlling or knowing the pixel encoding currently, so there is no way for it to ever get the right values here. That applies to a lot of the other values as well (they are explicitly RGB or YCC). The idea was that this property sets the infoframe/MSA/SDP value exactly, and other properties should be added to for use userspace to control the pixel encoding/colorspace conversion(if desired, or userspace just makes sure to directly feed in correct kind of data). I'm all for getting userspace control over pixel encoding but even then the kernel always knows which pixel encoding is selected and which InfoFrame has to be sent. Is there a reason why userspace would want to control the variant explicitly to the wrong value? I've asked this before but haven't seen an answer: Is there an existing upstream userspace project that makes use of this property (other than what Joshua is working on in gamescope right now)? That would help us understand the intent better. The intent was to control the infoframe colorimetry bits, nothing more. No idea what real userspace there was, if any. Controlling the infoframe alone isn't useful at all unless you can guarantee the wire encoding, which we cannot do. I don't think giving userspace explicit control over the exact infoframe values is the right thing to do. +1 Only userspace knows what kind of data it's stuffing into the pixels (and/or how it configures the csc units/etc.) to generate them. Yes, but userspace doesn't control or know whether we drive RGB or YCbCr on the wire. In fact, in some cases our driver needs to fallback to YCbCr420 for bandwidth reasons. There is currently no way for userspace to know that and I don't think it makes sense. People want that control as well for whatever reason. We've been asked to allow YCbCr 4:4:4 output many times. The automagic 4:2:0 fallback I think is rather fundementally incompatible with fancy color management. How would we even know whether to use eg. BT.2020 vs. BT.709 matrix? In i915 that stuff is just always BT.709 limited range, no questions asked. That's what the Colorspace property *should* be determining here. That's what we have it set up to do in SteamOS/my tree right now. We use what we're telling the display, i.e., the value in the colorspace property. That way we know whether to use a BT.2020 or BT.709 matrix. And given how these things have gone in the past I think that is likey to bite someone at in the future. Also not what this property was meant to do nor does on any other driver AFAIK. I don't see how it's fundamentally incompatible with fancy color management stuff. If we start forbidding drivers from falling back to YCbCr (whether 4:4:4 or 4:2:0) we will break existing behavior on amdgpu and will see bug reports. The compositors could deal with that if/when they start doing the full color management stuff. The current stuff only really works when the kernel is allowed to do whatever it wants. So I think if userspace wants real color management it's going to have to set up the whole pipeline. And for that we need at least one new property to control the RGB->YCbCr conversion (or to explicitly avoid it). I mentioned this in my commit description, we absolutely should offer fine control here eventually. I don't think we need to solve that problem here though. And given that the proposed patch just swept all the non-BT.2020 issues under the rug makes me think no one has actually come up with any kind of consistent plan for anything else really. Does anyone actually use the non-BT.2020 colorspace stuff? No idea if anyone is using any of it. It's a bit hard to do right now outside the full passthrough case since we have no properties to control how the hardware will convert stuff. No, every userspace knows that encoding of the output buffer before going to the wire format is RGB. It's the only way you can have planes alpha-blend, or mix and match RGB and NV12, etc. Anyways, sounds like what you're basically proposing is getting rid of this property and starting from scratch. Hmm. I guess one option would be to add that property to control the output encoding, but include a few extra "automagic" values to it which would retain the kernel's freedom to select whether to do the RGB->YCbCr conversion or not. enum
Re: [PATCH 3/3] drm/connector: Deprecate split for BT.2020 in drm_colorspace enum
On 2/3/23 14:34, Ville Syrjälä wrote: > On Fri, Feb 03, 2023 at 09:25:38PM +0200, Ville Syrjälä wrote: >> On Fri, Feb 03, 2023 at 08:56:55PM +0200, Ville Syrjälä wrote: >>> On Fri, Feb 03, 2023 at 01:28:20PM -0500, Harry Wentland wrote: On 2/3/23 11:00, Ville Syrjälä wrote: > On Fri, Feb 03, 2023 at 10:24:52AM -0500, Harry Wentland wrote: >> >> >> On 2/3/23 10:19, Ville Syrjälä wrote: >>> On Fri, Feb 03, 2023 at 09:39:42AM -0500, Harry Wentland wrote: On 2/3/23 07:59, Sebastian Wick wrote: > On Fri, Feb 3, 2023 at 11:40 AM Ville Syrjälä > wrote: >> >> On Fri, Feb 03, 2023 at 02:07:44AM +, Joshua Ashton wrote: >>> Userspace has no way of controlling or knowing the pixel encoding >>> currently, so there is no way for it to ever get the right values >>> here. >> >> That applies to a lot of the other values as well (they are >> explicitly RGB or YCC). The idea was that this property sets the >> infoframe/MSA/SDP value exactly, and other properties should be >> added to for use userspace to control the pixel encoding/colorspace >> conversion(if desired, or userspace just makes sure to >> directly feed in correct kind of data). > > I'm all for getting userspace control over pixel encoding but even > then the kernel always knows which pixel encoding is selected and > which InfoFrame has to be sent. Is there a reason why userspace would > want to control the variant explicitly to the wrong value? > I've asked this before but haven't seen an answer: Is there an existing upstream userspace project that makes use of this property (other than what Joshua is working on in gamescope right now)? That would help us understand the intent better. >>> >>> The intent was to control the infoframe colorimetry bits, >>> nothing more. No idea what real userspace there was, if any. >>> I don't think giving userspace explicit control over the exact infoframe values is the right thing to do. >>> >>> Only userspace knows what kind of data it's stuffing into >>> the pixels (and/or how it configures the csc units/etc.) to >>> generate them. >>> >> >> Yes, but userspace doesn't control or know whether we drive >> RGB or YCbCr on the wire. In fact, in some cases our driver >> needs to fallback to YCbCr420 for bandwidth reasons. There >> is currently no way for userspace to know that and I don't >> think it makes sense. > > People want that control as well for whatever reason. We've > been asked to allow YCbCr 4:4:4 output many times. > > The automagic 4:2:0 fallback I think is rather fundementally > incompatible with fancy color management. How would we even > know whether to use eg. BT.2020 vs. BT.709 matrix? In i915 > that stuff is just always BT.709 limited range, no questions > asked. > We use what we're telling the display, i.e., the value in the colorspace property. That way we know whether to use a BT.2020 or BT.709 matrix. >>> >>> And given how these things have gone in the past I think >>> that is likey to bite someone at in the future. Also not >>> what this property was meant to do nor does on any other >>> driver AFAIK. >>> I don't see how it's fundamentally incompatible with fancy color management stuff. If we start forbidding drivers from falling back to YCbCr (whether 4:4:4 or 4:2:0) we will break existing behavior on amdgpu and will see bug reports. >>> >>> The compositors could deal with that if/when they start doing >>> the full color management stuff. The current stuff only really >>> works when the kernel is allowed to do whatever it wants. >>> > So I think if userspace wants real color management it's > going to have to set up the whole pipeline. And for that > we need at least one new property to control the RGB->YCbCr > conversion (or to explicitly avoid it). > > And given that the proposed patch just swept all the > non-BT.2020 issues under the rug makes me think no > one has actually come up with any kind of consistent > plan for anything else really. > Does anyone actually use the non-BT.2020 colorspace stuff? >>> >>> No idea if anyone is using any of it. It's a bit hard to do >>> right now outside the full passthrough case since we have no >>> properties to control how the hardware will convert stuff. >>> >>> Anyways, sounds like what you're basically proposing is >>> getting rid of this property and starting from scratch. >> >> Hmm. I guess one option would be to add that property to >> control the output encoding, but include a few extra >> "automagic" values to it which would retain the kernel's >>
Re: [PATCH 3/3] drm/connector: Deprecate split for BT.2020 in drm_colorspace enum
On Fri, Feb 03, 2023 at 09:25:38PM +0200, Ville Syrjälä wrote: > On Fri, Feb 03, 2023 at 08:56:55PM +0200, Ville Syrjälä wrote: > > On Fri, Feb 03, 2023 at 01:28:20PM -0500, Harry Wentland wrote: > > > > > > > > > On 2/3/23 11:00, Ville Syrjälä wrote: > > > > On Fri, Feb 03, 2023 at 10:24:52AM -0500, Harry Wentland wrote: > > > >> > > > >> > > > >> On 2/3/23 10:19, Ville Syrjälä wrote: > > > >>> On Fri, Feb 03, 2023 at 09:39:42AM -0500, Harry Wentland wrote: > > > > > > > > > On 2/3/23 07:59, Sebastian Wick wrote: > > > > On Fri, Feb 3, 2023 at 11:40 AM Ville Syrjälä > > > > wrote: > > > >> > > > >> On Fri, Feb 03, 2023 at 02:07:44AM +, Joshua Ashton wrote: > > > >>> Userspace has no way of controlling or knowing the pixel encoding > > > >>> currently, so there is no way for it to ever get the right values > > > >>> here. > > > >> > > > >> That applies to a lot of the other values as well (they are > > > >> explicitly RGB or YCC). The idea was that this property sets the > > > >> infoframe/MSA/SDP value exactly, and other properties should be > > > >> added to for use userspace to control the pixel encoding/colorspace > > > >> conversion(if desired, or userspace just makes sure to > > > >> directly feed in correct kind of data). > > > > > > > > I'm all for getting userspace control over pixel encoding but even > > > > then the kernel always knows which pixel encoding is selected and > > > > which InfoFrame has to be sent. Is there a reason why userspace > > > > would > > > > want to control the variant explicitly to the wrong value? > > > > > > > > > > I've asked this before but haven't seen an answer: Is there an > > > existing > > > upstream userspace project that makes use of this property (other > > > than > > > what Joshua is working on in gamescope right now)? That would help us > > > understand the intent better. > > > >>> > > > >>> The intent was to control the infoframe colorimetry