https://bugs.freedesktop.org/show_bug.cgi?id=73788
--- Comment #10 from Alex Deucher agd5f@yahoo.com --- (In reply to comment #7)
(In reply to comment #4)
Is this a regression? Was dpm working previously at some point, if so when?
It worked fine in 3.11 and 3.12. The problem appeared somewhere during the development of 3.13. At those point vgaswitcheroo didn't work and I had to stick to older versions of the kernel.
Any chance you could bisect?