net: amend the fix for SO_BSDCOMPAT gsopt infoleak
[pandora-kernel.git] / net / mac80211 / ht.c
1 /*
2  * HT handling
3  *
4  * Copyright 2003, Jouni Malinen <jkmaline@cc.hut.fi>
5  * Copyright 2002-2005, Instant802 Networks, Inc.
6  * Copyright 2005-2006, Devicescape Software, Inc.
7  * Copyright 2006-2007  Jiri Benc <jbenc@suse.cz>
8  * Copyright 2007, Michael Wu <flamingice@sourmilk.net>
9  * Copyright 2007-2008, Intel Corporation
10  *
11  * This program is free software; you can redistribute it and/or modify
12  * it under the terms of the GNU General Public License version 2 as
13  * published by the Free Software Foundation.
14  */
15
16 #include <linux/ieee80211.h>
17 #include <net/wireless.h>
18 #include <net/mac80211.h>
19 #include "ieee80211_i.h"
20 #include "sta_info.h"
21 #include "wme.h"
22
23 void ieee80211_ht_cap_ie_to_sta_ht_cap(struct ieee80211_supported_band *sband,
24                                        struct ieee80211_ht_cap *ht_cap_ie,
25                                        struct ieee80211_sta_ht_cap *ht_cap)
26 {
27         u8 ampdu_info, tx_mcs_set_cap;
28         int i, max_tx_streams;
29
30         BUG_ON(!ht_cap);
31
32         memset(ht_cap, 0, sizeof(*ht_cap));
33
34         if (!ht_cap_ie)
35                 return;
36
37         ht_cap->ht_supported = true;
38
39         ht_cap->cap = le16_to_cpu(ht_cap_ie->cap_info) & sband->ht_cap.cap;
40         ht_cap->cap &= ~IEEE80211_HT_CAP_SM_PS;
41         ht_cap->cap |= sband->ht_cap.cap & IEEE80211_HT_CAP_SM_PS;
42
43         ampdu_info = ht_cap_ie->ampdu_params_info;
44         ht_cap->ampdu_factor =
45                 ampdu_info & IEEE80211_HT_AMPDU_PARM_FACTOR;
46         ht_cap->ampdu_density =
47                 (ampdu_info & IEEE80211_HT_AMPDU_PARM_DENSITY) >> 2;
48
49         /* own MCS TX capabilities */
50         tx_mcs_set_cap = sband->ht_cap.mcs.tx_params;
51
52         /* can we TX with MCS rates? */
53         if (!(tx_mcs_set_cap & IEEE80211_HT_MCS_TX_DEFINED))
54                 return;
55
56         /* Counting from 0, therefore +1 */
57         if (tx_mcs_set_cap & IEEE80211_HT_MCS_TX_RX_DIFF)
58                 max_tx_streams =
59                         ((tx_mcs_set_cap & IEEE80211_HT_MCS_TX_MAX_STREAMS_MASK)
60                                 >> IEEE80211_HT_MCS_TX_MAX_STREAMS_SHIFT) + 1;
61         else
62                 max_tx_streams = IEEE80211_HT_MCS_TX_MAX_STREAMS;
63
64         /*
65          * 802.11n D5.0 20.3.5 / 20.6 says:
66          * - indices 0 to 7 and 32 are single spatial stream
67          * - 8 to 31 are multiple spatial streams using equal modulation
68          *   [8..15 for two streams, 16..23 for three and 24..31 for four]
69          * - remainder are multiple spatial streams using unequal modulation
70          */
71         for (i = 0; i < max_tx_streams; i++)
72                 ht_cap->mcs.rx_mask[i] =
73                         sband->ht_cap.mcs.rx_mask[i] & ht_cap_ie->mcs.rx_mask[i];
74
75         if (tx_mcs_set_cap & IEEE80211_HT_MCS_TX_UNEQUAL_MODULATION)
76                 for (i = IEEE80211_HT_MCS_UNEQUAL_MODULATION_START_BYTE;
77                      i < IEEE80211_HT_MCS_MASK_LEN; i++)
78                         ht_cap->mcs.rx_mask[i] =
79                                 sband->ht_cap.mcs.rx_mask[i] &
80                                         ht_cap_ie->mcs.rx_mask[i];
81
82         /* handle MCS rate 32 too */
83         if (sband->ht_cap.mcs.rx_mask[32/8] & ht_cap_ie->mcs.rx_mask[32/8] & 1)
84                 ht_cap->mcs.rx_mask[32/8] |= 1;
85 }
86
87 /*
88  * ieee80211_enable_ht should be called only after the operating band
89  * has been determined as ht configuration depends on the hw's
90  * HT abilities for a specific band.
