IEEE80211_FEXT_USEHT40
if (ic->ic_flags_ext & IEEE80211_FEXT_USEHT40)
ic->ic_flags_ext |= IEEE80211_FEXT_USEHT40;
if (flags & IEEE80211_FEXT_USEHT40) {
(ic->ic_flags_ext & IEEE80211_FEXT_USEHT40) ? 40 : 20;
(ic->ic_flags_ext & IEEE80211_FEXT_USEHT40)) {