ALSA: usb-audio: Unify mixer resume and reset_resume procedure

USB-audio driver assumes that the normal resume would preserve the
device configuration while reset_resume wouldn't, and tries to restore
the mixer elements only at reset_resume callback.  However, this seems
too naive, and some devices do behave differently, resetting the
volume at the normal resume; this resulted in the inconsistent volume
that surprised users.

This patch changes the mixer resume code to handle both the normal and
reset resume in the same way, always restoring the original mixer
element values.  This allows us to unify the both callbacks as well as
dropping the no longer used reset_resume field, which ends up with a
good code reduction.

A slight behavior change by this patch is that now we assign
restore_mixer_value() as the default resume callback, and the function
is no longer called at reset-resume when the resume callback is
overridden by the quirk function.  That is, if needed, the quirk
resume function would have to handle similarly as
restore_mixer_value() by itself.

Reported-by: En-Shuo Hsu <enshuo@chromium.org>
Cc: Yu-Hsuan Hsu <yuhsuan@chromium.org>
Link: https://lore.kernel.org/r/CADDZ45UPsbpAAqP6=ZkTT8BE-yLii4Y7xSDnjK550G2DhQsMew@mail.gmail.com
Link: https://lore.kernel.org/r/20210910105155.12862-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>

1 files changed, 4 insertions, 14 deletions

diff --git a/sound/usb/card.c b/sound/usb/card.c
index fd570a42f043..1764b9302d46 100644
--- a/sound/usb/card.c
+++ b/sound/usb/card.c
@@ -1054,7 +1054,7 @@ static int usb_audio_suspend(struct usb_interface *intf, pm_message_t message)
 	return 0;
 }
 
-static int __usb_audio_resume(struct usb_interface *intf, bool reset_resume)
+static int usb_audio_resume(struct usb_interface *intf)
 {
 	struct snd_usb_audio *chip = usb_get_intfdata(intf);
 	struct snd_usb_stream *as;
@@ -1080,7 +1080,7 @@ static int __usb_audio_resume(struct usb_interface *intf, bool reset_resume)
 	 * we just notify and restart the mixers
 	 */
 	list_for_each_entry(mixer, &chip->mixer_list, list) {
-		err = snd_usb_mixer_resume(mixer, reset_resume);
+		err = snd_usb_mixer_resume(mixer);
 		if (err < 0)
 			goto err_out;
 	}
@@ -1100,20 +1100,10 @@ err_out:
 	atomic_dec(&chip->active); /* allow autopm after this point */
 	return err;
 }
-
-static int usb_audio_resume(struct usb_interface *intf)
-{
-	return __usb_audio_resume(intf, false);
-}
-
-static int usb_audio_reset_resume(struct usb_interface *intf)
-{
-	return __usb_audio_resume(intf, true);
-}
 #else
 #define usb_audio_suspend	NULL
 #define usb_audio_resume	NULL
-#define usb_audio_reset_resume	NULL
+#define usb_audio_resume	NULL
 #endif		/* CONFIG_PM */
 
 static const struct usb_device_id usb_audio_ids [] = {
@@ -1135,7 +1125,7 @@ static struct usb_driver usb_audio_driver = {
 	.disconnect =	usb_audio_disconnect,
 	.suspend =	usb_audio_suspend,
 	.resume =	usb_audio_resume,
-	.reset_resume =	usb_audio_reset_resume,
+	.reset_resume =	usb_audio_resume,
 	.id_table =	usb_audio_ids,
 	.supports_autosuspend = 1,
 };