diff --git a/drivers/tty/serial/qcom_geni_serial.c b/drivers/tty/serial/qcom_geni_serial.c
index 8582479f0211..444c74eeab7d 100644
--- a/drivers/tty/serial/qcom_geni_serial.c
+++ b/drivers/tty/serial/qcom_geni_serial.c
@@ -1053,6 +1053,11 @@ static int setup_fifos(struct qcom_geni_serial_port *port)
 		(port->tx_fifo_depth * port->tx_fifo_width) / BITS_PER_BYTE;
 
 	if (port->rx_buf && (old_rx_fifo_depth != port->rx_fifo_depth) && port->rx_fifo_depth) {
+		/*
+		 * Use krealloc rather than krealloc_array because rx_buf is
+		 * accessed as 1 byte entries as well as 4 byte entries so it's
+		 * not necessarily an array.
+		 */
 		port->rx_buf = devm_krealloc(uport->dev, port->rx_buf,
 					     port->rx_fifo_depth * sizeof(u32),
 					     GFP_KERNEL);