Comment # 2 on bug 68805 from kwahoo2@wp.pl

I have very similar config to your (3.11 + DPM + oibaf PPA) except HD 6670
instead 6310 - but vdpainfo output looks exactly the same. However, I cannot
confirm your issue. I am curious what is your
/sys/kernel/debug/dri/0/radeon_pm_info?

Mine:
sudo cat /sys/kernel/debug/dri/0/radeon_pm_info
uvd    vclk: 70000 dclk: 56000
power level 0    sclk: 80000 mclk: 100000 vddc: 1100 vddci: 0