diff --git a/drivers/staging/comedi/comedi_buf.c b/drivers/staging/comedi/comedi_buf.c
index 3ef3ddabf139..3df045b25cb3 100644
--- a/drivers/staging/comedi/comedi_buf.c
+++ b/drivers/staging/comedi/comedi_buf.c
@@ -369,7 +369,7 @@ static unsigned int comedi_buf_munge(struct comedi_subdevice *s,
 	unsigned int count = 0;
 	const unsigned int num_sample_bytes = comedi_bytes_per_sample(s);
 
-	if (!s->munge || (async->cmd.flags & CMDF_RAWDATA)) {
+	if (!s->munge || (async->cmd.flags & CMDF_RAWDATA) || async->cmd.chanlist_len == 0) {
 		async->munge_count += num_bytes;
 		count = num_bytes;
 	} else {