drm/bridge: Fix atomic state ops documentation

The drm_bridge_funcs atomic_state_duplicate and atomic_state_destroy
operations are erroneously documented as having a default implementation
if not implemented in bridge drivers. This isn't correct, fix the
documentation.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200226112514.12455-6-laurent.pinchart@ideasonboard.com

diff --git a/include/drm/drm_bridge.h b/include/drm/drm_bridge.h
index 999faaa..38de129 100644 (file)
--- a/include/drm/drm_bridge.h
+++ b/include/drm/drm_bridge.h
@@ -349,9 +349,11 @@ struct drm_bridge_funcs {
         * Duplicate the current bridge state object (which is guaranteed to be
         * non-NULL).
         *
-        * The atomic_duplicate_state() hook is optional. When not implemented
-        * the core allocates a drm_bridge_state object and calls
-        * __drm_atomic_helper_bridge_duplicate_state() to initialize it.
+        * The atomic_duplicate_state hook is mandatory if the bridge
+        * implements any of the atomic hooks, and should be left unassigned
+        * otherwise. For bridges that don't subclass &drm_bridge_state, the
+        * drm_atomic_helper_bridge_duplicate_state() helper function shall be
+        * used to implement this hook.
         *
         * RETURNS:
         * A valid drm_bridge_state object or NULL if the allocation fails.
@@ -364,8 +366,11 @@ struct drm_bridge_funcs {
         * Destroy a bridge state object previously allocated by
         * &drm_bridge_funcs.atomic_duplicate_state().
         *
-        * The atomic_destroy_state hook is optional. When not implemented the
-        * core calls kfree() on the state.
+        * The atomic_destroy_state hook is mandatory if the bridge implements
+        * any of the atomic hooks, and should be left unassigned otherwise.
+        * For bridges that don't subclass &drm_bridge_state, the
+        * drm_atomic_helper_bridge_destroy_state() helper function shall be
+        * used to implement this hook.
         */
        void (*atomic_destroy_state)(struct drm_bridge *bridge,
                                     struct drm_bridge_state *state);
@@ -474,7 +479,10 @@ struct drm_bridge_funcs {
         * This function is called at attach time.
         *
         * The atomic_reset hook is mandatory if the bridge implements any of
-        * the atomic hooks, and should be left unassigned otherwise.
+        * the atomic hooks, and should be left unassigned otherwise. For
+        * bridges that don't subclass &drm_bridge_state, the
+        * drm_atomic_helper_bridge_reset() helper function shall be used to
+        * implement this hook.
         *
         * Note that the atomic_reset() semantics is not exactly matching the
         * reset() semantics found on other components (connector, plane, ...).