diff --git a/sound/usb/stream.c b/sound/usb/stream.c
index ca76ba5b5c0b2..2f6d39c2ba7c8 100644
--- a/sound/usb/stream.c
+++ b/sound/usb/stream.c
@@ -193,16 +193,16 @@ static int usb_chmap_ctl_get(struct snd_kcontrol *kcontrol,
 	struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
 	struct snd_usb_substream *subs = info->private_data;
 	struct snd_pcm_chmap_elem *chmap = NULL;
-	int i;
+	int i = 0;
 
-	memset(ucontrol->value.integer.value, 0,
-	       sizeof(ucontrol->value.integer.value));
 	if (subs->cur_audiofmt)
 		chmap = subs->cur_audiofmt->chmap;
 	if (chmap) {
 		for (i = 0; i < chmap->channels; i++)
 			ucontrol->value.integer.value[i] = chmap->map[i];
 	}
+	for (; i < subs->channels_max; i++)
+		ucontrol->value.integer.value[i] = 0;
 	return 0;
 }