91  */
92 u32 ieee80211_enable_ht(struct ieee80211_sub_if_data *sdata,
93                         struct ieee80211_ht_info *hti,
94                         u16 ap_ht_cap_flags)
95 {
96         struct ieee80211_local *local = sdata->local;
97         struct ieee80211_supported_band *sband;
98         struct ieee80211_bss_ht_conf ht;
99         u32 changed = 0;
100         bool enable_ht = true, ht_changed;
101         enum nl80211_channel_type channel_type = NL80211_CHAN_NO_HT;
102
103         sband = local->hw.wiphy->bands[local->hw.conf.channel->band];
104
105         memset(&ht, 0, sizeof(ht));
106
107         /* HT is not supported */
108         if (!sband->ht_cap.ht_supported)
109                 enable_ht = false;
110
111         /* check that channel matches the right operating channel */
112         if (local->hw.conf.channel->center_freq !=
113             ieee80211_channel_to_frequency(hti->control_chan))
114                 enable_ht = false;
115
116         if (enable_ht) {
117                 channel_type = NL80211_CHAN_HT20;
118
119                 if (!(ap_ht_cap_flags & IEEE80211_HT_CAP_40MHZ_INTOLERANT) &&
120                     (sband->ht_cap.cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40) &&
121                     (hti->ht_param & IEEE80211_HT_PARAM_CHAN_WIDTH_ANY)) {
122                         switch(hti->ht_param & IEEE80211_HT_PARAM_CHA_SEC_OFFSET) {
123                         case IEEE80211_HT_PARAM_CHA_SEC_ABOVE:
124                                 channel_type = NL80211_CHAN_HT40PLUS;
125                                 break;
126                         case IEEE80211_HT_PARAM_CHA_SEC_BELOW:
127                                 channel_type = NL80211_CHAN_HT40MINUS;
128                                 break;
129                         }
130                 }
131         }
132
133         ht_changed = local->hw.conf.ht.enabled != enable_ht ||
134                      channel_type != local->hw.conf.ht.channel_type;
135
136         local->oper_channel_type = channel_type;
137         local->hw.conf.ht.enabled = enable_ht;
138
139         if (ht_changed)
140                 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_HT);
141
142         /* disable HT */
143         if (!enable_ht)
144                 return 0;
145
146         ht.operation_mode = le16_to_cpu(hti->operation_mode);
147
148         /* if bss configuration changed store the new one */
149         if (memcmp(&sdata->vif.bss_conf.ht, &ht, sizeof(ht))) {
150                 changed |= BSS_CHANGED_HT;
151                 sdata->vif.bss_conf.ht = ht;
152         }
153
154         return changed;
155 }
156
157 static void ieee80211_send_addba_request(struct ieee80211_sub_if_data *sdata,
158                                          const u8 *da, u16 tid,
159                                          u8 dialog_token, u16 start_seq_num,
160                                          u16 agg_size, u16 timeout)
161 {
162         struct ieee80211_local *local = sdata->local;
163         struct ieee80211_if_sta *ifsta = &sdata->u.sta;
164         struct sk_buff *skb;
165         struct ieee80211_mgmt *mgmt;
166         u16 capab;
167
168         skb = dev_alloc_skb(sizeof(*mgmt) + local->hw.extra_tx_headroom);
169
170         if (!skb) {
171                 printk(KERN_ERR "%s: failed to allocate buffer "
172                                 "for addba request frame\n", sdata->dev->name);
173                 return;
174         }
175         skb_reserve(skb, local->hw.extra_tx_headroom);
176         mgmt = (struct ieee80211_mgmt *) skb_put(skb, 24);
177         memset(mgmt, 0, 24);
178         memcpy(mgmt->da, da, ETH_ALEN);
179         memcpy(mgmt->sa, sdata->dev->dev_addr, ETH_ALEN);
180         if (sdata->vif.type == NL80211_IFTYPE_AP)
181                 memcpy(mgmt->bssid, sdata->dev->dev_addr, ETH_ALEN);
182         else
183                 memcpy(mgmt->bssid, ifsta->bssid, ETH_ALEN);
184
185         mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
186                                           IEEE80211_STYPE_ACTION);
187
188         skb_put(skb, 1 + sizeof(mgmt->u.action.u.addba_req));
189
190         mgmt->u.action.category = WLAN_CATEGORY_BACK;
191         mgmt->u.action.u.addba_req.action_code = WLAN_ACTION_ADDBA_REQ;
192
193         mgmt->u.action.u.addba_req.dialog_token = dialog_token;
194         capab = (u16)(1 << 1);          /* bit 1 aggregation policy */
195         capab |= (u16)(tid << 2);       /* bit 5:2 TID number */
196         capab |= (u16)(agg_size << 6);  /* bit 15:6 max size of aggergation */
197
198         mgmt->u.action.u.addba_req.capab = cpu_to_le16(capab);
199
200         mgmt->u.action.u.addba_req.timeout = cpu_to_le16(timeout);
201         mgmt->u.action.u.addba_req.start_seq_num =
202                                         cpu_to_le16(start_seq_num << 4);
203
204         ieee80211_tx_skb(sdata, skb, 0);
205 }
206
207 static void ieee80211_send_addba_resp(struct ieee80211_sub_if_data *sdata, u8 *da, u16 tid,
208                                       u8 dialog_token, u16 status, u16 policy,
209                                       u16 buf_size, u16 timeout)
210 {
211         struct ieee80211_if_sta *ifsta = &sdata->u.sta;
212         struct ieee80211_local *local = sdata->local;
213         struct sk_buff *skb;
214         struct ieee80211_mgmt *mgmt;
215         u16 capab;
216
217         skb = dev_alloc_skb(sizeof(*mgmt) + local->hw.extra_tx_headroom);
218
219         if (!skb) {
220                 printk(KERN_DEBUG "%s: failed to allocate buffer "
221                        "for addba resp frame\n", sdata->dev->name);
222                 return;
223         }
224
225         skb_reserve(skb, local->hw.extra_tx_headroom);
226         mgmt = (struct ieee80211_mgmt *) skb_put(skb, 24);
227         memset(mgmt, 0, 24);
228         memcpy(mgmt->da, da, ETH_ALEN);
229         memcpy(mgmt->sa, sdata->dev->dev_addr, ETH_ALEN);
230         if (sdata->vif.type == NL80211_IFTYPE_AP)
231                 memcpy(mgmt->bssid, sdata->dev->dev_addr, ETH_ALEN);
232         else
233                 memcpy(mgmt->bssid, ifsta->bssid, ETH_ALEN);
234         mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
235                                           IEEE80211_STYPE_ACTION);
236
237         skb_put(skb, 1 + sizeof(mgmt->u.action.u.addba_resp));
238         mgmt->u.action.category = WLAN_CATEGORY_BACK;
239         mgmt->u.action.u.addba_resp.action_code = WLAN_ACTION_ADDBA_RESP;
240         mgmt->u.action.u.addba_resp.dialog_token = dialog_token;
241
242         capab = (u16)(policy << 1);     /* bit 1 aggregation policy */
243         capab |= (u16)(tid << 2);       /* bit 5:2 TID number */
