drm/i915: Use our own workqueue to avoid wedging the system along with the GPU.

Signed-off-by: Eric Anholt <eric@anholt.net>
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 5bf4203..140bee1 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -1570,7 +1570,7 @@
 	}
 
 	if (was_empty && !dev_priv->mm.suspended)
-		schedule_delayed_work(&dev_priv->mm.retire_work, HZ);
+		queue_delayed_work(dev_priv->wq, &dev_priv->mm.retire_work, HZ);
 	return seqno;
 }
 
@@ -1719,7 +1719,7 @@
 	i915_gem_retire_requests(dev);
 	if (!dev_priv->mm.suspended &&
 	    !list_empty(&dev_priv->mm.request_list))
-		schedule_delayed_work(&dev_priv->mm.retire_work, HZ);
+		queue_delayed_work(dev_priv->wq, &dev_priv->mm.retire_work, HZ);
 	mutex_unlock(&dev->struct_mutex);
 }