diff --git a/drivers/net/wireless/ath/ath9k/ath9k.h b/drivers/net/wireless/ath/ath9k/ath9k.h
index 93b3793..26fc8ec 100644
--- a/drivers/net/wireless/ath/ath9k/ath9k.h
+++ b/drivers/net/wireless/ath/ath9k/ath9k.h
@@ -637,6 +637,8 @@ struct ath9k_vif_iter_data {
 	int nwds;      /* number of WDS vifs */
 	int nadhocs;   /* number of adhoc vifs */
 	int nocbs;     /* number of OCB vifs */
+	int nbcnvifs;  /* number of beaconing vifs */
+	struct ieee80211_vif *primary_beacon_vif;
 	struct ieee80211_vif *primary_sta;
 };
 
@@ -685,10 +687,11 @@ struct ath_beacon {
 };
 
 void ath9k_beacon_tasklet(unsigned long data);
-void ath9k_beacon_config(struct ath_softc *sc, struct ieee80211_vif *vif,
-			 u32 changed);
+void ath9k_beacon_config(struct ath_softc *sc, struct ieee80211_vif *main_vif,
+			 bool beacons);
 void ath9k_beacon_assign_slot(struct ath_softc *sc, struct ieee80211_vif *vif);
 void ath9k_beacon_remove_slot(struct ath_softc *sc, struct ieee80211_vif *vif);
+void ath9k_beacon_ensure_primary_slot(struct ath_softc *sc);
 void ath9k_set_beacon(struct ath_softc *sc);
 bool ath9k_csa_is_finished(struct ath_softc *sc, struct ieee80211_vif *vif);
 void ath9k_csa_update(struct ath_softc *sc);
diff --git a/drivers/net/wireless/ath/ath9k/beacon.c b/drivers/net/wireless/ath/ath9k/beacon.c
index d8b4971..e36f947 100644
--- a/drivers/net/wireless/ath/ath9k/beacon.c
+++ b/drivers/net/wireless/ath/ath9k/beacon.c
@@ -209,7 +209,6 @@ void ath9k_beacon_assign_slot(struct ath_softc *sc, struct ieee80211_vif *vif)
 	}
 
 	sc->beacon.bslot[avp->av_bslot] = vif;
-	sc->nbcnvifs++;
 
 	ath_dbg(common, CONFIG, "Added interface at beacon slot: %d\n",
 		avp->av_bslot);
@@ -220,15 +219,12 @@ void ath9k_beacon_remove_slot(struct ath_softc *sc, struct ieee80211_vif *vif)
 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
 	struct ath_vif *avp = (void *)vif->drv_priv;
 	struct ath_buf *bf = avp->av_bcbuf;
-	struct ath_beacon_config *cur_conf = &sc->cur_chan->beacon;
 
 	ath_dbg(common, CONFIG, "Removing interface at beacon slot: %d\n",
 		avp->av_bslot);
 
 	tasklet_disable(&sc->bcon_tasklet);
 
-	cur_conf->enable_beacon &= ~BIT(avp->av_bslot);
-
 	if (bf && bf->bf_mpdu) {
 		struct sk_buff *skb = bf->bf_mpdu;
 		dma_unmap_single(sc->dev, bf->bf_buf_addr,
@@ -240,12 +236,73 @@ void ath9k_beacon_remove_slot(struct ath_softc *sc, struct ieee80211_vif *vif)
 
 	avp->av_bcbuf = NULL;
 	sc->beacon.bslot[avp->av_bslot] = NULL;
-	sc->nbcnvifs--;
 	list_add_tail(&bf->list, &sc->beacon.bbuf);
 