244         capab |= (u16)(buf_size << 6);  /* bit 15:6 max size of aggregation */
245
246         mgmt->u.action.u.addba_resp.capab = cpu_to_le16(capab);
247         mgmt->u.action.u.addba_resp.timeout = cpu_to_le16(timeout);
248         mgmt->u.action.u.addba_resp.status = cpu_to_le16(status);
249
250         ieee80211_tx_skb(sdata, skb, 0);
251 }
252
253 static void ieee80211_send_delba(struct ieee80211_sub_if_data *sdata,
254                                  const u8 *da, u16 tid,
255                                  u16 initiator, u16 reason_code)
256 {
257         struct ieee80211_local *local = sdata->local;
258         struct ieee80211_if_sta *ifsta = &sdata->u.sta;
259         struct sk_buff *skb;
260         struct ieee80211_mgmt *mgmt;
261         u16 params;
262
263         skb = dev_alloc_skb(sizeof(*mgmt) + local->hw.extra_tx_headroom);
264
265         if (!skb) {
266                 printk(KERN_ERR "%s: failed to allocate buffer "
267                                         "for delba frame\n", sdata->dev->name);
268                 return;
269         }
270
271         skb_reserve(skb, local->hw.extra_tx_headroom);
272         mgmt = (struct ieee80211_mgmt *) skb_put(skb, 24);
273         memset(mgmt, 0, 24);
274         memcpy(mgmt->da, da, ETH_ALEN);
275         memcpy(mgmt->sa, sdata->dev->dev_addr, ETH_ALEN);
276         if (sdata->vif.type == NL80211_IFTYPE_AP)
277                 memcpy(mgmt->bssid, sdata->dev->dev_addr, ETH_ALEN);
278         else
279                 memcpy(mgmt->bssid, ifsta->bssid, ETH_ALEN);
280         mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
281                                           IEEE80211_STYPE_ACTION);
282
283         skb_put(skb, 1 + sizeof(mgmt->u.action.u.delba));
284
285         mgmt->u.action.category = WLAN_CATEGORY_BACK;
286         mgmt->u.action.u.delba.action_code = WLAN_ACTION_DELBA;
287         params = (u16)(initiator << 11);        /* bit 11 initiator */
288         params |= (u16)(tid << 12);             /* bit 15:12 TID number */
289
290         mgmt->u.action.u.delba.params = cpu_to_le16(params);
291         mgmt->u.action.u.delba.reason_code = cpu_to_le16(reason_code);
292
293         ieee80211_tx_skb(sdata, skb, 0);
294 }
295
296 void ieee80211_send_bar(struct ieee80211_sub_if_data *sdata, u8 *ra, u16 tid, u16 ssn)
297 {
298         struct ieee80211_local *local = sdata->local;
299         struct sk_buff *skb;
300         struct ieee80211_bar *bar;
301         u16 bar_control = 0;
302
303         skb = dev_alloc_skb(sizeof(*bar) + local->hw.extra_tx_headroom);
304         if (!skb) {
305                 printk(KERN_ERR "%s: failed to allocate buffer for "
306                         "bar frame\n", sdata->dev->name);
307                 return;
308         }
309         skb_reserve(skb, local->hw.extra_tx_headroom);
310         bar = (struct ieee80211_bar *)skb_put(skb, sizeof(*bar));
311         memset(bar, 0, sizeof(*bar));
312         bar->frame_control = cpu_to_le16(IEEE80211_FTYPE_CTL |
313                                          IEEE80211_STYPE_BACK_REQ);
314         memcpy(bar->ra, ra, ETH_ALEN);
315         memcpy(bar->ta, sdata->dev->dev_addr, ETH_ALEN);
316         bar_control |= (u16)IEEE80211_BAR_CTRL_ACK_POLICY_NORMAL;
317         bar_control |= (u16)IEEE80211_BAR_CTRL_CBMTID_COMPRESSED_BA;
318         bar_control |= (u16)(tid << 12);
319         bar->control = cpu_to_le16(bar_control);
320         bar->start_seq_num = cpu_to_le16(ssn);
321
322         ieee80211_tx_skb(sdata, skb, 0);
323 }
324
325 void ieee80211_sta_stop_rx_ba_session(struct ieee80211_sub_if_data *sdata, u8 *ra, u16 tid,
326                                         u16 initiator, u16 reason)
327 {
328         struct ieee80211_local *local = sdata->local;
329         struct ieee80211_hw *hw = &local->hw;
330         struct sta_info *sta;
331         int ret, i;
332
333         rcu_read_lock();
334
335         sta = sta_info_get(local, ra);
336         if (!sta) {
337                 rcu_read_unlock();
338                 return;
339         }
340
341         /* check if TID is in operational state */
342         spin_lock_bh(&sta->lock);
343         if (sta->ampdu_mlme.tid_state_rx[tid]
344                                 != HT_AGG_STATE_OPERATIONAL) {
345                 spin_unlock_bh(&sta->lock);
346                 rcu_read_unlock();
347                 return;
348         }
349         sta->ampdu_mlme.tid_state_rx[tid] =
350                 HT_AGG_STATE_REQ_STOP_BA_MSK |
351                 (initiator << HT_AGG_STATE_INITIATOR_SHIFT);
352         spin_unlock_bh(&sta->lock);
353
354         /* stop HW Rx aggregation. ampdu_action existence
355          * already verified in session init so we add the BUG_ON */
356         BUG_ON(!local->ops->ampdu_action);
357
358 #ifdef CONFIG_MAC80211_HT_DEBUG
359         printk(KERN_DEBUG "Rx BA session stop requested for %pM tid %u\n",
360                ra, tid);
361 #endif /* CONFIG_MAC80211_HT_DEBUG */
362
363         ret = local->ops->ampdu_action(hw, IEEE80211_AMPDU_RX_STOP,
364                                        &sta->sta, tid, NULL);
365         if (ret)
366                 printk(KERN_DEBUG "HW problem - can not stop rx "
367                                 "aggregation for tid %d\n", tid);
368
369         /* shutdown timer has not expired */
370         if (initiator != WLAN_BACK_TIMER)
371                 del_timer_sync(&sta->ampdu_mlme.tid_rx[tid]->session_timer);
372
373         /* check if this is a self generated aggregation halt */
374         if (initiator == WLAN_BACK_RECIPIENT || initiator == WLAN_BACK_TIMER)
375                 ieee80211_send_delba(sdata, ra, tid, 0, reason);
376
377         /* free the reordering buffer */
378         for (i = 0; i < sta->ampdu_mlme.tid_rx[tid]->buf_size; i++) {
379                 if (sta->ampdu_mlme.tid_rx[tid]->reorder_buf[i]) {
380                         /* release the reordered frames */
381                         dev_kfree_skb(sta->ampdu_mlme.tid_rx[tid]->reorder_buf[i]);
382                         sta->ampdu_mlme.tid_rx[tid]->stored_mpdu_num--;
383                         sta->ampdu_mlme.tid_rx[tid]->reorder_buf[i] = NULL;
384                 }
385         }
386         /* free resources */
387         kfree(sta->ampdu_mlme.tid_rx[tid]->reorder_buf);
388         kfree(sta->ampdu_mlme.tid_rx[tid]);
389         sta->ampdu_mlme.tid_rx[tid] = NULL;
390         sta->ampdu_mlme.tid_state_rx[tid] = HT_AGG_STATE_IDLE;
391
392         rcu_read_unlock();
393 }
394
395
396 /*
397  * After sending add Block Ack request we activated a timer until
398  * add Block Ack response will arrive from the recipient.
