bwn_plcp_getofdm
static uint8_t bwn_plcp_getofdm(const uint8_t);
offset += (bwn_plcp_getofdm(rate) & 0x000f) * 2;
txhdr->phyrate = (BWN_ISOFDMRATE(rate)) ? bwn_plcp_getofdm(rate) :
txhdr->phyrate_rts = bwn_plcp_getofdm(rts_rate);
d = bwn_plcp_getofdm(rate);