Re: Media system Summit
Hello all, Le jeudi 12 juillet 2012 06:18:08 Mauro Carvalho Chehab, vous avez écrit : We have set aside the second day of the kernel summit (Tuesday 28 August) as mini-summit day. So far we have only the PCI mini summit on this day Not sure what happened (or maybe my proposal were not clear enough), but I've submitted a proposal to have a media system summit on KS/2011. Last year was very productive for media developers, so we'd like to do it again ;) Do you guys expect to discuss anything relevant to userland? (V4L? DVB? ...?) -- Rémi Denis-Courmont http://www.remlab.net/ http://fi.linkedin.com/in/remidenis -- To unsubscribe from this list: send the line unsubscribe linux-media in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [Ksummit-2012-discuss] Device-tree cross-subsystem binding workshop [was Media system Summit]
On 07/13/12 04:20, Olof Johansson wrote: On Thu, Jul 12, 2012 at 12:03 PM, Hans Verkuil hverk...@xs4all.nl wrote: On Thu July 12 2012 18:48:23 Olof Johansson wrote: On Thu, Jul 12, 2012 at 9:18 AM, Mark Brown broo...@opensource.wolfsonmicro.com wrote: On Thu, Jul 12, 2012 at 10:08:04AM +0200, Sylwester Nawrocki wrote: I'd like to add a Common device tree bindings for media devices topic to the agenda for consideration. It'd be nice to get this to join up with ASoC... There's a handful of various subsystems that have similar topics, maybe slice it the other way and do a device-tree/ACPI breakout that cuts across the various areas instead? Communication really needs to be two-way: Crafting good bindings for a complex piece of hardware isn't trivial and having someone know both the subsystem and device tree principles is rare. At least getting all those people into the same room would be good. I'm not so sure: I think that most decisions that need to be made are quite subsystem specific. Trying to figure out how to implement DT for multiple subsystems in one workshop seems unlikely to succeed, simply because of lack of time. I also don't think there is much overlap between subsystems in this respect, so while the DT implementation for one subsystem is discussed, the representatives of other subsystems are twiddling their thumbs. It might be more productive to have one or two DT experts around who rotate over the various workshops that have to deal with the DT and can offer advice. One of the real problems right now is the lack of DT reviewers and general reviewer fatigue. In particular, many of the proposed bindings tend to have the same issues (focusing too much on how the platform_data is structured today and not on what the hardware actually is), and a few other similar things. Based on that I don't think it's a better solution to have the same few people walk from room to room to cover the same thing multiple times. No one has to sit there the whole day and listen on it all, but for those who are genuinely interested in how other subsystems will handle these bindings, I think it would be very useful to learn from how they made their decisions. Don't work in a vacuum, etc. So, I'd like to formally propose this as a mini-summit or workshop or whatever you might want to call it. I can help organize it together with Rob and Grant if needed (especially since Grant has a lot of other things going on at the moment). If there's insufficent interest to do this as a separate event we can try to accomodate for it as part of the ARM mini-summit, but squeezing all of that in with the rest of the ARM activities in one day will be hard. +1 -- Regards, Igor. -- To unsubscribe from this list: send the line unsubscribe linux-media in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [Ksummit-2012-discuss] Device-tree cross-subsystem binding workshop [was Media system Summit]
On Thu, Jul 12, 2012 at 06:20:27PM -0700, Olof Johansson wrote: On Thu, Jul 12, 2012 at 12:03 PM, Hans Verkuil hverk...@xs4all.nl wrote: I'm not so sure: I think that most decisions that need to be made are quite subsystem specific. Trying to figure out how to implement DT for multiple subsystems in one workshop seems unlikely to succeed, simply because of lack of time. I also don't think there is much overlap between subsystems in this respect, so while the DT implementation for one subsystem is discussed, the representatives of other subsystems are twiddling their thumbs. I'm seeing an awful lot of common patterns in the way the hardware is structured here, we shouldn't be redoing the handling of all these patterns. Obviously there will be subsystem specific stuff too but there's a lot of repetitive boiler plate in the high level hookup. -- To unsubscribe from this list: send the line unsubscribe linux-media in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [Ksummit-2012-discuss] Device-tree cross-subsystem binding workshop [was Media system Summit]
