if_class = sysfs_get_device_attr(interface_dev, "bInterfaceClass");
if (!if_class) {
info("%s: cannot get bInterfaceClass attribute", interface_dev->name);
if_class = sysfs_get_device_attr(interface_dev, "bInterfaceClass");
if (!if_class) {
info("%s: cannot get bInterfaceClass attribute", interface_dev->name);