diff --git a/drivers/net/wireless/ath/ar9170/main.c b/drivers/net/wireless/ath/ar9170/main.c
index 32bf79e..a9111e1 100644
--- a/drivers/net/wireless/ath/ar9170/main.c
+++ b/drivers/net/wireless/ath/ar9170/main.c
@@ -1945,7 +1945,8 @@
 static int ar9170_ampdu_action(struct ieee80211_hw *hw,
 			       struct ieee80211_vif *vif,
 			       enum ieee80211_ampdu_mlme_action action,
-			       struct ieee80211_sta *sta, u16 tid, u16 *ssn)
+			       struct ieee80211_sta *sta, u16 tid, u16 *ssn,
+			       u8 buf_size)
 {
 	switch (action) {
 	case IEEE80211_AMPDU_RX_START:
diff --git a/drivers/net/wireless/ath/ath9k/htc_drv_main.c b/drivers/net/wireless/ath/ath9k/htc_drv_main.c
index 187af5b..f14f37d 100644
--- a/drivers/net/wireless/ath/ath9k/htc_drv_main.c
+++ b/drivers/net/wireless/ath/ath9k/htc_drv_main.c
@@ -1549,7 +1549,7 @@
 				  struct ieee80211_vif *vif,
 				  enum ieee80211_ampdu_mlme_action action,
 				  struct ieee80211_sta *sta,
-				  u16 tid, u16 *ssn)
+				  u16 tid, u16 *ssn, u8 buf_size)
 {
 	struct ath9k_htc_priv *priv = hw->priv;
 	struct ath9k_htc_sta *ista;
diff --git a/drivers/net/wireless/ath/ath9k/main.c b/drivers/net/wireless/ath/ath9k/main.c
index 174c016..c03184e 100644
--- a/drivers/net/wireless/ath/ath9k/main.c
+++ b/drivers/net/wireless/ath/ath9k/main.c
@@ -2165,7 +2165,7 @@
 			      struct ieee80211_vif *vif,
 			      enum ieee80211_ampdu_mlme_action action,
 			      struct ieee80211_sta *sta,
-			      u16 tid, u16 *ssn)
+			      u16 tid, u16 *ssn, u8 buf_size)
 {
 	struct ath_wiphy *aphy = hw->priv;
 	struct ath_softc *sc = aphy->sc;
diff --git a/drivers/net/wireless/ath/carl9170/main.c b/drivers/net/wireless/ath/carl9170/main.c
index 870df8c..ecfb80b 100644
--- a/drivers/net/wireless/ath/carl9170/main.c
+++ b/drivers/net/wireless/ath/carl9170/main.c
@@ -1279,7 +1279,7 @@
 				    struct ieee80211_vif *vif,
 				    enum ieee80211_ampdu_mlme_action action,
 				    struct ieee80211_sta *sta,
-				    u16 tid, u16 *ssn)
+				    u16 tid, u16 *ssn, u8 buf_size)
 {
 	struct ar9170 *ar = hw->priv;
 	struct carl9170_sta_info *sta_info = (void *) sta->drv_priv;
diff --git a/drivers/net/wireless/iwlwifi/iwl-agn.c b/drivers/net/wireless/iwlwifi/iwl-agn.c
index 36335b1..8b045a4 100644
--- a/drivers/net/wireless/iwlwifi/iwl-agn.c
+++ b/drivers/net/wireless/iwlwifi/iwl-agn.c
@@ -3393,7 +3393,8 @@
 int iwlagn_mac_ampdu_action(struct ieee80211_hw *hw,
 			    struct ieee80211_vif *vif,
 			    enum ieee80211_ampdu_mlme_action action,
-			    struct ieee80211_sta *sta, u16 tid, u16 *ssn)
+			    struct ieee80211_sta *sta, u16 tid, u16 *ssn,
+			    u8 buf_size)
 {
 	struct iwl_priv *priv = hw->priv;
 	int ret = -EINVAL;
diff --git a/drivers/net/wireless/iwlwifi/iwl-agn.h b/drivers/net/wireless/iwlwifi/iwl-agn.h
index da30358..822221a 100644
--- a/drivers/net/wireless/iwlwifi/iwl-agn.h
+++ b/drivers/net/wireless/iwlwifi/iwl-agn.h
@@ -349,7 +349,8 @@
 int iwlagn_mac_ampdu_action(struct ieee80211_hw *hw,
 			    struct ieee80211_vif *vif,
 			    enum ieee80211_ampdu_mlme_action action,
-			    struct ieee80211_sta *sta, u16 tid, u16 *ssn);
+			    struct ieee80211_sta *sta, u16 tid, u16 *ssn,
+			    u8 buf_size);
 int iwlagn_mac_sta_add(struct ieee80211_hw *hw,
 		       struct ieee80211_vif *vif,
 		       struct ieee80211_sta *sta);
diff --git a/drivers/net/wireless/mac80211_hwsim.c b/drivers/net/wireless/mac80211_hwsim.c
index 454f045..5d39b28 100644
--- a/drivers/net/wireless/mac80211_hwsim.c
+++ b/drivers/net/wireless/mac80211_hwsim.c
@@ -943,7 +943,8 @@
 static int mac80211_hwsim_ampdu_action(struct ieee80211_hw *hw,
 				       struct ieee80211_vif *vif,
 				       enum ieee80211_ampdu_mlme_action action,
-				       struct ieee80211_sta *sta, u16 tid, u16 *ssn)
+				       struct ieee80211_sta *sta, u16 tid, u16 *ssn,
+				       u8 buf_size)
 {
 	switch (action) {
 	case IEEE80211_AMPDU_TX_START:
diff --git a/drivers/net/wireless/mwl8k.c b/drivers/net/wireless/mwl8k.c
index 809f2bf..106b427 100644
--- a/drivers/net/wireless/mwl8k.c
+++ b/drivers/net/wireless/mwl8k.c
@@ -4356,7 +4356,8 @@
 static int
 mwl8k_ampdu_action(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
 		   enum ieee80211_ampdu_mlme_action action,
-		   struct ieee80211_sta *sta, u16 tid, u16 *ssn)
+		   struct ieee80211_sta *sta, u16 tid, u16 *ssn,
+		   u8 buf_size)
 {
 	switch (action) {
 	case IEEE80211_AMPDU_RX_START:
diff --git a/drivers/net/wireless/rt2x00/rt2800lib.c b/drivers/net/wireless/rt2x00/rt2800lib.c
index a25be62..f8ba01c 100644
--- a/drivers/net/wireless/rt2x00/rt2800lib.c
+++ b/drivers/net/wireless/rt2x00/rt2800lib.c
@@ -3533,7 +3533,8 @@
 
