1 files changed, 60 insertions, 3 deletions

diff --git a/net/dsa/dsa2.c b/net/dsa/dsa2.c
index 8814fa0e44c8..c18b22c0bf55 100644
--- a/net/dsa/dsa2.c
+++ b/net/dsa/dsa2.c
@@ -822,7 +822,7 @@ static int dsa_switch_setup_tag_protocol(struct dsa_switch *ds)
 	int err;
 
 	if (tag_ops->proto == dst->default_proto)
-		return 0;
+		goto connect;
 
 	dsa_switch_for_each_cpu_port(cpu_dp, ds) {
 		rtnl_lock();
@@ -836,7 +836,30 @@ static int dsa_switch_setup_tag_protocol(struct dsa_switch *ds)
 		}
 	}
 
+connect:
+	if (tag_ops->connect) {
+		err = tag_ops->connect(ds);
+		if (err)
+			return err;
+	}
+
+	if (ds->ops->connect_tag_protocol) {
+		err = ds->ops->connect_tag_protocol(ds, tag_ops->proto);
+		if (err) {
+			dev_err(ds->dev,
+				"Unable to connect to tag protocol \"%s\": %pe\n",
+				tag_ops->name, ERR_PTR(err));
+			goto disconnect;
+		}
+	}
+
 	return 0;
+
+disconnect:
+	if (tag_ops->disconnect)
+		tag_ops->disconnect(ds);
+
+	return err;
 }
 
 static int dsa_switch_setup(struct dsa_switch *ds)
@@ -1136,6 +1159,37 @@ static void dsa_tree_teardown(struct dsa_switch_tree *dst)
 	dst->setup = false;
 }
 
+static int dsa_tree_bind_tag_proto(struct dsa_switch_tree *dst,
+				   const struct dsa_device_ops *tag_ops)
+{
+	const struct dsa_device_ops *old_tag_ops = dst->tag_ops;
+	struct dsa_notifier_tag_proto_info info;
+	int err;
+
+	dst->tag_ops = tag_ops;
+
+	/* Notify the switches from this tree about the connection
+	 * to the new tagger
+	 */
+	info.tag_ops = tag_ops;
+	err = dsa_tree_notify(dst, DSA_NOTIFIER_TAG_PROTO_CONNECT, &info);
+	if (err && err != -EOPNOTSUPP)
+		goto out_disconnect;
+
+	/* Notify the old tagger about the disconnection from this tree */
+	info.tag_ops = old_tag_ops;
+	dsa_tree_notify(dst, DSA_NOTIFIER_TAG_PROTO_DISCONNECT, &info);
+
+	return 0;
+
+out_disconnect:
+	info.tag_ops = tag_ops;
+	dsa_tree_notify(dst, DSA_NOTIFIER_TAG_PROTO_DISCONNECT, &info);
+	dst->tag_ops = old_tag_ops;
+
+	return err;
+}
+
 /* Since the dsa/tagging sysfs device attribute is per master, the assumption
  * is that all DSA switches within a tree share the same tagger, otherwise
  * they would have formed disjoint trees (different "dsa,member" values).
@@ -1168,12 +1222,15 @@ int dsa_tree_change_tag_proto(struct dsa_switch_tree *dst,
 			goto out_unlock;
 	}
 
+	/* Notify the tag protocol change */
 	info.tag_ops = tag_ops;
 	err = dsa_tree_notify(dst, DSA_NOTIFIER_TAG_PROTO, &info);
 	if (err)
-		goto out_unwind_tagger;
+		return err;
 
-	dst->tag_ops = tag_ops;
+	err = dsa_tree_bind_tag_proto(dst, tag_ops);
+	if (err)
+		goto out_unwind_tagger;
 
 	rtnl_unlock();