e2d121bf2745eaf80844c9eaf0f81a95ef474a5d
[linux-2.6.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_ht_cap *ht_cap_ie,
24                                        struct ieee80211_sta_ht_cap *ht_cap)
25 {
26
27         BUG_ON(!ht_cap);
28
29         memset(ht_cap, 0, sizeof(*ht_cap));
30
31         if (ht_cap_ie) {
32                 u8 ampdu_info = ht_cap_ie->ampdu_params_info;
33
34                 ht_cap->ht_supported = true;
35                 ht_cap->cap = le16_to_cpu(ht_cap_ie->cap_info);
36                 ht_cap->ampdu_factor =
37                         ampdu_info & IEEE80211_HT_AMPDU_PARM_FACTOR;
38                 ht_cap->ampdu_density =
39                         (ampdu_info & IEEE80211_HT_AMPDU_PARM_DENSITY) >> 2;
40                 memcpy(&ht_cap->mcs, &ht_cap_ie->mcs, sizeof(ht_cap->mcs));
41         } else
42                 ht_cap->ht_supported = false;
43 }
44
45 void ieee80211_ht_info_ie_to_ht_bss_info(
46                         struct ieee80211_ht_info *ht_add_info_ie,
47                         struct ieee80211_ht_bss_info *bss_info)
48 {
49         BUG_ON(!bss_info);
50
51         memset(bss_info, 0, sizeof(*bss_info));
52
53         if (ht_add_info_ie) {
54                 u16 op_mode;
55                 op_mode = le16_to_cpu(ht_add_info_ie->operation_mode);
56
57                 bss_info->primary_channel = ht_add_info_ie->control_chan;
58                 bss_info->bss_cap = ht_add_info_ie->ht_param;
59                 bss_info->bss_op_mode = (u8)(op_mode & 0xff);
60         }
61 }
62
63 /*
64  * ieee80211_handle_ht should be called only after the operating band
65  * has been determined as ht configuration depends on the hw's
66  * HT abilities for a specific band.
67  */
68 u32 ieee80211_handle_ht(struct ieee80211_local *local,
69                         struct ieee80211_sta_ht_cap *req_ht_cap,
70                         struct ieee80211_ht_bss_info *req_bss_cap)
71 {
72         struct ieee80211_conf *conf = &local->hw.conf;
73         struct ieee80211_supported_band *sband;
74         struct ieee80211_sta_ht_cap ht_cap;
75         struct ieee80211_ht_bss_info ht_bss_conf;
76         u32 changed = 0;
77         int i;
78         u8 max_tx_streams;
79         u8 tx_mcs_set_cap;
80         bool enable_ht = true;
81
82         sband = local->hw.wiphy->bands[conf->channel->band];
83
84         memset(&ht_cap, 0, sizeof(ht_cap));
85         memset(&ht_bss_conf, 0, sizeof(struct ieee80211_ht_bss_info));
86
87         /* HT is not supported */
88         if (!sband->ht_cap.ht_supported)
89                 enable_ht = false;
90
91         /* disable HT */
92         if (!enable_ht) {
93                 if (conf->flags & IEEE80211_CONF_SUPPORT_HT_MODE)
94                         changed |= BSS_CHANGED_HT;
95                 conf->flags &= ~IEEE80211_CONF_SUPPORT_HT_MODE;
96                 conf->ht_cap.ht_supported = false;
97                 return changed;
98         }
99
100
101         if (!(conf->flags & IEEE80211_CONF_SUPPORT_HT_MODE))
102                 changed |= BSS_CHANGED_HT;
103
104         conf->flags |= IEEE80211_CONF_SUPPORT_HT_MODE;
105         ht_cap.ht_supported = true;
106
107         ht_cap.cap = req_ht_cap->cap & sband->ht_cap.cap;
108         ht_cap.cap &= ~IEEE80211_HT_CAP_SM_PS;
109         ht_cap.cap |= sband->ht_cap.cap & IEEE80211_HT_CAP_SM_PS;
110
111         ht_bss_conf.primary_channel = req_bss_cap->primary_channel;
112         ht_bss_conf.bss_cap = req_bss_cap->bss_cap;
113         ht_bss_conf.bss_op_mode = req_bss_cap->bss_op_mode;
114
115         ht_cap.ampdu_factor = req_ht_cap->ampdu_factor;
116         ht_cap.ampdu_density = req_ht_cap->ampdu_density;
117
118         /* own MCS TX capabilities */
119         tx_mcs_set_cap = sband->ht_cap.mcs.tx_params;
120
121         /*
122          * configure supported Tx MCS according to requested MCS
123          * (based in most cases on Rx capabilities of peer) and self
