On Fri, 2018-05-18 at 13:08 +0300, Pekka Paalanen wrote: > On Fri, 18 May 2018 08:25:26 +0000 > Sandeep Chandak <ba.sand...@tataelxsi.co.in> wrote: > > > Hi Pekka, > > > > Thanks for a detailed response, need some more clarifications > > though > > > > The final solution will use drm-backend we are in process of > > getting > > the drm-backend work on the platform, while we use x11-backend for > > development. > > > > a) I assume from Shared-CRTC support you mean monitors with same > > resolutions, refresh rate etc. So cloned mode is supported for use > > cases for displays with similar properties for resolution, refresh > > rate etc. > > Yes. It literally means using the same CRTC to feed several > connectors, > which means they share the video mode and timings. This requires > explicit support in hardware, and whether it is available varies > between chips. > > > Is this supported for x11-backend also? > > Not currently, and there are no plans to do so. You would simply have > two windows with the same content, and I'm not sure what the benefit > of > supporting that would be. The only visible difference is that all > heads > advertise their own wl_output globals, so in clone mode you would get > two (or more) wl_outputs that behave identically while reporting > per-monitor details. > > If independent-CRTC mode worked, you could just use that with the > x11-backend, as the only difference with a proper configuration would > be the output timings, and the x11-backend is bad with timings > anyway. > > > As you mentioned > > Independent-CRTC mode (i.e monitors with different refresh rate > > etc), > > cloning is not supported currently. Can you please confirm if this > > understanding is correct? > > Yes. > > You can read more about the clone mode design here: > https://emea01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fph > abricator.freedesktop.org%2FT7727&data=02%7C01%7Cmarius- > cristian.vlad%40nxp.com%7Cfa1425f456fb4107c98e08d5bca75666%7C686ea1d3 > bc2b4c6fa92cd99c5c301635%7C0%7C0%7C636622349257323713&sdata=tFViB1BXM > 5Yct6wifjnZbaja7dmWYu1pdvWNAK3phv8%3D&reserved=0 > > > b) Different configuration for us means - Either a single or > > multiple > > compositor instance (running on same physical hardware) driving > > different monitors to display different composited content. In this > > case the displays can be placed far off from each other. I assume > > this would be supported. Please confirm? > > Sorry, I'm not sure I understand. The only case I have talked about > here is a single Weston compositor instance controlling all outputs. > > It has been impossible to run more than one compositor instance on > the > same DRM device node, and this is still true today with Weston. DRM > leases is a new kernel feature that would allow one compositor to > "lease" some display resources to another compositor instance, but > the > Weston support for giving out leases is only coming, and Weston > running > on a lease development has not started yet AFAIK.
Some attempts have been posted albeit they haven't got too much review, and will have to be adapted due to clone changes. https://lists.freedesktop.org/archives/wayland-devel/2018-February/0369 47.html > > If your system has multiple display devices (DRM card device nodes), > then it should be possible to run a Weston instance on each > simultaneously, though I'm not sure it has been tested. > > Different Weston instances are naturally independent from each other, > but the outputs inside a single instance are all naturally part of > the > same extended desktop without isolation between the outputs. It is > possible to write code to isolate outputs at the window manager > level, > but I'm not sure it would be enough for a nice user experience. Hence > for independent seats, I would recommed separate Weston instances. > > If your aim is to use a single computer to drive several physical > seats > (monitors, input devices), then if you have a DRM card device node > for > each seat it should be mostly a configuration issue to get that > running. If you need to share the same DRM card node between several > physical seats, then you would need a single host compositor and > guest > compositors for each seat. This could use DRM leases, fullscreen- > shell > extension, or normal fullscreen windows in the host compositor, but I > believe they would all require some development effort. > > > c) Extended/Tiled mode for us means - Multiple monitors connected > > to > > form a larger display (e.g. Video wall use case), just wanted to > > confirm can this be achieved with a single compositor instance? > > Theoretically yes, in practice the current state of Weston might fall > a > little short. > > The extended mode is the only mode Weston does at the moment, so > that's > good. Where it falls short are output timings (we have nothing to > actually synchronize the output refresh cycles, so you can have > timing > differences up to the longest refresh period) and layout > configuration, > as I mentioned before. I do think that developing Weston to implement > these lacking features would be welcome. Synchronizing outputs will > need also kernel driver and API support, mind. > > > Thanks, > pq > > > > -----Original Message----- > > From: Pekka Paalanen [mailto:ppaala...@gmail.com] > > Sent: 17 May 2018 17:48 > > To: Sandeep Chandak <ba.sand...@tataelxsi.co.in> > > Cc: wayland-devel@lists.freedesktop.org > > Subject: Re: Positioning and Multi display support for Weston > > Wayland > > > > On Wed, 16 May 2018 06:41:08 +0000 > > Sandeep Chandak <ba.sand...