mac80211: restructure HT code

Create two new files, agg-tx.c and agg-rx.c to make it clearer
which code is common (ht.c) and which is specific (agg-*.c).

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 593 insertions, 0 deletions

diff --git a/net/mac80211/agg-tx.c b/net/mac80211/agg-tx.c
new file mode 100644
index 000000000000..6ab731fecc20
--- /dev/null
+++ b/net/mac80211/agg-tx.c
@@ -0,0 +1,593 @@
+/*
+ * HT handling
+ *
+ * Copyright 2003, Jouni Malinen <jkmaline@cc.hut.fi>
+ * Copyright 2002-2005, Instant802 Networks, Inc.
+ * Copyright 2005-2006, Devicescape Software, Inc.
+ * Copyright 2006-2007  Jiri Benc <jbenc@suse.cz>
+ * Copyright 2007, Michael Wu <flamingice@sourmilk.net>
+ * Copyright 2007-2009, Intel Corporation
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/ieee80211.h>
+#include <net/mac80211.h>
+#include "ieee80211_i.h"
+#include "wme.h"
+
+static void ieee80211_send_addba_request(struct ieee80211_sub_if_data *sdata,
+                                         const u8 *da, u16 tid,
+                                         u8 dialog_token, u16 start_seq_num,
+                                         u16 agg_size, u16 timeout)
+{
+        struct ieee80211_local *local = sdata->local;
+        struct ieee80211_if_sta *ifsta = &sdata->u.sta;
+        struct sk_buff *skb;
+        struct ieee80211_mgmt *mgmt;
+        u16 capab;
+
+        skb = dev_alloc_skb(sizeof(*mgmt) + local->hw.extra_tx_headroom);
+
+        if (!skb) {
+                printk(KERN_ERR "%s: failed to allocate buffer "
+                                "for addba request frame\n", sdata->dev->name);
+                return;
+        }
+        skb_reserve(skb, local->hw.extra_tx_headroom);
+        mgmt = (struct ieee80211_mgmt *) skb_put(skb, 24);
+        memset(mgmt, 0, 24);
+        memcpy(mgmt->da, da, ETH_ALEN);
+        memcpy(mgmt->sa, sdata->dev->dev_addr, ETH_ALEN);
+        if (sdata->vif.type == NL80211_IFTYPE_AP)
+                memcpy(mgmt->bssid, sdata->dev->dev_addr, ETH_ALEN);
+        else
+                memcpy(mgmt->bssid, ifsta->bssid, ETH_ALEN);
+
+        mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
+                                          IEEE80211_STYPE_ACTION);
+
+        skb_put(skb, 1 + sizeof(mgmt->u.action.u.addba_req));
+
+        mgmt->u.action.category = WLAN_CATEGORY_BACK;
+        mgmt->u.action.u.addba_req.action_code = WLAN_ACTION_ADDBA_REQ;
+
+        mgmt->u.action.u.addba_req.dialog_token = dialog_token;
+        capab = (u16)(1 << 1);          /* bit 1 aggregation policy */
+        capab |= (u16)(tid << 2);       /* bit 5:2 TID number */
+        capab |= (u16)(agg_size << 6);  /* bit 15:6 max size of aggergation */
+
+        mgmt->u.action.u.addba_req.capab = cpu_to_le16(capab);
+
+        mgmt->u.action.u.addba_req.timeout = cpu_to_le16(timeout);
+        mgmt->u.action.u.addba_req.start_seq_num =
+                                        cpu_to_le16(start_seq_num << 4);
+
+        ieee80211_tx_skb(sdata, skb, 1);
+}
+
+void ieee80211_send_bar(struct ieee80211_sub_if_data *sdata, u8 *ra, u16 tid, u16 ssn)
+{
+        struct ieee80211_local *local = sdata->local;
+        struct sk_buff *skb;
+        struct ieee80211_bar *bar;
+        u16 bar_control = 0;
+
+        skb = dev_alloc_skb(sizeof(*bar) + local->hw.extra_tx_headroom);
+        if (!skb) {
+                printk(KERN_ERR "%s: failed to allocate buffer for "
+                        "bar frame\n", sdata->dev->name);
