- if (des.iSerialNumber == 0) {
- serial_num[0] = '\0';
- } else if ((ret = libusb_get_string_descriptor_ascii(hdl,
- des.iSerialNumber, (unsigned char *) serial_num,
- sizeof(serial_num))) < 0) {
- sr_warn("Failed to get serial number string descriptor: %s.",
- libusb_error_name(ret));
- continue;
+ serial_num[0] = '\0';
+ if (des.iSerialNumber != 0) {
+ ret = libusb_get_string_descriptor_ascii(hdl,
+ des.iSerialNumber,
+ (uint8_t *)serial_num, sizeof(serial_num));
+ if (ret < 0) {
+ sr_warn("Cannot get USB serial number: %s.",
+ libusb_error_name(ret));
+ continue;
+ }