1 files changed, 2 insertions, 0 deletions

diff --git a/include/linux/usb/serial.h b/include/linux/usb/serial.h
index d528b8045150..704a1ab8240c 100644
--- a/include/linux/usb/serial.h
+++ b/include/linux/usb/serial.h
@@ -320,6 +320,8 @@ extern struct usb_serial_port *usb_serial_port_get_by_minor(unsigned int minor);
 extern void usb_serial_put(struct usb_serial *serial);
 extern int usb_serial_generic_open(struct tty_struct *tty,
         struct usb_serial_port *port);
+extern int usb_serial_generic_write_start(struct usb_serial_port *port,
+                                                        gfp_t mem_flags);
 extern int usb_serial_generic_write(struct tty_struct *tty,
         struct usb_serial_port *port, const unsigned char *buf, int count);
 extern void usb_serial_generic_close(struct usb_serial_port *port);