On 1/3/23 19:46, Rob Clark wrote:
drive-by thought/concern, what are the odds that there is some wayland compositor out there that creates an fb for every window surface, even if it later decides to composite on the GPU because the display does not support the format? It seems like there is a non-zero chance of breaking userspace..
As Simon pointed out, drivers like i915 and AMDGPU already reject IOCTLs with invalid parameters, as you can see on [1] and [2], so this patch would make the behavior more consistent between the drivers. That said, I don't believe that this patch would break userspace, as userspace already needs to handle with the existing drivers. [1] https://cgit.freedesktop.org/drm/drm-misc/tree/drivers/gpu/drm/i915/display/intel_fb.c#n1917 [2] https://cgit.freedesktop.org/drm/drm-misc/tree/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c#n1124 Best Regards, - Maíra Canal
BR, -R