+                return;
+        }
+        skb_reserve(skb, local->hw.extra_tx_headroom);
+        bar = (struct ieee80211_bar *)skb_put(skb, sizeof(*bar));
+        memset(bar, 0, sizeof(*bar));
+        bar->frame_control = cpu_to_le16(IEEE80211_FTYPE_CTL |
+                                         IEEE80211_STYPE_BACK_REQ);
+        memcpy(bar->ra, ra, ETH_ALEN);
+        memcpy(bar->ta, sdata->dev->dev_addr, ETH_ALEN);
+        bar_control |= (u16)IEEE80211_BAR_CTRL_ACK_POLICY_NORMAL;
+        bar_control |= (u16)IEEE80211_BAR_CTRL_CBMTID_COMPRESSED_BA;
+        bar_control |= (u16)(tid << 12);
+        bar->control = cpu_to_le16(bar_control);
+        bar->start_seq_num = cpu_to_le16(ssn);
+
+        ieee80211_tx_skb(sdata, skb, 0);
+}
+
+/*
+ * After sending add Block Ack request we activated a timer until
+ * add Block Ack response will arrive from the recipient.
+ * If this timer expires sta_addba_resp_timer_expired will be executed.
+ */
+static void sta_addba_resp_timer_expired(unsigned long data)
+{
+        /* not an elegant detour, but there is no choice as the timer passes
+         * only one argument, and both sta_info and TID are needed, so init
+         * flow in sta_info_create gives the TID as data, while the timer_to_id
+         * array gives the sta through container_of */
+        u16 tid = *(u8 *)data;
+        struct sta_info *temp_sta = container_of((void *)data,
+                struct sta_info, timer_to_tid[tid]);
+
+        struct ieee80211_local *local = temp_sta->local;
+        struct ieee80211_hw *hw = &local->hw;
+        struct sta_info *sta;
+        u8 *state;
+
+        rcu_read_lock();
+
+        sta = sta_info_get(local, temp_sta->sta.addr);
+        if (!sta) {
+                rcu_read_unlock();
+                return;
+        }
+
+        state = &sta->ampdu_mlme.tid_state_tx[tid];
+        /* check if the TID waits for addBA response */
+        spin_lock_bh(&sta->lock);
+        if (!(*state & HT_ADDBA_REQUESTED_MSK)) {
+                spin_unlock_bh(&sta->lock);
+                *state = HT_AGG_STATE_IDLE;
+#ifdef CONFIG_MAC80211_HT_DEBUG
+                printk(KERN_DEBUG "timer expired on tid %d but we are not "
+                                "expecting addBA response there", tid);
+#endif
+                goto timer_expired_exit;
+        }
+
+#ifdef CONFIG_MAC80211_HT_DEBUG
+        printk(KERN_DEBUG "addBA response timer expired on tid %d\n", tid);
+#endif
+
+        /* go through the state check in stop_BA_session */
+        *state = HT_AGG_STATE_OPERATIONAL;
+        spin_unlock_bh(&sta->lock);
+        ieee80211_stop_tx_ba_session(hw, temp_sta->sta.addr, tid,
+                                     WLAN_BACK_INITIATOR);
+
+timer_expired_exit:
+        rcu_read_unlock();
+}
+
+int ieee80211_start_tx_ba_session(struct ieee80211_hw *hw, u8 *ra, u16 tid)
+{
+        struct ieee80211_local *local = hw_to_local(hw);
+        struct sta_info *sta;
+        struct ieee80211_sub_if_data *sdata;
+        u16 start_seq_num;
+        u8 *state;
+        int ret = 0;
+
+        if ((tid >= STA_TID_NUM) || !(hw->flags & IEEE80211_HW_AMPDU_AGGREGATION))
+                return -EINVAL;
+
+#ifdef CONFIG_MAC80211_HT_DEBUG
+        printk(KERN_DEBUG "Open BA session requested for %pM tid %u\n",
+               ra, tid);
+#endif /* CONFIG_MAC80211_HT_DEBUG */
+
+        rcu_read_lock();
+
+        sta = sta_info_get(local, ra);
+        if (!sta) {
+#ifdef CONFIG_MAC80211_HT_DEBUG
