drm/i915: Wait for the bo if a display flip is pipelined on the other ring

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index e773333..b57ce03 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -2926,7 +2926,7 @@
 	i915_gem_object_flush_gpu_write_domain(obj);
 
 	/* Currently, we are always called from an non-interruptible context. */
-	if (!pipelined) {
+	if (pipelined != obj->ring) {
 		ret = i915_gem_object_wait_rendering(obj, false);
 		if (ret)
 			return ret;