bits, > > > >>> nothing more. No idea what real userspace there was, if any. > > > >>> > > > > > > I don't think giving userspace explicit control over the exact > > > infoframe > > > values is the right thing to do. > > > >>> > > > >>> Only userspace knows what kind of data it's stuffing into > > > >>> the pixels (and/or how it configures the csc units/etc.) to > > > >>> generate them. > > > >>> > > > >> > > > >> Yes, but userspace doesn't control or know whether we drive > > > >> RGB or YCbCr on the wire. In fact, in some cases our driver > > > >> needs to fallback to YCbCr420 for bandwidth reasons. There > > > >> is currently no way for userspace to know that and I don't > > > >> think it makes sense. > > > > > > > > People want that control as well for whatever reason. We've > > > > been asked to allow YCbCr 4:4:4 output many times. > > > > > > > > The automagic 4:2:0 fallback I think is rather fundementally > > > > incompatible with fancy color management. How would we even > > > > know whether to use eg. BT.2020 vs. BT.709 matrix? In i915 > > > > that stuff is just always BT.709 limited range, no questions > > > > asked. > > > > > > > > > > We use what we're telling the display, i.e., the value in the > > > colorspace property. That way we know whether to use a BT.2020 > > > or BT.709 matrix. > > > > And given how these things have gone in the past I think > > that is likey to bite someone at in the future. Also not > > what this property was meant to do nor does on any other > > driver AFAIK. > > > > > I don't see how it's fundamentally incompatible with fancy > > > color management stuff. > > > > > > If we start forbidding drivers from falling back to YCbCr > > > (whether 4:4:4 or 4:2:0) we will break existing behavior on > > > amdgpu and will see bug reports. > > > > The compositors could deal with that if/when they start doing > > the full color management stuff. The current stuff only really > > works when the kernel is allowed to do whatever it wants. > > > > > > > > > So I think if userspace wants real color management it's > > > > going to have to set up the whole pipeline. And for that > > > > we need at least one new property to control the RGB->YCbCr > > > > conversion (or to explicitly avoid it). > > > > > > > > And given that the proposed patch just swept all the > > > > non-BT.2020 issues under the rug makes me think no > > > > one has actually come up with any kind of consistent > > > > plan for anything else really. > > > > > > > > > > Does anyone actually use the non-BT.2020 colorspace stuff? > > > > No idea if anyone is using any of it. It's a bit hard to do > > right now outside the full passthrough case since we have no > > properties to control how the hardware will convert stuff. > > > > Anyways, sounds like what you're basically proposing is > > getting rid of this property and starting from scratch. > > Hmm. I
Re: [PATCH 3/3] drm/connector: Deprecate split for BT.2020 in drm_colorspace enum
On 2/3/23 14:25, Ville Syrjälä wrote:
> On Fri, Feb 03, 2023 at 08:56:55PM +0200, Ville Syrjälä wrote:
>> On Fri, Feb 03, 2023 at 01:28:20PM -0500, Harry Wentland wrote:
>>>
>>>
>>> On 2/3/23 11:00, Ville Syrjälä wrote:
On Fri, Feb 03, 2023 at 10:24:52AM -0500, Harry Wentland wrote:
>
>
> On 2/3/23 10:19, Ville Syrjälä wrote:
>> On Fri, Feb 03, 2023 at 09:39:42AM -0500, Harry Wentland wrote:
>>>
>>>
>>> On 2/3/23 07:59, Sebastian Wick wrote:
On Fri, Feb 3, 2023 at 11:40 AM Ville Syrjälä
wrote:
>
> On Fri, Feb 03, 2023 at 02:07:44AM +, Joshua Ashton wrote:
>> Userspace has no way of controlling or knowing the pixel encoding
>> currently, so there is no way for it to ever get the right values
>> here.
>
> That applies to a lot of the other values as well (they are
> explicitly RGB or YCC). The idea was that this property sets the
> infoframe/MSA/SDP value exactly, and other properties should be
> added to for use userspace to control the pixel encoding/colorspace
> conversion(if desired, or userspace just makes sure to
> directly feed in correct kind of data).
I'm all for getting userspace control over pixel encoding but even
then the kernel always knows which pixel encoding is selected and
which InfoFrame has to be sent. Is there a reason why userspace would
want to control the variant explicitly to the wrong value?
>>>
>>> I've asked this before but haven't seen an answer: Is there an existing
>>> upstream userspace project that makes use of this property (other than
>>> what Joshua is working on in gamescope right now)? That would help us
>>> understand the intent better.
>>
>> The intent was to control the infoframe colorimetry bits,
>> nothing more. No idea what real userspace there was, if any.
>>
>>>
>>> I don't think giving userspace explicit control over the exact infoframe
>>> values is the right thing to do.
>>
>> Only userspace knows what kind of data it's stuffing into
>> the pixels (and/or how it configures the csc units/etc.) to
>> generate them.
>>
>
> Yes, but userspace doesn't control or know whether we drive
> RGB or YCbCr on the wire. In fact, in some cases our driver
> needs to fallback to YCbCr420 for bandwidth reasons. There
> is currently no way for userspace to know that and I don't
> think it makes sense.
People want that control as well for whatever reason. We've
been asked to allow YCbCr 4:4:4 output many times.
The automagic 4:2:0 fallback I think is rather fundementally
incompatible with fancy color management. How would we even
know whether to use eg. BT.2020 vs. BT.709 matrix? In i915
that stuff is just always BT.709 limited range, no questions
asked.
>>>
>>> We use what we're telling the display, i.e., the value in the
>>> colorspace property. That way we know whether to use a BT.2020
>>> or BT.709 matrix.
>>
>> And given how these things have gone in the past I think
>> that is likey to bite someone at in the future. Also not
>> what this property was meant to do nor does on any other
>> driver AFAIK.
>>
>>> I don't see how it's fundamentally incompatible with fancy
>>> color management stuff.
>>>
>>> If we start forbidding drivers from falling back to YCbCr
>>> (whether 4:4:4 or 4:2:0) we will break existing behavior on
>>> amdgpu and will see bug reports.
>>
>> The compositors could deal with that if/when they start doing
>> the full color management stuff. The current stuff only really
>> works when the kernel is allowed to do whatever it wants.
>>
>>>
So I think if userspace wants real color management it's
going to have to set up the whole pipeline. And for that
we need at least one new property to control the RGB->YCbCr
conversion (or to explicitly avoid it).
And given that the proposed patch just swept all the
non-BT.2020 issues under the rug makes me think no
one has actually come up with any kind of consistent
plan for anything else really.
>>>
>>> Does anyone actually use the non-BT.2020 colorspace stuff?
>>
>> No idea if anyone is using any of it. It's a bit hard to do
>> right now outside the full passthrough case since we have no
>> properties to control how the hardware will convert stuff.
>>
>> Anyways, sounds like what you're basically proposing is
>> getting rid of this property and starting from scratch.
>
> Hmm. I guess one option would be to add that property to
> control the output encoding, but include a few extra
> "automagic" values to it which would retain the kernel's
> freedom to select whether to do the RGB->YCbCr conversion
> or not.
>
> enum output_encoding {
> auto rgb=default/nodata,ycbcr=bt601
> auto rgb=default/nodata,ycbcr=bt709
>
Re: [PATCH 3/3] drm/connector: Deprecate split for BT.2020 in drm_colorspace enum
On Fri, Feb 03, 2023 at 08:56:55PM +0200, Ville Syrjälä wrote:
> On Fri, Feb 03, 2023 at 01:28:20PM -0500, Harry Wentland wrote:
> >
> >
> > On 2/3/23 11:00, Ville Syrjälä wrote:
> > > On Fri, Feb 03, 2023 at 10:24:52AM -0500, Harry Wentland wrote:
> > >>
> > >>
> > >> On 2/3/23 10:19, Ville Syrjälä wrote:
> > >>> On Fri, Feb 03, 2023 at 09:39:42AM -0500, Harry Wentland wrote:
> >
> >
> > On 2/3/23 07:59, Sebastian Wick wrote:
> > > On Fri, Feb 3, 2023 at 11:40 AM Ville Syrjälä
> > > wrote:
> > >>
> > >> On Fri, Feb 03, 2023 at 02:07:44AM +, Joshua Ashton wrote:
> > >>> Userspace has no way of controlling or knowing the pixel encoding
> > >>> currently, so there is no way for it to ever get the right values
> > >>> here.
> > >>
> > >> That applies to a lot of the other values as well (they are
> > >> explicitly RGB or YCC). The idea was that this property sets the
> > >> infoframe/MSA/SDP value exactly, and other properties should be
> > >> added to for use userspace to control the pixel encoding/colorspace
> > >> conversion(if desired, or userspace just makes sure to
> > >> directly feed in correct kind of data).
> > >
> > > I'm all for getting userspace control over pixel encoding but even
> > > then the kernel always knows which pixel encoding is selected and
> > > which InfoFrame has to be sent. Is there a reason why userspace would
> > > want to control the variant explicitly to the wrong value?
> > >
> >
> > I've asked this before but haven't seen an answer: Is there an existing
> > upstream userspace project that makes use of this property (other than
> > what Joshua is working on in gamescope right now)? That would help us
> > understand the intent better.
> > >>>
> > >>> The intent was to control the infoframe colorimetry bits,
> > >>> nothing more. No idea what real userspace there was, if any.
> > >>>
> >
> > I don't think giving userspace explicit control over the exact
> > infoframe
> > values is the right thing to do.
> > >>>
> > >>> Only userspace knows what kind of data it's stuffing into
> > >>> the pixels (and/or how it configures the csc units/etc.) to
> > >>> generate them.
> > >>>
> > >>
> > >> Yes, but userspace doesn't control or know whether we drive
> > >> RGB or YCbCr on the wire. In fact, in some cases our driver
> > >> needs to fallback to YCbCr420 for bandwidth reasons. There
> > >> is currently no way for userspace to know that and I don't
> > >> think it makes sense.
> > >
> > > People want that control as well for whatever reason. We've
> > > been asked to allow YCbCr 4:4:4 output many times.
> > >
> > > The automagic 4:2:0 fallback I think is rather fundementally
> > > incompatible with fancy color management. How would we even
> > > know whether to use eg. BT.2020 vs. BT.709 matrix? In i915
> > > that stuff is just always BT.709 limited range, no questions
> > > asked.
> > >
> >
> > We use what we're telling the display, i.e., the value in the
> > colorspace property. That way we know whether to use a BT.2020
> > or BT.709 matrix.
>
> And given how these things have gone in the past I think
> that is likey to bite someone at in the future. Also not
> what this property was meant to do nor does on any other
> driver AFAIK.
