https://bugs.freedesktop.org/show_bug.cgi?id=26891

--- Comment #57 from Austin Lund austin.lund@gmail.com --- I can confirm on my machine (macbookpro8,2) that v3.9-rc4 doesn't work and v3.9-rc3 does work.

Looking at the changes in drivers/gpu/drm/radeon between these two versions doesn't reveal anything that stands out as the culprit. Does anyone want to bisect?