124          * Tx MCS capabilities (as defined by low level driver HW
125          * Tx capabilities)
126          */
127
128         /* can we TX with MCS rates? */
129         if (!(tx_mcs_set_cap & IEEE80211_HT_MCS_TX_DEFINED))
130                 goto check_changed;
131
132         /* Counting from 0, therefore +1 */
133         if (tx_mcs_set_cap & IEEE80211_HT_MCS_TX_RX_DIFF)
134                 max_tx_streams =
135                         ((tx_mcs_set_cap & IEEE80211_HT_MCS_TX_MAX_STREAMS_MASK)
136                                 >> IEEE80211_HT_MCS_TX_MAX_STREAMS_SHIFT) + 1;
137         else
138                 max_tx_streams = IEEE80211_HT_MCS_TX_MAX_STREAMS;
139
140         /*
141          * 802.11n D5.0 20.3.5 / 20.6 says:
142          * - indices 0 to 7 and 32 are single spatial stream
143          * - 8 to 31 are multiple spatial streams using equal modulation
144          *   [8..15 for two streams, 16..23 for three and 24..31 for four]
145          * - remainder are multiple spatial streams using unequal modulation
146          */
147         for (i = 0; i < max_tx_streams; i++)
148                 ht_cap.mcs.rx_mask[i] =
149                         sband->ht_cap.mcs.rx_mask[i] &
150                                         req_ht_cap->mcs.rx_mask[i];
151
152         if (tx_mcs_set_cap & IEEE80211_HT_MCS_TX_UNEQUAL_MODULATION)
153                 for (i = IEEE80211_HT_MCS_UNEQUAL_MODULATION_START_BYTE;
154                      i < IEEE80211_HT_MCS_MASK_LEN; i++)
155                         ht_cap.mcs.rx_mask[i] =
156                                 sband->ht_cap.mcs.rx_mask[i] &
157                                         req_ht_cap->mcs.rx_mask[i];
158
159         /* handle MCS rate 32 too */
160         if (sband->ht_cap.mcs.rx_mask[32/8] &
161             req_ht_cap->mcs.rx_mask[32/8] & 1)
162                 ht_cap.mcs.rx_mask[32/8] |= 1;
163
164  check_changed:
165         /* if bss configuration changed store the new one */
166         if (memcmp(&conf->ht_cap, &ht_cap, sizeof(ht_cap)) ||
167             memcmp(&conf->ht_bss_conf, &ht_bss_conf, sizeof(ht_bss_conf))) {
168                 changed |= BSS_CHANGED_HT;
169                 memcpy(&conf->ht_cap, &ht_cap, sizeof(ht_cap));
170                 memcpy(&conf->ht_bss_conf, &ht_bss_conf, sizeof(ht_bss_conf));
171         }
172
173         return changed;
174 }
175
176 static void ieee80211_send_addba_request(struct ieee80211_sub_if_data *sdata,
177                                          const u8 *da, u16 tid,
178                                          u8 dialog_token, u16 start_seq_num,
179                                          u16 agg_size, u16 timeout)
180 {
181         struct ieee80211_local *local = sdata->local;
182         struct ieee80211_if_sta *ifsta = &sdata->u.sta;
183         struct sk_buff *skb;
184         struct ieee80211_mgmt *mgmt;
185         u16 capab;
186
187         skb = dev_alloc_skb(sizeof(*mgmt) + local->hw.extra_tx_headroom);
188
189         if (!skb) {
190                 printk(KERN_ERR "%s: failed to allocate buffer "
191                                 "for addba request frame\n", sdata->dev->name);
192                 return;
193         }
194         skb_reserve(skb, local->hw.extra_tx_headroom);
195         mgmt = (struct ieee80211_mgmt *) skb_put(skb, 24);
196         memset(mgmt, 0, 24);
197         memcpy(mgmt->da, da, ETH_ALEN);
198         memcpy(mgmt->sa, sdata->dev->dev_addr, ETH_ALEN);
199         if (sdata->vif.type == NL80211_IFTYPE_AP)
200                 memcpy(mgmt->bssid, sdata->dev->dev_addr, ETH_ALEN);
201         else
202                 memcpy(mgmt->bssid, ifsta->bssid, ETH_ALEN);
203
204         mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
205                                           IEEE80211_STYPE_ACTION);
206
207         skb_put(skb, 1 + sizeof(mgmt->u.action.u.addba_req));
208
209         mgmt->u.action.category = WLAN_CATEGORY_BACK;
