mac80211: A-MPDU MLME use dynamic allocation

This patch alters the A-MPDU MLME in sta_info to use dynamic allocation,
thus drastically improving memory usage - from a constant ~2 Kbyte in
the previous (static) allocation to a lower limit of ~200 Byte and an upper
limit of ~2 Kbyte.

Signed-off-by: Ron Rindjunsky <ron.rindjunsky@intel.com>
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

6 files changed, 150 insertions, 99 deletions

diff --git a/net/mac80211/debugfs_sta.c b/net/mac80211/debugfs_sta.c
index 62354de0199..256ea880d28 100644
--- a/net/mac80211/debugfs_sta.c
+++ b/net/mac80211/debugfs_sta.c
@@ -169,27 +169,30 @@ static ssize_t sta_agg_status_read(struct file *file, char __user *userbuf,
 	p += scnprintf(p, sizeof(buf)+buf-p, "\n RX  :");
 	for (i = 0; i < STA_TID_NUM; i++)
 		p += scnprintf(p, sizeof(buf)+buf-p, "%5d",
-	sta->ampdu_mlme.tid_rx[i].state);
+			sta->ampdu_mlme.tid_state_rx[i]);
 
 	p += scnprintf(p, sizeof(buf)+buf-p, "\n DTKN:");
 	for (i = 0; i < STA_TID_NUM; i++)
 		p += scnprintf(p, sizeof(buf)+buf-p, "%5d",
-			sta->ampdu_mlme.tid_rx[i].dialog_token);
+			sta->ampdu_mlme.tid_state_rx[i]?
+			sta->ampdu_mlme.tid_rx[i]->dialog_token : 0);
 
 	p += scnprintf(p, sizeof(buf)+buf-p, "\n TX  :");
 	for (i = 0; i < STA_TID_NUM; i++)
 		p += scnprintf(p, sizeof(buf)+buf-p, "%5d",
-			sta->ampdu_mlme.tid_tx[i].state);
+			sta->ampdu_mlme.tid_state_tx[i]);
 
 	p += scnprintf(p, sizeof(buf)+buf-p, "\n DTKN:");
 	for (i = 0; i < STA_TID_NUM; i++)
 		p += scnprintf(p, sizeof(buf)+buf-p, "%5d",
-			sta->ampdu_mlme.tid_tx[i].dialog_token);
+			sta->ampdu_mlme.tid_state_tx[i]?
+			sta->ampdu_mlme.tid_tx[i]->dialog_token : 0);
 
 	p += scnprintf(p, sizeof(buf)+buf-p, "\n SSN :");
 	for (i = 0; i < STA_TID_NUM; i++)
 		p += scnprintf(p, sizeof(buf)+buf-p, "%5d",
-			sta->ampdu_mlme.tid_tx[i].ssn);
+			sta->ampdu_mlme.tid_state_tx[i]?
+			sta->ampdu_mlme.tid_tx[i]->ssn : 0);
 
 	p += scnprintf(p, sizeof(buf)+buf-p, "\n");
 
@@ -230,12 +233,12 @@ static ssize_t sta_agg_status_write(struct file *file,
 			strcpy(state, "off ");
 			ieee80211_sta_stop_rx_ba_session(dev, da, tid_num, 0,
 					WLAN_REASON_QSTA_REQUIRE_SETUP);
-			sta->ampdu_mlme.tid_rx[tid_num].state |=
+			sta->ampdu_mlme.tid_state_rx[tid_num] |=
 					HT_AGG_STATE_DEBUGFS_CTL;
 			tid_static_rx[tid_num] = 0;
 		} else {
 			strcpy(state, "on ");
-			sta->ampdu_mlme.tid_rx[tid_num].state &=
+			sta->ampdu_mlme.tid_state_rx[tid_num] &=
 					~HT_AGG_STATE_DEBUGFS_CTL;
 			tid_static_rx[tid_num] = 1;
 		}
diff --git a/net/mac80211/ieee80211.c b/net/mac80211/ieee80211.c
index 616ce10d2a3..8c0f782d21e 100644
--- a/net/mac80211/ieee80211.c
+++ b/net/mac80211/ieee80211.c
@@ -569,12 +569,12 @@ int ieee80211_start_tx_ba_session(struct ieee80211_hw *hw, u8 *ra, u16 tid)
 	spin_lock_bh(&sta->ampdu_mlme.ampdu_tx);
 
