Comment # 21 on bug 91202 from Guido Winkelmann

(In reply to Alex Deucher from comment #19)
> DAL is still being actively developed.  The latest branch is here:
> https://cgit.freedesktop.org/~agd5f/linux/log/?h=amd-staging-4.7

I just tried booting with that kernel (commit
f67b5d7409ed6f4c5b353932bcafffea995094be). It doesn't solve this issue for me.
(Branch drm-next-4.7-wip-dal did.)