https://bugzilla.kernel.org/show_bug.cgi?id=91371
--- Comment #4 from Adis Hamzić adis@hamzadis.com --- (In reply to Michel Dänzer from comment #3)
(In reply to Adis Hamzić from comment #2)
Have the same issue since my kernel update yesterday.
What kernel version did you update from? Can you bisect?
According to the logs it's was 3.14.27, but I can't see anything in the diff that relates to radeon:
[2015-01-19 19:54] [ALPM] upgraded linux314 (3.14.27-1 -> 3.14.28-1)
I'll try to compile and install the old version and see if the issue is still there.