>
> > I don't see how it's fundamentally incompatible with fancy
> > color management stuff.
> >
> > If we start forbidding drivers from falling back to YCbCr
> > (whether 4:4:4 or 4:2:0) we will break existing behavior on
> > amdgpu and will see bug reports.
>
> The compositors could deal with that if/when they start doing
> the full color management stuff. The current stuff only really
> works when the kernel is allowed to do whatever it wants.
>
> >
> > > So I think if userspace wants real color management it's
> > > going to have to set up the whole pipeline. And for that
> > > we need at least one new property to control the RGB->YCbCr
> > > conversion (or to explicitly avoid it).
> > >
> > > And given that the proposed patch just swept all the
> > > non-BT.2020 issues under the rug makes me think no
> > > one has actually come up with any kind of consistent
> > > plan for anything else really.
> > >
> >
> > Does anyone actually use the non-BT.2020 colorspace stuff?
>
> No idea if anyone is using any of it. It's a bit hard to do
> right now outside the full passthrough case since we have no
> properties to control how the hardware will convert stuff.
>
> Anyways, sounds like what you're basically proposing is
> getting rid of this property and starting from scratch.
Hmm. I guess one option would be to add that property to
control the output encoding, but include a few extra
"automagic" values to it which would retain the kernel's
freedom to select whether to do the RGB->YCbCr conversion
or not.
enum output_encoding {
auto rgb=default/nodata,ycbcr=bt601
auto
Re: [PATCH 3/3] drm/connector: Deprecate split for BT.2020 in drm_colorspace enum
On 2/3/23 13:56, Ville Syrjälä wrote: > On Fri, Feb 03, 2023 at 01:28:20PM -0500, Harry Wentland wrote: >> >> >> On 2/3/23 11:00, Ville Syrjälä wrote: >>> On Fri, Feb 03, 2023 at 10:24:52AM -0500, Harry Wentland wrote: On 2/3/23 10:19, Ville Syrjälä wrote: > On Fri, Feb 03, 2023 at 09:39:42AM -0500, Harry Wentland wrote: >> >> >> On 2/3/23 07:59, Sebastian Wick wrote: >>> On Fri, Feb 3, 2023 at 11:40 AM Ville Syrjälä >>> wrote: On Fri, Feb 03, 2023 at 02:07:44AM +, Joshua Ashton wrote: > Userspace has no way of controlling or knowing the pixel encoding > currently, so there is no way for it to ever get the right values > here. That applies to a lot of the other values as well (they are explicitly RGB or YCC). The idea was that this property sets the infoframe/MSA/SDP value exactly, and other properties should be added to for use userspace to control the pixel encoding/colorspace conversion(if desired, or userspace just makes sure to directly feed in correct kind of data). >>> >>> I'm all for getting userspace control over pixel encoding but even >>> then the kernel always knows which pixel encoding is selected and >>> which InfoFrame has to be sent. Is there a reason why userspace would >>> want to control the variant explicitly to the wrong value? >>> >> >> I've asked this before but haven't seen an answer: Is there an existing >> upstream userspace project that makes use of this property (other than >> what Joshua is working on in gamescope right now)? That would help us >> understand the intent better. > > The intent was to control the infoframe colorimetry bits, > nothing more. No idea what real userspace there was, if any. > >> >> I don't think giving userspace explicit control over the exact infoframe >> values is the right thing to do. > > Only userspace knows what kind of data it's stuffing into > the pixels (and/or how it configures the csc units/etc.) to > generate them. > Yes, but userspace doesn't control or know whether we drive RGB or YCbCr on the wire. In fact, in some cases our driver needs to fallback to YCbCr420 for bandwidth reasons. There is currently no way for userspace to know that and I don't think it makes sense. >>> >>> People want that control as well for whatever reason. We've >>> been asked to allow YCbCr 4:4:4 output many times. >>> >>> The automagic 4:2:0 fallback I think is rather fundementally >>> incompatible with fancy color management. How would we even >>> know whether to use eg. BT.2020 vs. BT.709 matrix? In i915 >>> that stuff is just always BT.709 limited range, no questions >>> asked. >>> >> >> We use what we're telling the display, i.e., the value in the >> colorspace property. That way we know whether to use a BT.2020 >> or BT.709 matrix. > > And given how these things have gone in the past I think > that is likey to bite someone at in the future. Also not > what this property was meant to do nor does on any other > driver AFAIK. > It has implementations in other drivers but I have yet to see anyone using it. Without that it does nothing, unless there are proprietary userspace pieces that make use of this. >> I don't see how it's fundamentally incompatible with fancy >> color management stuff. >> >> If we start forbidding drivers from falling back to YCbCr >> (whether 4:4:4 or 4:2:0) we will break existing behavior on >> amdgpu and will see bug reports. > > The compositors could deal with that if/when they start doing > the full color management stuff. The current stuff only really > works when the kernel is allowed to do whatever it wants. > The compositor could deal with it but this feels like the compositor taking over things that should really be in the hands of a display driver. >> >>> So I think if userspace wants real color management it's >>> going to have to set up the whole pipeline. And for that >>> we need at least one new property to control the RGB->YCbCr >>> conversion (or to explicitly avoid it). >>> >>> And given that the proposed patch just swept all the >>> non-BT.2020 issues under the rug makes me think no >>> one has actually come up with any kind of consistent >>> plan for anything else really. >>> >> >> Does anyone actually use the non-BT.2020 colorspace stuff? > > No idea if anyone is using any of it. It's a bit hard to do > right now outside the full passthrough case since we have no > properties to control how the hardware will convert stuff. > > Anyways, sounds like what you're basically proposing is > getting rid of this property and starting from scratch. > Maybe that's the right approach. My initial idea was to tag along an existing property but that turns out to be challenging when that existing property doesn't even have a userspace implementation.
Re: [PATCH 3/3] drm/connector: Deprecate split for BT.2020 in drm_colorspace enum
On Fri, Feb 03, 2023 at 01:28:20PM -0500, Harry Wentland wrote: > > > On 2/3/23 11:00, Ville Syrjälä wrote: > > On Fri, Feb 03, 2023 at 10:24:52AM -0500, Harry Wentland wrote: > >> > >> > >> On 2/3/23 10:19, Ville Syrjälä wrote: > >>> On Fri, Feb 03, 2023 at 09:39:42AM -0500, Harry Wentland wrote: > > > On 2/3/23 07:59, Sebastian Wick wrote: > > On Fri, Feb 3, 2023 at 11:40 AM Ville Syrjälä > > wrote: > >> > >> On Fri, Feb 03, 2023 at 02:07:44AM +, Joshua Ashton wrote: > >>> Userspace has no way of controlling or knowing the pixel encoding > >>> currently, so there is no way for it to ever get the right values > >>> here. > >> > >> That applies to a lot of the other values as well (they are > >> explicitly RGB or YCC). The idea was that this property sets the > >> infoframe/MSA/SDP value exactly, and other properties should be > >> added to for use userspace to control the pixel encoding/colorspace > >> conversion(if desired, or userspace just makes sure to > >> directly feed in correct kind of data). > > > > I'm all for getting userspace control over pixel encoding but even > > then the kernel always knows which pixel encoding is selected and > > which InfoFrame has to be sent. Is there a reason why userspace would > > want to control the variant explicitly to the wrong value? > > > > I've asked this before but haven't seen an answer: Is there an existing > upstream userspace project that makes use of this property (other than > what Joshua is working on in gamescope right now)? That would help us > understand the intent better. > >>> > >>> The intent was to control the infoframe colorimetry bits, > >>> nothing more. No idea what real userspace there was, if any. > >>> > > I don't think giving userspace explicit control over the exact infoframe > values is the right thing to do. > >>> > >>> Only userspace knows what kind of data it's stuffing into > >>> the pixels (and/or how it configures the csc units/etc.) to > >>> generate them. > >>> > >> > >> Yes, but userspace doesn't control or know whether we drive > >> RGB or YCbCr on the wire. In fact, in some cases our driver > >> needs to fallback to YCbCr420 for bandwidth reasons. There > >> is currently no way for userspace to know that and I don't > >> think it makes sense. > > > > People want that control as well for whatever reason. We've > > been asked to allow YCbCr 4:4:4 output many times. > > > > The automagic 4:2:0 fallback I think is rather fundementally > > incompatible with fancy color management. How would we even > > know whether to use eg. BT.2020 vs. BT.709 matrix? In i915 > > that stuff is just always BT.709 limited range, no questions > > asked. > > > > We use what we're telling the display, i.e., the value in the > colorspace property. That way we know whether to use a BT.2020 > or BT.709 matrix. And given how these things have gone in the past I think that is likey to bite someone at in the future. Also not what this property was meant to do nor does on any other driver AFAIK. > I don't see how it's fundamentally incompatible with fancy > color management stuff. > > If we start forbidding drivers from falling back to YCbCr > (whether 4:4:4 or 4:2:0) we will break existing behavior on > amdgpu and will see bug reports. The compositors could deal with that if/when they start doing the full color management stuff. The current stuff only really works when the kernel is allowed to do whatever it wants. > > > So I think if userspace wants real color management it's > > going to have to set up the whole pipeline. And for that > > we need at least one new property to control the RGB->YCbCr > > conversion (or to explicitly avoid it). > > > > And given that the proposed patch just swept all the > > non-BT.2020 issues under the rug makes me think no > > one has actually come up with any kind of consistent > > plan for anything else really. > > > > Does anyone actually use the non-BT.2020 colorspace stuff? No idea if anyone is using any of it. It's a bit hard to do right now outside the full passthrough case since we have no properties to control how the hardware will convert stuff. Anyways, sounds like what you're basically proposing is getting rid of this property and starting from scratch. -- Ville Syrjälä Intel
Re: [PATCH 3/3] drm/connector: Deprecate split for BT.2020 in drm_colorspace enum
