ath9k: Check for active GO in mgd_prepare_tx()

If a GO interface is active when we receive a
mgd_prepare_tx() call, then we need to send
out a new NoA before switching to a new context.
Signed-off-by: NSujith Manoharan <c_manoha@qca.qualcomm.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

drivers/net/wireless/ath/ath9k/ath9k.h

@@ -385,6 +385,7 @@ struct ath_chanctx_sched {
 	bool wait_switch;
 	bool force_noa_update;
 	bool extend_absence;
+	bool mgd_prepare_tx;
 	enum ath_chanctx_state state;
 	u8 beacon_miss;
 
@@ -977,6 +978,7 @@ struct ath_softc {
 	struct ath_chanctx_sched sched;
 	struct ath_offchannel offchannel;
 	struct ath_chanctx *next_chan;
+	struct completion go_beacon;
 #endif
 
 	unsigned long driver_data;

drivers/net/wireless/ath/ath9k/channel.c

@@ -421,6 +421,9 @@ void ath_chanctx_event(struct ath_softc *sc, struct ieee80211_vif *vif,
 				"Move chanctx state from WAIT_FOR_TIMER to WAIT_FOR_BEACON\n");
 		}
 
+		if (sc->sched.mgd_prepare_tx)
+			sc->sched.state = ATH_CHANCTX_STATE_WAIT_FOR_BEACON;
+
 		/*
 		 * When a context becomes inactive, for example,
 		 * disassociation of a station context, the NoA
@@ -547,6 +550,15 @@ void ath_chanctx_event(struct ath_softc *sc, struct ieee80211_vif *vif,
 		}
 
 		sc->sched.beacon_pending = false;
+
+		if (sc->sched.mgd_prepare_tx) {
+			sc->sched.mgd_prepare_tx = false;
+			complete(&sc->go_beacon);
+			ath_dbg(common, CHAN_CTX,
+				"Beacon sent, complete go_beacon\n");
+			break;
+		}
+
 		if (sc->sched.state != ATH_CHANCTX_STATE_WAIT_FOR_BEACON)
 			break;
 
@@ -1263,6 +1275,8 @@ void ath9k_init_channel_context(struct ath_softc *sc)
 		    (unsigned long)sc);
 	setup_timer(&sc->sched.timer, ath_chanctx_timer,
 		    (unsigned long)sc);
+
+	init_completion(&sc->go_beacon);
 }
 
 void ath9k_deinit_channel_context(struct ath_softc *sc)

drivers/net/wireless/ath/ath9k/main.c

@@ -2474,7 +2474,11 @@ static void ath9k_mgd_prepare_tx(struct ieee80211_hw *hw,
 	struct ath_softc *sc = hw->priv;
 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
 	struct ath_vif *avp = (struct ath_vif *) vif->drv_priv;
+	struct ath_beacon_config *cur_conf;
+	struct ath_chanctx *go_ctx;
+	unsigned long timeout;
 	bool changed = false;
+	u32 beacon_int;
 
 	if (!test_bit(ATH_OP_MULTI_CHANNEL, &common->op_flags))
 		return;
@@ -2485,19 +2489,46 @@ static void ath9k_mgd_prepare_tx(struct ieee80211_hw *hw,
 	mutex_lock(&sc->mutex);
 
 	spin_lock_bh(&sc->chan_lock);
-	if (sc->next_chan || (sc->cur_chan != avp->chanctx)) {
-		sc->next_chan = avp->chanctx;
+	if (sc->next_chan || (sc->cur_chan != avp->chanctx))
 		changed = true;
+	spin_unlock_bh(&sc->chan_lock);
+
+	if (!changed)
+		goto out;
+
+	go_ctx = ath_is_go_chanctx_present(sc);
+
+	if (go_ctx) {
+		/*
+		 * Wait till the GO interface gets a chance
+		 * to send out an NoA.
+		 */
+		spin_lock_bh(&sc->chan_lock);
+		sc->sched.mgd_prepare_tx = true;
+		cur_conf = &go_ctx->beacon;
+		beacon_int = TU_TO_USEC(cur_conf->beacon_interval);
+		spin_unlock_bh(&sc->chan_lock);
+
+		timeout = usecs_to_jiffies(beacon_int);
+		init_completion(&sc->go_beacon);
+
+		if (wait_for_completion_timeout(&sc->go_beacon,
+						timeout) == 0)
+			ath_dbg(common, CHAN_CTX,
+				"Failed to send new NoA\n");
 	}
+
 	ath_dbg(common, CHAN_CTX,
-		"%s: Set chanctx state to FORCE_ACTIVE, changed: %d\n",
-		__func__, changed);
+		"%s: Set chanctx state to FORCE_ACTIVE for vif: %pM\n",
+		__func__, vif->addr);
+
+	spin_lock_bh(&sc->chan_lock);
+	sc->next_chan = avp->chanctx;
 	sc->sched.state = ATH_CHANCTX_STATE_FORCE_ACTIVE;
 	spin_unlock_bh(&sc->chan_lock);
 
-	if (changed)
-		ath_chanctx_set_next(sc, true);
-
+	ath_chanctx_set_next(sc, true);
+out:
 	mutex_unlock(&sc->mutex);
 }