Comment # 8 on bug 67276 from Joshua Cov.

(In reply to comment #7)
> (In reply to comment #5)
> > 
> > Can this commit be the culprit of the problem?
> 
> Yes, it could be.  As I said, it was a fix for the new reservation code
> which it sounds like you didn't pull in.

I'll take a look later if I can backport the reservation code back to 3.10 (if
it's worth). I see some commits (280cf2118675..8f262540e61c7, or especially
ecff665f5e in git://people.freedesktop.org/~airlied/linux drm-next) but I think
it's easier to just remove commit 1b6e5fd5f4fc152064f4f71cea0bcfeb49e29b8b from
your patchset and see if the problem still occurs in the next 3-4 days.