Alex, thanks for your thorough testing. Sad to hear that those patches don't do
anything :(

3.7.10 is not in between 3.7 and 3.8, it is on the "stable" release branch. But
it's good to know that it works fine. (And you should definitely stay on 3.7.10
vs 3.7 -- there were a couple of annoying bugs fixed in there, both nouveau-
and security-related.)

I'm afraid it might be bisect time -- if there are more differences, I don't
see them. Knowing the exact commit may be able to refocus things. However this
is not nearly as painful as you might think. I think it makes most sense to
only bisect in drivers/gpu/drm/nouveau. Here's a basic guide:
https://www.kernel.org/pub/software/scm/git/docs/git-bisect.html (you'll
obviously need a linux git checkout, as well as the git tool).

You'll want to do something like

git bisect start v3.8 v3.7 -- drivers/gpu/drm/nouveau

This should start you off (there will be ~7 kernel compiles, so really not that
bad). Then you mark the kernels as good/bad and proceed. Please provide the
full bisection log when you're done.