https://bugs.freedesktop.org/show_bug.cgi?id=99710
--- Comment #11 from garththeisen@hotmail.com --- (In reply to Sandeep from comment #10)
I tried the 4.11.0 kernel since I suspected that the buggy change might also be present in the point releases, but that also caused a hang whenplaying Left 4 Dead 2. Will try older kernels and see if they work correctly (which they should since this hang definitely wasn't present 2 months ago).
Yep, Sandeep, I think this behaviour is tied to DPM issues highlighted in Bug 91880 : 'Radeonsi on Grenada cards (r9 390) exceptionally unstable and poorly performing'. I suggest following, reading, and commenting on that issue.