rate_lowest_index
rate_idx = rate_lowest_index(&il->bands[info->band], sta);
rate_idx = rate_lowest_index(sband, sta);
lq_sta->last_txrate_idx = rate_lowest_index(sband, sta);
rate_idx = rate_lowest_index(sband, sta);
lq_sta->last_txrate_idx = rate_lowest_index(sband, sta);
rate_idx = rate_lowest_index(
ctl_rate = &sband->bitrates[rate_lowest_index(sband, sta)];