ret = libusb_bulk_transfer(usb->devhdl, 2 | LIBUSB_ENDPOINT_OUT,
(unsigned char *)&cfg, len, &transferred, USB_TIMEOUT);
if (ret < 0 || transferred != len) {
ret = libusb_bulk_transfer(usb->devhdl, 2 | LIBUSB_ENDPOINT_OUT,
(unsigned char *)&cfg, len, &transferred, USB_TIMEOUT);
if (ret < 0 || transferred != len) {