+                printk(KERN_DEBUG "Could not find the station\n");
+#endif
+                ret = -ENOENT;
+                goto exit;
+        }
+
+        spin_lock_bh(&sta->lock);
+
+        /* we have tried too many times, receiver does not want A-MPDU */
+        if (sta->ampdu_mlme.addba_req_num[tid] > HT_AGG_MAX_RETRIES) {
+                ret = -EBUSY;
+                goto err_unlock_sta;
+        }
+
+        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
+                printk(KERN_DEBUG "BA request denied - session is not "
+                                 "idle on tid %u\n", tid);
+#endif /* CONFIG_MAC80211_HT_DEBUG */
+                ret = -EAGAIN;
+                goto err_unlock_sta;
+        }
+
+        /* 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]) {
+#ifdef CONFIG_MAC80211_HT_DEBUG
+                if (net_ratelimit())
+                        printk(KERN_ERR "allocate tx mlme to tid %d failed\n",
+                                        tid);
+#endif
+                ret = -ENOMEM;
+                goto err_unlock_sta;
+        }
+        /* 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);
+
+        if (hw->ampdu_queues) {
+                /* create a new queue for this aggregation */
+                ret = ieee80211_ht_agg_queue_add(local, sta, tid);
+
+                /* case no queue is available to aggregation
+                 * don't switch to aggregation */
+                if (ret) {
+#ifdef CONFIG_MAC80211_HT_DEBUG
+                        printk(KERN_DEBUG "BA request denied - "
+                               "queue unavailable for tid %d\n", tid);
+#endif /* CONFIG_MAC80211_HT_DEBUG */
+                        goto err_unlock_queue;
+                }
+        }
+        sdata = sta->sdata;
+
+        /* Ok, the Addba frame hasn't been sent yet, but if the driver calls the
+         * call back right away, it must see that the flow has begun */
+        *state |= HT_ADDBA_REQUESTED_MSK;
+
+        /* This is slightly racy because the queue isn't stopped */
+        start_seq_num = sta->tid_seq[tid];
+
+        if (local->ops->ampdu_action)
+                ret = local->ops->ampdu_action(hw, IEEE80211_AMPDU_TX_START,
+                                               &sta->sta, tid, &start_seq_num);
+
+        if (ret) {
+                /* No need to requeue the packets in the agg queue, since we
+                 * held the tx lock: no packet could be enqueued to the newly
+                 * allocated queue */
+                if (hw->ampdu_queues)
+                        ieee80211_ht_agg_queue_remove(local, sta, tid, 0);
+#ifdef CONFIG_MAC80211_HT_DEBUG
+                printk(KERN_DEBUG "BA request denied - HW unavailable for"
+                                        " tid %d\n", tid);
+#endif /* CONFIG_MAC80211_HT_DEBUG */
+                *state = HT_AGG_STATE_IDLE;
+                goto err_unlock_queue;
+        }
+
+        /* Will put all the packets in the new SW queue */
+        if (hw->ampdu_queues)
+                ieee80211_requeue(local, ieee802_1d_to_ac[tid]);
+        spin_unlock_bh(&sta->lock);
+
+        /* send an addBA request */
+        sta->ampdu_mlme.dialog_token_allocator++;
+        sta->ampdu_mlme.tid_tx[tid]->dialog_token =
+                        sta->ampdu_mlme.dialog_token_allocator;
+        sta->ampdu_mlme.tid_tx[tid]->ssn = start_seq_num;
+
+
+        ieee80211_send_addba_request(sta->sdata, ra, tid,