 int rt2800_ampdu_action(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
 			enum ieee80211_ampdu_mlme_action action,
-			struct ieee80211_sta *sta, u16 tid, u16 *ssn)
+			struct ieee80211_sta *sta, u16 tid, u16 *ssn,
+			u8 buf_size)
 {
 	int ret = 0;
 
diff --git a/drivers/net/wireless/rt2x00/rt2800lib.h b/drivers/net/wireless/rt2x00/rt2800lib.h
index e3c995a..3efafb7 100644
--- a/drivers/net/wireless/rt2x00/rt2800lib.h
+++ b/drivers/net/wireless/rt2x00/rt2800lib.h
@@ -198,7 +198,8 @@
 u64 rt2800_get_tsf(struct ieee80211_hw *hw);
 int rt2800_ampdu_action(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
 			enum ieee80211_ampdu_mlme_action action,
-			struct ieee80211_sta *sta, u16 tid, u16 *ssn);
+			struct ieee80211_sta *sta, u16 tid, u16 *ssn,
+			u8 buf_size);
 int rt2800_get_survey(struct ieee80211_hw *hw, int idx,
 		      struct survey_info *survey);
 
diff --git a/drivers/net/wireless/rtlwifi/core.c b/drivers/net/wireless/rtlwifi/core.c
index d6a924a..25d2d66 100644
--- a/drivers/net/wireless/rtlwifi/core.c
+++ b/drivers/net/wireless/rtlwifi/core.c
@@ -748,7 +748,8 @@
 static int rtl_op_ampdu_action(struct ieee80211_hw *hw,
 			       struct ieee80211_vif *vif,
 			       enum ieee80211_ampdu_mlme_action action,
-			       struct ieee80211_sta *sta, u16 tid, u16 * ssn)
+			       struct ieee80211_sta *sta, u16 tid, u16 *ssn,
+			       u8 buf_size)
 {
 	struct rtl_priv *rtlpriv = rtl_priv(hw);
 
diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index d024fc5..5afe341 100644
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -1731,6 +1731,10 @@
  * 	ieee80211_ampdu_mlme_action. Starting sequence number (@ssn)
  * 	is the first frame we expect to perform the action on. Notice
  * 	that TX/RX_STOP can pass NULL for this parameter.
+ *	The @buf_size parameter is only valid when the action is set to
+ *	%IEEE80211_AMPDU_TX_OPERATIONAL and indicates the peer's reorder
+ *	buffer size (number of subframes) for this session -- aggregates
+ *	containing more subframes than this may not be transmitted to the peer.
  *	Returns a negative error code on failure.
  *	The callback can sleep.
  *
@@ -1833,7 +1837,8 @@
 	int (*ampdu_action)(struct ieee80211_hw *hw,
 			    struct ieee80211_vif *vif,
 			    enum ieee80211_ampdu_mlme_action action,
-			    struct ieee80211_sta *sta, u16 tid, u16 *ssn);
+			    struct ieee80211_sta *sta, u16 tid, u16 *ssn,
+			    u8 buf_size);
 	int (*get_survey)(struct ieee80211_hw *hw, int idx,
 		struct survey_info *survey);
 	void (*rfkill_poll)(struct ieee80211_hw *hw);
diff --git a/net/mac80211/agg-rx.c b/net/mac80211/agg-rx.c
index 002db5e..1f51f41 100644
--- a/net/mac80211/agg-rx.c
+++ b/net/mac80211/agg-rx.c
@@ -76,7 +76,7 @@
 #endif /* CONFIG_MAC80211_HT_DEBUG */
 
 	if (drv_ampdu_action(local, sta->sdata, IEEE80211_AMPDU_RX_STOP,
-			     &sta->sta, tid, NULL))
+			     &sta->sta, tid, NULL, 0))
 		printk(KERN_DEBUG "HW problem - can not stop rx "
 				"aggregation for tid %d\n", tid);
 
@@ -297,7 +297,7 @@
 	}
 
 	ret = drv_ampdu_action(local, sta->sdata, IEEE80211_AMPDU_RX_START,
-			       &sta->sta, tid, &start_seq_num);
+			       &sta->sta, tid, &start_seq_num, 0);
 #ifdef CONFIG_MAC80211_HT_DEBUG
 	printk(KERN_DEBUG "Rx A-MPDU request on tid %d result %d\n", tid, ret);
 #endif /* CONFIG_MAC80211_HT_DEBUG */
diff --git a/net/mac80211/agg-tx.c b/net/mac80211/agg-tx.c
index 9cc472c..42f7c90 100644
--- a/net/mac80211/agg-tx.c
+++ b/net/mac80211/agg-tx.c
@@ -190,7 +190,7 @@
 
 	ret = drv_ampdu_action(local, sta->sdata,
 			       IEEE80211_AMPDU_TX_STOP,
-			       &sta->sta, tid, NULL);
+			       &sta->sta, tid, NULL, 0);
 
 	/* HW shall not deny going back to legacy */
 	if (WARN_ON(ret)) {
@@ -311,7 +311,7 @@
 	start_seq_num = sta->tid_seq[tid] >> 4;
 
 	ret = drv_ampdu_action(local, sdata, IEEE80211_AMPDU_TX_START,
-			       &sta->sta, tid, &start_seq_num);
+			       &sta->sta, tid, &start_seq_num, 0);
 	if (ret) {
 #ifdef CONFIG_MAC80211_HT_DEBUG
 		printk(KERN_DEBUG "BA request denied - HW unavailable for"
@@ -487,7 +487,8 @@
 
 	drv_ampdu_action(local, sta->sdata,
 			 IEEE80211_AMPDU_TX_OPERATIONAL,
-			 &sta->sta, tid, NULL);
+			 &sta->sta, tid, NULL,
+			 sta->ampdu_mlme.tid_tx[tid]->buf_size);
 
 	/*
 	 * synchronize with TX path, while splicing the TX path
@@ -742,9 +743,11 @@
 {
 	struct tid_ampdu_tx *tid_tx;
 	u16 capab, tid;
+	u8 buf_size;
 
 	capab = le16_to_cpu(mgmt->u.action.u.addba_resp.capab);
 	tid = (capab & IEEE80211_ADDBA_PARAM_TID_MASK) >> 2;
+	buf_size = (capab & IEEE80211_ADDBA_PARAM_BUF_SIZE_MASK) >> 6;
 
 	mutex_lock(&sta->ampdu_mlme.mtx);
 
