drm/i915: Use synchronize_srcu_expedited() for resets

We impose upon ourselves a strict timeout for resets (to ensure forward
progress by use of a failsafe). Prefer to use the expedited
synchronisation function in this case to reduce the likelihood of a
spurious delay being treated as a deadlock.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190211135040.1234-2-chris@chris-wilson.co.ukReviewed-by: Mika Kuoppala <mika.kuoppala@intel.com>

drivers/gpu/drm/i915/i915_reset.c

@@ -1138,7 +1138,7 @@ static void i915_reset_device(struct drm_i915_private *i915,
 		intel_prepare_reset(i915);
 
 		/* Flush everyone using a resource about to be clobbered */
-		synchronize_srcu(&error->reset_backoff_srcu);
+		synchronize_srcu_expedited(&error->reset_backoff_srcu);
 
 		mutex_lock(&error->wedge_mutex);
 		i915_reset(i915, engine_mask, reason);