ath_extend_tsf
uint64_t tsf = ath_extend_tsf(sc, rstamp,
sc->sc_rx_th.wr_tsf = htole64(ath_extend_tsf(sc, rs->rs_tstamp, tsf));
rstamp = ath_extend_tsf(sc, rs->rs_tstamp, tsf);
rstamp = ath_extend_tsf(sc, rs->rs_tstamp, tsf);