d7b9935a34
During system suspend, the "wait for ring buffer to empty" loop would always time out after three seconds, because the faster cached ring buffer head read would always return zero. Force the slow-and-careful PIO read on all but the first iterations of the loop to fix it. This also removes the unused (and useless) 'actual_head' variable that tried to approximate doing this, but did it incorrectly. Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Rafael J. Wysocki <rjw@sisk.pl> Cc: Jesse Barnes <jbarnes@virtuousgeek.org> Cc: Dave Airlie <airlied@linux.ie> Cc: DRI mailing list <dri-devel@lists.freedesktop.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>