diff --git a/drivers/net/wireless/ath/ath9k/htc.h b/drivers/net/wireless/ath/ath9k/htc.h
index 707c5b418dc6126ba5e86a0f9c0ee7ce78ba7f7c..124dfedb0fd1b352b5e1a386c55ec5b91074726a 100644
--- a/drivers/net/wireless/ath/ath9k/htc.h
+++ b/drivers/net/wireless/ath/ath9k/htc.h
@@ -407,9 +407,17 @@ static inline void ath9k_htc_err_stat_rx(struct ath9k_htc_priv *priv,
 #define MIN_SWBA_RESPONSE     10 /* in TUs */
 
 struct htc_beacon {
+	enum {
+		OK,		/* no change needed */
+		UPDATE,		/* update pending */
+		COMMIT		/* beacon sent, commit change */
+	} updateslot;		/* slot time update fsm */
+
 	struct ieee80211_vif *bslot[ATH9K_HTC_MAX_BCN_VIF];
 	u32 bmisscnt;
 	u32 beaconq;
+	int slottime;
+	int slotupdate;
 };
 
 struct ath_btcoex {
diff --git a/drivers/net/wireless/ath/ath9k/htc_drv_init.c b/drivers/net/wireless/ath/ath9k/htc_drv_init.c
index 4b3b4dd49a424178ecf7d731e221df64d1c53997..8a3bd5fe3a548f9ac438691ea57a1f583f0291af 100644
--- a/drivers/net/wireless/ath/ath9k/htc_drv_init.c
+++ b/drivers/net/wireless/ath/ath9k/htc_drv_init.c
@@ -520,6 +520,7 @@ static int ath9k_init_priv(struct ath9k_htc_priv *priv,
 
 	for (i = 0; i < ATH9K_HTC_MAX_BCN_VIF; i++)
 		priv->beacon.bslot[i] = NULL;
+	priv->beacon.slottime = ATH9K_SLOT_TIME_9;
 
 	ath9k_cmn_init_channels_rates(common);
 	ath9k_cmn_init_crypto(ah);
diff --git a/drivers/net/wireless/ath/ath9k/htc_drv_main.c b/drivers/net/wireless/ath/ath9k/htc_drv_main.c
index b82a7c43eb6e9c72431477e1a2f56c248f2e7d2b..f46cd0250e488217ca4aa517be12924e3b61c6a8 100644
--- a/drivers/net/wireless/ath/ath9k/htc_drv_main.c
+++ b/drivers/net/wireless/ath/ath9k/htc_drv_main.c
@@ -1500,6 +1500,7 @@ static void ath9k_htc_bss_info_changed(struct ieee80211_hw *hw,
 	struct ath9k_htc_priv *priv = hw->priv;
 	struct ath_hw *ah = priv->ah;
 	struct ath_common *common = ath9k_hw_common(ah);
+	int slottime;
 
 	mutex_lock(&priv->mutex);
 	ath9k_htc_ps_wakeup(priv);
@@ -1575,11 +1576,21 @@ static void ath9k_htc_bss_info_changed(struct ieee80211_hw *hw,
 
 	if (changed & BSS_CHANGED_ERP_SLOT) {
 		if (bss_conf->use_short_slot)
-			ah->slottime = 9;
+			slottime = 9;
 		else
-			ah->slottime = 20;
-
-		ath9k_hw_init_global_settings(ah);
+			slottime = 20;
+		if (vif->type == NL80211_IFTYPE_AP) {
+			/*
+			 * Defer update, so that connected stations can adjust
+			 * their settings at the same time.
+			 * See beacon.c for more details
+			 */
+			priv->beacon.slottime = slottime;
+			priv->beacon.updateslot = UPDATE;
+		} else {
+			ah->slottime = slottime;
+			ath9k_hw_init_global_settings(ah);
+		}
 	}
 
 	if (changed & BSS_CHANGED_HT)