[Mesa-dev] Concern about proposed patch "egl/android: remove HAL_PIXEL_FORMAT_BGRA_8888 support"

[Ilia Mirkin]

Without commenting on Android-specific issues, of which I'm blissfully
unaware, all NVIDIA G80+ (i.e. DX10+) GPUs support both RGBA8 and
BGRA8 for display and color rendering:

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/gpu/drm/nouveau/dispnv50/base507c.c#n206

However the nouveau gallium driver only sets the BGRA variant as
PIPE_BIND_DISPLAY_TARGET since supporting both RGBA and BGRA caused
issues, as I recall. And the legacy AddFB() call defaults to BGRA8, so
that has to remain working. I think this may affect which configs are
made available.

[Also note that only Kepler+ NVIDIA GPUs support RGB10 ordering, so we
prefer BGR10 everywhere to make life easier. But I think that's out of
scope for this discussion.]

Cheers,

  -ilia

On Thu, Aug 15, 2019 at 3:49 PM Mauro Rossi <issor.oruam at gmail.com> wrote:
>
> Hi,
>
> sorry if I'm communicating in dedicated thread, but I don't know how to reply to existing one.
>
> The proposed patch is based on the wrong assumption that all drivers used with Android have RGBA_8888, which is not correct, for example nouveau does not support RGBA on primary planes, infact we have a fallback to simpler EGL query in android-x86 and we use BGRA_8888 (pixel format = 5)
>
> If patch does not solve a specific problem and it will cause a regression at least in nouveau, it is recommended to abandon the patch
>
> Thanks for your feedbacks
>
> Mauro
> _______________________________________________
> mesa-dev mailing list
> mesa-dev at lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/mesa-dev