(In reply to DanglingPointerException from comment #36)
> [drm:gmc_v7_0_sw_init [amdgpu]] *ERROR* Failed to load mc firmware!
> [drm:amdgpu_device_init.cold.31 [amdgpu]] *ERROR* sw_init of IP block
> <gmc_v7_0> failed -2
> [drm] amdgpu: finishing device.

The driver is not able to find the firmware when it loads.  Please make sure
the initrd contains the firmware if you are using one.  Please note that when
using amdgpu, the firmware must be in /lib/firmware/amdgpu rather than
/lib/firmware/radeon.