Index: head/sys/dev/usb/serial/uplcom.c
===================================================================
--- head/sys/dev/usb/serial/uplcom.c
+++ head/sys/dev/usb/serial/uplcom.c
@@ -166,7 +166,7 @@
 /* prototypes */
 
 static usb_error_t uplcom_reset(struct uplcom_softc *, struct usb_device *);
-static usb_error_t uplcom_pl2303_do(struct usb_device *, int8_t, uint8_t,
+static usb_error_t uplcom_pl2303_do(struct usb_device *, uint8_t, uint8_t,
 			uint16_t, uint16_t, uint16_t);
 static int	uplcom_pl2303_init(struct usb_device *, uint8_t);
 static void	uplcom_free(struct ucom_softc *);
@@ -514,7 +514,7 @@
 }
 
 static usb_error_t
-uplcom_pl2303_do(struct usb_device *udev, int8_t req_type, uint8_t request,
+uplcom_pl2303_do(struct usb_device *udev, uint8_t req_type, uint8_t request,
     uint16_t value, uint16_t index, uint16_t length)
 {
 	struct usb_device_request req;