On 2/3/23 11:00, Ville Syrjälä wrote: > On Fri, Feb 03, 2023 at 10:24:52AM -0500, Harry Wentland wrote: >> >> >> On 2/3/23 10:19, Ville Syrjälä wrote: >>> On Fri, Feb 03, 2023 at 09:39:42AM -0500, Harry Wentland wrote: On 2/3/23 07:59, Sebastian Wick wrote: > On Fri, Feb 3, 2023 at 11:40 AM Ville Syrjälä > wrote: >> >> On Fri, Feb 03, 2023 at 02:07:44AM +, Joshua Ashton wrote: >>> Userspace has no way of controlling or knowing the pixel encoding >>> currently, so there is no way for it to ever get the right values here. >> >> That applies to a lot of the other values as well (they are >> explicitly RGB or YCC). The idea was that this property sets the >> infoframe/MSA/SDP value exactly, and other properties should be >> added to for use userspace to control the pixel encoding/colorspace >> conversion(if desired, or userspace just makes sure to >> directly feed in correct kind of data). > > I'm all for getting userspace control over pixel encoding but even > then the kernel always knows which pixel encoding is selected and > which InfoFrame has to be sent. Is there a reason why userspace would > want to control the variant explicitly to the wrong value? > I've asked this before but haven't seen an answer: Is there an existing upstream userspace project that makes use of this property (other than what Joshua is working on in gamescope right now)? That would help us understand the intent better. >>> >>> The intent was to control the infoframe colorimetry bits, >>> nothing more. No idea what real userspace there was, if any. >>> I don't think giving userspace explicit control over the exact infoframe values is the right thing to do. >>> >>> Only userspace knows what kind of data it's stuffing into >>> the pixels (and/or how it configures the csc units/etc.) to >>> generate them. >>> >> >> Yes, but userspace doesn't control or know whether we drive >> RGB or YCbCr on the wire. In fact, in some cases our driver >> needs to fallback to YCbCr420 for bandwidth reasons. There >> is currently no way for userspace to know that and I don't >> think it makes sense. > > People want that control as well for whatever reason. We've > been asked to allow YCbCr 4:4:4 output many times. > > The automagic 4:2:0 fallback I think is rather fundementally > incompatible with fancy color management. How would we even > know whether to use eg. BT.2020 vs. BT.709 matrix? In i915 > that stuff is just always BT.709 limited range, no questions > asked. > We use what we're telling the display, i.e., the value in the colorspace property. That way we know whether to use a BT.2020 or BT.709 matrix. I don't see how it's fundamentally incompatible with fancy color management stuff. If we start forbidding drivers from falling back to YCbCr (whether 4:4:4 or 4:2:0) we will break existing behavior on amdgpu and will see bug reports. > So I think if userspace wants real color management it's > going to have to set up the whole pipeline. And for that > we need at least one new property to control the RGB->YCbCr > conversion (or to explicitly avoid it). > > And given that the proposed patch just swept all the > non-BT.2020 issues under the rug makes me think no > one has actually come up with any kind of consistent > plan for anything else really. > Does anyone actually use the non-BT.2020 colorspace stuff? Harry >> >> Userspace needs full control of framebuffer pixel formats, >> as well as control over DEGAMMA, GAMMA, CTM color operations. >> It also needs to be able to select whether to drive the panel >> as sRGB or BT.2020/PQ but it doesn't make sense for it to >> control the pixel encoding on the wire (RGB vs YCbCr). >> >>> I really don't want a repeat of the disaster of the >>> 'Broadcast RGB' which has coupled together the infoframe >>> and automagic conversion stuff. And I think this one would >>> be about 100x worse given this property has something >>> to do with actual colorspaces as well. >>> >> >> I'm unaware of this disaster. Could you elaborate? > > The property now controls both the infoframe stuff (and > whatever super vague stuff DP has for it in MSA) and > full->limited range compression in the display pipeline. > And as a result there is no way to eg. allow already > limited range input, which is what some people wanted. > > And naturally it's all made a lot more terrible by all > the displays that fail to implement the spec correctly, > but that's another topic. >
Re: [PATCH 3/3] drm/connector: Deprecate split for BT.2020 in drm_colorspace enum
On Fri, Feb 03, 2023 at 10:24:52AM -0500, Harry Wentland wrote: > > > On 2/3/23 10:19, Ville Syrjälä wrote: > > On Fri, Feb 03, 2023 at 09:39:42AM -0500, Harry Wentland wrote: > >> > >> > >> On 2/3/23 07:59, Sebastian Wick wrote: > >>> On Fri, Feb 3, 2023 at 11:40 AM Ville Syrjälä > >>> wrote: > > On Fri, Feb 03, 2023 at 02:07:44AM +, Joshua Ashton wrote: > > Userspace has no way of controlling or knowing the pixel encoding > > currently, so there is no way for it to ever get the right values here. > > That applies to a lot of the other values as well (they are > explicitly RGB or YCC). The idea was that this property sets the > infoframe/MSA/SDP value exactly, and other properties should be > added to for use userspace to control the pixel encoding/colorspace > conversion(if desired, or userspace just makes sure to > directly feed in correct kind of data). > >>> > >>> I'm all for getting userspace control over pixel encoding but even > >>> then the kernel always knows which pixel encoding is selected and > >>> which InfoFrame has to be sent. Is there a reason why userspace would > >>> want to control the variant explicitly to the wrong value? > >>> > >> > >> I've asked this before but haven't seen an answer: Is there an existing > >> upstream userspace project that makes use of this property (other than > >> what Joshua is working on in gamescope right now)? That would help us > >> understand the intent better. > > > > The intent was to control the infoframe colorimetry bits, > > nothing more. No idea what real userspace there was, if any. > > > >> > >> I don't think giving userspace explicit control over the exact infoframe > >> values is the right thing to do. > > > > Only userspace knows what kind of data it's stuffing into > > the pixels (and/or how it configures the csc units/etc.) to > > generate them. > > > > Yes, but userspace doesn't control or know whether we drive > RGB or YCbCr on the wire. In fact, in some cases our driver > needs to fallback to YCbCr420 for bandwidth reasons. There > is currently no way for userspace to know that and I don't > think it makes sense. People want that control as well for whatever reason. We've been asked to allow YCbCr 4:4:4 output many times. The automagic 4:2:0 fallback I think is rather fundementally incompatible with fancy color management. How would we even know whether to use eg. BT.2020 vs. BT.709 matrix? In i915 that stuff is just always BT.709 limited range, no questions asked. So I think if userspace wants real color management it's going to have to set up the whole pipeline. And for that we need at least one new property to control the RGB->YCbCr conversion (or to explicitly avoid it). And given that the proposed patch just swept all the non-BT.2020 issues under the rug makes me think no one has actually come up with any kind of consistent plan for anything else really. > > Userspace needs full control of framebuffer pixel formats, > as well as control over DEGAMMA, GAMMA, CTM color operations. > It also needs to be able to select whether to drive the panel > as sRGB or BT.2020/PQ but it doesn't make sense for it to > control the pixel encoding on the wire (RGB vs YCbCr). > > > I really don't want a repeat of the disaster of the > > 'Broadcast RGB' which has coupled together the infoframe > > and automagic conversion stuff. And I think this one would > > be about 100x worse given this property has something > > to do with actual colorspaces as well. > > > > I'm unaware of this disaster. Could you elaborate? The property now controls both the infoframe stuff (and whatever super vague stuff DP has for it in MSA) and full->limited range compression in the display pipeline. And as a result there is no way to eg. allow already limited range input, which is what some people wanted. And naturally it's all made a lot more terrible by all the displays that fail to implement the spec correctly, but that's another topic. -- Ville Syrjälä Intel
Re: [PATCH 3/3] drm/connector: Deprecate split for BT.2020 in drm_colorspace enum
On 2/3/23 10:19, Ville Syrjälä wrote: > On Fri, Feb 03, 2023 at 09:39:42AM -0500, Harry Wentland wrote: >> >> >> On 2/3/23 07:59, Sebastian Wick wrote: >>> On Fri, Feb 3, 2023 at 11:40 AM Ville Syrjälä >>> wrote: On Fri, Feb 03, 2023 at 02:07:44AM +, Joshua Ashton wrote: > Userspace has no way of controlling or knowing the pixel encoding > currently, so there is no way for it to ever get the right values here. That applies to a lot of the other values as well (they are explicitly RGB or YCC). The idea was that this property sets the infoframe/MSA/SDP value exactly, and other properties should be added to for use userspace to control the pixel encoding/colorspace conversion(if desired, or userspace just makes sure to directly feed in correct kind of data). >>> >>> I'm all for getting userspace control over pixel encoding but even >>> then the kernel always knows which pixel encoding is selected and >>> which InfoFrame has to be sent. Is there a reason why userspace would >>> want to control the variant explicitly to the wrong value? >>> >> >> I've asked this before but haven't seen an answer: Is there an existing >> upstream userspace project that makes use of this property (other than >> what Joshua is working on in gamescope right now)? That would help us >> understand the intent better. > > The intent was to control the infoframe colorimetry bits, > nothing more. No idea what real userspace there was, if any. > >> >> I don't think giving userspace explicit control over the exact infoframe >> values is the right thing to do. > > Only userspace knows what kind of data it's stuffing into > the pixels (and/or how it configures the csc units/etc.) to > generate them. > Yes, but userspace doesn't control or know whether we drive RGB or YCbCr on the wire. In fact, in some cases our driver needs to fallback to YCbCr420 for bandwidth reasons. There is currently no way for userspace to know that and I don't think it makes sense. Userspace needs full control of framebuffer pixel formats, as well as control over DEGAMMA, GAMMA, CTM color operations. It also needs to be able to select whether to drive the panel as sRGB or BT.2020/PQ but it doesn't make sense for it to control the pixel encoding on the wire (RGB vs YCbCr). > I really don't want a repeat of the disaster of the > 'Broadcast RGB' which has coupled together the infoframe > and automagic conversion stuff. And I think this one would > be about 100x worse given this property has something > to do with actual colorspaces as well. > I'm unaware of this disaster. Could you elaborate? Harry
Re: [PATCH 3/3] drm/connector: Deprecate split for BT.2020 in drm_colorspace enum
On Fri, Feb 03, 2023 at 09:39:42AM -0500, Harry Wentland wrote: > > > On 2/3/23 07:59, Sebastian Wick wrote: > > On Fri, Feb 3, 2023 at 11:40 AM Ville Syrjälä > > wrote: > >> > >> On Fri, Feb 03, 2023 at 02:07:44AM +, Joshua Ashton wrote: > >>> Userspace has no way of controlling or knowing the pixel encoding > >>> currently, so there is no way for it to ever get the right values here. > >> > >> That applies to a lot of the other values as well (they are > >> explicitly RGB or YCC). The idea was that this property sets the > >> infoframe/MSA/SDP value exactly, and other properties should be > >> added to for use userspace to control the pixel encoding/colorspace > >> conversion(if desired, or userspace just makes sure to > >> directly feed in correct kind of data). > > > > I'm all for getting userspace control over pixel encoding but even > > then the kernel always knows which pixel encoding is selected and > > which InfoFrame has to be sent. Is there a reason why userspace would > > want to control the variant explicitly to the wrong value? > > > > I've asked this before but haven't seen an answer: Is there an existing > upstream userspace project that makes use of this property (other than > what Joshua is working on in gamescope right now)? That would help us > understand the intent better. The intent was to control the infoframe colorimetry bits, nothing more. No idea what real userspace there was, if any. > > I don't think giving userspace explicit control over the exact infoframe > values is the right thing to do. Only userspace knows what kind of data it's stuffing into the pixels (and/or how it configures the csc units/etc.) to generate them. I really don't want a repeat of the disaster of the 'Broadcast RGB' which has coupled together the infoframe and automagic conversion stuff. And I think this one would be about 100x worse given this property has something to do with actual colorspaces as well. -- Ville Syrjälä Intel
Re: [PATCH 3/3] drm/connector: Deprecate split for BT.2020 in drm_colorspace enum
On 2/2/23 21:07, Joshua Ashton wrote:
> Userspace has no way of controlling or knowing the pixel encoding
> currently, so there is no way for it to ever get the right values here.