399  * If this timer expires sta_addba_resp_timer_expired will be executed.
400  */
401 static void sta_addba_resp_timer_expired(unsigned long data)
402 {
403         /* not an elegant detour, but there is no choice as the timer passes
404          * only one argument, and both sta_info and TID are needed, so init
405          * flow in sta_info_create gives the TID as data, while the timer_to_id
406          * array gives the sta through container_of */
407         u16 tid = *(u8 *)data;
408         struct sta_info *temp_sta = container_of((void *)data,
409                 struct sta_info, timer_to_tid[tid]);
410
411         struct ieee80211_local *local = temp_sta->local;
412         struct ieee80211_hw *hw = &local->hw;
413         struct sta_info *sta;
414         u8 *state;
415
416         rcu_read_lock();
417
418         sta = sta_info_get(local, temp_sta->sta.addr);
419         if (!sta) {
420                 rcu_read_unlock();
421                 return;
422         }
423
424         state = &sta->ampdu_mlme.tid_state_tx[tid];
425         /* check if the TID waits for addBA response */
426         spin_lock_bh(&sta->lock);
427         if (!(*state & HT_ADDBA_REQUESTED_MSK)) {
428                 spin_unlock_bh(&sta->lock);
429                 *state = HT_AGG_STATE_IDLE;
430 #ifdef CONFIG_MAC80211_HT_DEBUG
431                 printk(KERN_DEBUG "timer expired on tid %d but we are not "
432                                 "expecting addBA response there", tid);
433 #endif
434                 goto timer_expired_exit;
435         }
436
437 #ifdef CONFIG_MAC80211_HT_DEBUG
438         printk(KERN_DEBUG "addBA response timer expired on tid %d\n", tid);
439 #endif
440
441         /* go through the state check in stop_BA_session */
442         *state = HT_AGG_STATE_OPERATIONAL;
443         spin_unlock_bh(&sta->lock);
444         ieee80211_stop_tx_ba_session(hw, temp_sta->sta.addr, tid,
445                                      WLAN_BACK_INITIATOR);
446
447 timer_expired_exit:
448         rcu_read_unlock();
449 }
450
451 void ieee80211_sta_tear_down_BA_sessions(struct ieee80211_sub_if_data *sdata, u8 *addr)
452 {
453         struct ieee80211_local *local = sdata->local;
454         int i;
455
456         for (i = 0; i <  STA_TID_NUM; i++) {
457                 ieee80211_stop_tx_ba_session(&local->hw, addr, i,
458                                              WLAN_BACK_INITIATOR);
459                 ieee80211_sta_stop_rx_ba_session(sdata, addr, i,
460                                                  WLAN_BACK_RECIPIENT,
461                                                  WLAN_REASON_QSTA_LEAVE_QBSS);
462         }
463 }
464
465 int ieee80211_start_tx_ba_session(struct ieee80211_hw *hw, u8 *ra, u16 tid)
466 {
467         struct ieee80211_local *local = hw_to_local(hw);
468         struct sta_info *sta;
469         struct ieee80211_sub_if_data *sdata;
470         u16 start_seq_num;
471         u8 *state;
472         int ret = 0;
473
474         if ((tid >= STA_TID_NUM) || !(hw->flags & IEEE80211_HW_AMPDU_AGGREGATION))
475                 return -EINVAL;
476
477 #ifdef CONFIG_MAC80211_HT_DEBUG
478         printk(KERN_DEBUG "Open BA session requested for %pM tid %u\n",
479                ra, tid);
480 #endif /* CONFIG_MAC80211_HT_DEBUG */
481
482         rcu_read_lock();
483
484         sta = sta_info_get(local, ra);
485         if (!sta) {
486 #ifdef CONFIG_MAC80211_HT_DEBUG
487                 printk(KERN_DEBUG "Could not find the station\n");
488 #endif
489                 ret = -ENOENT;
490                 goto exit;
491         }
492
493         spin_lock_bh(&sta->lock);
494
495         /* we have tried too many times, receiver does not want A-MPDU */
496         if (sta->ampdu_mlme.addba_req_num[tid] > HT_AGG_MAX_RETRIES) {
497                 ret = -EBUSY;
498                 goto err_unlock_sta;
499         }
500
501         state = &sta->ampdu_mlme.tid_state_tx[tid];
502         /* check if the TID is not in aggregation flow already */
503         if (*state != HT_AGG_STATE_IDLE) {
504 #ifdef CONFIG_MAC80211_HT_DEBUG
505                 printk(KERN_DEBUG "BA request denied - session is not "
506                                  "idle on tid %u\n", tid);
507 #endif /* CONFIG_MAC80211_HT_DEBUG */
508                 ret = -EAGAIN;
509                 goto err_unlock_sta;
510         }
511
512         /* prepare A-MPDU MLME for Tx aggregation */
513         sta->ampdu_mlme.tid_tx[tid] =
514                         kmalloc(sizeof(struct tid_ampdu_tx), GFP_ATOMIC);
515         if (!sta->ampdu_mlme.tid_tx[tid]) {
516 #ifdef CONFIG_MAC80211_HT_DEBUG
517                 if (net_ratelimit())
518                         printk(KERN_ERR "allocate tx mlme to tid %d failed\n",
519                                         tid);
520 #endif
521                 ret = -ENOMEM;
522                 goto err_unlock_sta;
523         }
524         /* Tx timer */
525         sta->ampdu_mlme.tid_tx[tid]->addba_resp_timer.function =
526                         sta_addba_resp_timer_expired;
527         sta->ampdu_mlme.tid_tx[tid]->addba_resp_timer.data =
528                         (unsigned long)&sta->timer_to_tid[tid];
529         init_timer(&sta->ampdu_mlme.tid_tx[tid]->addba_resp_timer);
530
531         if (hw->ampdu_queues) {
532                 /* create a new queue for this aggregation */
533                 ret = ieee80211_ht_agg_queue_add(local, sta, tid);
534
535                 /* case no queue is available to aggregation
536                  * don't switch to aggregation */
537                 if (ret) {
538 #ifdef CONFIG_MAC80211_HT_DEBUG
539                         printk(KERN_DEBUG "BA request denied - "
540                                "queue unavailable for tid %d\n", tid);
