ASoC: DAPM: Cover regression by kctl change notification fix

The recent fix for DAPM to correct the kctl change notification by the
commit 5af82c81 ("ASoC: DAPM: Fix missing kctl change
notifications") caused other regressions since it changed the behavior
of snd_soc_dapm_set_pin() that is called from several API functions.
Formerly it returned always 0 for success, but now it returns 0 or 1.

This patch addresses it, restoring the old behavior of
snd_soc_dapm_set_pin() while keeping the fix in
snd_soc_dapm_put_pin_switch().

Fixes: 5af82c81 ("ASoC: DAPM: Fix missing kctl change notifications")
Reported-by: Yu-Hsuan Hsu <yuhsuan@chromium.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://lore.kernel.org/r/20211105090925.20575-1-tiwai@suse.deSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/soc-dapm.c

@@ -2559,7 +2559,12 @@ static struct snd_soc_dapm_widget *dapm_find_widget(
 	return NULL;
 }
 
-static int snd_soc_dapm_set_pin(struct snd_soc_dapm_context *dapm,
+/*
+ * set the DAPM pin status:
+ * returns 1 when the value has been updated, 0 when unchanged, or a negative
+ * error code; called from kcontrol put callback
+ */
+static int __snd_soc_dapm_set_pin(struct snd_soc_dapm_context *dapm,
 				  const char *pin, int status)
 {
 	struct snd_soc_dapm_widget *w = dapm_find_widget(dapm, pin, true);
@@ -2586,6 +2591,18 @@ static int snd_soc_dapm_set_pin(struct snd_soc_dapm_context *dapm,
 	return ret;
 }
 
+/*
+ * similar as __snd_soc_dapm_set_pin(), but returns 0 when successful;
+ * called from several API functions below
+ */
+static int snd_soc_dapm_set_pin(struct snd_soc_dapm_context *dapm,
+				const char *pin, int status)
+{
+	int ret = __snd_soc_dapm_set_pin(dapm, pin, status);
+
+	return ret < 0 ? ret : 0;
+}
+
 /**
  * snd_soc_dapm_sync_unlocked - scan and power dapm paths
  * @dapm: DAPM context
@@ -3589,10 +3606,10 @@ int snd_soc_dapm_put_pin_switch(struct snd_kcontrol *kcontrol,
 	const char *pin = (const char *)kcontrol->private_value;
 	int ret;
 
-	if (ucontrol->value.integer.value[0])
-		ret = snd_soc_dapm_enable_pin(&card->dapm, pin);
-	else
-		ret = snd_soc_dapm_disable_pin(&card->dapm, pin);
+	mutex_lock_nested(&card->dapm_mutex, SND_SOC_DAPM_CLASS_RUNTIME);
+	ret = __snd_soc_dapm_set_pin(&card->dapm, pin,
+				     !!ucontrol->value.integer.value[0]);
+	mutex_unlock(&card->dapm_mutex);
 
 	snd_soc_dapm_sync(&card->dapm);
 	return ret;