diff --git a/drivers/tty/serial/pch_uart.c b/drivers/tty/serial/pch_uart.c
index 35cb9af893babe8e76096a9fc525c5e4710b6426..037368285301551400cc29c3cb4c979c29df8f80 100644
--- a/drivers/tty/serial/pch_uart.c
+++ b/drivers/tty/serial/pch_uart.c
@@ -45,6 +45,7 @@ enum {
 /* Set the max number of UART port
  * Intel EG20T PCH: 4 port
  * OKI SEMICONDUCTOR ML7213 IOH: 3 port
+ * OKI SEMICONDUCTOR ML7223 IOH: 2 port
 */
 #define PCH_UART_NR	4