Comment 11 for bug 41340

Does the machine hang completely, or just the screen and keyboard? Can you try to ssh in from another machine, before starting X with dri enabled? You might try running "sudo cat /proc/kmsg" in the ssh session to see if any error messages appear. You can also (before starting X) unload the savage and drm modules, and reload the drm module with "modprobe drm debug=1" which gives a lot of debug messages.