diff --git a/sound/drivers/aloop.c b/sound/drivers/aloop.c
index 0a08e63e9c66..1063a4377502 100644
--- a/sound/drivers/aloop.c
+++ b/sound/drivers/aloop.c
@@ -666,7 +666,9 @@ static void free_cable(struct snd_pcm_substream *substream)
 		return;
 	if (cable->streams[!substream->stream]) {
 		/* other stream is still alive */
+		spin_lock_irq(&cable->lock);
 		cable->streams[substream->stream] = NULL;
+		spin_unlock_irq(&cable->lock);
 	} else {
 		/* free the cable */
 		loopback->cables[substream->number][dev] = NULL;
@@ -705,7 +707,6 @@ static int loopback_open(struct snd_pcm_substream *substream)
 		loopback->cables[substream->number][dev] = cable;
 	}
 	dpcm->cable = cable;
-	cable->streams[substream->stream] = dpcm;
 
 	snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIODS);
 
@@ -737,6 +738,11 @@ static int loopback_open(struct snd_pcm_substream *substream)
 		runtime->hw = loopback_pcm_hardware;
 	else
 		runtime->hw = cable->hw;
+
+	spin_lock_irq(&cable->lock);
+	cable->streams[substream->stream] = dpcm;
+	spin_unlock_irq(&cable->lock);
+
  unlock:
 	if (err < 0) {
 		free_cable(substream);