 	tasklet_enable(&sc->bcon_tasklet);
 }
 
+void ath9k_beacon_ensure_primary_slot(struct ath_softc *sc)
+{
+	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
+	struct ieee80211_vif *vif;
+	struct ath_vif *avp;
+	s64 tsfadjust;
+	u32 offset;
+	int first_slot = ATH_BCBUF;
+	int slot;
+
+	tasklet_disable(&sc->bcon_tasklet);
+
+	/* Find first taken slot. */
+	for (slot = 0; slot < ATH_BCBUF; slot++) {
+		if (sc->beacon.bslot[slot]) {
+			first_slot = slot;
+			break;
+		}
+	}
+	if (first_slot == 0)
+		goto out;
+
+	/* Re-enumarate all slots, moving them forward. */
+	for (slot = 0; slot < ATH_BCBUF; slot++) {
+		if (slot + first_slot < ATH_BCBUF) {
+			vif = sc->beacon.bslot[slot + first_slot];
+			sc->beacon.bslot[slot] = vif;
+
+			if (vif) {
+				avp = (void *)vif->drv_priv;
+				avp->av_bslot = slot;
+			}
+		} else {
+			sc->beacon.bslot[slot] = NULL;
+		}
+	}
+
+	vif = sc->beacon.bslot[0];
+	if (WARN_ON(!vif))
+		goto out;
+
+	/* Get the tsf_adjust value for the new first slot. */
+	avp = (void *)vif->drv_priv;
+	tsfadjust = le64_to_cpu(avp->tsf_adjust);
+
+	ath_dbg(common, CONFIG,
+		"Adjusting global TSF after beacon slot reassignment: %lld\n",
+		(signed long long)tsfadjust);
+
+	/* Modify TSF as required and update the HW. */
+	avp->chanctx->tsf_val += tsfadjust;
+	if (sc->cur_chan == avp->chanctx) {
+		offset = ath9k_hw_get_tsf_offset(&avp->chanctx->tsf_ts, NULL);
+		ath9k_hw_settsf64(sc->sc_ah, avp->chanctx->tsf_val + offset);
+	}
+
+	/* The slots tsf_adjust will be updated by ath9k_beacon_config later. */
+
+out:
+	tasklet_enable(&sc->bcon_tasklet);
+}
+
 static int ath9k_beacon_choose_slot(struct ath_softc *sc)
 {
 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
@@ -274,26 +331,33 @@ static int ath9k_beacon_choose_slot(struct ath_softc *sc)
 	return slot;
 }
 
-static void ath9k_set_tsfadjust(struct ath_softc *sc, struct ieee80211_vif *vif)
+static void ath9k_set_tsfadjust(struct ath_softc *sc,
+				struct ath_beacon_config *cur_conf)
 {
 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
-	struct ath_vif *avp = (void *)vif->drv_priv;
-	struct ath_beacon_config *cur_conf = &avp->chanctx->beacon;
 	s64 tsfadjust;
+	int slot;
 
-	if (avp->av_bslot == 0)
-		return;
+	for (slot = 0; slot < ATH_BCBUF; slot++) {
+		struct ath_vif *avp;
 
-	/* tsf_adjust is added to the TSF value. We send out the beacon late,
-	 * so need to adjust the TSF starting point to be later in time (i.e.
-	 * the theoretical first beacon has a TSF of 0 after correction).
-	 */
-	tsfadjust = cur_conf->beacon_interval * avp->av_bslot;
-	tsfadjust = -TU_TO_USEC(tsfadjust) / ATH_BCBUF;
-	avp->tsf_adjust = cpu_to_le64(tsfadjust);
+		if (!sc->beacon.bslot[slot])
+			continue;
+
+		avp = (void *)sc->beacon.bslot[slot]->drv_priv;
 
-	ath_dbg(common, CONFIG, "tsfadjust is: %lld for bslot: %d\n",
-		(signed long long)tsfadjust, avp->av_bslot);
+		/* tsf_adjust is added to the TSF value. We send out the
+		 * beacon late, so need to adjust the TSF starting point to be
+		 * later in time (i.e. the theoretical first beacon has a TSF
+		 * of 0 after correction).
+		 */
+		tsfadjust = cur_conf->beacon_interval * avp->av_bslot;
+		tsfadjust = -TU_TO_USEC(tsfadjust) / ATH_BCBUF;
+		avp->tsf_adjust = cpu_to_le64(tsfadjust);
+
+		ath_dbg(common, CONFIG, "tsfadjust is: %lld for bslot: %d\n",
+			(signed long long)tsfadjust, avp->av_bslot);
+	}
 }
 
