mac80211: allow lowest basic rate for unicast management for mesh

Allow lowest basic rate to be used for unicast management frame in
mesh. Otherwise, the lowest supported rate is used for unicast
management frame, such as 1Mbps for 2.4GHz and 6Mbps for 5GHz. Rename
the rc_send_low_broadcast to re_send_low_basicrate since now it is
also applied to unicast management frame in mesh.
Signed-off-by: Chun-Yeow Yeoh <yeohchunyeow@cozybit.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

net/mac80211/rate.c

@@ -210,7 +210,7 @@ static bool rc_no_data_or_no_ack_use_min(struct ieee80211_tx_rate_control *txrc)
 		!ieee80211_is_data(fc);
 }
 
-static void rc_send_low_broadcast(s8 *idx, u32 basic_rates,
+static void rc_send_low_basicrate(s8 *idx, u32 basic_rates,
 				  struct ieee80211_supported_band *sband)
 {
 	u8 i;
@@ -263,28 +263,37 @@ static void __rate_control_send_low(struct ieee80211_hw *hw,
 }
 
 
-bool rate_control_send_low(struct ieee80211_sta *sta,
+bool rate_control_send_low(struct ieee80211_sta *pubsta,
 			   void *priv_sta,
 			   struct ieee80211_tx_rate_control *txrc)
 {
 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb);
 	struct ieee80211_supported_band *sband = txrc->sband;
+	struct sta_info *sta;
 	int mcast_rate;
+	bool use_basicrate = false;
 
-	if (!sta || !priv_sta || rc_no_data_or_no_ack_use_min(txrc)) {
-		__rate_control_send_low(txrc->hw, sband, sta, info);
+	if (!pubsta || !priv_sta || rc_no_data_or_no_ack_use_min(txrc)) {
+		__rate_control_send_low(txrc->hw, sband, pubsta, info);
 
-		if (!sta && txrc->bss) {
+		if (!pubsta && txrc->bss) {
 			mcast_rate = txrc->bss_conf->mcast_rate[sband->band];
 			if (mcast_rate > 0) {
 				info->control.rates[0].idx = mcast_rate - 1;
 				return true;
 			}
+			use_basicrate = true;
+		} else if (pubsta) {
+			sta = container_of(pubsta, struct sta_info, sta);
+			if (ieee80211_vif_is_mesh(&sta->sdata->vif))
+				use_basicrate = true;
+		}
 
-			rc_send_low_broadcast(&info->control.rates[0].idx,
+		if (use_basicrate)
+			rc_send_low_basicrate(&info->control.rates[0].idx,
 					      txrc->bss_conf->basic_rates,
 					      sband);
-		}
+
 		return true;
 	}
 	return false;