541 #endif /* CONFIG_MAC80211_HT_DEBUG */
542                         goto err_unlock_queue;
543                 }
544         }
545         sdata = sta->sdata;
546
547         /* Ok, the Addba frame hasn't been sent yet, but if the driver calls the
548          * call back right away, it must see that the flow has begun */
549         *state |= HT_ADDBA_REQUESTED_MSK;
550
551         /* This is slightly racy because the queue isn't stopped */
552         start_seq_num = sta->tid_seq[tid];
553
554         if (local->ops->ampdu_action)
555                 ret = local->ops->ampdu_action(hw, IEEE80211_AMPDU_TX_START,
556                                                &sta->sta, tid, &start_seq_num);
557
558         if (ret) {
559                 /* No need to requeue the packets in the agg queue, since we
560                  * held the tx lock: no packet could be enqueued to the newly
561                  * allocated queue */
562                 if (hw->ampdu_queues)
563                         ieee80211_ht_agg_queue_remove(local, sta, tid, 0);
564 #ifdef CONFIG_MAC80211_HT_DEBUG
565                 printk(KERN_DEBUG "BA request denied - HW unavailable for"
566                                         " tid %d\n", tid);
567 #endif /* CONFIG_MAC80211_HT_DEBUG */
568                 *state = HT_AGG_STATE_IDLE;
569                 goto err_unlock_queue;
570         }
571
572         /* Will put all the packets in the new SW queue */
573         if (hw->ampdu_queues)
574                 ieee80211_requeue(local, ieee802_1d_to_ac[tid]);
575         spin_unlock_bh(&sta->lock);
576
577         /* send an addBA request */
578         sta->ampdu_mlme.dialog_token_allocator++;
579         sta->ampdu_mlme.tid_tx[tid]->dialog_token =
580                         sta->ampdu_mlme.dialog_token_allocator;
581         sta->ampdu_mlme.tid_tx[tid]->ssn = start_seq_num;
582
583
584         ieee80211_send_addba_request(sta->sdata, ra, tid,
585                          sta->ampdu_mlme.tid_tx[tid]->dialog_token,
586                          sta->ampdu_mlme.tid_tx[tid]->ssn,
587                          0x40, 5000);
588         /* activate the timer for the recipient's addBA response */
589         sta->ampdu_mlme.tid_tx[tid]->addba_resp_timer.expires =
590                                 jiffies + ADDBA_RESP_INTERVAL;
591         add_timer(&sta->ampdu_mlme.tid_tx[tid]->addba_resp_timer);
592 #ifdef CONFIG_MAC80211_HT_DEBUG
593         printk(KERN_DEBUG "activated addBA response timer on tid %d\n", tid);
594 #endif
595         goto exit;
596
597 err_unlock_queue:
598         kfree(sta->ampdu_mlme.tid_tx[tid]);
599         sta->ampdu_mlme.tid_tx[tid] = NULL;
600         ret = -EBUSY;
601 err_unlock_sta:
602         spin_unlock_bh(&sta->lock);
603 exit:
604         rcu_read_unlock();
605         return ret;
606 }
607 EXPORT_SYMBOL(ieee80211_start_tx_ba_session);
608
609 int ieee80211_stop_tx_ba_session(struct ieee80211_hw *hw,
610                                  u8 *ra, u16 tid,
611                                  enum ieee80211_back_parties initiator)
612 {
613         struct ieee80211_local *local = hw_to_local(hw);
614         struct sta_info *sta;
615         u8 *state;
616         int ret = 0;
617
618         if (tid >= STA_TID_NUM)
619                 return -EINVAL;
620
621         rcu_read_lock();
622         sta = sta_info_get(local, ra);
623         if (!sta) {
624                 rcu_read_unlock();
625                 return -ENOENT;
626         }
627
628         /* check if the TID is in aggregation */
629         state = &sta->ampdu_mlme.tid_state_tx[tid];
630         spin_lock_bh(&sta->lock);
631
632         if (*state != HT_AGG_STATE_OPERATIONAL) {
633                 ret = -ENOENT;
634                 goto stop_BA_exit;
635         }
636
637 #ifdef CONFIG_MAC80211_HT_DEBUG
638         printk(KERN_DEBUG "Tx BA session stop requested for %pM tid %u\n",
639                ra, tid);
640 #endif /* CONFIG_MAC80211_HT_DEBUG */
641
642         if (hw->ampdu_queues)
643                 ieee80211_stop_queue(hw, sta->tid_to_tx_q[tid]);
644
645         *state = HT_AGG_STATE_REQ_STOP_BA_MSK |
646                 (initiator << HT_AGG_STATE_INITIATOR_SHIFT);
647
648         if (local->ops->ampdu_action)
649                 ret = local->ops->ampdu_action(hw, IEEE80211_AMPDU_TX_STOP,
650                                                &sta->sta, tid, NULL);
651
652         /* case HW denied going back to legacy */
653         if (ret) {
654                 WARN_ON(ret != -EBUSY);
655                 *state = HT_AGG_STATE_OPERATIONAL;
656                 if (hw->ampdu_queues)
657                         ieee80211_wake_queue(hw, sta->tid_to_tx_q[tid]);
658                 goto stop_BA_exit;
659         }
660
661 stop_BA_exit:
662         spin_unlock_bh(&sta->lock);
663         rcu_read_unlock();
664         return ret;
665 }
666 EXPORT_SYMBOL(ieee80211_stop_tx_ba_session);
667
668 void ieee80211_start_tx_ba_cb(struct ieee80211_hw *hw, u8 *ra, u16 tid)
669 {
670         struct ieee80211_local *local = hw_to_local(hw);
671         struct sta_info *sta;
672         u8 *state;
673
674         if (tid >= STA_TID_NUM) {
675 #ifdef CONFIG_MAC80211_HT_DEBUG
676                 printk(KERN_DEBUG "Bad TID value: tid = %d (>= %d)\n",
677                                 tid, STA_TID_NUM);
678 #endif
679                 return;
680         }
681
682         rcu_read_lock();
683         sta = sta_info_get(local, ra);
684         if (!sta) {
685                 rcu_read_unlock();
686 #ifdef CONFIG_MAC80211_HT_DEBUG
687                 printk(KERN_DEBUG "Could not find station: %pM\n", ra);
688 #endif
689                 return;
690         }
691
692         state = &sta->ampdu_mlme.tid_state_tx[tid];