210         mgmt->u.action.u.addba_req.action_code = WLAN_ACTION_ADDBA_REQ;
211
212         mgmt->u.action.u.addba_req.dialog_token = dialog_token;
213         capab = (u16)(1 << 1);          /* bit 1 aggregation policy */
214         capab |= (u16)(tid << 2);       /* bit 5:2 TID number */
215         capab |= (u16)(agg_size << 6);  /* bit 15:6 max size of aggergation */
216
217         mgmt->u.action.u.addba_req.capab = cpu_to_le16(capab);
218
219         mgmt->u.action.u.addba_req.timeout = cpu_to_le16(timeout);
220         mgmt->u.action.u.addba_req.start_seq_num =
221                                         cpu_to_le16(start_seq_num << 4);
222
223         ieee80211_tx_skb(sdata, skb, 0);
224 }
225
226 static void ieee80211_send_addba_resp(struct ieee80211_sub_if_data *sdata, u8 *da, u16 tid,
227                                       u8 dialog_token, u16 status, u16 policy,
228                                       u16 buf_size, u16 timeout)
229 {
230         struct ieee80211_if_sta *ifsta = &sdata->u.sta;
231         struct ieee80211_local *local = sdata->local;
232         struct sk_buff *skb;
233         struct ieee80211_mgmt *mgmt;
234         u16 capab;
235
236         skb = dev_alloc_skb(sizeof(*mgmt) + local->hw.extra_tx_headroom);
237
238         if (!skb) {
239                 printk(KERN_DEBUG "%s: failed to allocate buffer "
240                        "for addba resp frame\n", sdata->dev->name);
241                 return;
242         }
243
244         skb_reserve(skb, local->hw.extra_tx_headroom);
245         mgmt = (struct ieee80211_mgmt *) skb_put(skb, 24);
246         memset(mgmt, 0, 24);
247         memcpy(mgmt->da, da, ETH_ALEN);
248         memcpy(mgmt->sa, sdata->dev->dev_addr, ETH_ALEN);
249         if (sdata->vif.type == NL80211_IFTYPE_AP)
250                 memcpy(mgmt->bssid, sdata->dev->dev_addr, ETH_ALEN);
251         else
252                 memcpy(mgmt->bssid, ifsta->bssid, ETH_ALEN);
253         mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
254                                           IEEE80211_STYPE_ACTION);
255
256         skb_put(skb, 1 + sizeof(mgmt->u.action.u.addba_resp));
257         mgmt->u.action.category = WLAN_CATEGORY_BACK;
258         mgmt->u.action.u.addba_resp.action_code = WLAN_ACTION_ADDBA_RESP;
259         mgmt->u.action.u.addba_resp.dialog_token = dialog_token;
260
261         capab = (u16)(policy << 1);     /* bit 1 aggregation policy */
262         capab |= (u16)(tid << 2);       /* bit 5:2 TID number */
263         capab |= (u16)(buf_size << 6);  /* bit 15:6 max size of aggregation */
264
265         mgmt->u.action.u.addba_resp.capab = cpu_to_le16(capab);
266         mgmt->u.action.u.addba_resp.timeout = cpu_to_le16(timeout);
267         mgmt->u.action.u.addba_resp.status = cpu_to_le16(status);
268
269         ieee80211_tx_skb(sdata, skb, 0);
270 }
271
272 static void ieee80211_send_delba(struct ieee80211_sub_if_data *sdata,
273                                  const u8 *da, u16 tid,
274                                  u16 initiator, u16 reason_code)
275 {
276         struct ieee80211_local *local = sdata->local;
277         struct ieee80211_if_sta *ifsta = &sdata->u.sta;
278         struct sk_buff *skb;
279         struct ieee80211_mgmt *mgmt;
280         u16 params;
281
282         skb = dev_alloc_skb(sizeof(*mgmt) + local->hw.extra_tx_headroom);
283
284         if (!skb) {
285                 printk(KERN_ERR "%s: failed to allocate buffer "
286                                         "for delba frame\n", sdata->dev->name);
287                 return;
288         }
289
290         skb_reserve(skb, local->hw.extra_tx_headroom);
291         mgmt = (struct ieee80211_mgmt *) skb_put(skb, 24);
292         memset(mgmt, 0, 24);
293         memcpy(mgmt->da, da, ETH_ALEN);
294         memcpy(mgmt->sa, sdata->dev->dev_addr, ETH_ALEN);
295         if (sdata->vif.type == NL80211_IFTYPE_AP)
296                 memcpy(mgmt->bssid, sdata->dev->dev_addr, ETH_ALEN);
