struct usb_serial_port *port = (struct usb_serial_port *) tty->driver_data; 
struct usb_serial_port *port = tty->driver_data; 
static int serial_ioctl (struct tty_struct *tty, struct file * file, unsigned int cmd, unsigned long arg){	struct usb_serial_port *port = (struct usb_serial_port *) tty->driver_data;	int retval = -ENODEV;	dbg("%s - port %d, cmd 0x%.4x", __FUNCTION__, port->number, cmd);	if (!port->open_count) {		dbg ("%s - port not open", __FUNCTION__);		goto exit;	}	/* pass on to the driver specific version of this function if it is available */	if (port->serial->type->ioctl)		retval = port->serial->type->ioctl(port, file, cmd, arg);	else		retval = -ENOIOCTLCMD;exit:	return retval;}
4520	/local/tlutelli/issta_data/temp/c/2005_temp/2005/4520/81671ddb7e24e9d1f84812dba8ed810935f77d40/usb-serial.c/buggy/drivers/usb/serial/usb-serial.c