https://bugzilla.kernel.org/show_bug.cgi?id=69301
--- Comment #17 from Michel Dänzer michel@daenzer.net --- (In reply to Jan Outhuis from comment #15)
I've also done a Git bisect, but the outcome of that doesn't seem to make any sense: [...] So I guess I'll have to do that all over again. I'm not that familiar yet with doing bisections.
Did you explicitly set radeon.dpm=1 for the bisection? DPM wasn't enabled by default in 3.12.