+                         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 =
+                                jiffies + ADDBA_RESP_INTERVAL;
+        add_timer(&sta->ampdu_mlme.tid_tx[tid]->addba_resp_timer);
+#ifdef CONFIG_MAC80211_HT_DEBUG
+        printk(KERN_DEBUG "activated addBA response timer on tid %d\n", tid);
+#endif
+        goto exit;
+
+err_unlock_queue:
+        kfree(sta->ampdu_mlme.tid_tx[tid]);
+        sta->ampdu_mlme.tid_tx[tid] = NULL;
+        ret = -EBUSY;
+err_unlock_sta:
+        spin_unlock_bh(&sta->lock);
+exit:
+        rcu_read_unlock();
+        return ret;
+}
+EXPORT_SYMBOL(ieee80211_start_tx_ba_session);
+
+void ieee80211_start_tx_ba_cb(struct ieee80211_hw *hw, u8 *ra, u16 tid)
+{
+        struct ieee80211_local *local = hw_to_local(hw);
+        struct sta_info *sta;
+        u8 *state;
+
+        if (tid >= STA_TID_NUM) {
+#ifdef CONFIG_MAC80211_HT_DEBUG
+                printk(KERN_DEBUG "Bad TID value: tid = %d (>= %d)\n",
+                                tid, STA_TID_NUM);
+#endif
+                return;
+        }
+
+        rcu_read_lock();
+        sta = sta_info_get(local, ra);
+        if (!sta) {
+                rcu_read_unlock();
+#ifdef CONFIG_MAC80211_HT_DEBUG
+                printk(KERN_DEBUG "Could not find station: %pM\n", ra);
+#endif
+                return;
+        }
+
+        state = &sta->ampdu_mlme.tid_state_tx[tid];
+        spin_lock_bh(&sta->lock);
+
+        if (!(*state & HT_ADDBA_REQUESTED_MSK)) {
+#ifdef CONFIG_MAC80211_HT_DEBUG
+                printk(KERN_DEBUG "addBA was not requested yet, state is %d\n",
+                                *state);
+#endif
+                spin_unlock_bh(&sta->lock);
+                rcu_read_unlock();
+                return;
+        }
+
+        WARN_ON_ONCE(*state & HT_ADDBA_DRV_READY_MSK);
+
+        *state |= HT_ADDBA_DRV_READY_MSK;
+
+        if (*state == HT_AGG_STATE_OPERATIONAL) {
+#ifdef CONFIG_MAC80211_HT_DEBUG
+                printk(KERN_DEBUG "Aggregation is on for tid %d \n", tid);
+#endif
+                if (hw->ampdu_queues)
+                        ieee80211_wake_queue(hw, sta->tid_to_tx_q[tid]);
+        }
+        spin_unlock_bh(&sta->lock);
+        rcu_read_unlock();
+}
+EXPORT_SYMBOL(ieee80211_start_tx_ba_cb);
+
+
+int ieee80211_stop_tx_ba_session(struct ieee80211_hw *hw,
+                                 u8 *ra, u16 tid,
+                                 enum ieee80211_back_parties initiator)
+{
+        struct ieee80211_local *local = hw_to_local(hw);
+        struct sta_info *sta;
+        u8 *state;
+        int ret = 0;
+
+        if (tid >= STA_TID_NUM)
+                return -EINVAL;
+
+        rcu_read_lock();
+        sta = sta_info_get(local, ra);
+        if (!sta) {
+                rcu_read_unlock();
+                return -ENOENT;
+        }
+
+        /* check if the TID is in aggregation */
+        state = &sta->ampdu_mlme.tid_state_tx[tid];
+        spin_lock_bh(&sta->lock);
+
+        if (*state != HT_AGG_STATE_OPERATIONAL) {
+                ret = -ENOENT;
+                goto stop_BA_exit;
+        }
+
+#ifdef CONFIG_MAC80211_HT_DEBUG
+        printk(KERN_DEBUG "Tx BA session stop requested for %pM tid %u\n",
+               ra, tid);
+#endif /* CONFIG_MAC80211_HT_DEBUG */
+
+        if (hw->ampdu_queues)
+                ieee80211_stop_queue(hw, sta->tid_to_tx_q[tid]);
+
+        *state = HT_AGG_STATE_REQ_STOP_BA_MSK |
+                (initiator << HT_AGG_STATE_INITIATOR_SHIFT);
+
+        if (local->ops->ampdu_action)
