You will also need to copy the 6 files that are prefixed with "MULLINS" from http://people.freedesktop.org/~agd5f/radeon_ucode/ to /lib/firmware/radeon and probably reboot afterwards.
You will also need to copy the 6 files that are prefixed with "MULLINS" from http:// people. freedesktop. org/~agd5f/ radeon_ ucode/ to /lib/firmware/ radeon and probably reboot afterwards.