On Thu, Jul 12, 2012 at 09:55:07PM -0500, Rob Herring wrote: Perhaps part of the issue is we're trying to put too much into DT? I think this is definitely part of it, at times it feels like people have a shiny new toy so we're jumping into device tree really quickly for things that perhaps don't need to be pulled out of the code. Another part of it (and the big problem with translating platform data directly) is that platform data is easily fungible whereas device tree should in theory be an ABI and hence needs much closer scrutiny. -- To unsubscribe from this list: send the line unsubscribe linux-media in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: Media system Summit
Hi Mauro, On 07/12/2012 05:18 AM, Mauro Carvalho Chehab wrote: Em 11-07-2012 05:09, James Bottomley escreveu: Hi All, We have set aside the second day of the kernel summit (Tuesday 28 August) as mini-summit day. So far we have only the PCI mini summit on this day Not sure what happened (or maybe my proposal were not clear enough), but I've submitted a proposal to have a media system summit on KS/2011. Last year was very productive for media developers, so we'd like to do it again ;) Message-ID:4fec74ab.6070...@redhat.com Date: Thu, 28 Jun 2012 12:13:47 -0300 From: Mauro Carvalho Chehabmche...@redhat.com [Ksummit-2012-discuss] [ATTEND] media subsystem I'd like to have media subsystem discussions this year's at kernel summit. The media subsystem is one of the most active driver subsystem, and there are lots of things there that require face-to-face discussions, not only between subsystem developers, but also with other maintainers. In special, during KS/2011, it was identified the need of interacting with video and audio system people, in order to solve some common issues, like HDMI CEC and audio/video synchronization. The increasing complexity of SoC designs used by media devices requires API extensions at the media APIs in order to proper expose and control all hardware functionality on a standard way. A new API to better allow negotiating userspace and Kernelspace capabilities seem to be required. More discussions with regards to shared resources locking is needed, on devices that implement multiple API's, but not a the same time. The incompatibility between udev-182 and the existing drivers will also require lots of discussions, as that affects 64 media drivers, and changing them to comply with the current requirement of using request_firmware_nowait() won't work on several drivers. So, a solution (or a set of solutions) needs to be found, in order to fix such incompatibility. I'd like to add a Common device tree bindings for media devices topic to the agenda for consideration. There were some activities on creating device tree bindings for Samsung and SH Mobile SoCs but this didn't really kick off yet and a face to face discussions could help to bring device tree support in media subsystem to the level many other subsystems already have. -- Thanks, Sylwester -- To unsubscribe from this list: send the line unsubscribe linux-media in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [Ksummit-2012-discuss] Media system Summit
On Thu, Jul 12, 2012 at 10:08:04AM +0200, Sylwester Nawrocki wrote: I'd like to add a Common device tree bindings for media devices topic to the agenda for consideration. It'd be nice to get this to join up with ASoC... -- To unsubscribe from this list: send the line unsubscribe linux-media in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [Ksummit-2012-discuss] Media system Summit
On Thu, Jul 12, 2012 at 9:18 AM, Mark Brown broo...@opensource.wolfsonmicro.com wrote: On Thu, Jul 12, 2012 at 10:08:04AM +0200, Sylwester Nawrocki wrote: I'd like to add a Common device tree bindings for media devices topic to the agenda for consideration. It'd be nice to get this to join up with ASoC... There's a handful of various subsystems that have similar topics, maybe slice it the other way and do a device-tree/ACPI breakout that cuts across the various areas instead? Communication really needs to be two-way: Crafting good bindings for a complex piece of hardware isn't trivial and having someone know both the subsystem and device tree principles is rare. At least getting all those people into the same room would be good. There's obvious overlap with ARM here as well, since it's one of the current big pushers of DT use, but I think it would be better to hold this as a separate breakout from that. -Olof -- To unsubscribe from this list: send the line unsubscribe linux-media in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [Ksummit-2012-discuss] Media system Summit