>
> When we do add pixel_encoding control from userspace,we can pick the
> right value for the colorimetry packet based on the
> pixel_encoding + the colorspace.
>
> Let's deprecate these values, and have one BT.2020 colorspace entry
> that userspace can use.
>
Would be good to do the same for the other entries as well but those
are a bit more ambiguous since there are no clear _RGB variants and
the intention seems to be to use _DEFAULT for RGB.
> Note: _CYCC was effectively 'removed' by this change, but that was not
> possible to be taken advantage of anyway, as there is currently no
> pixel_encoding control so it would not be possible to output
> linear YCbCr.
>
> Signed-off-by: Joshua Ashton
>
> Cc: Pekka Paalanen
> Cc: Sebastian Wick
> Cc: vitaly.pros...@amd.com
> Cc: Uma Shankar
> Cc: Ville Syrjälä
> Cc: Joshua Ashton
> Cc: dri-de...@lists.freedesktop.org
> Cc: amd-gfx@lists.freedesktop.org
> ---
> drivers/gpu/drm/display/drm_hdmi_helper.c | 9 -
> drivers/gpu/drm/drm_connector.c | 12 ++--
> drivers/gpu/drm/i915/display/intel_dp.c | 20 +---
> include/drm/drm_connector.h | 19 ++-
> 4 files changed, 29 insertions(+), 31 deletions(-)
>
> diff --git a/drivers/gpu/drm/display/drm_hdmi_helper.c
> b/drivers/gpu/drm/display/drm_hdmi_helper.c
> index 0264abe55278..c85860600395 100644
> --- a/drivers/gpu/drm/display/drm_hdmi_helper.c
> +++ b/drivers/gpu/drm/display/drm_hdmi_helper.c
> @@ -99,8 +99,7 @@ EXPORT_SYMBOL(drm_hdmi_infoframe_set_hdr_metadata);
> #define HDMI_COLORIMETRY_OPYCC_601 (C(3) | EC(3) | ACE(0))
> #define HDMI_COLORIMETRY_OPRGB (C(3) | EC(4) | ACE(0))
> #define HDMI_COLORIMETRY_BT2020_CYCC (C(3) | EC(5) | ACE(0))
> -#define HDMI_COLORIMETRY_BT2020_RGB (C(3) | EC(6) | ACE(0))
> -#define HDMI_COLORIMETRY_BT2020_YCC (C(3) | EC(6) | ACE(0))
> +#define HDMI_COLORIMETRY_BT2020 (C(3) | EC(6) | ACE(0))
These definitions might still be useful to a driver that is populating
the infoframe. But since they're currently unused I have no strong
objection to removing them.
If we're dropping them should we also drop the _CYCC variant?
> #define HDMI_COLORIMETRY_DCI_P3_RGB_D65 (C(3) | EC(7) | ACE(0))
> #define HDMI_COLORIMETRY_DCI_P3_RGB_THEATER (C(3) | EC(7) | ACE(1))
>
> @@ -113,9 +112,9 @@ static const u32 hdmi_colorimetry_val[] = {
> [DRM_MODE_COLORIMETRY_SYCC_601] = HDMI_COLORIMETRY_SYCC_601,
> [DRM_MODE_COLORIMETRY_OPYCC_601] = HDMI_COLORIMETRY_OPYCC_601,
> [DRM_MODE_COLORIMETRY_OPRGB] = HDMI_COLORIMETRY_OPRGB,
> - [DRM_MODE_COLORIMETRY_BT2020_CYCC] = HDMI_COLORIMETRY_BT2020_CYCC,
> - [DRM_MODE_COLORIMETRY_BT2020_RGB] = HDMI_COLORIMETRY_BT2020_RGB,
> - [DRM_MODE_COLORIMETRY_BT2020_YCC] = HDMI_COLORIMETRY_BT2020_YCC,
> + [DRM_MODE_COLORIMETRY_BT2020_DEPRECATED_1] = HDMI_COLORIMETRY_BT2020,
> + [DRM_MODE_COLORIMETRY_BT2020_DEPRECATED_2] = HDMI_COLORIMETRY_BT2020,
> + [DRM_MODE_COLORIMETRY_BT2020] = HDMI_COLORIMETRY_BT2020,
> };
>
> #undef C
> diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c
> index 61c29ce74b03..58699ab15a6a 100644
> --- a/drivers/gpu/drm/drm_connector.c
> +++ b/drivers/gpu/drm/drm_connector.c
> @@ -1029,11 +1029,11 @@ static const struct drm_prop_enum_list
> hdmi_colorspaces[] = {
> /* Colorimetry based on IEC 61966-2-5 */
> { DRM_MODE_COLORIMETRY_OPRGB, "opRGB" },
> /* Colorimetry based on ITU-R BT.2020 */
> - { DRM_MODE_COLORIMETRY_BT2020_CYCC, "BT2020_CYCC" },
> + { DRM_MODE_COLORIMETRY_BT2020_DEPRECATED_1, "BT2020_DEPRECATED_1" },
> /* Colorimetry based on ITU-R BT.2020 */
> - { DRM_MODE_COLORIMETRY_BT2020_RGB, "BT2020_RGB" },
> + { DRM_MODE_COLORIMETRY_BT2020_DEPRECATED_2, "BT2020_DEPRECATED_2" },
> /* Colorimetry based on ITU-R BT.2020 */
> - { DRM_MODE_COLORIMETRY_BT2020_YCC, "BT2020_YCC" },
> + { DRM_MODE_COLORIMETRY_BT2020, "BT2020" },
> /* Added as part of Additional Colorimetry Extension in 861.G */
> { DRM_MODE_COLORIMETRY_DCI_P3_RGB_D65, "DCI-P3_RGB_D65" },
> { DRM_MODE_COLORIMETRY_DCI_P3_RGB_THEATER, "DCI-P3_RGB_Theater" },
> @@ -1054,7 +1054,7 @@ static const struct drm_prop_enum_list dp_colorspaces[]
> = {
> /* Colorimetry based on SMPTE RP 431-2 */
> { DRM_MODE_COLORIMETRY_DCI_P3_RGB_D65, "DCI-P3_RGB_D65" },
> /* Colorimetry based on ITU-R BT.2020 */
> - { DRM_MODE_COLORIMETRY_BT2020_RGB, "BT2020_RGB" },
> + { DRM_MODE_COLORIMETRY_BT2020, "BT2020" },
Above we've made the old _YCC value the new, non-deprecated BT2020
entry, but here you're using the _RGB one for that. Would it make
sense to make the old _YCC value deprecated
Re: [PATCH 3/3] drm/connector: Deprecate split for BT.2020 in drm_colorspace enum
On 2/3/23 07:59, Sebastian Wick wrote:
> On Fri, Feb 3, 2023 at 11:40 AM Ville Syrjälä
> wrote:
>>
>> On Fri, Feb 03, 2023 at 02:07:44AM +, Joshua Ashton wrote:
>>> Userspace has no way of controlling or knowing the pixel encoding
>>> currently, so there is no way for it to ever get the right values here.
>>
>> That applies to a lot of the other values as well (they are
>> explicitly RGB or YCC). The idea was that this property sets the
>> infoframe/MSA/SDP value exactly, and other properties should be
>> added to for use userspace to control the pixel encoding/colorspace
>> conversion(if desired, or userspace just makes sure to
>> directly feed in correct kind of data).
>
> I'm all for getting userspace control over pixel encoding but even
> then the kernel always knows which pixel encoding is selected and
> which InfoFrame has to be sent. Is there a reason why userspace would
> want to control the variant explicitly to the wrong value?
>
I've asked this before but haven't seen an answer: Is there an existing
upstream userspace project that makes use of this property (other than
what Joshua is working on in gamescope right now)? That would help us
understand the intent better.
I don't think giving userspace explicit control over the exact infoframe
values is the right thing to do.
Harry
>>
>>>
>>> When we do add pixel_encoding control from userspace,we can pick the
>>> right value for the colorimetry packet based on the
>>> pixel_encoding + the colorspace.
>>>
>>> Let's deprecate these values, and have one BT.2020 colorspace entry
>>> that userspace can use.
>>>
>>> Note: _CYCC was effectively 'removed' by this change, but that was not
>>> possible to be taken advantage of anyway, as there is currently no
>>> pixel_encoding control so it would not be possible to output
>>> linear YCbCr.
