drm/atomic: export drm_atomic_helper_wait_for_fences()

Signed-off-by: Rob Clark <robdclark@gmail.com>
Reviewed-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1458342904-23326-3-git-send-email-robdclark@gmail.com
diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c
index 9135111..00afa9f 100644
--- a/drivers/gpu/drm/drm_atomic_helper.c
+++ b/drivers/gpu/drm/drm_atomic_helper.c
@@ -984,7 +984,17 @@
 }
 EXPORT_SYMBOL(drm_atomic_helper_commit_modeset_enables);
 
-static void wait_for_fences(struct drm_device *dev,
+/**
+ * drm_atomic_helper_wait_for_fences - wait for fences stashed in plane state
+ * @dev: DRM device
+ * @state: atomic state object with old state structures
+ *
+ * For implicit sync, driver should fish the exclusive fence out from the
+ * incoming fb's and stash it in the drm_plane_state.  This is called after
+ * drm_atomic_helper_swap_state() so it uses the current plane state (and
+ * just uses the atomic state to find the changed planes)
+ */
+void drm_atomic_helper_wait_for_fences(struct drm_device *dev,
 			    struct drm_atomic_state *state)
 {
 	struct drm_plane *plane;
@@ -1002,6 +1012,7 @@
 		plane->state->fence = NULL;
 	}
 }
+EXPORT_SYMBOL(drm_atomic_helper_wait_for_fences);
 
 /**
  * drm_atomic_helper_framebuffer_changed - check if framebuffer has changed
@@ -1163,7 +1174,7 @@
 	 * current layout.
 	 */
 
-	wait_for_fences(dev, state);
+	drm_atomic_helper_wait_for_fences(dev, state);
 
 	drm_atomic_helper_commit_modeset_disables(dev, state);