On Fri,  8 Jul 2022 20:43:24 +0300 Oleksandr Mazur wrote:

+static int
+prestera_mdb_port_addr_obj_add(const struct switchdev_obj_port_mdb *mdb);
+static int
+prestera_mdb_port_addr_obj_del(struct prestera_port *port,
+			       const struct switchdev_obj_port_mdb *mdb);
+
+static void
+prestera_mdb_flush_bridge_port(struct prestera_bridge_port *br_port);
+static int
+prestera_mdb_port_add(struct prestera_mdb_entry *br_mdb,
+		      struct net_device *orig_dev,
+		      const unsigned char addr[ETH_ALEN], u16 vid);
+
+static void
+prestera_br_mdb_entry_put(struct prestera_br_mdb_entry *br_mdb_entry);
+static int prestera_br_mdb_mc_enable_sync(struct prestera_bridge *br_dev);
+static int prestera_br_mdb_sync(struct prestera_bridge *br_dev);
+static int prestera_br_mdb_port_add(struct prestera_br_mdb_entry *br_mdb,
+				    struct prestera_bridge_port *br_port);
+static void
+prestera_mdb_port_del(struct prestera_mdb_entry *mdb,
+		      struct net_device *orig_dev);

No forward declarations in the kernel, unless the there is a circular
dependency. You should be able to just order the functions correctly.

+	list_for_each_entry(br_mdb, &br_dev->br_mdb_entry_list,
+			    br_mdb_entry_node)
+		if ((err = prestera_mdb_enable_set(br_mdb, enable)))
+			return err;

Like checkpatch says, no assignments in the if statements.