>>>
>>> Signed-off-by: Joshua Ashton
>>>
>>> Cc: Pekka Paalanen
>>> Cc: Sebastian Wick
>>> Cc: vitaly.pros...@amd.com
>>> Cc: Uma Shankar
>>> Cc: Ville Syrjälä
>>> Cc: Joshua Ashton
>>> Cc: dri-de...@lists.freedesktop.org
>>> Cc: amd-gfx@lists.freedesktop.org
>>> ---
>>> drivers/gpu/drm/display/drm_hdmi_helper.c | 9 -
>>> drivers/gpu/drm/drm_connector.c | 12 ++--
>>> drivers/gpu/drm/i915/display/intel_dp.c | 20 +---
>>> include/drm/drm_connector.h | 19 ++-
>>> 4 files changed, 29 insertions(+), 31 deletions(-)
>>>
>>> diff --git a/drivers/gpu/drm/display/drm_hdmi_helper.c
>>> b/drivers/gpu/drm/display/drm_hdmi_helper.c
>>> index 0264abe55278..c85860600395 100644
>>> --- a/drivers/gpu/drm/display/drm_hdmi_helper.c
>>> +++ b/drivers/gpu/drm/display/drm_hdmi_helper.c
>>> @@ -99,8 +99,7 @@ EXPORT_SYMBOL(drm_hdmi_infoframe_set_hdr_metadata);
>>> #define HDMI_COLORIMETRY_OPYCC_601 (C(3) | EC(3) | ACE(0))
>>> #define HDMI_COLORIMETRY_OPRGB (C(3) | EC(4) |
>>> ACE(0))
>>> #define HDMI_COLORIMETRY_BT2020_CYCC (C(3) | EC(5) | ACE(0))
>>> -#define HDMI_COLORIMETRY_BT2020_RGB (C(3) | EC(6) | ACE(0))
>>> -#define HDMI_COLORIMETRY_BT2020_YCC (C(3) | EC(6) | ACE(0))
>>> +#define HDMI_COLORIMETRY_BT2020 (C(3) | EC(6) |
>>> ACE(0))
>>> #define HDMI_COLORIMETRY_DCI_P3_RGB_D65 (C(3) | EC(7) |
>>> ACE(0))
>>> #define HDMI_COLORIMETRY_DCI_P3_RGB_THEATER (C(3) | EC(7) | ACE(1))
>>>
>>> @@ -113,9 +112,9 @@ static const u32 hdmi_colorimetry_val[] = {
>>> [DRM_MODE_COLORIMETRY_SYCC_601] = HDMI_COLORIMETRY_SYCC_601,
>>> [DRM_MODE_COLORIMETRY_OPYCC_601] = HDMI_COLORIMETRY_OPYCC_601,
>>> [DRM_MODE_COLORIMETRY_OPRGB] = HDMI_COLORIMETRY_OPRGB,
>>> - [DRM_MODE_COLORIMETRY_BT2020_CYCC] = HDMI_COLORIMETRY_BT2020_CYCC,
>>> - [DRM_MODE_COLORIMETRY_BT2020_RGB] = HDMI_COLORIMETRY_BT2020_RGB,
>>> - [DRM_MODE_COLORIMETRY_BT2020_YCC] = HDMI_COLORIMETRY_BT2020_YCC,
>>> + [DRM_MODE_COLORIMETRY_BT2020_DEPRECATED_1] = HDMI_COLORIMETRY_BT2020,
>>> + [DRM_MODE_COLORIMETRY_BT2020_DEPRECATED_2] = HDMI_COLORIMETRY_BT2020,
>>> + [DRM_MODE_COLORIMETRY_BT2020] = HDMI_COLORIMETRY_BT2020,
>>> };
>>>
>>> #undef C
>>> diff --git a/drivers/gpu/drm/drm_connector.c
>>> b/drivers/gpu/drm/drm_connector.c
>>> index 61c29ce74b03..58699ab15a6a 100644
>>> --- a/drivers/gpu/drm/drm_connector.c
>>> +++ b/drivers/gpu/drm/drm_connector.c
>>> @@ -1029,11 +1029,11 @@ static const struct drm_prop_enum_list
>>> hdmi_colorspaces[] = {
>>> /* Colorimetry based on IEC 61966-2-5 */
>>> { DRM_MODE_COLORIMETRY_OPRGB, "opRGB" },
>>> /* Colorimetry based on ITU-R BT.2020 */
>>> - { DRM_MODE_COLORIMETRY_BT2020_CYCC, "BT2020_CYCC" },
>>> + { DRM_MODE_COLORIMETRY_BT2020_DEPRECATED_1, "BT2020_DEPRECATED_1" },
>>> /* Colorimetry based on ITU-R BT.2020 */
>>> - { DRM_MODE_COLORIMETRY_BT2020_RGB, "BT2020_RGB" },
>>> + { DRM_MODE_COLORIMETRY_BT2020_DEPRECATED_2, "BT2020_DEPRECATED_2" },
>>> /* Colorimetry based on ITU-R
Re: [PATCH 3/3] drm/connector: Deprecate split for BT.2020 in drm_colorspace enum
On Fri, Feb 03, 2023 at 02:52:50PM +0100, Sebastian Wick wrote: > On Fri, Feb 3, 2023 at 2:35 PM Ville Syrjälä > wrote: > > > > On Fri, Feb 03, 2023 at 01:59:07PM +0100, Sebastian Wick wrote: > > > On Fri, Feb 3, 2023 at 11:40 AM Ville Syrjälä > > > wrote: > > > > > > > > On Fri, Feb 03, 2023 at 02:07:44AM +, Joshua Ashton wrote: > > > > > Userspace has no way of controlling or knowing the pixel encoding > > > > > currently, so there is no way for it to ever get the right values > > > > > here. > > > > > > > > That applies to a lot of the other values as well (they are > > > > explicitly RGB or YCC). The idea was that this property sets the > > > > infoframe/MSA/SDP value exactly, and other properties should be > > > > added to for use userspace to control the pixel encoding/colorspace > > > > conversion(if desired, or userspace just makes sure to > > > > directly feed in correct kind of data). > > > > > > I'm all for getting userspace control over pixel encoding but even > > > then the kernel always knows which pixel encoding is selected and > > > which InfoFrame has to be sent. Is there a reason why userspace would > > > want to control the variant explicitly to the wrong value? > > > > What do you mean wrong value? Userspace sets it based on what > > kind of data it has generated (or asked the display hardware > > to generate if/when we get explicit control over that part). > > Wrong in the sense of sending the YCC variant when the pixel encoding > is RGB for example. > > Maybe I'm missing something here but my assumption is that the kernel > always has to know the pixel encoding anyway. The color pipeline also > assumes that the pixel values are RGB. User space might be able to > generate YCC content but for subsampling etc the pixel encoding still > has to be explicitly set. The kernel doesn't really know much atm. In theory you can just configure the thing to do a straight passthough and put anything you want into your pixels. > > So with the kernel always knowing exactly what pixel encoding is sent, > why do we need those variants? I just don't see why this is necessary. > > > > > -- > > Ville Syrjälä > > Intel > > -- Ville Syrjälä Intel
Re: [PATCH 3/3] drm/connector: Deprecate split for BT.2020 in drm_colorspace enum
On Fri, Feb 3, 2023 at 2:35 PM Ville Syrjälä wrote: > > On Fri, Feb 03, 2023 at 01:59:07PM +0100, Sebastian Wick wrote: > > On Fri, Feb 3, 2023 at 11:40 AM Ville Syrjälä > > wrote: > > > > > > On Fri, Feb 03, 2023 at 02:07:44AM +, Joshua Ashton wrote: > > > > Userspace has no way of controlling or knowing the pixel encoding > > > > currently, so there is no way for it to ever get the right values here. > > > > > > That applies to a lot of the other values as well (they are > > > explicitly RGB or YCC). The idea was that this property sets the > > > infoframe/MSA/SDP value exactly, and other properties should be > > > added to for use userspace to control the pixel encoding/colorspace > > > conversion(if desired, or userspace just makes sure to > > > directly feed in correct kind of data). > > > > I'm all for getting userspace control over pixel encoding but even > > then the kernel always knows which pixel encoding is selected and > > which InfoFrame has to be sent. Is there a reason why userspace would > > want to control the variant explicitly to the wrong value? > > What do you mean wrong value? Userspace sets it based on what > kind of data it has generated (or asked the display hardware > to generate if/when we get explicit control over that part). Wrong in the sense of sending the YCC variant when the pixel encoding is RGB for example. Maybe I'm missing something here but my assumption is that the kernel always has to know the pixel encoding anyway. The color pipeline also assumes that the pixel values are RGB. User space might be able to generate YCC content but for subsampling etc the pixel encoding still has to be explicitly set. So with the kernel always knowing exactly what pixel encoding is sent, why do we need those variants? I just don't see why this is necessary. > > -- > Ville Syrjälä > Intel >
Re: [PATCH 3/3] drm/connector: Deprecate split for BT.2020 in drm_colorspace enum
On Fri, Feb 03, 2023 at 01:59:07PM +0100, Sebastian Wick wrote: > On Fri, Feb 3, 2023 at 11:40 AM Ville Syrjälä > wrote: > > > > On Fri, Feb 03, 2023 at 02:07:44AM +, Joshua Ashton wrote: > > > Userspace has no way of controlling or knowing the pixel encoding > > > currently, so there is no way for it to ever get the right values here. > > > > That applies to a lot of the other values as well (they are > > explicitly RGB or YCC). The idea was that this property sets the > > infoframe/MSA/SDP value exactly, and other properties should be > > added to for use userspace to control the pixel encoding/colorspace > > conversion(if desired, or userspace just makes sure to > > directly feed in correct kind of data). > > I'm all for getting userspace control over pixel encoding but even > then the kernel always knows which pixel encoding is selected and > which InfoFrame has to be sent. Is there a reason why userspace would > want to control the variant explicitly to the wrong value? What do you mean wrong value? Userspace sets it based on what kind of data it has generated (or asked the display hardware to generate if/when we get explicit control over that part). -- Ville Syrjälä Intel
Re: [PATCH 3/3] drm/connector: Deprecate split for BT.2020 in drm_colorspace enum
On Fri, Feb 3, 2023 at 11:40 AM Ville Syrjälä
wrote:
>
> On Fri, Feb 03, 2023 at 02:07:44AM +, Joshua Ashton wrote:
> > Userspace has no way of controlling or knowing the pixel encoding
> > currently, so there is no way for it to ever get the right values here.
