https://bugs.freedesktop.org/show_bug.cgi?id=83792
--- Comment #5 from Tim Nelson wayland@wayland.id.au --- Just reporting back; blacklisting radeon as Alex specifies allows the machine to boot. "modprobe radeon" after boot makes it die. Unfortunately I only had a little time to put into it, so that's all my results at the moment, but I hope to put more time into it in the next couple of days.