Wayland information for r515 beta release

There are several areas in which the R515 NVIDIA driver lacks feature parity between X11 and Wayland. These may be due to limitations of the driver itself, the Wayland protocol, or the specific Wayland compositor in use. Over time this list is expected to shorten as missing functionality is implemented both in the driver and in upstream components, but the following captures the situation as of the release of this driver version. Note that this list assumes a compositor with reasonably complete support for graphics-related Wayland protocol extensions.

NVIDIA DRIVER LIMITATIONS

  • The VDPAU library, used for hardware accelerated video decoding and presentation, does not have native Wayland support and does not work with Xwayland.

  • The NvFBC desktop capture library does not have native Wayland support and does not work with Xwayland.

  • Variable display refresh rate capabilities such as G-Sync are not reported by nvidia-drm module, therefore this functionality is not available on Wayland.

  • Virtual reality displays, such as the SteamVR platform, require support for DRM display leasing which does not currently work.

  • EGL_EXT_platform_x11 is not supported with Xwayland.

  • The nvidia-drm module does not support the GAMMA_LUT, DEGAMMA_LUT, CTM, COLOR_ENCODING, or COLOR_RANGE connector properties, which may impact some compositor features related to color correction.

  • The nvidia-settings configuration tool has limited functionality on Wayland.

  • Front-buffer rendering in GLX does not work with Xwayland.

WAYLAND PROTOCOL OR COMPOSITOR LIMITATIONS

  • The following workstation features are not supported by any Wayland compositors or the Wayland protocol. They will also likely require new EGL extensions or other means to expose the related hardware functionality.

    • SLI and Multi-GPU Mosaic

    • Frame Lock and Genlock

    • Swap Groups

    • Advanced display pipeline features including warp and blend, pixel shift, and emulated YUV420.

    • Stereo rendering

  • There is no established public API through which Wayland compositors can power off video memory via RTD3.

  • Xwayland does not provide a suitable mechanism for our driver to synchronize application rendering with presentation, which can cause visual corruption in some circumstances.

  • Display multiplexers (muxes) are typically used in laptops with both integrated and discrete GPUs to provide a direct connection between the discrete GPU and the built-in display (internal mux) or an external display (external mux). On X11, the display mux can be automatically switched when a full-screen application is running on the discrete GPU, enabling enhanced display features and improved performance, but no Wayland compositors currently support this functionality.

  • Indirect GLX does not work with Xwayland because the Glamor rendering engine is not compatible with our EGL implementation.

  • Hardware overlays cannot be used by GLX applications with Xwayland.

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