>
> That applies to a lot of the other values as well (they are
> explicitly RGB or YCC). The idea was that this property sets the
> infoframe/MSA/SDP value exactly, and other properties should be
> added to for use userspace to control the pixel encoding/colorspace
> conversion(if desired, or userspace just makes sure to
> directly feed in correct kind of data).
I'm all for getting userspace control over pixel encoding but even
then the kernel always knows which pixel encoding is selected and
which InfoFrame has to be sent. Is there a reason why userspace would
want to control the variant explicitly to the wrong value?
>
> >
> > When we do add pixel_encoding control from userspace,we can pick the
> > right value for the colorimetry packet based on the
> > pixel_encoding + the colorspace.
> >
> > Let's deprecate these values, and have one BT.2020 colorspace entry
> > that userspace can use.
> >
> > Note: _CYCC was effectively 'removed' by this change, but that was not
> > possible to be taken advantage of anyway, as there is currently no
> > pixel_encoding control so it would not be possible to output
> > linear YCbCr.
> >
> > Signed-off-by: Joshua Ashton
> >
> > Cc: Pekka Paalanen
> > Cc: Sebastian Wick
> > Cc: vitaly.pros...@amd.com
> > Cc: Uma Shankar
> > Cc: Ville Syrjälä
> > Cc: Joshua Ashton
> > Cc: dri-de...@lists.freedesktop.org
> > Cc: amd-gfx@lists.freedesktop.org
> > ---
> > drivers/gpu/drm/display/drm_hdmi_helper.c | 9 -
> > drivers/gpu/drm/drm_connector.c | 12 ++--
> > drivers/gpu/drm/i915/display/intel_dp.c | 20 +---
> > include/drm/drm_connector.h | 19 ++-
> > 4 files changed, 29 insertions(+), 31 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/display/drm_hdmi_helper.c
> > b/drivers/gpu/drm/display/drm_hdmi_helper.c
> > index 0264abe55278..c85860600395 100644
> > --- a/drivers/gpu/drm/display/drm_hdmi_helper.c
> > +++ b/drivers/gpu/drm/display/drm_hdmi_helper.c
> > @@ -99,8 +99,7 @@ EXPORT_SYMBOL(drm_hdmi_infoframe_set_hdr_metadata);
> > #define HDMI_COLORIMETRY_OPYCC_601 (C(3) | EC(3) | ACE(0))
> > #define HDMI_COLORIMETRY_OPRGB (C(3) | EC(4) |
> > ACE(0))
> > #define HDMI_COLORIMETRY_BT2020_CYCC (C(3) | EC(5) | ACE(0))
> > -#define HDMI_COLORIMETRY_BT2020_RGB (C(3) | EC(6) | ACE(0))
> > -#define HDMI_COLORIMETRY_BT2020_YCC (C(3) | EC(6) | ACE(0))
> > +#define HDMI_COLORIMETRY_BT2020 (C(3) | EC(6) |
> > ACE(0))
> > #define HDMI_COLORIMETRY_DCI_P3_RGB_D65 (C(3) | EC(7) |
> > ACE(0))
> > #define HDMI_COLORIMETRY_DCI_P3_RGB_THEATER (C(3) | EC(7) | ACE(1))
> >
> > @@ -113,9 +112,9 @@ static const u32 hdmi_colorimetry_val[] = {
> > [DRM_MODE_COLORIMETRY_SYCC_601] = HDMI_COLORIMETRY_SYCC_601,
> > [DRM_MODE_COLORIMETRY_OPYCC_601] = HDMI_COLORIMETRY_OPYCC_601,
> > [DRM_MODE_COLORIMETRY_OPRGB] = HDMI_COLORIMETRY_OPRGB,
> > - [DRM_MODE_COLORIMETRY_BT2020_CYCC] = HDMI_COLORIMETRY_BT2020_CYCC,
> > - [DRM_MODE_COLORIMETRY_BT2020_RGB] = HDMI_COLORIMETRY_BT2020_RGB,
> > - [DRM_MODE_COLORIMETRY_BT2020_YCC] = HDMI_COLORIMETRY_BT2020_YCC,
> > + [DRM_MODE_COLORIMETRY_BT2020_DEPRECATED_1] = HDMI_COLORIMETRY_BT2020,
> > + [DRM_MODE_COLORIMETRY_BT2020_DEPRECATED_2] = HDMI_COLORIMETRY_BT2020,
> > + [DRM_MODE_COLORIMETRY_BT2020] = HDMI_COLORIMETRY_BT2020,
> > };
> >
> > #undef C
> > diff --git a/drivers/gpu/drm/drm_connector.c
> > b/drivers/gpu/drm/drm_connector.c
> > index 61c29ce74b03..58699ab15a6a 100644
> > --- a/drivers/gpu/drm/drm_connector.c
> > +++ b/drivers/gpu/drm/drm_connector.c
> > @@ -1029,11 +1029,11 @@ static const struct drm_prop_enum_list
> > hdmi_colorspaces[] = {
> > /* Colorimetry based on IEC 61966-2-5 */
> > { DRM_MODE_COLORIMETRY_OPRGB, "opRGB" },
> > /* Colorimetry based on ITU-R BT.2020 */
> > - { DRM_MODE_COLORIMETRY_BT2020_CYCC, "BT2020_CYCC" },
> > + { DRM_MODE_COLORIMETRY_BT2020_DEPRECATED_1, "BT2020_DEPRECATED_1" },
> > /* Colorimetry based on ITU-R BT.2020 */
> > - { DRM_MODE_COLORIMETRY_BT2020_RGB, "BT2020_RGB" },
> > + { DRM_MODE_COLORIMETRY_BT2020_DEPRECATED_2, "BT2020_DEPRECATED_2" },
> > /* Colorimetry based on ITU-R BT.2020 */
> > - { DRM_MODE_COLORIMETRY_BT2020_YCC, "BT2020_YCC" },
> > + { DRM_MODE_COLORIMETRY_BT2020, "BT2020" },
> > /* Added as part of Additional Colorimetry Extension in 861.G */
> > { DRM_MODE_COLORIMETRY_DCI_P3_RGB_D65, "DCI-P3_RGB_D65" },
> > { DRM_MODE_COLORIMETRY_DCI_P3_RGB_THEATER, "DCI-P3_RGB_Theater" },
> > @@ -1054,7 +1054,7 @@ static const struct drm_prop_enum_list
> >
Re: [PATCH 3/3] drm/connector: Deprecate split for BT.2020 in drm_colorspace enum
On Fri, Feb 03, 2023 at 02:07:44AM +, Joshua Ashton wrote:
> Userspace has no way of controlling or knowing the pixel encoding
> currently, so there is no way for it to ever get the right values here.
That applies to a lot of the other values as well (they are
explicitly RGB or YCC). The idea was that this property sets the
infoframe/MSA/SDP value exactly, and other properties should be
added to for use userspace to control the pixel encoding/colorspace
conversion(if desired, or userspace just makes sure to
directly feed in correct kind of data).
>
> When we do add pixel_encoding control from userspace,we can pick the
> right value for the colorimetry packet based on the
> pixel_encoding + the colorspace.
>
> Let's deprecate these values, and have one BT.2020 colorspace entry
> that userspace can use.
>
> Note: _CYCC was effectively 'removed' by this change, but that was not
> possible to be taken advantage of anyway, as there is currently no
> pixel_encoding control so it would not be possible to output
> linear YCbCr.
