[Intel-gfx] [PATCH 08/12] drm/i915: Add CCS capability for sprites

[Daniel Stone]

Hi Mika,

On 11 December 2017 at 11:11, Mika Kahola <mika.kahola at intel.com> wrote:
> On Thu, 2017-08-24 at 22:10 +0300, ville.syrjala at linux.intel.com wrote:
>> Allow sprites to scan out compressed framebuffers.
>>
>> Since different platforms have a different set of planes that
>> support CCS let's add a small helper to determine whether a
>> specific plane supports CCS or not. Currently that information
>> is spread around in many places, and not all the pieces of
>> code even agree with each other.
>>
>> In addition to allowing sprites to scan out compressed fbs,
>> the other fix here is that we stop rejecting them on pipe C
>> on CNL.
> Unfortunately, this patch didn't apply cleanly on top of the latest
> drm-tip. Overall, the patch looks good to me.

Did you manage to test this? When I tried, the DDB/watermark
allocation was too conservative for sprites, and never allowed enough
blocks to be able to use anything but linear or X-tiled on sprite
planes. The allocation was almost entirely taken up by the primary
plane, even if that itself was later set to linear or X-tiled.

I observed this on SKL with both 3200x1800 and 2560x1440 output sizes
(and primary plane sizes; no scaling), as well as APL with 1920x1080.

Cheers,
Daniel