+                ret = local->ops->ampdu_action(hw, IEEE80211_AMPDU_TX_STOP,
+                                               &sta->sta, tid, NULL);
+
+        /* case HW denied going back to legacy */
+        if (ret) {
+                WARN_ON(ret != -EBUSY);
+                *state = HT_AGG_STATE_OPERATIONAL;
+                if (hw->ampdu_queues)
+                        ieee80211_wake_queue(hw, sta->tid_to_tx_q[tid]);
+                goto stop_BA_exit;
+        }
+
+stop_BA_exit:
+        spin_unlock_bh(&sta->lock);
+        rcu_read_unlock();
+        return ret;
+}
+EXPORT_SYMBOL(ieee80211_stop_tx_ba_session);
+
+void ieee80211_stop_tx_ba_cb(struct ieee80211_hw *hw, u8 *ra, u8 tid)
+{
+        struct ieee80211_local *local = hw_to_local(hw);
+        struct sta_info *sta;
+        u8 *state;
+        int agg_queue;
+
+        if (tid >= STA_TID_NUM) {
+#ifdef CONFIG_MAC80211_HT_DEBUG
+                printk(KERN_DEBUG "Bad TID value: tid = %d (>= %d)\n",
+                                tid, STA_TID_NUM);
+#endif
+                return;
+        }
+
+#ifdef CONFIG_MAC80211_HT_DEBUG
+        printk(KERN_DEBUG "Stopping Tx BA session for %pM tid %d\n",
+               ra, tid);
+#endif /* CONFIG_MAC80211_HT_DEBUG */
+
+        rcu_read_lock();
+        sta = sta_info_get(local, ra);
+        if (!sta) {
+#ifdef CONFIG_MAC80211_HT_DEBUG
+                printk(KERN_DEBUG "Could not find station: %pM\n", ra);
+#endif
+                rcu_read_unlock();
+                return;
+        }
+        state = &sta->ampdu_mlme.tid_state_tx[tid];
+
+        /* NOTE: no need to use sta->lock in this state check, as
+         * ieee80211_stop_tx_ba_session will let only one stop call to
+         * pass through per sta/tid
+         */
+        if ((*state & HT_AGG_STATE_REQ_STOP_BA_MSK) == 0) {
+#ifdef CONFIG_MAC80211_HT_DEBUG
+                printk(KERN_DEBUG "unexpected callback to A-MPDU stop\n");
+#endif
+                rcu_read_unlock();
+                return;
+        }
+
+        if (*state & HT_AGG_STATE_INITIATOR_MSK)
+                ieee80211_send_delba(sta->sdata, ra, tid,
+                        WLAN_BACK_INITIATOR, WLAN_REASON_QSTA_NOT_USE);
+
+        if (hw->ampdu_queues) {
+                agg_queue = sta->tid_to_tx_q[tid];
+                ieee80211_ht_agg_queue_remove(local, sta, tid, 1);
+
+                /* We just requeued the all the frames that were in the
+                 * removed queue, and since we might miss a softirq we do
+                 * netif_schedule_queue.  ieee80211_wake_queue is not used
+                 * here as this queue is not necessarily stopped
+                 */
+                netif_schedule_queue(netdev_get_tx_queue(local->mdev,
+                                                         agg_queue));
+        }
+        spin_lock_bh(&sta->lock);
+        *state = HT_AGG_STATE_IDLE;
+        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->lock);
+
+        rcu_read_unlock();
+}
+EXPORT_SYMBOL(ieee80211_stop_tx_ba_cb);
+
+void ieee80211_start_tx_ba_cb_irqsafe(struct ieee80211_hw *hw,
+                                      const u8 *ra, u16 tid)
+{
+        struct ieee80211_local *local = hw_to_local(hw);
+        struct ieee80211_ra_tid *ra_tid;
+        struct sk_buff *skb = dev_alloc_skb(0);
+
+        if (unlikely(!skb)) {
+#ifdef CONFIG_MAC80211_HT_DEBUG
+                if (net_ratelimit())
+                        printk(KERN_WARNING "%s: Not enough memory, "