 	/* we have tried too many times, receiver does not want A-MPDU */
-	if (sta->ampdu_mlme.tid_tx[tid].addba_req_num >	HT_AGG_MAX_RETRIES) {
+	if (sta->ampdu_mlme.addba_req_num[tid] > HT_AGG_MAX_RETRIES) {
 		ret = -EBUSY;
 		goto start_ba_exit;
 	}
 
-	state = &sta->ampdu_mlme.tid_tx[tid].state;
+	state = &sta->ampdu_mlme.tid_state_tx[tid];
 	/* check if the TID is not in aggregation flow already */
 	if (*state != HT_AGG_STATE_IDLE) {
 #ifdef CONFIG_MAC80211_HT_DEBUG
@@ -585,6 +585,23 @@ int ieee80211_start_tx_ba_session(struct ieee80211_hw *hw, u8 *ra, u16 tid)
 		goto start_ba_exit;
 	}
 
+	/* prepare A-MPDU MLME for Tx aggregation */
+	sta->ampdu_mlme.tid_tx[tid] =
+			kmalloc(sizeof(struct tid_ampdu_tx), GFP_ATOMIC);
+	if (!sta->ampdu_mlme.tid_tx[tid]) {
+		if (net_ratelimit())
+			printk(KERN_ERR "allocate tx mlme to tid %d failed\n",
+					tid);
+		ret = -ENOMEM;
+		goto start_ba_exit;
+	}
+	/* Tx timer */
+	sta->ampdu_mlme.tid_tx[tid]->addba_resp_timer.function =
+			sta_addba_resp_timer_expired;
+	sta->ampdu_mlme.tid_tx[tid]->addba_resp_timer.data =
+			(unsigned long)&sta->timer_to_tid[tid];
+	init_timer(&sta->ampdu_mlme.tid_tx[tid]->addba_resp_timer);
+
 	/* ensure that TX flow won't interrupt us
 	 * until the end of the call to requeue function */
 	spin_lock_bh(&local->mdev->queue_lock);
@@ -596,11 +613,10 @@ int ieee80211_start_tx_ba_session(struct ieee80211_hw *hw, u8 *ra, u16 tid)
 	 * don't switch to aggregation */
 	if (ret) {
 #ifdef CONFIG_MAC80211_HT_DEBUG
-		printk(KERN_DEBUG "BA request denied - no queue available for"
+		printk(KERN_DEBUG "BA request denied - queue unavailable for"
 					" tid %d\n", tid);
 #endif /* CONFIG_MAC80211_HT_DEBUG */
-		spin_unlock_bh(&local->mdev->queue_lock);
-		goto start_ba_exit;
+		goto start_ba_err;
 	}
 	sdata = sta->sdata;
 
@@ -618,38 +634,40 @@ int ieee80211_start_tx_ba_session(struct ieee80211_hw *hw, u8 *ra, u16 tid)
 		 * allocated queue */
 		 ieee80211_ht_agg_queue_remove(local, sta, tid, 0);
 #ifdef CONFIG_MAC80211_HT_DEBUG
-		printk(KERN_DEBUG "BA request denied - HW or queue unavailable"
-				" for tid %d\n", tid);
+		printk(KERN_DEBUG "BA request denied - HW unavailable for"
+					" tid %d\n", tid);
 #endif /* CONFIG_MAC80211_HT_DEBUG */
-		spin_unlock_bh(&local->mdev->queue_lock);
 		*state = HT_AGG_STATE_IDLE;
-		goto start_ba_exit;
+		goto start_ba_err;
 	}
 
 	/* Will put all the packets in the new SW queue */
 	ieee80211_requeue(local, ieee802_1d_to_ac[tid]);
 	spin_unlock_bh(&local->mdev->queue_lock);
 