693         spin_lock_bh(&sta->lock);
694
695         if (!(*state & HT_ADDBA_REQUESTED_MSK)) {
696 #ifdef CONFIG_MAC80211_HT_DEBUG
697                 printk(KERN_DEBUG "addBA was not requested yet, state is %d\n",
698                                 *state);
699 #endif
700                 spin_unlock_bh(&sta->lock);
701                 rcu_read_unlock();
702                 return;
703         }
704
705         WARN_ON_ONCE(*state & HT_ADDBA_DRV_READY_MSK);
706
707         *state |= HT_ADDBA_DRV_READY_MSK;
708
709         if (*state == HT_AGG_STATE_OPERATIONAL) {
710 #ifdef CONFIG_MAC80211_HT_DEBUG
711                 printk(KERN_DEBUG "Aggregation is on for tid %d \n", tid);
712 #endif
713                 if (hw->ampdu_queues)
714                         ieee80211_wake_queue(hw, sta->tid_to_tx_q[tid]);
715         }
716         spin_unlock_bh(&sta->lock);
717         rcu_read_unlock();
718 }
719 EXPORT_SYMBOL(ieee80211_start_tx_ba_cb);
720
721 void ieee80211_stop_tx_ba_cb(struct ieee80211_hw *hw, u8 *ra, u8 tid)
722 {
723         struct ieee80211_local *local = hw_to_local(hw);
724         struct sta_info *sta;
725         u8 *state;
726         int agg_queue;
727
728         if (tid >= STA_TID_NUM) {
729 #ifdef CONFIG_MAC80211_HT_DEBUG
730                 printk(KERN_DEBUG "Bad TID value: tid = %d (>= %d)\n",
731                                 tid, STA_TID_NUM);
732 #endif
733                 return;
734         }
735
736 #ifdef CONFIG_MAC80211_HT_DEBUG
737         printk(KERN_DEBUG "Stopping Tx BA session for %pM tid %d\n",
738                ra, tid);
739 #endif /* CONFIG_MAC80211_HT_DEBUG */
740
741         rcu_read_lock();
742         sta = sta_info_get(local, ra);
743         if (!sta) {
744 #ifdef CONFIG_MAC80211_HT_DEBUG
745                 printk(KERN_DEBUG "Could not find station: %pM\n", ra);
746 #endif
747                 rcu_read_unlock();
748                 return;
749         }
750         state = &sta->ampdu_mlme.tid_state_tx[tid];
751
752         /* NOTE: no need to use sta->lock in this state check, as
753          * ieee80211_stop_tx_ba_session will let only one stop call to
754          * pass through per sta/tid
755          */
756         if ((*state & HT_AGG_STATE_REQ_STOP_BA_MSK) == 0) {
757 #ifdef CONFIG_MAC80211_HT_DEBUG
758                 printk(KERN_DEBUG "unexpected callback to A-MPDU stop\n");
759 #endif
760                 rcu_read_unlock();
761                 return;
762         }
763
764         if (*state & HT_AGG_STATE_INITIATOR_MSK)
765                 ieee80211_send_delba(sta->sdata, ra, tid,
766                         WLAN_BACK_INITIATOR, WLAN_REASON_QSTA_NOT_USE);
767
768         if (hw->ampdu_queues) {
769                 agg_queue = sta->tid_to_tx_q[tid];
770                 ieee80211_ht_agg_queue_remove(local, sta, tid, 1);
771
772                 /* We just requeued the all the frames that were in the
773                  * removed queue, and since we might miss a softirq we do
774                  * netif_schedule_queue.  ieee80211_wake_queue is not used
775                  * here as this queue is not necessarily stopped
776                  */
777                 netif_schedule_queue(netdev_get_tx_queue(local->mdev,
778                                                          agg_queue));
779         }
780         spin_lock_bh(&sta->lock);
781         *state = HT_AGG_STATE_IDLE;
782         sta->ampdu_mlme.addba_req_num[tid] = 0;
783         kfree(sta->ampdu_mlme.tid_tx[tid]);
784         sta->ampdu_mlme.tid_tx[tid] = NULL;
785         spin_unlock_bh(&sta->lock);
786
787         rcu_read_unlock();
788 }
789 EXPORT_SYMBOL(ieee80211_stop_tx_ba_cb);
790
791 void ieee80211_start_tx_ba_cb_irqsafe(struct ieee80211_hw *hw,
792                                       const u8 *ra, u16 tid)
793 {
794         struct ieee80211_local *local = hw_to_local(hw);
795         struct ieee80211_ra_tid *ra_tid;
796         struct sk_buff *skb = dev_alloc_skb(0);
797
798         if (unlikely(!skb)) {
799 #ifdef CONFIG_MAC80211_HT_DEBUG
800                 if (net_ratelimit())
801                         printk(KERN_WARNING "%s: Not enough memory, "
802                                "dropping start BA session", skb->dev->name);
803 #endif
804                 return;
805         }
806         ra_tid = (struct ieee80211_ra_tid *) &skb->cb;
807         memcpy(&ra_tid->ra, ra, ETH_ALEN);
808         ra_tid->tid = tid;
809
810         skb->pkt_type = IEEE80211_ADDBA_MSG;
811         skb_queue_tail(&local->skb_queue, skb);
812         tasklet_schedule(&local->tasklet);
813 }
814 EXPORT_SYMBOL(ieee80211_start_tx_ba_cb_irqsafe);
815
816 void ieee80211_stop_tx_ba_cb_irqsafe(struct ieee80211_hw *hw,
817                                      const u8 *ra, u16 tid)
818 {
819         struct ieee80211_local *local = hw_to_local(hw);
820         struct ieee80211_ra_tid *ra_tid;
821         struct sk_buff *skb = dev_alloc_skb(0);
822
823         if (unlikely(!skb)) {
824 #ifdef CONFIG_MAC80211_HT_DEBUG
825                 if (net_ratelimit())
826                         printk(KERN_WARNING "%s: Not enough memory, "
827                                "dropping stop BA session", skb->dev->name);
828 #endif
829                 return;
830         }
831         ra_tid = (struct ieee80211_ra_tid *) &skb->cb;
832         memcpy(&ra_tid->ra, ra, ETH_ALEN);
833         ra_tid->tid = tid;
834
835         skb->pkt_type = IEEE80211_DELBA_MSG;
836         skb_queue_tail(&local->skb_queue, skb);
837         tasklet_schedule(&local->tasklet);
838 }
839 EXPORT_SYMBOL(ieee80211_stop_tx_ba_cb_irqsafe);
840
841 /*
842  * After accepting the AddBA Request we activated a timer,
843  * resetting it after each frame that arrives from the originator.
