Comment # 4 on bug 107045 from Michel Dänzer

(In reply to taijian from comment #3)
> Also, so far I was always able to at least boot up with dc=0 and have it
> working, but that seems to be over with 4.18 (does not
> get past gdm login screen without freezing...).

Can you bisect that? That might lead us to the real issue here.