The waits we do here are generally so short that sleeping is a bad
idea unless we have an IRQ to wake us up.  Improves regression test
performance from 18 minutes to 3.5 minutes on gen7, which is now
consistent with the previous generation.
Signed-off-by: NEric Anholt <eric@anholt.net>
Tested-by: NEugeni Dodonov <eugeni.dodonov@intel.com>
Reviewed-by: NEugeni Dodonov <eugeni.dodonov@intel.com>
Acked-by: NKenneth Graunke <kenneth@whitecape.org>
Signed-off-by: NKeith Packard <keithp@keithp.com>