844  * if this timer expires ieee80211_sta_stop_rx_ba_session will be executed.
845  */
846 static void sta_rx_agg_session_timer_expired(unsigned long data)
847 {
848         /* not an elegant detour, but there is no choice as the timer passes
849          * only one argument, and various sta_info are needed here, so init
850          * flow in sta_info_create gives the TID as data, while the timer_to_id
851          * array gives the sta through container_of */
852         u8 *ptid = (u8 *)data;
853         u8 *timer_to_id = ptid - *ptid;
854         struct sta_info *sta = container_of(timer_to_id, struct sta_info,
855                                          timer_to_tid[0]);
856
857 #ifdef CONFIG_MAC80211_HT_DEBUG
858         printk(KERN_DEBUG "rx session timer expired on tid %d\n", (u16)*ptid);
859 #endif
860         ieee80211_sta_stop_rx_ba_session(sta->sdata, sta->sta.addr,
861                                          (u16)*ptid, WLAN_BACK_TIMER,
862                                          WLAN_REASON_QSTA_TIMEOUT);
863 }
864
865 void ieee80211_process_addba_request(struct ieee80211_local *local,
866                                      struct sta_info *sta,
867                                      struct ieee80211_mgmt *mgmt,
868                                      size_t len)
869 {
870         struct ieee80211_hw *hw = &local->hw;
871         struct ieee80211_conf *conf = &hw->conf;
872         struct tid_ampdu_rx *tid_agg_rx;
873         u16 capab, tid, timeout, ba_policy, buf_size, start_seq_num, status;
874         u8 dialog_token;
875         int ret = -EOPNOTSUPP;
876
877         /* extract session parameters from addba request frame */
878         dialog_token = mgmt->u.action.u.addba_req.dialog_token;
879         timeout = le16_to_cpu(mgmt->u.action.u.addba_req.timeout);
880         start_seq_num =
881                 le16_to_cpu(mgmt->u.action.u.addba_req.start_seq_num) >> 4;
882
883         capab = le16_to_cpu(mgmt->u.action.u.addba_req.capab);
884         ba_policy = (capab & IEEE80211_ADDBA_PARAM_POLICY_MASK) >> 1;
885         tid = (capab & IEEE80211_ADDBA_PARAM_TID_MASK) >> 2;
886         buf_size = (capab & IEEE80211_ADDBA_PARAM_BUF_SIZE_MASK) >> 6;
887
888         status = WLAN_STATUS_REQUEST_DECLINED;
889
890         /* sanity check for incoming parameters:
891          * check if configuration can support the BA policy
892          * and if buffer size does not exceeds max value */
893         /* XXX: check own ht delayed BA capability?? */
894         if (((ba_policy != 1)
895                 && (!(sta->sta.ht_cap.cap & IEEE80211_HT_CAP_DELAY_BA)))
896                 || (buf_size > IEEE80211_MAX_AMPDU_BUF)) {
897                 status = WLAN_STATUS_INVALID_QOS_PARAM;
898 #ifdef CONFIG_MAC80211_HT_DEBUG
899                 if (net_ratelimit())
900                         printk(KERN_DEBUG "AddBA Req with bad params from "
901                                 "%pM on tid %u. policy %d, buffer size %d\n",
902                                 mgmt->sa, tid, ba_policy,
903                                 buf_size);
904 #endif /* CONFIG_MAC80211_HT_DEBUG */
905                 goto end_no_lock;
906         }
907         /* determine default buffer size */
908         if (buf_size == 0) {
909                 struct ieee80211_supported_band *sband;
910
911                 sband = local->hw.wiphy->bands[conf->channel->band];
912                 buf_size = IEEE80211_MIN_AMPDU_BUF;
913                 buf_size = buf_size << sband->ht_cap.ampdu_factor;
914         }
915
916
917         /* examine state machine */
918         spin_lock_bh(&sta->lock);
919
920         if (sta->ampdu_mlme.tid_state_rx[tid] != HT_AGG_STATE_IDLE) {
921 #ifdef CONFIG_MAC80211_HT_DEBUG
922                 if (net_ratelimit())
923                         printk(KERN_DEBUG "unexpected AddBA Req from "
924                                 "%pM on tid %u\n",
925                                 mgmt->sa, tid);
926 #endif /* CONFIG_MAC80211_HT_DEBUG */
927                 goto end;
928         }
929
930         /* prepare A-MPDU MLME for Rx aggregation */
931         sta->ampdu_mlme.tid_rx[tid] =
932                         kmalloc(sizeof(struct tid_ampdu_rx), GFP_ATOMIC);
933         if (!sta->ampdu_mlme.tid_rx[tid]) {
934 #ifdef CONFIG_MAC80211_HT_DEBUG
935                 if (net_ratelimit())
936                         printk(KERN_ERR "allocate rx mlme to tid %d failed\n",
937                                         tid);
938 #endif
939                 goto end;
940         }
941         /* rx timer */
942         sta->ampdu_mlme.tid_rx[tid]->session_timer.function =
943                                 sta_rx_agg_session_timer_expired;
944         sta->ampdu_mlme.tid_rx[tid]->session_timer.data =
945                                 (unsigned long)&sta->timer_to_tid[tid];
946         init_timer(&sta->ampdu_mlme.tid_rx[tid]->session_timer);
947
948         tid_agg_rx = sta->ampdu_mlme.tid_rx[tid];
949
950         /* prepare reordering buffer */
951         tid_agg_rx->reorder_buf =
952                 kmalloc(buf_size * sizeof(struct sk_buff *), GFP_ATOMIC);
953         if (!tid_agg_rx->reorder_buf) {
954 #ifdef CONFIG_MAC80211_HT_DEBUG
955                 if (net_ratelimit())
956                         printk(KERN_ERR "can not allocate reordering buffer "
957                                "to tid %d\n", tid);
958 #endif
959                 kfree(sta->ampdu_mlme.tid_rx[tid]);
960                 goto end;
961         }
962         memset(tid_agg_rx->reorder_buf, 0,
963                 buf_size * sizeof(struct sk_buff *));
964
