https://bugs.freedesktop.org/show_bug.cgi?id=109001
--- Comment #14 from Alex Deucher alexdeucher@gmail.com --- (In reply to Matt Garman from comment #13)
If I set amdgpu.dc=0 on my Ryzen 5 2400g, the system hard-locks as soon as X starts (i.e. hard reset via physical power button required).
There is no non-DC code for raven, so if you set dc=0, the display hardware is not initialized and no display features are exposed to the OS. The GPU basically a render only device in that case.