On Thu, 12 Jul 2012, Hans Verkuil wrote: On Thu July 12 2012 18:48:23 Olof Johansson wrote: On Thu, Jul 12, 2012 at 9:18 AM, Mark Brown broo...@opensource.wolfsonmicro.com wrote: On Thu, Jul 12, 2012 at 10:08:04AM +0200, Sylwester Nawrocki wrote: I'd like to add a Common device tree bindings for media devices topic to the agenda for consideration. It'd be nice to get this to join up with ASoC... There's a handful of various subsystems that have similar topics, maybe slice it the other way and do a device-tree/ACPI breakout that cuts across the various areas instead? Communication really needs to be two-way: Crafting good bindings for a complex piece of hardware isn't trivial and having someone know both the subsystem and device tree principles is rare. At least getting all those people into the same room would be good. I'm not so sure: I think that most decisions that need to be made are quite subsystem specific. Trying to figure out how to implement DT for multiple subsystems in one workshop seems unlikely to succeed, simply because of lack of time. I also don't think there is much overlap between subsystems in this respect, so while the DT implementation for one subsystem is discussed, the representatives of other subsystems are twiddling their thumbs. It might be more productive to have one or two DT experts around who rotate over the various workshops that have to deal with the DT and can offer advice. I'm sure everyone has seen this, but just to have it mentioned here: a href=http://article.gmane.org/gmane.linux.drivers.video-input-infrastructure/50755; shameless self-advertisement/a I'm not sure whether the overlap with other subsystems is large or not, but there definitely is some, also with video (fbdev / drm), e.g., http://thread.gmane.org/gmane.linux.drivers.devicetree/17495 As for whether or not discuss DT for various subsystems together - why not do both? First short sessions in each subsystems, of course, this would only work if proposals have been prepared beforehand and at least preliminary discussions on the MLs have taken place, and then another (also short) combined session? Of course, it also depends on how much time we can and want to dedicate to this. Thanks Guennadi Regards, Hans There's obvious overlap with ARM here as well, since it's one of the current big pushers of DT use, but I think it would be better to hold this as a separate breakout from that. -Olof -- To unsubscribe from this list: send the line unsubscribe linux-media in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line unsubscribe linux-media in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html --- Guennadi Liakhovetski, Ph.D. Freelance Open-Source Software Developer http://www.open-technology.de/ -- To unsubscribe from this list: send the line unsubscribe linux-media in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Device-tree cross-subsystem binding workshop [was Media system Summit]
On Thu, Jul 12, 2012 at 12:03 PM, Hans Verkuil hverk...@xs4all.nl wrote: On Thu July 12 2012 18:48:23 Olof Johansson wrote: On Thu, Jul 12, 2012 at 9:18 AM, Mark Brown broo...@opensource.wolfsonmicro.com wrote: On Thu, Jul 12, 2012 at 10:08:04AM +0200, Sylwester Nawrocki wrote: I'd like to add a Common device tree bindings for media devices topic to the agenda for consideration. It'd be nice to get this to join up with ASoC... There's a handful of various subsystems that have similar topics, maybe slice it the other way and do a device-tree/ACPI breakout that cuts across the various areas instead? Communication really needs to be two-way: Crafting good bindings for a complex piece of hardware isn't trivial and having someone know both the subsystem and device tree principles is rare. At least getting all those people into the same room would be good. I'm not so sure: I think that most decisions that need to be made are quite subsystem specific. Trying to figure out how to implement DT for multiple subsystems in one workshop seems unlikely to succeed, simply because of lack of time. I also don't think there is much overlap between subsystems in this respect, so while the DT implementation for one subsystem is discussed, the representatives of other subsystems are twiddling their thumbs. It might be more productive to have one or two DT experts around who rotate over the various workshops that have to deal with the DT and can offer advice. One of the real problems right now is the lack of DT reviewers and general reviewer fatigue. In particular, many of the proposed bindings tend to have the same issues (focusing too much on how the platform_data is structured today and not on what the hardware actually is), and a few other similar things. Based on that I don't think it's a better solution to have the same few people walk from room to room to