297         else
298                 memcpy(mgmt->bssid, ifsta->bssid, ETH_ALEN);
299         mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
300                                           IEEE80211_STYPE_ACTION);
301
302         skb_put(skb, 1 + sizeof(mgmt->u.action.u.delba));
303
304         mgmt->u.action.category = WLAN_CATEGORY_BACK;
305         mgmt->u.action.u.delba.action_code = WLAN_ACTION_DELBA;
306         params = (u16)(initiator << 11);        /* bit 11 initiator */
307         params |= (u16)(tid << 12);             /* bit 15:12 TID number */
308
309         mgmt->u.action.u.delba.params = cpu_to_le16(params);
310         mgmt->u.action.u.delba.reason_code = cpu_to_le16(reason_code);
311
312         ieee80211_tx_skb(sdata, skb, 0);
313 }
314
315 void ieee80211_send_bar(struct ieee80211_sub_if_data *sdata, u8 *ra, u16 tid, u16 ssn)
316 {
317         struct ieee80211_local *local = sdata->local;
318         struct sk_buff *skb;
319         struct ieee80211_bar *bar;
320         u16 bar_control = 0;
321
322         skb = dev_alloc_skb(sizeof(*bar) + local->hw.extra_tx_headroom);
323         if (!skb) {
324                 printk(KERN_ERR "%s: failed to allocate buffer for "
325                         "bar frame\n", sdata->dev->name);
326                 return;
327         }
328         skb_reserve(skb, local->hw.extra_tx_headroom);
329         bar = (struct ieee80211_bar *)skb_put(skb, sizeof(*bar));
330         memset(bar, 0, sizeof(*bar));
331         bar->frame_control = cpu_to_le16(IEEE80211_FTYPE_CTL |
332                                          IEEE80211_STYPE_BACK_REQ);
333         memcpy(bar->ra, ra, ETH_ALEN);
334         memcpy(bar->ta, sdata->dev->dev_addr, ETH_ALEN);
335         bar_control |= (u16)IEEE80211_BAR_CTRL_ACK_POLICY_NORMAL;
336         bar_control |= (u16)IEEE80211_BAR_CTRL_CBMTID_COMPRESSED_BA;
337         bar_control |= (u16)(tid << 12);
338         bar->control = cpu_to_le16(bar_control);
339         bar->start_seq_num = cpu_to_le16(ssn);
340
341         ieee80211_tx_skb(sdata, skb, 0);
342 }
343
344 void ieee80211_sta_stop_rx_ba_session(struct ieee80211_sub_if_data *sdata, u8 *ra, u16 tid,
345                                         u16 initiator, u16 reason)
346 {
347         struct ieee80211_local *local = sdata->local;
348         struct ieee80211_hw *hw = &local->hw;
349         struct sta_info *sta;
350         int ret, i;
351
352         rcu_read_lock();
353
354         sta = sta_info_get(local, ra);
355         if (!sta) {
356                 rcu_read_unlock();
357                 return;
358         }
359
360         /* check if TID is in operational state */
361         spin_lock_bh(&sta->lock);
362         if (sta->ampdu_mlme.tid_state_rx[tid]
363                                 != HT_AGG_STATE_OPERATIONAL) {
364                 spin_unlock_bh(&sta->lock);
365                 rcu_read_unlock();
366                 return;
367         }
368         sta->ampdu_mlme.tid_state_rx[tid] =
369                 HT_AGG_STATE_REQ_STOP_BA_MSK |
370                 (initiator << HT_AGG_STATE_INITIATOR_SHIFT);
371         spin_unlock_bh(&sta->lock);
372
373         /* stop HW Rx aggregation. ampdu_action existence
374          * already verified in session init so we add the BUG_ON */
375         BUG_ON(!local->ops->ampdu_action);
376
377 #ifdef CONFIG_MAC80211_HT_DEBUG
378         printk(KERN_DEBUG "Rx BA session stop requested for %pM tid %u\n",
379                ra, tid);
380 #endif /* CONFIG_MAC80211_HT_DEBUG */
381
382         ret = local->ops->ampdu_action(hw, IEEE80211_AMPDU_RX_STOP,
383                                        &sta->sta, tid, NULL);
384         if (ret)
385                 printk(KERN_DEBUG "HW problem - can not stop rx "
386                                 "aggregation for tid %d\n", tid);
387
388         /* shutdown timer has not expired */
389         if (initiator != WLAN_BACK_TIMER)
