[PATCH 2/2] amd/display: add cursor check for YUV primary plane

[Kazlauskas, Nicholas]

On 2021-02-19 12:29 p.m., Simon Ser wrote:
> On Friday, February 19th, 2021 at 6:22 PM, Kazlauskas, Nicholas <nicholas.kazlauskas at amd.com> wrote:
> 
>> We can support cursor plane, but only if we have an overlay plane
>> enabled that's using XRGB/ARGB.
>>
>> This is what we do on Chrome OS for video playback:
>>
>> Cursor Plane - ARGB8888
>> Overlay Plane - ARGB8888 Desktop/UI with cutout for video
>> Primary Plane - NV12 video
>>
>> So this new check would break this usecase. It needs to check that there
>> isn't an XRGB/ARGB plane at the top of the blending chain instead.
> 
> Oh, interesting. I'll adjust the patch.
> 
> Related: how does this affect scaling? Right now there is a check that makes
> sure the cursor plane scaling matches the primary plane's. Should we instead
> check that the cursor plane scaling matches the top-most XRGB/ARGB plane's?
> 

Can't really do scaling on the cursor plane itself. It scales with the 
underlying pipe driving it so it'll only be correct if it matches that.

Primary plane isn't the correct check here since we always use the 
topmost pipe in the blending chain to draw the cursor - in the example I 
gave it'd have to match the overlay plane's scaling, not the primary 
plane's.

Regards,
Nicholas Kazlauskas