[PATCH] drm/amdgpu: Ensure that the modifier requested is supported by plane.

[Mark Yacoub]

On Wed, Mar 24, 2021 at 11:25 AM Daniel Stone <daniel at fooishbar.org> wrote:
>
> Hi Mark,
>
> On Wed, 24 Mar 2021 at 14:58, Mark Yacoub <markyacoub at chromium.org> wrote:
>>
>> So you mean it would make more sense to be more explicit in handling
>> DRM_FORMAT_MOD_INVALID as an incoming modifier (which will, just like
>> DRM_FORMAT_MOD_LINEAR, will return true in
>> dm_plane_format_mod_supported)?
>
>
> That's correct. Not passing any modifiers is the same as explicitly passing INVALID, both of which mean 'the driver will figure it out somehow'; that driver-specific determination is not the same as explicit LINEAR.
>
> (I cannot regret enough that INVALID is not 0.)
I feel you. When I tested it on a board that doesn't support
modifiers, the modifier value was Zero. when I checked it, it was
basically LINEAR.
I'll amend my changes to explicitly handle INVALID.
>
> Cheers,
> Daniel