@tataelxsi.co.in> wrote: > > > > > Hi, > > > > > > We are using Weston Wayland based compositing for our solution, > > > though we are able to render image, video text etc. > > > > > > We are using x11 backend along with desktop shell to build the > > > solution which requires rendering of multiple media contents > > > (image, videos etc) together. We are using following versions of > > > packages > > > > Hi, > > > > I presume the x11-backend is only for development purposes and the > > final product will run on DRM-backend instead. > > > > > > > > a) Weston - version 5.0 > > > > > > b) Wayland - version 1.15.0 > > > > > > c) Ubuntu 16.04 > > > > > > d) Hardware - Intel i5 processors > > > > > > e) Cairo - 1.14 with EGL/OpenGL ES enabled > > > > > > We have below queries for which we need some inputs > > > > > > > > > a) Positioning of windows - We would like to position > > > windows > > > to a specific x,y location. However, we see that Weston positions > > > it at a random location. We would like to confirm if positioning > > > of > > > windows to specific location is supported by Weston. > > > > No, you cannot position windows from the application into specific > > x,y coordinates chosen by the application. There are a couple of > > design approaches to achieve the positioning you want: > > > > What I would personally recommend is to modify the window manager > > to > > position your windows appropriately. You may need to write a new > > protocol extension so that the application can tell the special > > role > > of the window to the compositor, so that the compositor can place > > it > > correctly in the space it happens to have available. > > > > You could also write a protocol extension to allow explicit > > positioning of windows from applications, but that will have the > > problem that any single application will be completely unaware of > > any > > other applications' windows or desktop elements. Explicit > > positioning > > in applications may seem like an easy solution at first, but it > > really only works in extremely narrow use cases. I consider it as a > > workaround, not a solution. > > > > However, depending on your use case, there might be much more > > straightforward solutions. > > > > > > > > b) Multi display Support - We need to support following use > > > cases and would like to confirm if this is currently supported > > > by > > > Weston? > > > > > > * Cloned display (same content on multiple screens) > > > > Shared-CRTC clone mode is available in Weston upstream master > > branch, > > but the final patch to allow it to be configured is not yet > > reviewed: > > https://emea01.safelinks.protection.outlook.com/?url=https%3A%2F%2F > > patchwork.freedesktop.org%2Fpatch%2F217906%2F&data=02%7C01%7Cmarius > > -cristian.vlad%40nxp.com%7Cfa1425f456fb4107c98e08d5bca75666%7C686ea > > 1d3bc2b4c6fa92cd99c5c301635%7C0%7C0%7C636622349257323713&sdata=oGyj > > 1s15%2FZUtR0yS2FqdiPVrIJQVcx0ioyBz0fZrpAA%3D&reserved=0 > > > > Note, that shared-CRTC clone mode requires hardware support that > > recent Intel display controllers do not have as far as I know. > > > > Independent-CRTC clone mode is currently not supported due to > > design > > problems with damage tracking in libweston. Even if you could > > configure two weston_outputs to show the same area of the desktop, > > there would likely be problems with outdated contents on screen. > > This > > would be good to fix, but so far has not been a priority for > > anyone. > > > > > > > > * Extended display/Tiled (Multiple displays are combined to > > > form a single display) > > > > Weston supports extended display, but the output layout > > configuration > > is essentially missing. Currently you can only realize a single row > > of outputs in an implicit order. This too would be nice to fix. > > > > There is no synchronization implemented as that would require > > kernel > > interfaces and hardware support, either gen-lock or variable > > refresh > > rate. > > > > > > > > * Different (Different displays rendering different > > > content) > > > > How does this differ from Extended display? > > > > > > > > * Portrait/Landscape orientation (this we believe is > > > supported > > > via configuring Weston.ini) > > > > Yes. > > > > > > Thanks, > > pq > > _______________________________________________ > > wayland-devel mailing list > > wayland-devel@lists.freedesktop.org > > https://emea01.safelinks.protection.outlook.com/?url=https%3A%2F%2F > > lists.freedesktop.org%2Fmailman%2Flistinfo%2Fwayland- > > devel&data=02%7C01%7Cmarius- > > cristian.vlad%40nxp.com%7Cfa1425f456fb4107c98e08d5bca75666%7C686ea1 > > d3bc2b4c6fa92cd99c5c301635%7C0%7C0%7C636622349257323713&sdata=LBfV5 > > d7GBtqbiRI%2FYtYvepBh9m4TN2OVbFGgkPwlB0M%3D&reserved=0 > > _______________________________________________ > wayland-devel mailing list > wayland-devel@lists.freedesktop.org > https://emea01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fli > sts.freedesktop.org%2Fmailman%2Flistinfo%2Fwayland- > devel&data=02%7C01%7Cmarius- > cristian.vlad%40nxp.com%7Cfa1425f456fb4107c98e08d5bca75666%7C686ea1d3 > bc2b4c6fa92cd99c5c301635%7C0%7C0%7C636622349257333721&sdata=1NRxTyB5f > FU84UH%2B3XAwVGuj6zWp2ADThJUCXcSkFDo%3D&reserved=0 _______________________________________________ wayland-devel mailing list wayland-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/wayland-devel