drm/plane: Make ->atomic_update() mandatory

There is no use-case where it would be useful for drivers not to
implement this function and the transitional plane helpers already
require drivers to provide an implementation.

v2: add new requirement to kerneldoc

Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Thierry Reding <treding@nvidia.com>

2 files changed, 2 insertions, 2 deletions

diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c
index 541ba833ed36..6c72c57b2244 100644
--- a/drivers/gpu/drm/drm_atomic_helper.c
+++ b/drivers/gpu/drm/drm_atomic_helper.c
@@ -1108,7 +1108,7 @@ void drm_atomic_helper_commit_planes(struct drm_device *dev,
 
                 funcs = plane->helper_private;
 
-                if (!funcs || !funcs->atomic_update)
+                if (!funcs)
                         continue;
 
                 old_plane_state = old_state->plane_states[i];
diff --git a/include/drm/drm_plane_helper.h b/include/drm/drm_plane_helper.h
index a185392cafeb..06d0314a1352 100644
--- a/include/drm/drm_plane_helper.h
+++ b/include/drm/drm_plane_helper.h
@@ -52,7 +52,7 @@ extern int drm_crtc_init(struct drm_device *dev,
  * @prepare_fb: prepare a framebuffer for use by the plane
  * @cleanup_fb: cleanup a framebuffer when it's no longer used by the plane
  * @atomic_check: check that a given atomic state is valid and can be applied
- * @atomic_update: apply an atomic state to the plane
+ * @atomic_update: apply an atomic state to the plane (mandatory)
  *
  * The helper operations are called by the mid-layer CRTC helper.
  */