 bool ath9k_csa_is_finished(struct ath_softc *sc, struct ieee80211_vif *vif)
@@ -447,20 +511,28 @@ void ath9k_beacon_tasklet(unsigned long data)
  * Both nexttbtt and intval have to be in usecs.
  */
 static void ath9k_beacon_init(struct ath_softc *sc, u32 nexttbtt,
-			      u32 intval, bool reset_tsf)
+			      u32 intval)
 {
 	struct ath_hw *ah = sc->sc_ah;
 
 	ath9k_hw_disable_interrupts(ah);
-	if (reset_tsf)
-		ath9k_hw_reset_tsf(ah);
 	ath9k_beaconq_config(sc);
 	ath9k_hw_beaconinit(ah, nexttbtt, intval);
+	ah->imask |= ATH9K_INT_SWBA;
 	sc->beacon.bmisscnt = 0;
 	ath9k_hw_set_interrupts(ah);
 	ath9k_hw_enable_interrupts(ah);
 }
 
+static void ath9k_beacon_stop(struct ath_softc *sc)
+{
+	ath9k_hw_disable_interrupts(sc->sc_ah);
+	sc->sc_ah->imask &= ~(ATH9K_INT_SWBA | ATH9K_INT_BMISS);
+	sc->beacon.bmisscnt = 0;
+	ath9k_hw_set_interrupts(sc->sc_ah);
+	ath9k_hw_enable_interrupts(sc->sc_ah);
+}
+
 /*
  * For multi-bss ap support beacons are either staggered evenly over N slots or
  * burst together.  For the former arrange for the SWBA to be delivered for each
@@ -472,7 +544,7 @@ static void ath9k_beacon_config_ap(struct ath_softc *sc,
 	struct ath_hw *ah = sc->sc_ah;
 
 	ath9k_cmn_beacon_config_ap(ah, conf, ATH_BCBUF);
-	ath9k_beacon_init(sc, conf->nexttbtt, conf->intval, false);
+	ath9k_beacon_init(sc, conf->nexttbtt, conf->intval);
 }
 
 static void ath9k_beacon_config_sta(struct ath_hw *ah,
@@ -501,7 +573,7 @@ static void ath9k_beacon_config_adhoc(struct ath_softc *sc,
 
 	ath9k_cmn_beacon_config_adhoc(ah, conf);
 
-	ath9k_beacon_init(sc, conf->nexttbtt, conf->intval, conf->ibss_creator);
+	ath9k_beacon_init(sc, conf->nexttbtt, conf->intval);
 
 	/*
 	 * Set the global 'beacon has been configured' flag for the
@@ -511,44 +583,6 @@ static void ath9k_beacon_config_adhoc(struct ath_softc *sc,
 		set_bit(ATH_OP_BEACONS, &common->op_flags);
 }
 
-static bool ath9k_allow_beacon_config(struct ath_softc *sc,
-				      struct ieee80211_vif *vif)
-{
-	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
-	struct ath_vif *avp = (void *)vif->drv_priv;
-
-	if (ath9k_is_chanctx_enabled()) {
-		/*
-		 * If the VIF is not present in the current channel context,
-		 * then we can't do the usual opmode checks. Allow the
-		 * beacon config for the VIF to be updated in this case and
-		 * return immediately.
-		 */
-		if (sc->cur_chan != avp->chanctx)
-			return true;
-	}
-
-	if (sc->sc_ah->opmode == NL80211_IFTYPE_AP) {
-		if (vif->type != NL80211_IFTYPE_AP) {
-			ath_dbg(common, CONFIG,
-				"An AP interface is already present !\n");
-			return false;
-		}
-	}
-
-	if (sc->sc_ah->opmode == NL80211_IFTYPE_STATION) {
-		if ((vif->type == NL80211_IFTYPE_STATION) &&
-		    test_bit(ATH_OP_BEACONS, &common->op_flags) &&
-		    vif != sc->cur_chan->primary_sta) {
-			ath_dbg(common, CONFIG,
-				"Beacon already configured for a station interface\n");
-			return false;
-		}
-	}
-
-	return true;
-}
-
 static void ath9k_cache_beacon_config(struct ath_softc *sc,
 				      struct ath_chanctx *ctx,
 				      struct ieee80211_bss_conf *bss_conf)
@@ -584,87 +618,79 @@ static void ath9k_cache_beacon_config(struct ath_softc *sc,
 	if (cur_conf->dtim_period == 0)
 		cur_conf->dtim_period = 1;
 
