KDE KWin Preparing Preliminary Support For Running HDR Games

[oiaohm]

Thanks a lot for the provided context. I don't know if Nvidia wants to tackle that problem though, but considering they work on bringing explicit sync support to X, there is a slight chance that they finish up the needed work, or that someone else steps up.

Lets be real here. Nvidia work on explicit sync now is because xwayland will not allow them to load their own driver code into the process to emulate implicit sync. nvidia module inside X11 server emulates implicit sync. Having to implement implicit sync emulation is required to implicit CUDA and Opengl to specification.

https://on-demand.gputechconf.com/gtc-eu/2017/presentation/53023-debalina-bhattacharjee-eglstreams-interoperability-for-camera-cuda-and-opengl.pdf

Nvidia has no sign at the moment that they are going to work on X11 bare for new features. Also the history of nvidia working on X11 bare metal is them making proposals than getting some other developer to code the stuff by having their driver malfunction without it. This stunt has not been working with Xwayland.

Functional implicit sync in default opengl means means that opengl/opencl combination could work like the CUDA/Opengl combination. Nvidia demand for explicit sync is really nothing more than smoke and mirrors. Nvidia wants implicit sync to only work when it suits them so preventing competition.

[Quackdoc]

So unless someone like Nvidia takes up the maintainer ship of bare metal X11 server and gets the changes for HDR support into the X11 protocol the steam HDR games are not going to work with bare metal X11 server because the X11 protocol does not in fact support displaying mixed color mode.

I wonder how much of this can be shimmed by using nested compositors for mixed color mode.

[oiaohm]

I wonder how much of this can be shimmed by using nested compositors for mixed color mode.

This is when you straight up notice you are cursed location due to Nvidia.
xnest and xephyr with Nvidia don't support hardware graphical acceleration. Those working with wine have got to know that you with Nvidia you drop back to software rendering when you use any form of nesting.

The only hope you have that nested compositors will work with Nvidia hardware is that Wayland development will force them into it. Eglstreams is a very strict demonstration how much Nvidia does not want to-do this with how they attempted to sell the idea that process separation and stability was not important feature .

Yes nested solution is a option with AMD and Intel.

The broken xephyr support also equaled not being able to support newer X11 protocol features on older X11 bare metal server when you had Nvidia GPU.

Yes so much for the concept that Nvidia drivers have been fine right.

This is the problem hope for nested compositor that support all GPUs equals Wayland solution because Nvidia need to be dragged kicking and screaming into implementing support for this.

The ball like it or not for HDR support under bare metal X11 is in the Nvidia court and Nvidia is not interested in return it. Yes either X11 protocol extension by Nvidia that works and gets merged or Nvidia making X11 nesting in fact work with their hardware and getting those changes merged.

Its so likely that Xwayland on gamescope on bare metal X11 server will work before Xepher with hardware accelerated graphics works with Nvidia and it possible Xepher with Nvidia never gets hardware acceleration.

The hard reality is HDR like it or not if nothing changes on Linux is only going to come into functional usefulness any time soon for those who are using Wayland based solutions.