390                 del_timer_sync(&sta->ampdu_mlme.tid_rx[tid]->session_timer);
391
392         /* check if this is a self generated aggregation halt */
393         if (initiator == WLAN_BACK_RECIPIENT || initiator == WLAN_BACK_TIMER)
394                 ieee80211_send_delba(sdata, ra, tid, 0, reason);
395
396         /* free the reordering buffer */
397         for (i = 0; i < sta->ampdu_mlme.tid_rx[tid]->buf_size; i++) {
398                 if (sta->ampdu_mlme.tid_rx[tid]->reorder_buf[i]) {
399                         /* release the reordered frames */
400                         dev_kfree_skb(sta->ampdu_mlme.tid_rx[tid]->reorder_buf[i]);
401                         sta->ampdu_mlme.tid_rx[tid]->stored_mpdu_num--;
402                         sta->ampdu_mlme.tid_rx[tid]->reorder_buf[i] = NULL;
403                 }
404         }
405         /* free resources */
406         kfree(sta->ampdu_mlme.tid_rx[tid]->reorder_buf);
407         kfree(sta->ampdu_mlme.tid_rx[tid]);
408         sta->ampdu_mlme.tid_rx[tid] = NULL;
409         sta->ampdu_mlme.tid_state_rx[tid] = HT_AGG_STATE_IDLE;
410
411         rcu_read_unlock();
412 }
413
414
415 /*
416  * After sending add Block Ack request we activated a timer until
417  * add Block Ack response will arrive from the recipient.
418  * If this timer expires sta_addba_resp_timer_expired will be executed.
419  */
420 static void sta_addba_resp_timer_expired(unsigned long data)
421 {
422         /* not an elegant detour, but there is no choice as the timer passes
423          * only one argument, and both sta_info and TID are needed, so init
424          * flow in sta_info_create gives the TID as data, while the timer_to_id
425          * array gives the sta through container_of */
426         u16 tid = *(u8 *)data;
427         struct sta_info *temp_sta = container_of((void *)data,
428                 struct sta_info, timer_to_tid[tid]);
429
430         struct ieee80211_local *local = temp_sta->local;
431         struct ieee80211_hw *hw = &local->hw;
432         struct sta_info *sta;
433         u8 *state;
434
435         rcu_read_lock();
436
437         sta = sta_info_get(local, temp_sta->sta.addr);
438         if (!sta) {
439                 rcu_read_unlock();
440                 return;
441         }
442
443         state = &sta->ampdu_mlme.tid_state_tx[tid];
444         /* check if the TID waits for addBA response */
445         spin_lock_bh(&sta->lock);
446         if (!(*state & HT_ADDBA_REQUESTED_MSK)) {
447                 spin_unlock_bh(&sta->lock);
448                 *state = HT_AGG_STATE_IDLE;
449 #ifdef CONFIG_MAC80211_HT_DEBUG
450                 printk(KERN_DEBUG "timer expired on tid %d but we are not "
451                                 "expecting addBA response there", tid);
452 #endif
453                 goto timer_expired_exit;
454         }
455
456 #ifdef CONFIG_MAC80211_HT_DEBUG
457         printk(KERN_DEBUG "addBA response timer expired on tid %d\n", tid);
458 #endif
459
460         /* go through the state check in stop_BA_session */
461         *state = HT_AGG_STATE_OPERATIONAL;
462         spin_unlock_bh(&sta->lock);
463         ieee80211_stop_tx_ba_session(hw, temp_sta->sta.addr, tid,
464                                      WLAN_BACK_INITIATOR);
465
466 timer_expired_exit:
467         rcu_read_unlock();
468 }
469
470 void ieee80211_sta_tear_down_BA_sessions(struct ieee80211_sub_if_data *sdata, u8 *addr)
471 {
472         struct ieee80211_local *local = sdata->local;
473         int i;
474
475         for (i = 0; i <  STA_TID_NUM; i++) {
476                 ieee80211_stop_tx_ba_session(&local->hw, addr, i,
477                                              WLAN_BACK_INITIATOR);
478                 ieee80211_sta_stop_rx_ba_session(sdata, addr, i,
479                                                  WLAN_BACK_RECIPIENT,
480                                                  WLAN_REASON_QSTA_LEAVE_QBSS);
481         }
482 }
483