>
> Signed-off-by: Joshua Ashton
>
> Cc: Pekka Paalanen
> Cc: Sebastian Wick
> Cc: vitaly.pros...@amd.com
> Cc: Uma Shankar
> Cc: Ville Syrjälä
> Cc: Joshua Ashton
> Cc: dri-de...@lists.freedesktop.org
> Cc: amd-gfx@lists.freedesktop.org
> ---
> drivers/gpu/drm/display/drm_hdmi_helper.c | 9 -
> drivers/gpu/drm/drm_connector.c | 12 ++--
> drivers/gpu/drm/i915/display/intel_dp.c | 20 +---
> include/drm/drm_connector.h | 19 ++-
> 4 files changed, 29 insertions(+), 31 deletions(-)
>
> diff --git a/drivers/gpu/drm/display/drm_hdmi_helper.c
> b/drivers/gpu/drm/display/drm_hdmi_helper.c
> index 0264abe55278..c85860600395 100644
> --- a/drivers/gpu/drm/display/drm_hdmi_helper.c
> +++ b/drivers/gpu/drm/display/drm_hdmi_helper.c
> @@ -99,8 +99,7 @@ EXPORT_SYMBOL(drm_hdmi_infoframe_set_hdr_metadata);
> #define HDMI_COLORIMETRY_OPYCC_601 (C(3) | EC(3) | ACE(0))
> #define HDMI_COLORIMETRY_OPRGB (C(3) | EC(4) | ACE(0))
> #define HDMI_COLORIMETRY_BT2020_CYCC (C(3) | EC(5) | ACE(0))
> -#define HDMI_COLORIMETRY_BT2020_RGB (C(3) | EC(6) | ACE(0))
> -#define HDMI_COLORIMETRY_BT2020_YCC (C(3) | EC(6) | ACE(0))
> +#define HDMI_COLORIMETRY_BT2020 (C(3) | EC(6) | ACE(0))
> #define HDMI_COLORIMETRY_DCI_P3_RGB_D65 (C(3) | EC(7) | ACE(0))
> #define HDMI_COLORIMETRY_DCI_P3_RGB_THEATER (C(3) | EC(7) | ACE(1))
>
> @@ -113,9 +112,9 @@ static const u32 hdmi_colorimetry_val[] = {
> [DRM_MODE_COLORIMETRY_SYCC_601] = HDMI_COLORIMETRY_SYCC_601,
> [DRM_MODE_COLORIMETRY_OPYCC_601] = HDMI_COLORIMETRY_OPYCC_601,
> [DRM_MODE_COLORIMETRY_OPRGB] = HDMI_COLORIMETRY_OPRGB,
> - [DRM_MODE_COLORIMETRY_BT2020_CYCC] = HDMI_COLORIMETRY_BT2020_CYCC,
> - [DRM_MODE_COLORIMETRY_BT2020_RGB] = HDMI_COLORIMETRY_BT2020_RGB,
> - [DRM_MODE_COLORIMETRY_BT2020_YCC] = HDMI_COLORIMETRY_BT2020_YCC,
> + [DRM_MODE_COLORIMETRY_BT2020_DEPRECATED_1] = HDMI_COLORIMETRY_BT2020,
> + [DRM_MODE_COLORIMETRY_BT2020_DEPRECATED_2] = HDMI_COLORIMETRY_BT2020,
> + [DRM_MODE_COLORIMETRY_BT2020] = HDMI_COLORIMETRY_BT2020,
> };
>
> #undef C
> diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c
> index 61c29ce74b03..58699ab15a6a 100644
> --- a/drivers/gpu/drm/drm_connector.c
> +++ b/drivers/gpu/drm/drm_connector.c
> @@ -1029,11 +1029,11 @@ static const struct drm_prop_enum_list
> hdmi_colorspaces[] = {
> /* Colorimetry based on IEC 61966-2-5 */
> { DRM_MODE_COLORIMETRY_OPRGB, "opRGB" },
> /* Colorimetry based on ITU-R BT.2020 */
> - { DRM_MODE_COLORIMETRY_BT2020_CYCC, "BT2020_CYCC" },
> + { DRM_MODE_COLORIMETRY_BT2020_DEPRECATED_1, "BT2020_DEPRECATED_1" },
> /* Colorimetry based on ITU-R BT.2020 */
> - { DRM_MODE_COLORIMETRY_BT2020_RGB, "BT2020_RGB" },
> + { DRM_MODE_COLORIMETRY_BT2020_DEPRECATED_2, "BT2020_DEPRECATED_2" },
> /* Colorimetry based on ITU-R BT.2020 */
> - { DRM_MODE_COLORIMETRY_BT2020_YCC, "BT2020_YCC" },
> + { DRM_MODE_COLORIMETRY_BT2020, "BT2020" },
> /* Added as part of Additional Colorimetry Extension in 861.G */
> { DRM_MODE_COLORIMETRY_DCI_P3_RGB_D65, "DCI-P3_RGB_D65" },
> { DRM_MODE_COLORIMETRY_DCI_P3_RGB_THEATER, "DCI-P3_RGB_Theater" },
> @@ -1054,7 +1054,7 @@ static const struct drm_prop_enum_list dp_colorspaces[]
> = {
> /* Colorimetry based on SMPTE RP 431-2 */
> { DRM_MODE_COLORIMETRY_DCI_P3_RGB_D65, "DCI-P3_RGB_D65" },
> /* Colorimetry based on ITU-R BT.2020 */
> - { DRM_MODE_COLORIMETRY_BT2020_RGB, "BT2020_RGB" },
> + { DRM_MODE_COLORIMETRY_BT2020, "BT2020" },
> { DRM_MODE_COLORIMETRY_BT601_YCC, "BT601_YCC" },
> { DRM_MODE_COLORIMETRY_BT709_YCC, "BT709_YCC" },
> /* Standard Definition Colorimetry based on IEC 61966-2-4 */
> @@ -1066,9 +1066,9 @@ static const
[PATCH 3/3] drm/connector: Deprecate split for BT.2020 in drm_colorspace enum
Userspace has no way of controlling or knowing the pixel encoding
currently, so there is no way for it to ever get the right values here.
When we do add pixel_encoding control from userspace,we can pick the
right value for the colorimetry packet based on the
pixel_encoding + the colorspace.
Let's deprecate these values, and have one BT.2020 colorspace entry
that userspace can use.
Note: _CYCC was effectively 'removed' by this change, but that was not
possible to be taken advantage of anyway, as there is currently no
pixel_encoding control so it would not be possible to output
linear YCbCr.
Signed-off-by: Joshua Ashton
Cc: Pekka Paalanen
Cc: Sebastian Wick
Cc: vitaly.pros...@amd.com
Cc: Uma Shankar
Cc: Ville Syrjälä
Cc: Joshua Ashton
Cc: dri-de...@lists.freedesktop.org
Cc: amd-gfx@lists.freedesktop.org
---
drivers/gpu/drm/display/drm_hdmi_helper.c | 9 -
drivers/gpu/drm/drm_connector.c | 12 ++--
drivers/gpu/drm/i915/display/intel_dp.c | 20 +---
include/drm/drm_connector.h | 19 ++-
4 files changed, 29 insertions(+), 31 deletions(-)
diff --git a/drivers/gpu/drm/display/drm_hdmi_helper.c
b/drivers/gpu/drm/display/drm_hdmi_helper.c
index 0264abe55278..c85860600395 100644
--- a/drivers/gpu/drm/display/drm_hdmi_helper.c
+++ b/drivers/gpu/drm/display/drm_hdmi_helper.c
@@ -99,8 +99,7 @@ EXPORT_SYMBOL(drm_hdmi_infoframe_set_hdr_metadata);
#define HDMI_COLORIMETRY_OPYCC_601 (C(3) | EC(3) | ACE(0))
#define HDMI_COLORIMETRY_OPRGB (C(3) | EC(4) | ACE(0))
#define HDMI_COLORIMETRY_BT2020_CYCC (C(3) | EC(5) | ACE(0))
-#define HDMI_COLORIMETRY_BT2020_RGB(C(3) | EC(6) | ACE(0))
-#define HDMI_COLORIMETRY_BT2020_YCC(C(3) | EC(6) | ACE(0))
+#define HDMI_COLORIMETRY_BT2020(C(3) | EC(6) | ACE(0))
#define HDMI_COLORIMETRY_DCI_P3_RGB_D65(C(3) | EC(7) | ACE(0))
#define HDMI_COLORIMETRY_DCI_P3_RGB_THEATER(C(3) | EC(7) | ACE(1))
@@ -113,9 +112,9 @@ static const u32 hdmi_colorimetry_val[] = {
[DRM_MODE_COLORIMETRY_SYCC_601] = HDMI_COLORIMETRY_SYCC_601,
[DRM_MODE_COLORIMETRY_OPYCC_601] = HDMI_COLORIMETRY_OPYCC_601,
[DRM_MODE_COLORIMETRY_OPRGB] = HDMI_COLORIMETRY_OPRGB,
- [DRM_MODE_COLORIMETRY_BT2020_CYCC] = HDMI_COLORIMETRY_BT2020_CYCC,
- [DRM_MODE_COLORIMETRY_BT2020_RGB] = HDMI_COLORIMETRY_BT2020_RGB,
- [DRM_MODE_COLORIMETRY_BT2020_YCC] = HDMI_COLORIMETRY_BT2020_YCC,
+ [DRM_MODE_COLORIMETRY_BT2020_DEPRECATED_1] = HDMI_COLORIMETRY_BT2020,
+ [DRM_MODE_COLORIMETRY_BT2020_DEPRECATED_2] = HDMI_COLORIMETRY_BT2020,
+ [DRM_MODE_COLORIMETRY_BT2020] = HDMI_COLORIMETRY_BT2020,
};
#undef C
diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c
index 61c29ce74b03..58699ab15a6a 100644
--- a/drivers/gpu/drm/drm_connector.c
+++ b/drivers/gpu/drm/drm_connector.c
@@ -1029,11 +1029,11 @@ static const struct drm_prop_enum_list
hdmi_colorspaces[] = {
/* Colorimetry based on IEC 61966-2-5 */
{ DRM_MODE_COLORIMETRY_OPRGB, "opRGB" },
/* Colorimetry based on ITU-R BT.2020 */
- { DRM_MODE_COLORIMETRY_BT2020_CYCC, "BT2020_CYCC" },
+ { DRM_MODE_COLORIMETRY_BT2020_DEPRECATED_1, "BT2020_DEPRECATED_1" },
/* Colorimetry based on ITU-R BT.2020 */
- { DRM_MODE_COLORIMETRY_BT2020_RGB, "BT2020_RGB" },
+ { DRM_MODE_COLORIMETRY_BT2020_DEPRECATED_2, "BT2020_DEPRECATED_2" },
/* Colorimetry based on ITU-R BT.2020 */
- { DRM_MODE_COLORIMETRY_BT2020_YCC, "BT2020_YCC" },
+ { DRM_MODE_COLORIMETRY_BT2020, "BT2020" },
/* Added as part of Additional Colorimetry Extension in 861.G */
{ DRM_MODE_COLORIMETRY_DCI_P3_RGB_D65, "DCI-P3_RGB_D65" },
{ DRM_MODE_COLORIMETRY_DCI_P3_RGB_THEATER, "DCI-P3_RGB_Theater" },
@@ -1054,7 +1054,7 @@ static const struct drm_prop_enum_list dp_colorspaces[] =
{
/* Colorimetry based on SMPTE RP 431-2 */
{ DRM_MODE_COLORIMETRY_DCI_P3_RGB_D65, "DCI-P3_RGB_D65" },
/* Colorimetry based on ITU-R BT.2020 */
- { DRM_MODE_COLORIMETRY_BT2020_RGB, "BT2020_RGB" },
+ { DRM_MODE_COLORIMETRY_BT2020, "BT2020" },
{ DRM_MODE_COLORIMETRY_BT601_YCC, "BT601_YCC" },
{ DRM_MODE_COLORIMETRY_BT709_YCC, "BT709_YCC" },
/* Standard Definition Colorimetry based on IEC 61966-2-4 */
@@ -1066,9 +1066,9 @@ static const struct drm_prop_enum_list dp_colorspaces[] =
{
/* Colorimetry based on IEC 61966-2-5 [33] */
{ DRM_MODE_COLORIMETRY_OPYCC_601, "opYCC_601" },
/* Colorimetry based on ITU-R BT.2020 */
- { DRM_MODE_COLORIMETRY_BT2020_CYCC, "BT2020_CYCC" },
+ { DRM_MODE_COLORIMETRY_BT2020_DEPRECATED_1, "BT2020_DEPRECATED_1" },
/* Colorimetry based on ITU-R BT.2020 */
- { DRM_MODE_COLORIMETRY_BT2020_YCC, "BT2020_YCC" },
+ { DRM_MODE_COLORIMETRY_BT2020_DEPRECATED_2, "BT2020_DEPRECATED_2" },
