Updating to the latest drm-next-4.6-wip I could no longer log in to Gnome
through GDM, I just got a black screen after entering my passwd. startx +
gnome-session worked though.

However if I ran Unigine Heaven with Tessellation there, I saw I got the frames
in the wrong order sometimes. This doesn't happen otherwise.

Bisecting was easy and pointed to:
78d0e182b6c1f5336f6e8cbb197f403276dabc7f
drm/amdgpu: fix amdgpu_bo_pin_restricted VRAM placing v2

Reverting that commit on top of drm-next-4.6-wip also solved the problem.