Comment # 7 on bug 107560 from Michel Dänzer

(In reply to Jorge Blasio from comment #6)
> I've an almost identical issue, however I'm using HDMI and I can get back to
> the graphical session by switching to VT1 and then back to VT2.

Sounds like bug 107519, fixed in current xf86-video-amdgpu Git master.