+ __error:
+ up_write(&grp->list_mutex);
+ return err;
+}
+
+static void delete_and_unsubscribe_port(struct snd_seq_client *client,
+ struct snd_seq_client_port *port,
+ struct snd_seq_subscribers *subs,
+ bool is_src, bool ack)
+{
+ struct snd_seq_port_subs_info *grp;
+ struct list_head *list;
+ bool empty;
+
+ grp = is_src ? &port->c_src : &port->c_dest;
+ list = is_src ? &subs->src_list : &subs->dest_list;
+ down_write(&grp->list_mutex);
+ write_lock_irq(&grp->list_lock);
+ empty = list_empty(list);
+ if (!empty)
+ list_del_init(list);
+ grp->exclusive = 0;
+ write_unlock_irq(&grp->list_lock);
+ up_write(&grp->list_mutex);
+
+ if (!empty)
+ unsubscribe_port(client, port, grp, &subs->info, ack);
+}
+
+/* connect two ports */
+int snd_seq_port_connect(struct snd_seq_client *connector,
+ struct snd_seq_client *src_client,
+ struct snd_seq_client_port *src_port,
+ struct snd_seq_client *dest_client,
+ struct snd_seq_client_port *dest_port,
+ struct snd_seq_port_subscribe *info)
+{
+ struct snd_seq_subscribers *subs;
+ bool exclusive;
+ int err;
+
+ subs = kzalloc(sizeof(*subs), GFP_KERNEL);
+ if (!subs)
+ return -ENOMEM;
+
+ subs->info = *info;
+ atomic_set(&subs->ref_count, 0);
+ INIT_LIST_HEAD(&subs->src_list);
+ INIT_LIST_HEAD(&subs->dest_list);
+
+ exclusive = !!(info->flags & SNDRV_SEQ_PORT_SUBS_EXCLUSIVE);
+
+ err = check_and_subscribe_port(src_client, src_port, subs, true,
+ exclusive,
+ connector->number != src_client->number);
+ if (err < 0)
+ goto error;
+ err = check_and_subscribe_port(dest_client, dest_port, subs, false,
+ exclusive,
+ connector->number != dest_client->number);
+ if (err < 0)
+ goto error_dest;