drm/atomic-helper: Export framebuffer_changed()

The Rockchip driver cannot use drm_atomic_helper_wait_for_vblanks()
because it has hardware counters for neither vblanks nor scanlines.

In order to simplify re-implementing the functionality for this driver,
export the framebuffer_changed() helper so it can be reused.

Signed-off-by: John Keeping <john@metanate.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>

1 files changed, 4 insertions, 0 deletions

diff --git a/include/drm/drm_atomic_helper.h b/include/drm/drm_atomic_helper.h
index 89d008dc08e2..fe5efada9d68 100644
--- a/include/drm/drm_atomic_helper.h
+++ b/include/drm/drm_atomic_helper.h
@@ -42,6 +42,10 @@ int drm_atomic_helper_commit(struct drm_device *dev,
                              struct drm_atomic_state *state,
                              bool async);
 
+bool drm_atomic_helper_framebuffer_changed(struct drm_device *dev,
+                                           struct drm_atomic_state *old_state,
+                                           struct drm_crtc *crtc);
+
 void drm_atomic_helper_wait_for_vblanks(struct drm_device *dev,
                                         struct drm_atomic_state *old_state);