+	ath9k_set_tsfadjust(sc, cur_conf);
 }
 
-void ath9k_beacon_config(struct ath_softc *sc, struct ieee80211_vif *vif,
-			 u32 changed)
+void ath9k_beacon_config(struct ath_softc *sc, struct ieee80211_vif *main_vif,
+			 bool beacons)
 {
-	struct ieee80211_bss_conf *bss_conf = &vif->bss_conf;
-        struct ath_hw *ah = sc->sc_ah;
-        struct ath_common *common = ath9k_hw_common(ah);
-	struct ath_vif *avp = (void *)vif->drv_priv;
-	struct ath_chanctx *ctx = avp->chanctx;
+	struct ath_hw *ah = sc->sc_ah;
+	struct ath_common *common = ath9k_hw_common(ah);
+	struct ath_vif *avp;
+	struct ath_chanctx *ctx;
 	struct ath_beacon_config *cur_conf;
 	unsigned long flags;
+	bool enabled;
 	bool skip_beacon = false;
 
-	if (!ctx)
+	if (!beacons) {
+		clear_bit(ATH_OP_BEACONS, &common->op_flags);
+		ath9k_beacon_stop(sc);
 		return;
+	}
 
-	cur_conf = &avp->chanctx->beacon;
-	if (vif->type == NL80211_IFTYPE_AP)
-		ath9k_set_tsfadjust(sc, vif);
-
-	if (!ath9k_allow_beacon_config(sc, vif))
+	if (WARN_ON(!main_vif))
 		return;
 
-	if (vif->type == NL80211_IFTYPE_STATION) {
-		ath9k_cache_beacon_config(sc, ctx, bss_conf);
-		if (ctx != sc->cur_chan)
-			return;
+	avp = (void *)main_vif->drv_priv;
+	ctx = avp->chanctx;
+	cur_conf = &ctx->beacon;
+	enabled = cur_conf->enable_beacon;
+	cur_conf->enable_beacon = beacons;
+
+	if (sc->sc_ah->opmode == NL80211_IFTYPE_STATION) {
+		ath9k_cache_beacon_config(sc, ctx, &main_vif->bss_conf);
 
 		ath9k_set_beacon(sc);
 		set_bit(ATH_OP_BEACONS, &common->op_flags);
 		return;
 	}
 
-	/*
-	 * Take care of multiple interfaces when
-	 * enabling/disabling SWBA.
-	 */
-	if (changed & BSS_CHANGED_BEACON_ENABLED) {
-		bool enabled = cur_conf->enable_beacon;
-
-		if (!bss_conf->enable_beacon) {
-			cur_conf->enable_beacon &= ~BIT(avp->av_bslot);
-		} else {
-			cur_conf->enable_beacon |= BIT(avp->av_bslot);
-			if (!enabled)
-				ath9k_cache_beacon_config(sc, ctx, bss_conf);
-		}
-	}
-
-	if (ctx != sc->cur_chan)
-		return;
+	/* Update the beacon configuration. */
+	ath9k_cache_beacon_config(sc, ctx, &main_vif->bss_conf);
 
