From a2ff19f7b70118ced291a28d5313469914de451b Mon Sep 17 00:00:00 2001 From: Takashi Iwai Date: Fri, 9 Mar 2018 22:23:31 +0100 Subject: [PATCH] ALSA: seq: Clear client entry before deleting else at closing When releasing a client, we need to clear the clienttab[] entry at first, then call snd_seq_queue_client_leave(). Otherwise, the in-flight cell in the queue might be picked up by the timer interrupt via snd_seq_check_queue() before calling snd_seq_queue_client_leave(), and it's delivered to another queue while the client is clearing queues. This may eventually result in an uncleared cell remaining in a queue, and the later snd_seq_pool_delete() may need to wait for a long time until the event gets really processed. By moving the clienttab[] clearance at the beginning of release, any event delivery of a cell belonging to this client will fail at a later point, since snd_seq_client_ptr() returns NULL. Thus the cell that was picked up by the timer interrupt will be returned immediately without further delivery, and the long stall of snd_seq_delete_pool() can be avoided, too. Cc: Signed-off-by: Takashi Iwai --- sound/core/seq/seq_clientmgr.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/sound/core/seq/seq_clientmgr.c b/sound/core/seq/seq_clientmgr.c index 918338dea5b9..61a07fe34cd2 100644 --- a/sound/core/seq/seq_clientmgr.c +++ b/sound/core/seq/seq_clientmgr.c @@ -255,12 +255,12 @@ static int seq_free_client1(struct snd_seq_client *client) if (!client) return 0; - snd_seq_delete_all_ports(client); - snd_seq_queue_client_leave(client->number); spin_lock_irqsave(&clients_lock, flags); clienttablock[client->number] = 1; clienttab[client->number] = NULL; spin_unlock_irqrestore(&clients_lock, flags); + snd_seq_delete_all_ports(client); + snd_seq_queue_client_leave(client->number); snd_use_lock_sync(&client->use_lock); snd_seq_queue_client_termination(client->number); if (client->pool) -- 2.45.2