Without this bit sets we get broken rendering and
lockups.

fglrx sets this bit.

Bugs that should be fixed by this patch :
https://bugs.freedesktop.org/show_bug.cgi?id=49792
https://bugzilla.kernel.org/show_bug.cgi?id=43207
https://bugs.freedesktop.org/show_bug.cgi?id=39282Signed-off-by: NJerome Glisse <jglisse@redhat.com>
Cc: stable@vger.kernel.org
Acked-by: NAlex Deucher <alexander.deucher@amd.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>