-	/* We have most probably almost emptied the legacy queue */
-	/* ieee80211_wake_queue(local_to_hw(local), ieee802_1d_to_ac[tid]); */
-
 	/* send an addBA request */
 	sta->ampdu_mlme.dialog_token_allocator++;
-	sta->ampdu_mlme.tid_tx[tid].dialog_token =
+	sta->ampdu_mlme.tid_tx[tid]->dialog_token =
 			sta->ampdu_mlme.dialog_token_allocator;
-	sta->ampdu_mlme.tid_tx[tid].ssn = start_seq_num;
+	sta->ampdu_mlme.tid_tx[tid]->ssn = start_seq_num;
 
 	ieee80211_send_addba_request(sta->sdata->dev, ra, tid,
-			 sta->ampdu_mlme.tid_tx[tid].dialog_token,
-			 sta->ampdu_mlme.tid_tx[tid].ssn,
+			 sta->ampdu_mlme.tid_tx[tid]->dialog_token,
+			 sta->ampdu_mlme.tid_tx[tid]->ssn,
 			 0x40, 5000);
 
 	/* activate the timer for the recipient's addBA response */
-	sta->ampdu_mlme.tid_tx[tid].addba_resp_timer.expires =
+	sta->ampdu_mlme.tid_tx[tid]->addba_resp_timer.expires =
 				jiffies + ADDBA_RESP_INTERVAL;
-	add_timer(&sta->ampdu_mlme.tid_tx[tid].addba_resp_timer);
+	add_timer(&sta->ampdu_mlme.tid_tx[tid]->addba_resp_timer);
 	printk(KERN_DEBUG "activated addBA response timer on tid %d\n", tid);
+	goto start_ba_exit;
 
+start_ba_err:
+	kfree(sta->ampdu_mlme.tid_tx[tid]);
+	sta->ampdu_mlme.tid_tx[tid] = NULL;
+	spin_unlock_bh(&local->mdev->queue_lock);
+	ret = -EBUSY;
 start_ba_exit:
 	spin_unlock_bh(&sta->ampdu_mlme.ampdu_tx);
 	rcu_read_unlock();
@@ -683,7 +701,7 @@ int ieee80211_stop_tx_ba_session(struct ieee80211_hw *hw,
 	}
 
 	/* check if the TID is in aggregation */
-	state = &sta->ampdu_mlme.tid_tx[tid].state;
+	state = &sta->ampdu_mlme.tid_state_tx[tid];
 	spin_lock_bh(&sta->ampdu_mlme.ampdu_tx);
 
 	if (*state != HT_AGG_STATE_OPERATIONAL) {
@@ -741,7 +759,7 @@ void ieee80211_start_tx_ba_cb(struct ieee80211_hw *hw, u8 *ra, u16 tid)
 		return;
 	}
 
-	state = &sta->ampdu_mlme.tid_tx[tid].state;
+	state = &sta->ampdu_mlme.tid_state_tx[tid];
 	spin_lock_bh(&sta->ampdu_mlme.ampdu_tx);
 
 	if (!(*state & HT_ADDBA_REQUESTED_MSK)) {
@@ -790,7 +808,7 @@ void ieee80211_stop_tx_ba_cb(struct ieee80211_hw *hw, u8 *ra, u8 tid)
 		rcu_read_unlock();
 		return;
 	}
-	state = &sta->ampdu_mlme.tid_tx[tid].state;
+	state = &sta->ampdu_mlme.tid_state_tx[tid];
 
 	spin_lock_bh(&sta->ampdu_mlme.ampdu_tx);
 	if ((*state & HT_AGG_STATE_REQ_STOP_BA_MSK) == 0) {
@@ -819,7 +837,9 @@ void ieee80211_stop_tx_ba_cb(struct ieee80211_hw *hw, u8 *ra, u8 tid)
 	 * necessarily stopped */
 	netif_schedule(local->mdev);
 	*state = HT_AGG_STATE_IDLE;
-	sta->ampdu_mlme.tid_tx[tid].addba_req_num = 0;
+	sta->ampdu_mlme.addba_req_num[tid] = 0;
+	kfree(sta->ampdu_mlme.tid_tx[tid]);
+	sta->ampdu_mlme.tid_tx[tid] = NULL;
 	spin_unlock_bh(&sta->ampdu_mlme.ampdu_tx);
 
 	rcu_read_unlock();
diff --git a/net/mac80211/ieee80211_sta.c b/net/mac80211/ieee80211_sta.c
index cf51ca6804d..f9cf2f18789 100644
--- a/net/mac80211/ieee80211_sta.c
+++ b/net/mac80211/ieee80211_sta.c
@@ -1216,12 +1216,11 @@ static void ieee80211_sta_process_addba_request(struct net_device *dev,
 		buf_size = buf_size << sband->ht_info.ampdu_factor;
 	}
 