965         if (local->ops->ampdu_action)
966                 ret = local->ops->ampdu_action(hw, IEEE80211_AMPDU_RX_START,
967                                                &sta->sta, tid, &start_seq_num);
968 #ifdef CONFIG_MAC80211_HT_DEBUG
969         printk(KERN_DEBUG "Rx A-MPDU request on tid %d result %d\n", tid, ret);
970 #endif /* CONFIG_MAC80211_HT_DEBUG */
971
972         if (ret) {
973                 kfree(tid_agg_rx->reorder_buf);
974                 kfree(tid_agg_rx);
975                 sta->ampdu_mlme.tid_rx[tid] = NULL;
976                 goto end;
977         }
978
979         /* change state and send addba resp */
980         sta->ampdu_mlme.tid_state_rx[tid] = HT_AGG_STATE_OPERATIONAL;
981         tid_agg_rx->dialog_token = dialog_token;
982         tid_agg_rx->ssn = start_seq_num;
983         tid_agg_rx->head_seq_num = start_seq_num;
984         tid_agg_rx->buf_size = buf_size;
985         tid_agg_rx->timeout = timeout;
986         tid_agg_rx->stored_mpdu_num = 0;
987         status = WLAN_STATUS_SUCCESS;
988 end:
989         spin_unlock_bh(&sta->lock);
990
991 end_no_lock:
992         ieee80211_send_addba_resp(sta->sdata, sta->sta.addr, tid,
993                                   dialog_token, status, 1, buf_size, timeout);
994 }
995
996 void ieee80211_process_addba_resp(struct ieee80211_local *local,
997                                   struct sta_info *sta,
998                                   struct ieee80211_mgmt *mgmt,
999                                   size_t len)
1000 {
1001         struct ieee80211_hw *hw = &local->hw;
1002         u16 capab;
1003         u16 tid, start_seq_num;
1004         u8 *state;
1005
1006         capab = le16_to_cpu(mgmt->u.action.u.addba_resp.capab);
1007         tid = (capab & IEEE80211_ADDBA_PARAM_TID_MASK) >> 2;
1008
1009         state = &sta->ampdu_mlme.tid_state_tx[tid];
1010
1011         spin_lock_bh(&sta->lock);
1012
1013         if (!(*state & HT_ADDBA_REQUESTED_MSK)) {
1014                 spin_unlock_bh(&sta->lock);
1015                 return;
1016         }
1017
1018         if (mgmt->u.action.u.addba_resp.dialog_token !=
1019                 sta->ampdu_mlme.tid_tx[tid]->dialog_token) {
1020                 spin_unlock_bh(&sta->lock);
1021 #ifdef CONFIG_MAC80211_HT_DEBUG
1022                 printk(KERN_DEBUG "wrong addBA response token, tid %d\n", tid);
1023 #endif /* CONFIG_MAC80211_HT_DEBUG */
1024                 return;
1025         }
1026
1027         del_timer_sync(&sta->ampdu_mlme.tid_tx[tid]->addba_resp_timer);
1028 #ifdef CONFIG_MAC80211_HT_DEBUG
1029         printk(KERN_DEBUG "switched off addBA timer for tid %d \n", tid);
1030 #endif /* CONFIG_MAC80211_HT_DEBUG */
1031         if (le16_to_cpu(mgmt->u.action.u.addba_resp.status)
1032                         == WLAN_STATUS_SUCCESS) {
1033                 *state |= HT_ADDBA_RECEIVED_MSK;
1034                 sta->ampdu_mlme.addba_req_num[tid] = 0;
1035
1036                 if (*state == HT_AGG_STATE_OPERATIONAL &&
1037                     local->hw.ampdu_queues)
1038                         ieee80211_wake_queue(hw, sta->tid_to_tx_q[tid]);
1039
1040                 if (local->ops->ampdu_action) {
1041                         (void)local->ops->ampdu_action(hw,
1042                                                IEEE80211_AMPDU_TX_RESUME,
1043                                                &sta->sta, tid, &start_seq_num);
1044                 }
1045 #ifdef CONFIG_MAC80211_HT_DEBUG
1046                 printk(KERN_DEBUG "Resuming TX aggregation for tid %d\n", tid);
1047 #endif /* CONFIG_MAC80211_HT_DEBUG */
1048                 spin_unlock_bh(&sta->lock);
1049         } else {
1050                 sta->ampdu_mlme.addba_req_num[tid]++;
1051                 /* this will allow the state check in stop_BA_session */
1052                 *state = HT_AGG_STATE_OPERATIONAL;
1053                 spin_unlock_bh(&sta->lock);
1054                 ieee80211_stop_tx_ba_session(hw, sta->sta.addr, tid,
1055                                              WLAN_BACK_INITIATOR);
1056         }
1057 }
1058
1059 void ieee80211_process_delba(struct ieee80211_sub_if_data *sdata,
1060                              struct sta_info *sta,
1061                              struct ieee80211_mgmt *mgmt, size_t len)
1062 {
1063         struct ieee80211_local *local = sdata->local;
1064         u16 tid, params;
1065         u16 initiator;
1066
1067         params = le16_to_cpu(mgmt->u.action.u.delba.params);
1068         tid = (params & IEEE80211_DELBA_PARAM_TID_MASK) >> 12;
1069         initiator = (params & IEEE80211_DELBA_PARAM_INITIATOR_MASK) >> 11;
1070
1071 #ifdef CONFIG_MAC80211_HT_DEBUG
1072         if (net_ratelimit())
1073                 printk(KERN_DEBUG "delba from %pM (%s) tid %d reason code %d\n",
1074                         mgmt->sa, initiator ? "initiator" : "recipient", tid,
1075                         mgmt->u.action.u.delba.reason_code);
1076 #endif /* CONFIG_MAC80211_HT_DEBUG */
1077
1078         if (initiator == WLAN_BACK_INITIATOR)
1079                 ieee80211_sta_stop_rx_ba_session(sdata, sta->sta.addr, tid,
1080                                                  WLAN_BACK_INITIATOR, 0);
1081         else { /* WLAN_BACK_RECIPIENT */
1082                 spin_lock_bh(&sta->lock);
1083                 sta->ampdu_mlme.tid_state_tx[tid] =
1084                                 HT_AGG_STATE_OPERATIONAL;
1085                 spin_unlock_bh(&sta->lock);
1086                 ieee80211_stop_tx_ba_session(&local->hw, sta->sta.addr, tid,
1087                                              WLAN_BACK_RECIPIENT);
1088         }
1089 }