https://bugzilla.kernel.org/show_bug.cgi?id=103561
--- Comment #2 from Christoph Haag haagch.christoph@googlemail.com --- Created attachment 197781 --> https://bugzilla.kernel.org/attachment.cgi?id=197781&action=edit dmesg from 4.4-rc5
The call trace looks a bit different with linux 4.4-rc5.
There are also copious amounts of intel and btrfs issues, relevant radeon issue starts at line 2876.