 	/*
 	 * Configure the HW beacon registers only when we have a valid
 	 * beacon interval.
 	 */
 	if (cur_conf->beacon_interval) {
-		/*
-		 * If we are joining an existing IBSS network, start beaconing
-		 * only after a TSF-sync has taken place. Ensure that this
-		 * happens by setting the appropriate flags.
+		/* Special case to sync the TSF when joining an existing IBSS.
+		 * This is only done if no AP interface is active.
+		 * Note that mac80211 always resets the TSF when creating a new
+		 * IBSS interface.
 		 */
-		if ((changed & BSS_CHANGED_IBSS) && !bss_conf->ibss_creator &&
-		    bss_conf->enable_beacon) {
+		if (sc->sc_ah->opmode == NL80211_IFTYPE_ADHOC &&
+		    !enabled && beacons && !main_vif->bss_conf.ibss_creator) {
 			spin_lock_irqsave(&sc->sc_pm_lock, flags);
 			sc->ps_flags |= PS_BEACON_SYNC | PS_WAIT_FOR_BEACON;
 			spin_unlock_irqrestore(&sc->sc_pm_lock, flags);
 			skip_beacon = true;
-		} else {
-			ath9k_set_beacon(sc);
 		}
 
 		/*
 		 * Do not set the ATH_OP_BEACONS flag for IBSS joiner mode
 		 * here, it is done in ath9k_beacon_config_adhoc().
 		 */
-		if (cur_conf->enable_beacon && !skip_beacon)
+		if (beacons && !skip_beacon) {
 			set_bit(ATH_OP_BEACONS, &common->op_flags);
-		else
+			ath9k_set_beacon(sc);
+		} else {
 			clear_bit(ATH_OP_BEACONS, &common->op_flags);
+			ath9k_beacon_stop(sc);
+		}
+	} else {
+		clear_bit(ATH_OP_BEACONS, &common->op_flags);
+		ath9k_beacon_stop(sc);
 	}
 }
 
diff --git a/drivers/net/wireless/ath/ath9k/common.h b/drivers/net/wireless/ath/ath9k/common.h
index d237373..f0ab6f9 100644
--- a/drivers/net/wireless/ath/ath9k/common.h
+++ b/drivers/net/wireless/ath/ath9k/common.h
@@ -50,6 +50,7 @@
 #define IEEE80211_MS_TO_TU(x)   (((x) * 1000) / 1024)
 
 struct ath_beacon_config {
+	struct ieee80211_vif *main_vif;
 	int beacon_interval;
 	u16 dtim_period;
 	u16 bmiss_timeout;
diff --git a/drivers/net/wireless/ath/ath9k/main.c b/drivers/net/wireless/ath/ath9k/main.c
index 820df45..7594650 100644
--- a/drivers/net/wireless/ath/ath9k/main.c
+++ b/drivers/net/wireless/ath/ath9k/main.c
@@ -910,6 +910,22 @@ static bool ath9k_uses_beacons(int type)
 	}
 }
 
+static void ath9k_vif_iter_set_beacon(struct ath9k_vif_iter_data *iter_data,
+				      struct ieee80211_vif *vif)
+{
+	/* Use the first (configured) interface, but prefering AP interfaces. */
+	if (!iter_data->primary_beacon_vif) {
+		iter_data->primary_beacon_vif = vif;
+	} else {
+		if (iter_data->primary_beacon_vif->type != NL80211_IFTYPE_AP &&
+		    vif->type == NL80211_IFTYPE_AP)
+		iter_data->primary_beacon_vif = vif;
+	}
+
+	iter_data->beacons = true;
+	iter_data->nbcnvifs += 1;
+}
+
 static void ath9k_vif_iter(struct ath9k_vif_iter_data *iter_data,
 			   u8 *mac, struct ieee80211_vif *vif)
 {
@@ -931,6 +947,8 @@ static void ath9k_vif_iter(struct ath9k_vif_iter_data *iter_data,
 	switch (vif->type) {
 	case NL80211_IFTYPE_AP:
 		iter_data->naps++;
+		if (vif->bss_conf.enable_beacon)
+			ath9k_vif_iter_set_beacon(iter_data, vif);
 		break;
 	case NL80211_IFTYPE_STATION:
 		iter_data->nstations++;
@@ -943,12 +961,12 @@ static void ath9k_vif_iter(struct ath9k_vif_iter_data *iter_data,
 	case NL80211_IFTYPE_ADHOC:
 		iter_data->nadhocs++;
 		if (vif->bss_conf.enable_beacon)
-			iter_data->beacons = true;
+			ath9k_vif_iter_set_beacon(iter_data, vif);
 		break;
 	case NL80211_IFTYPE_MESH_POINT:
 		iter_data->nmeshes++;
 		if (vif->bss_conf.enable_beacon)
-			iter_data->beacons = true;
+			ath9k_vif_iter_set_beacon(iter_data, vif);
 		break;
 	case NL80211_IFTYPE_WDS:
 		iter_data->nwds++;
@@ -1081,7 +1099,6 @@ void ath9k_calculate_summary_state(struct ath_softc *sc,
 	struct ath_hw *ah = sc->sc_ah;
 	struct ath_common *common = ath9k_hw_common(ah);
 	struct ath9k_vif_iter_data iter_data;
-	struct ath_beacon_config *cur_conf;
 
