(In reply to comment #3)
> Does this patch set help:
> http://lists.freedesktop.org/archives/dri-devel/2014-April/057512.html

Which tree does this apply to?

I applied it to 3.14 but the third patch was rejected and the resulting kernel
crashed on any attempt to open a GL window.

On Linus' master the third patch was rejected as well but at least I was able
to enable desktop effects and start mplayer. Still got problems with the screen
suddenly going blank and the system freezing (had those before as well but much
less frequently, maybe due to lower GL usage).