Make sure you've installed the updated rlc and uvd microcode and that it is available to the driver during boot (in your initrd, etc.). You can grab the latest ucode here: http://git.kernel.org/cgit/linux/kernel/git/firmware/linux-firmware.git or here: http://people.freedesktop.org/~agd5f/radeon_ucode/ You need BTC_rlc.bin and SUMO_uvd.bin for UVD on your chip.