https://bugs.freedesktop.org/show_bug.cgi?id=91278
--- Comment #31 from Mathias Tillman master.homer@gmail.com --- Small update: I have been able to run it for a total of 7 hours (2 + 2 + 3) without a hang on the latest drm-next-4.4-wip. Tried the latest drm-fixes-4.3 and it hung after about 30 minutes, so I definitely think there's something in 4.4 that fixes it. I will do a bisect to see if I can figure out what, more exactly, is the fix.