diff --git a/sound/usb/caiaq/input.c b/sound/usb/caiaq/input.c
index 5c70fdf61cc1..2db4d1332df1 100644
--- a/sound/usb/caiaq/input.c
+++ b/sound/usb/caiaq/input.c
@@ -330,7 +330,7 @@ static void snd_usb_caiaq_tks4_dispatch(struct snd_usb_caiaqdev *cdev,
 {
 	struct device *dev = caiaqdev_to_dev(cdev);
 
-	while (len) {
+	while (len >= TKS4_MSGBLOCK_SIZE) {
 		unsigned int i, block_id = (buf[0] << 8) | buf[1];
 
 		switch (block_id) {