mac80211: Fix calculation of minimal channel width

When calculating the minimal channel width for channel context,
the current operation Rx channel width of a station was used and not
the overall channel width capability of the station, i.e., both for
Tx and Rx.

Fix ieee80211_get_sta_bw() to use the maximal channel width the
station is capable. While at it make the function static.

Signed-off-by: Ilan Peer <ilan.peer@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Link: https://lore.kernel.org/r/iwlwifi.20201206145305.4387040b99a0.I74bcf19238f75a5960c4098b10e355123d933281@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

net/mac80211/chan.c

@@ -191,11 +191,13 @@ ieee80211_find_reservation_chanctx(struct ieee80211_local *local,
 	return NULL;
 }
 
-enum nl80211_chan_width ieee80211_get_sta_bw(struct ieee80211_sta *sta)
+static enum nl80211_chan_width ieee80211_get_sta_bw(struct sta_info *sta)
 {
-	switch (sta->bandwidth) {
+	enum ieee80211_sta_rx_bandwidth width = ieee80211_sta_cap_rx_bw(sta);
+
+	switch (width) {
 	case IEEE80211_STA_RX_BW_20:
-		if (sta->ht_cap.ht_supported)
+		if (sta->sta.ht_cap.ht_supported)
 			return NL80211_CHAN_WIDTH_20;
 		else
 			return NL80211_CHAN_WIDTH_20_NOHT;
@@ -232,7 +234,7 @@ ieee80211_get_max_required_bw(struct ieee80211_sub_if_data *sdata)
 		    !(sta->sdata->bss && sta->sdata->bss == sdata->bss))
 			continue;
 
-		max_bw = max(max_bw, ieee80211_get_sta_bw(&sta->sta));
+		max_bw = max(max_bw, ieee80211_get_sta_bw(sta));
 	}
 	rcu_read_unlock();
 

net/mac80211/ieee80211_i.h

@@ -2277,7 +2277,6 @@ int ieee80211_check_combinations(struct ieee80211_sub_if_data *sdata,
 				 enum ieee80211_chanctx_mode chanmode,
 				 u8 radar_detect);
 int ieee80211_max_num_channels(struct ieee80211_local *local);
-enum nl80211_chan_width ieee80211_get_sta_bw(struct ieee80211_sta *sta);
 void ieee80211_recalc_chanctx_chantype(struct ieee80211_local *local,
 				       struct ieee80211_chanctx *ctx);