+                               "dropping start BA session", skb->dev->name);
+#endif
+                return;
+        }
+        ra_tid = (struct ieee80211_ra_tid *) &skb->cb;
+        memcpy(&ra_tid->ra, ra, ETH_ALEN);
+        ra_tid->tid = tid;
+
+        skb->pkt_type = IEEE80211_ADDBA_MSG;
+        skb_queue_tail(&local->skb_queue, skb);
+        tasklet_schedule(&local->tasklet);
+}
+EXPORT_SYMBOL(ieee80211_start_tx_ba_cb_irqsafe);
+
+void ieee80211_stop_tx_ba_cb_irqsafe(struct ieee80211_hw *hw,
+                                     const u8 *ra, u16 tid)
+{
+        struct ieee80211_local *local = hw_to_local(hw);
+        struct ieee80211_ra_tid *ra_tid;
+        struct sk_buff *skb = dev_alloc_skb(0);
+
+        if (unlikely(!skb)) {
+#ifdef CONFIG_MAC80211_HT_DEBUG
+                if (net_ratelimit())
+                        printk(KERN_WARNING "%s: Not enough memory, "
+                               "dropping stop BA session", skb->dev->name);
+#endif
+                return;
+        }
+        ra_tid = (struct ieee80211_ra_tid *) &skb->cb;
+        memcpy(&ra_tid->ra, ra, ETH_ALEN);
+        ra_tid->tid = tid;
+
+        skb->pkt_type = IEEE80211_DELBA_MSG;
+        skb_queue_tail(&local->skb_queue, skb);
+        tasklet_schedule(&local->tasklet);
+}
+EXPORT_SYMBOL(ieee80211_stop_tx_ba_cb_irqsafe);
+
+void ieee80211_process_addba_resp(struct ieee80211_local *local,
+                                  struct sta_info *sta,
+                                  struct ieee80211_mgmt *mgmt,
+                                  size_t len)
+{
+        struct ieee80211_hw *hw = &local->hw;
+        u16 capab;
+        u16 tid, start_seq_num;
+        u8 *state;
+
+        capab = le16_to_cpu(mgmt->u.action.u.addba_resp.capab);
+        tid = (capab & IEEE80211_ADDBA_PARAM_TID_MASK) >> 2;
+
+        state = &sta->ampdu_mlme.tid_state_tx[tid];
+
+        spin_lock_bh(&sta->lock);
+
+        if (!(*state & HT_ADDBA_REQUESTED_MSK)) {
+                spin_unlock_bh(&sta->lock);
+                return;
+        }
+
+        if (mgmt->u.action.u.addba_resp.dialog_token !=
+                sta->ampdu_mlme.tid_tx[tid]->dialog_token) {
+                spin_unlock_bh(&sta->lock);
+#ifdef CONFIG_MAC80211_HT_DEBUG
+                printk(KERN_DEBUG "wrong addBA response token, tid %d\n", tid);
+#endif /* CONFIG_MAC80211_HT_DEBUG */
+                return;
+        }
+
+        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) {
+                *state |= HT_ADDBA_RECEIVED_MSK;
+                sta->ampdu_mlme.addba_req_num[tid] = 0;
+
+                if (*state == HT_AGG_STATE_OPERATIONAL &&
+                    local->hw.ampdu_queues)
+                        ieee80211_wake_queue(hw, sta->tid_to_tx_q[tid]);
+
+                if (local->ops->ampdu_action) {
+                        (void)local->ops->ampdu_action(hw,
+                                               IEEE80211_AMPDU_TX_RESUME,
+                                               &sta->sta, tid, &start_seq_num);
+                }
+#ifdef CONFIG_MAC80211_HT_DEBUG
+                printk(KERN_DEBUG "Resuming TX aggregation for tid %d\n", tid);
+#endif /* CONFIG_MAC80211_HT_DEBUG */
+                spin_unlock_bh(&sta->lock);
+        } else {
+                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->lock);
+                ieee80211_stop_tx_ba_session(hw, sta->sta.addr, tid,
+                                             WLAN_BACK_INITIATOR);
+        }
+}