- /* Try to send shutdown message, if the device is gone, this will just fail. */
- transfer_buffer = kmalloc (0x12, GFP_KERNEL);
- if (transfer_buffer) {
- usb_control_msg (port->serial->dev,
- usb_rcvctrlpipe(port->serial->dev, 0),
- VISOR_CLOSE_NOTIFICATION, 0xc2,
- 0x0000, 0x0000,
- transfer_buffer, 0x12, 300);
- kfree (transfer_buffer);
+ mutex_lock(&port->serial->disc_mutex);
+ if (!port->serial->disconnected) {
+ /* Try to send shutdown message, unless the device is gone */
+ transfer_buffer = kmalloc (0x12, GFP_KERNEL);
+ if (transfer_buffer) {
+ usb_control_msg (port->serial->dev,
+ usb_rcvctrlpipe(port->serial->dev, 0),
+ VISOR_CLOSE_NOTIFICATION, 0xc2,
+ 0x0000, 0x0000,
+ transfer_buffer, 0x12, 300);
+ kfree (transfer_buffer);
+ }