usbd_xfer_set_frame_len
usbd_xfer_set_frame_len(xfer, 0, usbd_xfer_max_len(xfer));
usbd_xfer_set_frame_len(xfer, nframes, pos);
usbd_xfer_set_frame_len(xfer, 0, usbd_xfer_max_len(xfer));
usbd_xfer_set_frame_len(xfer, nframes, pos);
usbd_xfer_set_frame_len(xfer, 0, usbd_xfer_max_len(xfer));
usbd_xfer_set_frame_len(xfer, 0, usbd_xfer_max_len(xfer));
usbd_xfer_set_frame_len(xfer, 0, m->m_pkthdr.len);
usbd_xfer_set_frame_len(xfer, 0, (m->m_pkthdr.len + 2));
usbd_xfer_set_frame_len(xfer, 0, size);
usbd_xfer_set_frame_len(xfer, 0, dlen);
usbd_xfer_set_frame_len(xfer, 0, len);
usbd_xfer_set_frame_len(xfer, 0, usbd_xfer_max_len(xfer));
usbd_xfer_set_frame_len(xfer, 0, size);
usbd_xfer_set_frame_len(xfer, 0, len);
usbd_xfer_set_frame_len(xfer, 0, usbd_xfer_max_len(xfer));
void usbd_xfer_set_frame_len(struct usb_xfer *xfer, usb_frcount_t frindex,