Re: [PATCH 5/7] drm/uAPI: Add "preferred color format" drm property as setting for userspace

[Andri Yngvason]

Hi,

mið., 10. jan. 2024 kl. 09:27 skrifaði Maxime Ripard <mripard@xxxxxxxxxx>:
> On Tue, Jan 09, 2024 at 06:11:02PM +0000, Andri Yngvason wrote:
> > From: Werner Sembach <wse@xxxxxxxxxxxxxxxxxxx>
> >
> > Add a new general drm property "preferred color format" which can be used
> > by userspace to tell the graphic drivers to which color format to use.
> >
> > Possible options are:
> >     - auto (default/current behaviour)
> >     - rgb
> >     - ycbcr444
> >     - ycbcr422 (not supported by both amdgpu and i915)
> >     - ycbcr420
> >
> > In theory the auto option should choose the best available option for the
> > current setup, but because of bad internal conversion some monitors look
> > better with rgb and some with ycbcr444.
>
> I looked at the patch and I couldn't find what is supposed to happen if
> you set it to something else than auto, and the driver can't match that.
> Are we supposed to fallback to the "auto" behaviour, or are we suppose
> to reject the mode entirely?
>
> The combination with the active output format property suggests the
> former, but we should document it explicitly.

It is also my understanding that it should fall back to the "auto"
behaviour. I will add this to the documentation.

Thanks,
Andri