usb_cache_string
prod_info = usb_cache_string(es58x_dev->udev, ES58X_PROD_INFO_IDX);
udev->product = usb_cache_string(udev, udev->descriptor.iProduct);
udev->manufacturer = usb_cache_string(udev,
udev->serial = usb_cache_string(udev, udev->descriptor.iSerialNumber);
EXPORT_SYMBOL_GPL(usb_cache_string);
cp->string = usb_cache_string(dev, cp->desc.iConfiguration);
alt->string = usb_cache_string(udev, alt->desc.iInterface);
extern char *usb_cache_string(struct usb_device *udev, int index);