https://bugs.freedesktop.org/show_bug.cgi?id=109246
--- Comment #12 from Michel Dänzer michel@daenzer.net --- (In reply to tme from comment #9)
Setting amdgpu.dc=1 on 4.15.18 and 4.16.18 does not reproduce the problem. It does, however, reproduce on 4.17.19.
Can you bisect between 4.16.18 and 4.17.19?
(I see some HPD filtering related changes between them, Nicholas / Harry maybe you can take a look if anything jumps out?)