Comment 49 for bug 1158689

You really need to figure out how to do things inside the git tree and not do some sort of crazy export. That will speed things up by an order of magnitude.

To get the list of nouveau changes between 3.4 and 3.5:

git log v3.4..v3.5 -- drivers/gpu/drm/nouveau

To do a bisect between 3.4 and 3.5, same instructions as before, but use v3.5 as the bad tag and v3.4 as the good tag.

Looking through the list of changes, c420b2dc8dc3cdd507214f4df5c5f96f08812cbe stands out as a big one, as does 5e120f6e4b3f35b741c5445dfc755f50128c3c44 which actually introduces the nv84+ fence mechanism.

This had actually previously occurred to me, but a quick thing to try out is to switch to the nv17 fence and see what happens. You can do this by editing the logic in drivers/gpu/drm/nouveau/nouveau_drm.c:nouveau_accel_init, and just replace nv84_fence_create with nv50_fence_create (which will make a nv50+ appropriate nv17 fence impl).