tree 8c718b415d6af80ab838490f8b09e8710b5e109f
parent 6ee3b5a12740eddc5a76e130b6cc7cc64468d1f7
author Chris Wilson <chris@chris-wilson.co.uk> 1300966623 +0000
committer Chris Wilson <chris@chris-wilson.co.uk> 1301560272 +0100

drm/i915: Busy-spin wait_for condition in atomic contexts

During modesetting, we need to wait for the hardware to report
readiness by polling the registers. Normally, we call msleep() between
reads, because some state changes may take a whole vblank or more
to complete. However during a panic, we are in an atomic context and
cannot sleep. Instead, busy spin polling the termination condition.

References: https://bugzilla.kernel.org/show_bug.cgi?id=31772
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Keith Packard <keithp@keithp.com>
Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>