Function close_device

backend/usb-libusb.c:691–796

 */

static int				/* I - 0 on success, -1 on failure */
close_device(usb_printer_t *printer)	/* I - Printer */
{
  struct libusb_device_descriptor devdesc;
                                        /* Current device descriptor */
  struct libusb_config_descriptor *confptr;
                                        /* Pointer to current configuration */


  if (printer->handle)
  {
   /*
    * Release interfaces before closing so that we know all data is written
    * to the device...
    */

    int errcode;			/* Return value of libusb function */
    int number1,			/* Interface number */
	number2;			/* Configuration number */

    errcode =
      libusb_get_config_descriptor(printer->device, printer->conf, &confptr);
    if (errcode >= 0)
    {
      number1 = confptr->interface[printer->iface].
	altsetting[printer->altset].bInterfaceNumber;
      libusb_release_interface(printer->handle, number1);

      number2 = confptr->bConfigurationValue;

      libusb_free_config_descriptor(confptr);

     /*
      * If we have changed the configuration from one valid configuration
      * to another, restore the old one
      */
      if (printer->origconf > 0 && printer->origconf != number2)
      {
	fprintf(stderr, "DEBUG: Restoring USB device configuration: %d -> %d\n",
		number2, printer->origconf);
	if ((errcode = libusb_set_configuration(printer->handle,
						printer->origconf)) < 0)
	{
	  if (errcode != LIBUSB_ERROR_BUSY)
	  {
	    errcode =
	      libusb_get_device_descriptor (printer->device, &devdesc);
	    if (errcode < 0)
	      fprintf(stderr,
		      "DEBUG: Failed to set configuration %d\n",
		      printer->origconf);
	    else
	      fprintf(stderr,
		      "DEBUG: Failed to set configuration %d for %04x:%04x\n",
		      printer->origconf, devdesc.idVendor, devdesc.idProduct);
	  }
	}
      }