(In reply to comment #42)
> Created attachment 102992 [details] [review] [review]
> Possible fix v3.
> 
> Updated and largely simplified patch.
> 
> I'm running the third piglit test with it now and so far the system seems to
> be stable.

Been running (not piglit) for a few days now without crashing.

I see it and a couple more fixes are now in agd5f drm-fixes-3.16-wip, so will
try that.