https://bugs.freedesktop.org/show_bug.cgi?id=77677
--- Comment #32 from Garrett socalfisher@gmail.com --- "Only s/w decode works, UVD will produced trashed sound, so if that's the default for xbmc it could be something worth testing."
I tested software decode (disabling all vdpau) in Openelec (XBMC) and it works perfectly. Sound and picture is perfect. radeon.dpm=0 still. Let me know if you need anything else