https://bugs.freedesktop.org/show_bug.cgi?id=89256
--- Comment #3 from Michel Dänzer michel@daenzer.net --- Does it work better with current Mesa Git master? Specifically, this commit might help at least for the rendering artifacts:
http://cgit.freedesktop.org/mesa/mesa/commit/?id=7692704b144b2aa9a57767a4321...