[REGRESSION, i915]: Periodic stalls with 2.6.36-rc2

[Chris Wilson]

On Tue, 24 Aug 2010 08:57:41 +0100, Sitsofe Wheeler <sitsofe at yahoo.com> wrote:
> The stalls became a bit better with the patch but there were still very
> small pauses but the tearing with more recent X bits is definitely still
> there. Additionally videos in totem would play as a tiny one pixel high
> row about a quarter of the screen across at the top left of the screen.
> It also seems that X has started having trouble refreshing itself so
> sometimes new windows are invisible (especially with compiz).

Ok, I'm a little happier that the hangcheck could be just another symptom
of the problem...

I think it is safe to assume that the bug is in i915, so restricting the
bisect to just drm seems plausible:

git bisect start drivers/gpu/drm
git bisect good 2.6.36-rc1
git bisect bad 2.6.36-rc2

And yes, it does apppear that the false detection rate for TV has changed.
The suspicion is that the change to intel_wait_for_vblank() is actually
causing issues here.

-- 
Chris Wilson, Intel Open Source Technology Centre