https://bugs.freedesktop.org/show_bug.cgi?id=65963
--- Comment #6 from Damian Nowak nowaker@geozone.pl --- Not an LLVM issue, just hung with a downgraded LLVM 3.4. So the problem has to be in mesa. I will now try to find the latest working version of mesa. Starting from 10.1.4 for now.
Regarding recent two hangs. One was total, and I had to hard reset. The other, that happened 10 minutes after reboot, wasn't that bad. After `pkill -9 kdm` from SSH I was able to CTRL+ALT+F1. The error was "EQ overflow" again of course, but has got a different stacktrace just a little bit.
However, X wasn't able to start again. I had to reboot.
[ 480.971] (EE) RADEON(0): [drm] Failed to open DRM device for pci:0000:01:00.0: No such file or directory