https://bugs.freedesktop.org/show_bug.cgi?id=83505
--- Comment #5 from Alex Deucher agd5f@yahoo.com --- (In reply to comment #3)
Same issue on another machine with ASRock K7S41GX motherboard and Radeon RV280 with 3.14 Kernel from Debian Wheezy-Backport.
RV280 does not support dpm so this parameter is useless for this asic.