[lkml]   [2018]   [May]   [30]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
Patch in this message
Subject[PATCH 3.2 124/153] ALSA: seq: Clear client entry before deleting else at closing
3.2.102-rc1 review patch.  If anyone has any objections, please let me know.


From: Takashi Iwai <>

commit a2ff19f7b70118ced291a28d5313469914de451b upstream.

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.

Signed-off-by: Takashi Iwai <>
Signed-off-by: Ben Hutchings <>
sound/core/seq/seq_clientmgr.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

--- a/sound/core/seq/seq_clientmgr.c
+++ b/sound/core/seq/seq_clientmgr.c
@@ -270,12 +270,12 @@ static int seq_free_client1(struct snd_s

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);
if (client->pool)
 \ /
  Last update: 2018-05-30 13:41    [W:0.695 / U:0.100 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site