[Intel-gfx] [PATCH v3] drm/i915: add immutable zpos plane properties

[Maarten Lankhorst]

Op 16-04-2019 om 15:20 schreef Ville Syrjälä:
> On Sat, Apr 13, 2019 at 11:13:27AM +0000, Simon Ser wrote:
>> From: Ville Syrjälä <ville.syrjala at linux.intel.com>
>>
>> This adds basic immutable support for the zpos property. The zpos increases
>> from bottom to top: primary, sprites, cursor.
> I was thinking a bit about how we might go about testing this.
>
> We probably want a basic test that just checks that if any
> plane has a zpos prop then all planes should have it.
This would be a good test for BAT.
> A functional test would stack the planes up in some way and
> compare against a software rendered reference. IIRC there was 
> a zpos test case floating around but that depended on alpha
> blending which we don't necessarily have.

But with semi-overlapping planes you would accomplish the same, without alpha dependency.

Something like this?

[BG]   [Sprite 1]    [Cursor]
  [Primary]   [Sprite 2]

Perhaps primary fullscreen to prevent issues with hw that doesn't support partial planes?

~Maarten