https://bugzilla.kernel.org/show_bug.cgi?id=198745
--- Comment #21 from Kyle De'Vir (kyle.devir@mykolab.com) ---
I don't see any DC or other DRM change in the stable kernel between 4.15.5 and 4.15.6.
What about any of the other point releases? I tried without your patch, and amdgpu.dc=1 mysteriously just works... so strange that it just didn't before.
I don't understand what even happened, and that's even more frustrating than it not working... urgh. :/