@@ -767,12 +770,23 @@
 
 	if (le16_to_cpu(mgmt->u.action.u.addba_resp.status)
 			== WLAN_STATUS_SUCCESS) {
+		/*
+		 * IEEE 802.11-2007 7.3.1.14:
+		 * In an ADDBA Response frame, when the Status Code field
+		 * is set to 0, the Buffer Size subfield is set to a value
+		 * of at least 1.
+		 */
+		if (!buf_size)
+			goto out;
+
 		if (test_and_set_bit(HT_AGG_STATE_RESPONSE_RECEIVED,
 				     &tid_tx->state)) {
 			/* ignore duplicate response */
 			goto out;
 		}
 
+		tid_tx->buf_size = buf_size;
+
 		if (test_bit(HT_AGG_STATE_DRV_READY, &tid_tx->state))
 			ieee80211_agg_tx_operational(local, sta, tid);
 
diff --git a/net/mac80211/driver-ops.h b/net/mac80211/driver-ops.h
index 98d5899..78af32d 100644
--- a/net/mac80211/driver-ops.h
+++ b/net/mac80211/driver-ops.h
@@ -382,17 +382,17 @@
 				   struct ieee80211_sub_if_data *sdata,
 				   enum ieee80211_ampdu_mlme_action action,
 				   struct ieee80211_sta *sta, u16 tid,
-				   u16 *ssn)
+				   u16 *ssn, u8 buf_size)
 {
 	int ret = -EOPNOTSUPP;
 
 	might_sleep();
 
-	trace_drv_ampdu_action(local, sdata, action, sta, tid, ssn);
+	trace_drv_ampdu_action(local, sdata, action, sta, tid, ssn, buf_size);
 
 	if (local->ops->ampdu_action)
 		ret = local->ops->ampdu_action(&local->hw, &sdata->vif, action,
-					       sta, tid, ssn);
+					       sta, tid, ssn, buf_size);
 
 	trace_drv_return_int(local, ret);
 
diff --git a/net/mac80211/driver-trace.h b/net/mac80211/driver-trace.h
index 49c8421..fbabbc2 100644
--- a/net/mac80211/driver-trace.h
+++ b/net/mac80211/driver-trace.h
@@ -784,9 +784,9 @@
 		 struct ieee80211_sub_if_data *sdata,
 		 enum ieee80211_ampdu_mlme_action action,
 		 struct ieee80211_sta *sta, u16 tid,
-		 u16 *ssn),
+		 u16 *ssn, u8 buf_size),
 
-	TP_ARGS(local, sdata, action, sta, tid, ssn),
+	TP_ARGS(local, sdata, action, sta, tid, ssn, buf_size),
 
 	TP_STRUCT__entry(
 		LOCAL_ENTRY
@@ -794,6 +794,7 @@
 		__field(u32, action)
 		__field(u16, tid)
 		__field(u16, ssn)
+		__field(u8, buf_size)
 		VIF_ENTRY
 	),
 
@@ -804,11 +805,13 @@
 		__entry->action = action;
 		__entry->tid = tid;
 		__entry->ssn = ssn ? *ssn : 0;
+		__entry->buf_size = buf_size;
 	),
 
 	TP_printk(
-		LOCAL_PR_FMT VIF_PR_FMT STA_PR_FMT " action:%d tid:%d",
-		LOCAL_PR_ARG, VIF_PR_ARG, STA_PR_ARG, __entry->action, __entry->tid
+		LOCAL_PR_FMT VIF_PR_FMT STA_PR_FMT " action:%d tid:%d buf:%d",
+		LOCAL_PR_ARG, VIF_PR_ARG, STA_PR_ARG, __entry->action,
+		__entry->tid, __entry->buf_size
 	)
 );
 
diff --git a/net/mac80211/sta_info.h b/net/mac80211/sta_info.h
index bbdd2a8..ca0b690 100644
--- a/net/mac80211/sta_info.h
+++ b/net/mac80211/sta_info.h
@@ -82,6 +82,7 @@
  * @state: session state (see above)
  * @stop_initiator: initiator of a session stop
  * @tx_stop: TX DelBA frame when stopping
+ * @buf_size: reorder buffer size at receiver
  *
  * This structure's lifetime is managed by RCU, assignments to
  * the array holding it must hold the aggregation mutex.
@@ -101,6 +102,7 @@
 	u8 dialog_token;
 	u8 stop_initiator;
 	bool tx_stop;
+	u8 buf_size;
 };
 
 /**