Re: [PATCH v16 3/7] drm/vkms: Drop YUV formats TODO

Louis Chauvet
2025-01-31T13:02:25Z

On 31/01/25 - 09:40, José Expósito wrote:
> Hi Louis,
>
> Thanks a lot for the patches.
>
> I'm not well versed in YUV color formats, so I did my best reading the kernel
> documentation before reviewing this series... But I'll most likely ask some
> basic/dump questions.
>
> > From: Arthur Grillo <arthurgrillo@riseup.net>
> >
> > VKMS has support for YUV formats now. Remove the task from the TODO
> > list.
> >
> > Signed-off-by: Arthur Grillo <arthurgrillo@riseup.net>
> > Signed-off-by: Louis Chauvet <louis.chauvet@bootlin.com>
> > ---
> > Documentation/gpu/vkms.rst | 3 +--
> > 1 file changed, 1 insertion(+), 2 deletions(-)
> >
> > diff --git a/Documentation/gpu/vkms.rst b/Documentation/gpu/vkms.rst
> > index ba04ac7c2167a9d484c54c69a09a2fb8f2d9c0aa..13b866c3617cd44043406252d3caa912c931772f 100644
> > --- a/Documentation/gpu/vkms.rst
> > +++ b/Documentation/gpu/vkms.rst
> > @@ -122,8 +122,7 @@ There's lots of plane features we could add support for:
> >
> > - Scaling.
> >
> > -- Additional buffer formats, especially YUV formats for video like NV12.
> > - Low/high bpp RGB formats would also be interesting.
> > +- Additional buffer formats. Low/high bpp RGB formats would be interesting.
>
> I see that you implemented support for 6 DRM_FORMAT_NV* formats, but
> DRM_FORMAT_NV15, DRM_FORMAT_NV20 and DRM_FORMAT_NV30 are not implemented.
>
> The same applies to DRM_FORMAT_Y210 or DRM_FORMAT_YUV410 among others.
>
> Could it be useful to implement all of them in the future? If so, should we add
> it to the ToDo list?

I don't think we need "all of them" (there are ≈100 + all the modifiers),
but definitly all the commonly used ones (I have some of the "common" one
ready here [1], I just wait for the YUV series to be accepted to avoid
conflicts).

> It might be a great task to get started in kernel development, as there are
> already similar examples and tests.

I don't think we need to specify which format are missing, the point
"Additionnal buffer formats. [...]" seems sufficient. If you think this is
relevant, I can add "Easy task" so beginners will find it easier?

[1]:https://lore.kernel.org/all/20241122-b4-new-color-formats-v3-0-23f7776197c9@bootlin.com/

> >
> > - Async updates (currently only possible on cursor plane using the legacy
> > cursor api).
> >