/* Send the control message. */
ret = libusb_control_transfer(devhdl, LIBUSB_REQUEST_TYPE_VENDOR |
LIBUSB_ENDPOINT_OUT, CMD_START, 0x0000, 0x0000,
(unsigned char *)&cmd, sizeof(cmd), 100);
if (ret < 0) {
/* Send the control message. */
ret = libusb_control_transfer(devhdl, LIBUSB_REQUEST_TYPE_VENDOR |
LIBUSB_ENDPOINT_OUT, CMD_START, 0x0000, 0x0000,
(unsigned char *)&cmd, sizeof(cmd), 100);
if (ret < 0) {