-	tid_agg_rx = &sta->ampdu_mlme.tid_rx[tid];
 
 	/* examine state machine */
 	spin_lock_bh(&sta->ampdu_mlme.ampdu_rx);
 
-	if (tid_agg_rx->state != HT_AGG_STATE_IDLE) {
+	if (sta->ampdu_mlme.tid_state_rx[tid] != HT_AGG_STATE_IDLE) {
 #ifdef CONFIG_MAC80211_HT_DEBUG
 		if (net_ratelimit())
 			printk(KERN_DEBUG "unexpected AddBA Req from "
@@ -1231,6 +1230,24 @@ static void ieee80211_sta_process_addba_request(struct net_device *dev,
 		goto end;
 	}
 
+	/* prepare A-MPDU MLME for Rx aggregation */
+	sta->ampdu_mlme.tid_rx[tid] =
+			kmalloc(sizeof(struct tid_ampdu_rx), GFP_ATOMIC);
+	if (!sta->ampdu_mlme.tid_rx[tid]) {
+		if (net_ratelimit())
+			printk(KERN_ERR "allocate rx mlme to tid %d failed\n",
+					tid);
+		goto end;
+	}
+	/* rx timer */
+	sta->ampdu_mlme.tid_rx[tid]->session_timer.function =
+				sta_rx_agg_session_timer_expired;
+	sta->ampdu_mlme.tid_rx[tid]->session_timer.data =
+				(unsigned long)&sta->timer_to_tid[tid];
+	init_timer(&sta->ampdu_mlme.tid_rx[tid]->session_timer);
+
+	tid_agg_rx = sta->ampdu_mlme.tid_rx[tid];
+
 	/* prepare reordering buffer */
 	tid_agg_rx->reorder_buf =
 		kmalloc(buf_size * sizeof(struct sk_buf *), GFP_ATOMIC);
@@ -1238,6 +1255,7 @@ static void ieee80211_sta_process_addba_request(struct net_device *dev,
 		if (net_ratelimit())
 			printk(KERN_ERR "can not allocate reordering buffer "
 			       "to tid %d\n", tid);
+		kfree(sta->ampdu_mlme.tid_rx[tid]);
 		goto end;
 	}
 	memset(tid_agg_rx->reorder_buf, 0,
@@ -1252,11 +1270,13 @@ static void ieee80211_sta_process_addba_request(struct net_device *dev,
 
 	if (ret) {
 		kfree(tid_agg_rx->reorder_buf);
+		kfree(tid_agg_rx);
+		sta->ampdu_mlme.tid_rx[tid] = NULL;
 		goto end;
 	}
 
 	/* change state and send addba resp */
-	tid_agg_rx->state = HT_AGG_STATE_OPERATIONAL;
+	sta->ampdu_mlme.tid_state_rx[tid] = HT_AGG_STATE_OPERATIONAL;
 	tid_agg_rx->dialog_token = dialog_token;
 	tid_agg_rx->ssn = start_seq_num;
 	tid_agg_rx->head_seq_num = start_seq_num;
@@ -1295,39 +1315,37 @@ static void ieee80211_sta_process_addba_resp(struct net_device *dev,
 	capab = le16_to_cpu(mgmt->u.action.u.addba_resp.capab);
 	tid = (capab & IEEE80211_ADDBA_PARAM_TID_MASK) >> 2;
 
-	state = &sta->ampdu_mlme.tid_tx[tid].state;
+	state = &sta->ampdu_mlme.tid_state_tx[tid];
 
 	spin_lock_bh(&sta->ampdu_mlme.ampdu_tx);
 