 	ath_chanctx_check_active(sc, ctx);
 
@@ -1103,13 +1120,12 @@ void ath9k_calculate_summary_state(struct ath_softc *sc,
 	ath_hw_setbssidmask(common);
 
 	if (iter_data.naps > 0) {
-		cur_conf = &ctx->beacon;
 		ath9k_hw_set_tsfadjust(ah, true);
 		ah->opmode = NL80211_IFTYPE_AP;
-		if (cur_conf->enable_beacon)
-			iter_data.beacons = true;
 	} else {
 		ath9k_hw_set_tsfadjust(ah, false);
+		if (iter_data.beacons)
+			ath9k_beacon_ensure_primary_slot(sc);
 
 		if (iter_data.nmeshes)
 			ah->opmode = NL80211_IFTYPE_MESH_POINT;
@@ -1134,7 +1150,6 @@ void ath9k_calculate_summary_state(struct ath_softc *sc,
 			ctx->switch_after_beacon = true;
 	}
 
-	ah->imask &= ~ATH9K_INT_SWBA;
 	if (ah->opmode == NL80211_IFTYPE_STATION) {
 		bool changed = (iter_data.primary_sta != ctx->primary_sta);
 
@@ -1151,16 +1166,12 @@ void ath9k_calculate_summary_state(struct ath_softc *sc,
 			if (ath9k_hw_mci_is_enabled(sc->sc_ah))
 				ath9k_mci_update_wlan_channels(sc, true);
 		}
-	} else if (iter_data.beacons) {
-		ah->imask |= ATH9K_INT_SWBA;
 	}
+	sc->nbcnvifs = iter_data.nbcnvifs;
+	ath9k_beacon_config(sc, iter_data.primary_beacon_vif,
+			    iter_data.beacons);
 	ath9k_hw_set_interrupts(ah);
 
-	if (iter_data.beacons)
-		set_bit(ATH_OP_BEACONS, &common->op_flags);
-	else
-		clear_bit(ATH_OP_BEACONS, &common->op_flags);
-
 	if (ah->slottime != iter_data.slottime) {
 		ah->slottime = iter_data.slottime;
 		ath9k_hw_init_global_settings(ah);
@@ -1777,9 +1788,7 @@ static void ath9k_bss_info_changed(struct ieee80211_hw *hw,
 	if ((changed & BSS_CHANGED_BEACON_ENABLED) ||
 	    (changed & BSS_CHANGED_BEACON_INT) ||
 	    (changed & BSS_CHANGED_BEACON_INFO)) {
-		ath9k_beacon_config(sc, vif, changed);
-		if (changed & BSS_CHANGED_BEACON_ENABLED)
-			ath9k_calculate_summary_state(sc, avp->chanctx);
+		ath9k_calculate_summary_state(sc, avp->chanctx);
 	}
 
 	if ((avp->chanctx == sc->cur_chan) &&
