ATHN_NUM_LEGACY_RATES
txrate = ATHN_NUM_LEGACY_RATES + ni->ni_txmcs;
ridx = ATHN_NUM_LEGACY_RATES + i;
an->fallback[ridx] = ATHN_NUM_LEGACY_RATES + i;
an->fallback[ridx] = ATHN_NUM_LEGACY_RATES + j;
#define ATHN_NUM_RATES (ATHN_NUM_LEGACY_RATES + ATHN_NUM_MCS)