RAL_RX_DESC_SIZE
.bufsize = (RAL_FRAME_SIZE + RAL_RX_DESC_SIZE),
if (len < (int)(RAL_RX_DESC_SIZE + IEEE80211_MIN_LEN)) {
len -= RAL_RX_DESC_SIZE;
usbd_copy_out(pc, len, &sc->sc_rx_desc, RAL_RX_DESC_SIZE);