+	if (!(*state & HT_ADDBA_REQUESTED_MSK)) {
+		spin_unlock_bh(&sta->ampdu_mlme.ampdu_tx);
+		printk(KERN_DEBUG "state not HT_ADDBA_REQUESTED_MSK:"
+			"%d\n", *state);
+		goto addba_resp_exit;
+	}
+
 	if (mgmt->u.action.u.addba_resp.dialog_token !=
-		sta->ampdu_mlme.tid_tx[tid].dialog_token) {
+		sta->ampdu_mlme.tid_tx[tid]->dialog_token) {
 		spin_unlock_bh(&sta->ampdu_mlme.ampdu_tx);
 #ifdef CONFIG_MAC80211_HT_DEBUG
 		printk(KERN_DEBUG "wrong addBA response token, tid %d\n", tid);
 #endif /* CONFIG_MAC80211_HT_DEBUG */
-		rcu_read_unlock();
-		return;
+		goto addba_resp_exit;
 	}
 
-	del_timer_sync(&sta->ampdu_mlme.tid_tx[tid].addba_resp_timer);
+	del_timer_sync(&sta->ampdu_mlme.tid_tx[tid]->addba_resp_timer);
 #ifdef CONFIG_MAC80211_HT_DEBUG
 	printk(KERN_DEBUG "switched off addBA timer for tid %d \n", tid);
 #endif /* CONFIG_MAC80211_HT_DEBUG */
 	if (le16_to_cpu(mgmt->u.action.u.addba_resp.status)
 			== WLAN_STATUS_SUCCESS) {
-		if (!(*state & HT_ADDBA_REQUESTED_MSK)) {
-			spin_unlock_bh(&sta->ampdu_mlme.ampdu_tx);
-			printk(KERN_DEBUG "state not HT_ADDBA_REQUESTED_MSK:"
-				"%d\n", *state);
-			rcu_read_unlock();
-			return;
-		}
-
 		if (*state & HT_ADDBA_RECEIVED_MSK)
 			printk(KERN_DEBUG "double addBA response\n");
 
 		*state |= HT_ADDBA_RECEIVED_MSK;
-		sta->ampdu_mlme.tid_tx[tid].addba_req_num = 0;
+		sta->ampdu_mlme.addba_req_num[tid] = 0;
 
 		if (*state == HT_AGG_STATE_OPERATIONAL) {
 			printk(KERN_DEBUG "Aggregation on for tid %d \n", tid);
@@ -1339,13 +1357,15 @@ static void ieee80211_sta_process_addba_resp(struct net_device *dev,
 	} else {
 		printk(KERN_DEBUG "recipient rejected agg: tid %d \n", tid);
 
-		sta->ampdu_mlme.tid_tx[tid].addba_req_num++;
+		sta->ampdu_mlme.addba_req_num[tid]++;
 		/* this will allow the state check in stop_BA_session */
 		*state = HT_AGG_STATE_OPERATIONAL;
 		spin_unlock_bh(&sta->ampdu_mlme.ampdu_tx);
 		ieee80211_stop_tx_ba_session(hw, sta->addr, tid,
 					     WLAN_BACK_INITIATOR);
 	}
+
+addba_resp_exit:
 	rcu_read_unlock();
 }
 
@@ -1411,13 +1431,13 @@ void ieee80211_sta_stop_rx_ba_session(struct net_device *dev, u8 *ra, u16 tid,
 
 	/* check if TID is in operational state */
 	spin_lock_bh(&sta->ampdu_mlme.ampdu_rx);
-	if (sta->ampdu_mlme.tid_rx[tid].state
+	if (sta->ampdu_mlme.tid_state_rx[tid]
 				!= HT_AGG_STATE_OPERATIONAL) {
 		spin_unlock_bh(&sta->ampdu_mlme.ampdu_rx);
 		rcu_read_unlock();
 		return;
 	}
-	sta->ampdu_mlme.tid_rx[tid].state =
+	sta->ampdu_mlme.tid_state_rx[tid] =
 		HT_AGG_STATE_REQ_STOP_BA_MSK |
 		(initiator << HT_AGG_STATE_INITIATOR_SHIFT);
 		spin_unlock_bh(&sta->ampdu_mlme.ampdu_rx);
@@ -1434,25 +1454,27 @@ void ieee80211_sta_stop_rx_ba_session(struct net_device *dev, u8 *ra, u16 tid,
 
