https://bugs.freedesktop.org/show_bug.cgi?id=66963
--- Comment #178 from Thierry Vignaud thierry.vignaud@gmail.com --- (In reply to comment #172)
Is there any patch I can try against 3.12.6?
You can try disabling additional dpm features as per comment 94.
The patch seems to fix the issue. Booting with only the second half is not enough (the voltage_control & the gfx_clock_gating changes): I experienced black screen freeze on boot & disabled accel another time.