cover the same thing multiple times. No one has to sit there the whole day and listen on it all, but for those who are genuinely interested in how other subsystems will handle these bindings, I think it would be very useful to learn from how they made their decisions. Don't work in a vacuum, etc. So, I'd like to formally propose this as a mini-summit or workshop or whatever you might want to call it. I can help organize it together with Rob and Grant if needed (especially since Grant has a lot of other things going on at the moment). If there's insufficent interest to do this as a separate event we can try to accomodate for it as part of the ARM mini-summit, but squeezing all of that in with the rest of the ARM activities in one day will be hard. -Olof -- To unsubscribe from this list: send the line unsubscribe linux-media in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [Ksummit-2012-discuss] Media system Summit
On Thu, Jul 12, 2012 at 2:05 PM, Guennadi Liakhovetski g.liakhovet...@gmx.de wrote: On Thu, 12 Jul 2012, Hans Verkuil wrote: On Thu July 12 2012 18:48:23 Olof Johansson wrote: On Thu, Jul 12, 2012 at 9:18 AM, Mark Brown broo...@opensource.wolfsonmicro.com wrote: On Thu, Jul 12, 2012 at 10:08:04AM +0200, Sylwester Nawrocki wrote: I'd like to add a Common device tree bindings for media devices topic to the agenda for consideration. It'd be nice to get this to join up with ASoC... There's a handful of various subsystems that have similar topics, maybe slice it the other way and do a device-tree/ACPI breakout that cuts across the various areas instead? Communication really needs to be two-way: Crafting good bindings for a complex piece of hardware isn't trivial and having someone know both the subsystem and device tree principles is rare. At least getting all those people into the same room would be good. I'm not so sure: I think that most decisions that need to be made are quite subsystem specific. Trying to figure out how to implement DT for multiple subsystems in one workshop seems unlikely to succeed, simply because of lack of time. I also don't think there is much overlap between subsystems in this respect, so while the DT implementation for one subsystem is discussed, the representatives of other subsystems are twiddling their thumbs. It might be more productive to have one or two DT experts around who rotate over the various workshops that have to deal with the DT and can offer advice. I'm sure everyone has seen this, but just to have it mentioned here: a href=http://article.gmane.org/gmane.linux.drivers.video-input-infrastructure/50755; shameless self-advertisement/a I hadn't seen it, since you didn't cc devicetree-discuss. Well, I'm also generally behind on list email right now since I am travelling but I couldn't find it in any list folder I subscribe to. As for whether or not discuss DT for various subsystems together - why not do both? First short sessions in each subsystems, of course, this would only work if proposals have been prepared beforehand and at least preliminary discussions on the MLs have taken place, and then another (also short) combined session? Of course, it also depends on how much time we can and want to dedicate to this. The agenda for such a day should probably be partially broken down per subsystem, yes, and it would make sense for people from the various areas to describe the kind of setup that they need to be able to define, similar to how you did in your writeup above. In some cases it would be a matter of in-person review/discussion/arguments of already proposed bindings, in other cases it would probably be a seeding discussion for upcoming bindings instead. Having the latter piggy-back on hearing what's discussed with the former category would likely be a good idea. -Olof -- To unsubscribe from this list: send the line unsubscribe linux-media in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: Device-tree cross-subsystem binding workshop [was Media system Summit]
On 07/12/2012 08:20 PM, Olof Johansson wrote: On Thu, Jul 12, 2012 at 12:03 PM, Hans Verkuil hverk...@xs4all.nl wrote: On Thu July 12 2012 18:48:23 Olof Johansson wrote: On Thu, Jul 12, 2012 at 9:18 AM, Mark Brown broo...