[PATCH 4/4] drm/i915: Avoid early timeout during AUX transfers

Imre Deak
2016-06-28T10:37:42Z

Since wait_for_atomic doesn't re-check the wait-for condition after
expiry of the timeout it can fail when called from non-atomic context
even if the condition is set correctly before the expiry. Fix this by
using the non-atomic wait_for instead.

Due to the relatively long 10ms timeout, probably this didn't cause any
real problems, but fix it in any case for consistency.

Fixes: 0351b93992aa ("drm/i915: Do not lie about atomic timeout granularity")
CC: Chris Wilson <chris@chris-wilson.co.uk>
CC: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
---
drivers/gpu/drm/i915/intel_dp.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index c3742a0..6d586b7 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -727,7 +727,7 @@ intel_dp_aux_wait_done(struct intel_dp *intel_dp, bool has_aux_irq)
done = wait_event_timeout(dev_priv->gmbus_wait_queue, C,
msecs_to_jiffies_timeout(10));
else
- done = wait_for_atomic(C, 10) == 0;
+ done = wait_for(C, 10) == 0;
if (!done)
DRM_ERROR("dp aux hw did not signal timeout (has irq: %i)!\n",
has_aux_irq);
--
2.5.0