 	/* shutdown timer has not expired */
 	if (initiator != WLAN_BACK_TIMER)
-		del_timer_sync(&sta->ampdu_mlme.tid_rx[tid].
-					session_timer);
+		del_timer_sync(&sta->ampdu_mlme.tid_rx[tid]->session_timer);
 
 	/* check if this is a self generated aggregation halt */
 	if (initiator == WLAN_BACK_RECIPIENT || initiator == WLAN_BACK_TIMER)
 		ieee80211_send_delba(dev, ra, tid, 0, reason);
 
 	/* free the reordering buffer */
-	for (i = 0; i < sta->ampdu_mlme.tid_rx[tid].buf_size; i++) {
-		if (sta->ampdu_mlme.tid_rx[tid].reorder_buf[i]) {
+	for (i = 0; i < sta->ampdu_mlme.tid_rx[tid]->buf_size; i++) {
+		if (sta->ampdu_mlme.tid_rx[tid]->reorder_buf[i]) {
 			/* release the reordered frames */
-			dev_kfree_skb(sta->ampdu_mlme.tid_rx[tid].reorder_buf[i]);
-			sta->ampdu_mlme.tid_rx[tid].stored_mpdu_num--;
-			sta->ampdu_mlme.tid_rx[tid].reorder_buf[i] = NULL;
+			dev_kfree_skb(sta->ampdu_mlme.tid_rx[tid]->reorder_buf[i]);
+			sta->ampdu_mlme.tid_rx[tid]->stored_mpdu_num--;
+			sta->ampdu_mlme.tid_rx[tid]->reorder_buf[i] = NULL;
 		}
 	}
-	kfree(sta->ampdu_mlme.tid_rx[tid].reorder_buf);
+	/* free resources */
+	kfree(sta->ampdu_mlme.tid_rx[tid]->reorder_buf);
+	kfree(sta->ampdu_mlme.tid_rx[tid]);
+	sta->ampdu_mlme.tid_rx[tid] = NULL;
+	sta->ampdu_mlme.tid_state_rx[tid] = HT_AGG_STATE_IDLE;
 
-	sta->ampdu_mlme.tid_rx[tid].state = HT_AGG_STATE_IDLE;
 	rcu_read_unlock();
 }
 
@@ -1491,7 +1513,7 @@ static void ieee80211_sta_process_delba(struct net_device *dev,
 						 WLAN_BACK_INITIATOR, 0);
 	else { /* WLAN_BACK_RECIPIENT */
 		spin_lock_bh(&sta->ampdu_mlme.ampdu_tx);
-		sta->ampdu_mlme.tid_tx[tid].state =
+		sta->ampdu_mlme.tid_state_tx[tid] =
 				HT_AGG_STATE_OPERATIONAL;
 		spin_unlock_bh(&sta->ampdu_mlme.ampdu_tx);
 		ieee80211_stop_tx_ba_session(&local->hw, sta->addr, tid,
@@ -1528,7 +1550,7 @@ void sta_addba_resp_timer_expired(unsigned long data)
 		return;
 	}
 
-	state = &sta->ampdu_mlme.tid_tx[tid].state;
+	state = &sta->ampdu_mlme.tid_state_tx[tid];
 	/* check if the TID waits for addBA response */
 	spin_lock_bh(&sta->ampdu_mlme.ampdu_tx);
 	if (!(*state & HT_ADDBA_REQUESTED_MSK)) {
diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index 644d2774469..d9c6ed5be4f 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -1514,9 +1514,10 @@ ieee80211_rx_h_ctrl(struct ieee80211_rx_data *rx)
 		if (!rx->sta)
 			return RX_CONTINUE;
 		tid = le16_to_cpu(bar->control) >> 12;
-		tid_agg_rx = &(rx->sta->ampdu_mlme.tid_rx[tid]);
-		if (tid_agg_rx->state != HT_AGG_STATE_OPERATIONAL)
+		if (rx->sta->ampdu_mlme.tid_state_rx[tid]
+					!= HT_AGG_STATE_OPERATIONAL)
 			return RX_CONTINUE;
+		tid_agg_rx = rx->sta->ampdu_mlme.tid_rx[tid];
 
 		start_seq_num = le16_to_cpu(bar->start_seq_num) >> 4;
 