@opensource.wolfsonmicro.com wrote: On Thu, Jul 12, 2012 at 10:08:04AM +0200, Sylwester Nawrocki wrote: I'd like to add a Common device tree bindings for media devices topic to the agenda for consideration. It'd be nice to get this to join up with ASoC... There's a handful of various subsystems that have similar topics, maybe slice it the other way and do a device-tree/ACPI breakout that cuts across the various areas instead? Communication really needs to be two-way: Crafting good bindings for a complex piece of hardware isn't trivial and having someone know both the subsystem and device tree principles is rare. At least getting all those people into the same room would be good. I'm not so sure: I think that most decisions that need to be made are quite subsystem specific. Trying to figure out how to implement DT for multiple subsystems in one workshop seems unlikely to succeed, simply because of lack of time. I also don't think there is much overlap between subsystems in this respect, so while the DT implementation for one subsystem is discussed, the representatives of other subsystems are twiddling their thumbs. It might be more productive to have one or two DT experts around who rotate over the various workshops that have to deal with the DT and can offer advice. One of the real problems right now is the lack of DT reviewers and general reviewer fatigue. In particular, many of the proposed bindings tend to have the same issues (focusing too much on how the platform_data is structured today and not on what the hardware actually is), and a few other similar things. Agreed. It's hard to review things spanning across all subsystems and define something which works well across platforms. Often within a single subsystem we repeat things as platforms one by one convert to DT. On the other hand, I guess re-occurring review issues is a common problem across the kernel. Perhaps part of the issue is we're trying to put too much into DT? It's unfortunate that other than the recovering PPC developers now working on ARM, there has not been a lot of review from folks that have worked with DT for a bit longer. Based on that I don't think it's a better solution to have the same few people walk from room to room to cover the same thing multiple times. No one has to sit there the whole day and listen on it all, but for those who are genuinely interested in how other subsystems will handle these bindings, I think it would be very useful to learn from how they made their decisions. Don't work in a vacuum, etc. So, I'd like to formally propose this as a mini-summit or workshop or whatever you might want to call it. I can help organize it together with Rob and Grant if needed (especially since Grant has a lot of other things going on at the moment). If there's insufficent interest to do this as a separate event we can try to accomodate for it as part of the ARM mini-summit, but squeezing all of that in with the rest of the ARM activities in one day will be hard. I happy to help organize it. I think keeping it separate from ARM mini-summit is better otherwise we may end up with somewhat the same group of ARM developers as past DT discussions. Rob -Olof -- To unsubscribe from this list: send the line unsubscribe linux-media in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Media system Summit
Em 11-07-2012 05:09, James Bottomley escreveu: Hi All, We have set aside the second day of the kernel summit (Tuesday 28 August) as mini-summit day. So far we have only the PCI mini summit on this day Not sure what happened (or maybe my proposal were not clear enough), but I've submitted a proposal to have a media system summit on KS/2011. Last year was very productive for media developers, so we'd like to do it again ;) Message-ID: 4fec74ab.6070...@redhat.com Date: Thu, 28 Jun 2012 12:13:47 -0300 From: Mauro Carvalho Chehab mche...@redhat.com [Ksummit-2012-discuss] [ATTEND] media subsystem I'd like to have media subsystem discussions this year's at kernel summit. The media subsystem is one of the most active driver subsystem, and there are lots of things there that require face-to-face discussions, not only between subsystem developers, but also with other maintainers. In special, during KS/2011, it was identified the need of interacting with video and audio system people, in order to solve some common issues, like HDMI CEC and audio/video synchronization. The increasing complexity of SoC designs used by media devices requires API extensions at the media APIs in order to proper expose and control all hardware functionality on a standard way. A new API to better allow negotiating userspace and Kernelspace capabilities seem to be required. More discussions with regards to shared resources locking is needed, on devices that implement multiple API's, but not a the same time. The incompatibility between udev-182 and the existing drivers will also require lots of discussions, as that affects 64 media drivers, and changing them to comply with the current requirement of using request_firmware_nowait() won't work on several drivers. So, a solution (or a set of solutions) needs to be found, in order to fix such incompatibility. Thanks, Mauro -- To unsubscribe from this list: send the line unsubscribe linux-media in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
