mac80211: notify driver for change in multicast rates

With drivers implementing rate control in driver or firmware
rate_control_send_low() may not get called, and thus the
driver needs to know about changes in the multicast rate.

Add and use a new BSS change flag for this.
Signed-off-by: Pradeep Kumar Chitrapu <pradeepc@codeaurora.org>
[rewrite commit message]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

include/net/mac80211.h

@@ -302,6 +302,8 @@ struct ieee80211_vif_chanctx_switch {
  * @BSS_CHANGED_MU_GROUPS: VHT MU-MIMO group id or user position changed
  * @BSS_CHANGED_KEEP_ALIVE: keep alive options (idle period or protected
  *	keep alive) changed.
+ * @BSS_CHANGED_MCAST_RATE: Multicast Rate setting changed for this interface
+ *
  */
 enum ieee80211_bss_change {
 	BSS_CHANGED_ASSOC		= 1<<0,
@@ -329,6 +331,7 @@ enum ieee80211_bss_change {
 	BSS_CHANGED_OCB                 = 1<<22,
 	BSS_CHANGED_MU_GROUPS		= 1<<23,
 	BSS_CHANGED_KEEP_ALIVE		= 1<<24,
+	BSS_CHANGED_MCAST_RATE		= 1<<25,
 
 	/* when adding here, make sure to change ieee80211_reconfig */
 };

net/mac80211/cfg.c

@@ -2313,6 +2313,8 @@ static int ieee80211_set_mcast_rate(struct wiphy *wiphy, struct net_device *dev,
 	memcpy(sdata->vif.bss_conf.mcast_rate, rate,
 	       sizeof(int) * NUM_NL80211_BANDS);
 
+	ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_MCAST_RATE);
+
 	return 0;
 }
 

net/mac80211/ibss.c

@@ -1839,7 +1839,7 @@ int ieee80211_ibss_join(struct ieee80211_sub_if_data *sdata,
 		  IEEE80211_HT_OP_MODE_PROTECTION_NONHT_MIXED
 		| IEEE80211_HT_PARAM_RIFS_MODE;
 
-	changed |= BSS_CHANGED_HT;
+	changed |= BSS_CHANGED_HT | BSS_CHANGED_MCAST_RATE;
 	ieee80211_bss_info_change_notify(sdata, changed);
 
 	sdata->smps_mode = IEEE80211_SMPS_OFF;

net/mac80211/mesh.c

@@ -880,7 +880,8 @@ int ieee80211_start_mesh(struct ieee80211_sub_if_data *sdata)
 		      BSS_CHANGED_BEACON_ENABLED |
 		      BSS_CHANGED_HT |
 		      BSS_CHANGED_BASIC_RATES |
-		      BSS_CHANGED_BEACON_INT;
+		      BSS_CHANGED_BEACON_INT |
+		      BSS_CHANGED_MCAST_RATE;
 
 	local->fif_other_bss++;
 	/* mesh ifaces must set allmulti to forward mcast traffic */

net/mac80211/util.c

@@ -1968,7 +1968,8 @@ int ieee80211_reconfig(struct ieee80211_local *local)
 			  BSS_CHANGED_CQM |
 			  BSS_CHANGED_QOS |
 			  BSS_CHANGED_IDLE |
-			  BSS_CHANGED_TXPOWER;
+			  BSS_CHANGED_TXPOWER |
+			  BSS_CHANGED_MCAST_RATE;
 
 		if (sdata->vif.mu_mimo_owner)
 			changed |= BSS_CHANGED_MU_GROUPS;