https://bugzilla.kernel.org/show_bug.cgi?id=113861
--- Comment #8 from centuryplague@yandex.com --- (In reply to Michel Dänzer from comment #6)
Does radeon.runpm=0 on the kernel command line avoid the problem?
Yes, I tried moments ago and radeon.runpm=0 allows x to start! Had no tried that.
(In reply to Alex Deucher from comment #7)
Probably the same issue as reported here: https://lists.freedesktop.org/archives/dri-devel/2016-March/102379.html Does reverting dbb17a21c131eca94eb31136eee9a7fe5aff00d9 fix it?
That sounds exactly the same. I can't compile tonight and may not get it to work for a couple days (non standard setup). I'll mention to the other guy.