From 77dee6b71989b05fa3bcbcc360e26bb7928098cb Mon Sep 17 00:00:00 2001 From: Takashi Iwai Date: Fri, 8 Jul 2016 08:05:19 +0200 Subject: [PATCH] ALSA: ctl: Stop notification after disconnection [ Upstream commit f388cdcdd160687c6650833f286b9c89c50960ff ] snd_ctl_remove() has a notification for the removal event. It's superfluous when done during the device got disconnected. Although the notification itself is mostly harmless, it may potentially be harmful, and should be suppressed. Actually some components PCM may free ctl elements during the disconnect or free callbacks, thus it's no theoretical issue. This patch adds the check of card->shutdown flag for avoiding unnecessary notifications after (or during) the disconnect. Cc: Signed-off-by: Takashi Iwai Signed-off-by: Sasha Levin --- sound/core/control.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/sound/core/control.c b/sound/core/control.c index 82a638a01b24..733b803af271 100644 --- a/sound/core/control.c +++ b/sound/core/control.c @@ -150,6 +150,8 @@ void snd_ctl_notify(struct snd_card *card, unsigned int mask, if (snd_BUG_ON(!card || !id)) return; + if (card->shutdown) + return; read_lock(&card->ctl_files_rwlock); #if IS_ENABLED(CONFIG_SND_MIXER_OSS) card->mixer_oss_change_count++;