https://bugs.freedesktop.org/show_bug.cgi?id=66963
--- Comment #156 from Sergey orbitgray@ukr.net --- (In reply to comment #154)
With the people getting hangs and GPU resets, with DPM on: are you using KDE or GNOME?
I've noticed problems with KDE and the rv6xx and sometimes doing a soft power cycle of laptop will result in the display hanging when it attempts to set up kernel mode setting (KMS).
I use Fluxbox and still see hand issue. Boot time hang is not likely to be related to DE, since it happens during KMS.
Sometimes it hangs during ordinary work (video playing etc.), then it might recover but usually it don't. And you can see in dmesg that GPU was stuck.