drm/i915: Avoid early timeout during AUX transfers

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>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
CC: drm-intel-fixes@lists.freedesktop.org
Link: http://patchwork.freedesktop.org/patch/msgid/1467110253-16046-5-git-send-email-imre.deak@intel.com
(cherry picked from commit 713a6b668932213247b394559bc229cd0fec2777)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>

diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index 49c582d..40745e3 100644 (file)
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -663,7 +663,7 @@ 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);