https://bugs.freedesktop.org/show_bug.cgi?id=67187
--- Comment #9 from Harald Judt h.judt@gmx.at --- Ok, it happened a second time with a similar message; this seems to occur randomly and unpredictibly as always.
It is definitely a UVD-only issue. I've applied the radeon.no_uvd patch some guy wrote from here: http://pastebin.com/0mRGb224. Now with uvd turned off, 32 out of 32 attempts have been successful. No more hibernate problems, but UVD doesn't work of course.