https://bugs.freedesktop.org/show_bug.cgi?id=100745
--- Comment #9 from Michel Dänzer michel@daenzer.net --- (In reply to Benjamin Bellec from comment #8)
I hit the same problem today after enabling amdgpu.dc=1 The screen doesn't light up at all if I boot the kernel with amdgpu.dc=1
AFAICT this report is about the non-DC code, please file your own report about the issue with DC.