diff --git a/drivers/usb/serial/ipaq.c b/drivers/usb/serial/ipaq.c
index 5e15dec9f315f319eab3ed98091ed57d6ba7d09c..d9fb3768a2d7b1ba869e4275bcc6ec9d29d1ed2c 100644
--- a/drivers/usb/serial/ipaq.c
+++ b/drivers/usb/serial/ipaq.c
@@ -570,6 +570,11 @@ static struct usb_serial_driver ipaq_device = {
 	.description =		"PocketPC PDA",
 	.usb_driver = 		&ipaq_driver,
 	.id_table =		ipaq_id_table,
+	/*
+	 * some devices have an extra endpoint, which
+	 * must be ignored as it would make the core
+	 * create a second port which oopses when used
+	 */
 	.num_ports =		1,
 	.open =			ipaq_open,
 	.close =		ipaq_close,