@@ -2123,11 +2124,12 @@ static u8 ieee80211_rx_reorder_ampdu(struct ieee80211_local *local,
 
 	qc = skb->data + ieee80211_get_hdrlen(fc) - QOS_CONTROL_LEN;
 	tid = qc[0] & QOS_CONTROL_TID_MASK;
-	tid_agg_rx = &(sta->ampdu_mlme.tid_rx[tid]);
 
-	if (tid_agg_rx->state != HT_AGG_STATE_OPERATIONAL)
+	if (sta->ampdu_mlme.tid_state_rx[tid] != HT_AGG_STATE_OPERATIONAL)
 		goto end_reorder;
 
+	tid_agg_rx = sta->ampdu_mlme.tid_rx[tid];
+
 	/* null data frames are excluded */
 	if (unlikely(fc & IEEE80211_STYPE_NULLFUNC))
 		goto end_reorder;
diff --git a/net/mac80211/sta_info.c b/net/mac80211/sta_info.c
index 3b84c16cf05..f708367092d 100644
--- a/net/mac80211/sta_info.c
+++ b/net/mac80211/sta_info.c
@@ -170,9 +170,16 @@ void sta_info_destroy(struct sta_info *sta)
 		dev_kfree_skb_any(skb);
 
 	for (i = 0; i <  STA_TID_NUM; i++) {
-		del_timer_sync(&sta->ampdu_mlme.tid_rx[i].session_timer);
-		del_timer_sync(&sta->ampdu_mlme.tid_tx[i].addba_resp_timer);
+		spin_lock_bh(&sta->ampdu_mlme.ampdu_rx);
+		if (sta->ampdu_mlme.tid_rx[i])
+		  del_timer_sync(&sta->ampdu_mlme.tid_rx[i]->session_timer);
+		spin_unlock_bh(&sta->ampdu_mlme.ampdu_rx);
+		spin_lock_bh(&sta->ampdu_mlme.ampdu_tx);
+		if (sta->ampdu_mlme.tid_tx[i])
+		  del_timer_sync(&sta->ampdu_mlme.tid_tx[i]->addba_resp_timer);
+		spin_unlock_bh(&sta->ampdu_mlme.ampdu_tx);
 	}
+
 	rate_control_free_sta(sta->rate_ctrl, sta->rate_ctrl_priv);
 	rate_control_put(sta->rate_ctrl);
 
