ALSA: usb-audio: Save mixer status only once at suspend
The suspend callback of usb-audio driver may be called multiple times
per suspend when multiple USB interfaces are bound to a single sound
card instance. In such a case, it's superfluous to save the mixer
values multiple times. This patch fixes it by checking the counter.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/usb/card.c b/sound/usb/card.c
index 893d5a1..e769d39 100644
--- a/sound/usb/card.c
+++ b/sound/usb/card.c
@@ -695,8 +695,9 @@
chip->autosuspended = 1;
}
- list_for_each_entry(mixer, &chip->mixer_list, list)
- snd_usb_mixer_suspend(mixer);
+ if (chip->num_suspended_intf == 1)
+ list_for_each_entry(mixer, &chip->mixer_list, list)
+ snd_usb_mixer_suspend(mixer);
return 0;
}
