iwm_rval2ridx
int iwm_rval2ridx(int);
int min_ridx = iwm_rval2ridx(ieee80211_min_basic_rate(ic));
int ridx_min = iwm_rval2ridx(ieee80211_min_basic_rate(ic));
ridx_min = iwm_rval2ridx(ieee80211_min_basic_rate(ic));