ALSA: ctl: Stop notification after disconnection

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: <[email protected]> Signed-off-by: Takashi Iwai <[email protected]>
klaby · Jul 8, 2016 · f388cdc · f388cdc
1 parent 8a13209
commit f388cdc
Showing 1 changed file with 2 additions and 0 deletions.
diff --git a/sound/core/control.c b/sound/core/control.c
@@ -160,6 +160,8 @@ 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++;