usb_data_xfer_append
xfer_block = usb_data_xfer_append(xfer, NULL, 0,
xfer_block = usb_data_xfer_append(xfer, NULL, 0,
xfer_block = usb_data_xfer_append(xfer,
xfer_block = usb_data_xfer_append(xfer, NULL, 0,
xfer_block = usb_data_xfer_append(xfer, NULL, 0,
xfer_block = usb_data_xfer_append(xfer, NULL, 0,
struct usb_data_xfer_block *usb_data_xfer_append(struct usb_data_xfer *xfer,