Otherwise, if we lost the race, the pipestat bit would be set without being
reflected in IIR, and we would never clear the pipestat bit so the pipe
event would never be generated again, and all vblank waits would time out.
Signed-off-by: NEric Anholt <eric@anholt.net>
Acked-by: NKeith Packard <keithp@keithp.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>