@@ -227,18 +234,13 @@ struct sta_info *sta_info_alloc(struct ieee80211_sub_if_data *sdata,
 		sta->timer_to_tid[i] = i;
 		/* tid to tx queue: initialize according to HW (0 is valid) */
 		sta->tid_to_tx_q[i] = local->hw.queues;
-		/* rx timers */
-		sta->ampdu_mlme.tid_rx[i].session_timer.function =
-			sta_rx_agg_session_timer_expired;
-		sta->ampdu_mlme.tid_rx[i].session_timer.data =
-			(unsigned long)&sta->timer_to_tid[i];
-		init_timer(&sta->ampdu_mlme.tid_rx[i].session_timer);
-		/* tx timers */
-		sta->ampdu_mlme.tid_tx[i].addba_resp_timer.function =
-			sta_addba_resp_timer_expired;
-		sta->ampdu_mlme.tid_tx[i].addba_resp_timer.data =
-			(unsigned long)&sta->timer_to_tid[i];
-		init_timer(&sta->ampdu_mlme.tid_tx[i].addba_resp_timer);
+		/* rx */
+		sta->ampdu_mlme.tid_state_rx[i] = HT_AGG_STATE_IDLE;
+		sta->ampdu_mlme.tid_rx[i] = NULL;
+		/* tx */
+		sta->ampdu_mlme.tid_state_tx[i] = HT_AGG_STATE_IDLE;
+		sta->ampdu_mlme.tid_tx[i] = NULL;
+		sta->ampdu_mlme.addba_req_num[i] = 0;
 	}
 	skb_queue_head_init(&sta->ps_tx_buf);
 	skb_queue_head_init(&sta->tx_filtered);
diff --git a/net/mac80211/sta_info.h b/net/mac80211/sta_info.h
index 5d6b43652e1..af5a791e21f 100644
--- a/net/mac80211/sta_info.h
+++ b/net/mac80211/sta_info.h
@@ -68,43 +68,37 @@ enum ieee80211_sta_info_flags {
 /**
  * struct tid_ampdu_tx - TID aggregation information (Tx).
  *
- * @state: TID's state in session state machine.
- * @dialog_token: dialog token for aggregation session
- * @ssn: Starting Sequence Number expected to be aggregated.
  * @addba_resp_timer: timer for peer's response to addba request
- * @addba_req_num: number of times addBA request has been sent.
+ * @ssn: Starting Sequence Number expected to be aggregated.
+ * @dialog_token: dialog token for aggregation session
  */
 struct tid_ampdu_tx {
-	u8 state;
-	u8 dialog_token;
-	u16 ssn;
 	struct timer_list addba_resp_timer;
-	u8 addba_req_num;
+	u16 ssn;
+	u8 dialog_token;
 };
 
 /**
  * struct tid_ampdu_rx - TID aggregation information (Rx).
  *
- * @state: TID's state in session state machine.
- * @dialog_token: dialog token for aggregation session
- * @ssn: Starting Sequence Number expected to be aggregated.
- * @buf_size: buffer size for incoming A-MPDUs
- * @timeout: reset timer value.
  * @head_seq_num: head sequence number in reordering buffer.
  * @stored_mpdu_num: number of MPDUs in reordering buffer
  * @reorder_buf: buffer to reorder incoming aggregated MPDUs
  * @session_timer: check if peer keeps Tx-ing on the TID (by timeout value)
+ * @ssn: Starting Sequence Number expected to be aggregated.
+ * @buf_size: buffer size for incoming A-MPDUs
+ * @timeout: reset timer value.
+ * @dialog_token: dialog token for aggregation session
  */
 struct tid_ampdu_rx {
-	u8 state;
-	u8 dialog_token;
-	u16 ssn;
-	u16 buf_size;
-	u16 timeout;
 	u16 head_seq_num;
 	u16 stored_mpdu_num;
 	struct sk_buff **reorder_buf;
 	struct timer_list session_timer;
+	u16 ssn;
+	u16 buf_size;
+	u16 timeout;
+	u8 dialog_token;
 };
 
 /**
@@ -133,16 +127,24 @@ enum plink_state {
 /**
  * struct sta_ampdu_mlme - STA aggregation information.
  *
+ * @tid_state_rx: TID's state in Rx session state machine.
  * @tid_rx: aggregation info for Rx per TID
- * @tid_tx: aggregation info for Tx per TID
  * @ampdu_rx: for locking sections in aggregation Rx flow
+ * @tid_state_tx: TID's state in Tx session state machine.
+ * @tid_tx: aggregation info for Tx per TID
+ * @addba_req_num: number of times addBA request has been sent.
  * @ampdu_tx: for locking sectionsi in aggregation Tx flow
  * @dialog_token_allocator: dialog token enumerator for each new session;
  */
 struct sta_ampdu_mlme {
-	struct tid_ampdu_rx tid_rx[STA_TID_NUM];
-	struct tid_ampdu_tx tid_tx[STA_TID_NUM];
+	/* rx */
+	u8 tid_state_rx[STA_TID_NUM];
+	struct tid_ampdu_rx *tid_rx[STA_TID_NUM];
 	spinlock_t ampdu_rx;
+	/* tx */
+	u8 tid_state_tx[STA_TID_NUM];
+	struct tid_ampdu_tx *tid_tx[STA_TID_NUM];
+	u8 addba_req_num[STA_TID_NUM];
 	spinlock_t ampdu_tx;
 	u8 dialog_token_allocator;
 };