While the pull request more than a week ago with the latest Radeon DPM changes believed this important dynamic power management code was in good shape, some more fixes were turned out to be needed. Alex Deucher sent in another round of Radeon DRM fixes for Linux 3.11 on Wednesday evening. This latest round takes care of hangs with DPM on some RV6xx series (Radeon HD 3000) graphics processors and separately fixes suspend-and-resume when using UVD video decoding.
Some of the individual changes this round include properly handling power management on GPU resets, adjusting thermal protection requirements for DPM, fixing spread spectrum setup, adjusting the power state properly for unified video decoding on Radeon HD 7000 (Souther Islands GPUs), and other UVD/DPM-related changes.
As Phoronix tests have shown, Radeon DPM is fantastic for lower temperatures and better power consumption while delivering better performance for some graphics cards with this open-source driver. Radeon DPM isn't enabled by default on Linux 3.11 but there's an easy how-to for following to enable dynamic power management / re-clocking.
More details on the latest batch of changes can be found via the mailing list pull request.