[PATCH 1/2] drm/amdgpu: Enable scatter gather display support

[Michel Dänzer]

On 2018-03-07 10:47 AM, Christian König wrote:
> 
> See when I tested this the DDX and Mesa where unmodified, so both still
> assumed VRAM as placement for scanout BOs, but the kernel forced scanout
> BOs into GTT for testing.
> 
> So what happened was that on scanout we moved the VRAM BO to GTT and
> after unpinning it on the first command submission which used the BO we
> moved it back to VRAM again.
> 
> So as long as we don't want a severe performance penalty when you
> combine old userspace with new kernel using a kernel parameter to force
> scanout from GTT is not possible.

That means we either need to come up with a different workaround for
hardware issues transitioning between scanout from VRAM and GTT, or we
can't scan out from GTT in that case.


-- 
Earthling Michel Dänzer               |               http://www.amd.com
Libre software enthusiast             |             Mesa and X developer