[PATCH] USB: ftdi_sio - fix memory leak and tidy up write bulk callback

The patch frees the bulk write urb's transfer buffer in the write
bulk callback (the buffer is allocated dynamically when the urb is
submitted).  The patch also tidies up the write bulk callback
function a little bit - removing some unnecessary paranoid checks
and scheduling a soft interrupt regardless of the port's open count
(for consistency with other usb serial drivers).

drivers/usb/serial/ftdi_sio.c

@@ -17,6 +17,11 @@
  * See http://ftdi-usb-sio.sourceforge.net for upto date testing info
  *	and extra documentation
  *
+ * (19/Aug/2003) Ian Abbott
+ *      Freed urb's transfer buffer in write bulk callback.
+ *      Omitted some paranoid checks in write bulk callback that don't matter.
+ *      Scheduled work in write bulk callback regardless of port's open count.
+ *
  * (05/Aug/2003) Ian Abbott
  *      Added VID/PID for ID TECH IDT1221U USB to RS-232 adapter.
  *      VID/PID provided by Steve Briggs.
@@ -1391,31 +1396,21 @@ static int ftdi_write (struct usb_serial_port *port, int from_user,
 static void ftdi_write_bulk_callback (struct urb *urb, struct pt_regs *regs)
 {
 	struct usb_serial_port *port = (struct usb_serial_port *)urb->context;
-	struct usb_serial *serial = get_usb_serial (port, __FUNCTION__);
 
-	dbg("%s", __FUNCTION__);
+	/* free up the transfer buffer, as usb_free_urb() does not do this */
+	kfree (urb->transfer_buffer);
 
 	if (port_paranoia_check (port, __FUNCTION__))
 		return;
 	
+	dbg("%s - port %d", __FUNCTION__, port->number);
+	
 	if (urb->status) {
 		dbg("nonzero write bulk status received: %d", urb->status);
 		return;
 	}
 
-	if (!serial) {
-		dbg("%s - bad serial pointer, exiting", __FUNCTION__);
-		return;
-	}
-
-	/* Have to check for validity of queueing up the tasks */
-	dbg("%s - port->open_count = %d", __FUNCTION__, port->open_count);
-
- 	if (port->open_count > 0){
-		schedule_work(&port->work);
-	} 
-
-	return;
+	schedule_work(&port->work);
 } /* ftdi_write_bulk_callback */