ALSA controls should return 1 if the value in the control changed but the
control put operation fsl_xcvr_arc_mode_put() only returns 0 or a negative
error code, causing ALSA to not generate any change events.

Add a suitable check in the function before updating the arc_mode
variable.

Fixes: 28564486866f ("ASoC: fsl_xcvr: Add XCVR ASoC CPU DAI driver")
Signed-off-by: Shengjiu Wang <shengjiu.wang@nxp.com>
---
 sound/soc/fsl/fsl_xcvr.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/sound/soc/fsl/fsl_xcvr.c b/sound/soc/fsl/fsl_xcvr.c
index de25d9e667ee..109e3e03f455 100644
--- a/sound/soc/fsl/fsl_xcvr.c
+++ b/sound/soc/fsl/fsl_xcvr.c
@@ -167,10 +167,17 @@ static int fsl_xcvr_arc_mode_put(struct snd_kcontrol *kcontrol,
 	struct fsl_xcvr *xcvr = snd_soc_dai_get_drvdata(dai);
 	struct soc_enum *e = (struct soc_enum *)kcontrol->private_value;
 	unsigned int *item = ucontrol->value.enumerated.item;
+	int val = snd_soc_enum_item_to_val(e, item[0]);
+	int ret;
 
-	xcvr->arc_mode = snd_soc_enum_item_to_val(e, item[0]);
+	if (val < 0 || val > 1)
+		return -EINVAL;
 
-	return 0;
+	ret = (xcvr->arc_mode != val);
+
+	xcvr->arc_mode = val;
+
+	return ret;
 }
 
 static int fsl_xcvr_arc_mode_get(struct snd_kcontrol *kcontrol,
-- 
2.34.1