https://bugs.freedesktop.org/show_bug.cgi?id=100058
--- Comment #2 from Edward O'Callaghan funfunctor@folklore1984.net --- OK so we narrowed the problem down to dpm.
(12:17:01 AM) mulander: yep, blacklisted radeon, amdgpu.dpm=0 and booted to X properly without a crash