484 int ieee80211_start_tx_ba_session(struct ieee80211_hw *hw, u8 *ra, u16 tid)
485 {
486         struct ieee80211_local *local = hw_to_local(hw);
487         struct sta_info *sta;
488         struct ieee80211_sub_if_data *sdata;
489         u16 start_seq_num;
490         u8 *state;
491         int ret;
492
493         if (tid >= STA_TID_NUM)
494                 return -EINVAL;
495
496 #ifdef CONFIG_MAC80211_HT_DEBUG
497         printk(KERN_DEBUG "Open BA session requested for %pM tid %u\n",
498                ra, tid);
499 #endif /* CONFIG_MAC80211_HT_DEBUG */
500
501         rcu_read_lock();
502
503         sta = sta_info_get(local, ra);
504         if (!sta) {
505 #ifdef CONFIG_MAC80211_HT_DEBUG
506                 printk(KERN_DEBUG "Could not find the station\n");
507 #endif
508                 ret = -ENOENT;
509                 goto exit;
510         }
511
512         spin_lock_bh(&sta->lock);
513
514         /* we have tried too many times, receiver does not want A-MPDU */
515         if (sta->ampdu_mlme.addba_req_num[tid] > HT_AGG_MAX_RETRIES) {
516                 ret = -EBUSY;
517                 goto err_unlock_sta;
518         }
519
520         state = &sta->ampdu_mlme.tid_state_tx[tid];
521         /* check if the TID is not in aggregation flow already */
522         if (*state != HT_AGG_STATE_IDLE) {
523 #ifdef CONFIG_MAC80211_HT_DEBUG
524                 printk(KERN_DEBUG "BA request denied - session is not "
525                                  "idle on tid %u\n", tid);
526 #endif /* CONFIG_MAC80211_HT_DEBUG */
527                 ret = -EAGAIN;
528                 goto err_unlock_sta;
529         }
530
531         /* prepare A-MPDU MLME for Tx aggregation */
532         sta->ampdu_mlme.tid_tx[tid] =
533                         kmalloc(sizeof(struct tid_ampdu_tx), GFP_ATOMIC);
534         if (!sta->ampdu_mlme.tid_tx[tid]) {
535 #ifdef CONFIG_MAC80211_HT_DEBUG
536                 if (net_ratelimit())
537                         printk(KERN_ERR "allocate tx mlme to tid %d failed\n",
538                                         tid);
539 #endif
540                 ret = -ENOMEM;
541                 goto err_unlock_sta;
542         }
543         /* Tx timer */
544         sta->ampdu_mlme.tid_tx[tid]->addba_resp_timer.function =
545                         sta_addba_resp_timer_expired;
546         sta->ampdu_mlme.tid_tx[tid]->addba_resp_timer.data =
547                         (unsigned long)&sta->timer_to_tid[tid];
548         init_timer(&sta->ampdu_mlme.tid_tx[tid]->addba_resp_timer);
549
550         /* create a new queue for this aggregation */
551         ret = ieee80211_ht_agg_queue_add(local, sta, tid);
552
553         /* case no queue is available to aggregation
554          * don't switch to aggregation */
555         if (ret) {
556 #ifdef CONFIG_MAC80211_HT_DEBUG
557                 printk(KERN_DEBUG "BA request denied - queue unavailable for"
558                                         " tid %d\n", tid);
559 #endif /* CONFIG_MAC80211_HT_DEBUG */
560                 goto err_unlock_queue;
561         }
562         sdata = sta->sdata;
563
564         /* Ok, the Addba frame hasn't been sent yet, but if the driver calls the
565          * call back right away, it must see that the flow has begun */
566         *state |= HT_ADDBA_REQUESTED_MSK;
567
568         /* This is slightly racy because the queue isn't stopped */
569         start_seq_num = sta->tid_seq[tid];
570
571         if (local->ops->ampdu_action)
572                 ret = local->ops->ampdu_action(hw, IEEE80211_AMPDU_TX_START,
573                                                &sta->sta, tid, &start_seq_num);
574
575         if (ret) {
576                 /* No need to requeue the packets in the agg queue, since we
577                  * held the tx lock: no packet could be enqueued to the newly
578                  * allocated queue */
579                 ieee80211_ht_agg_queue_remove(local, sta, tid, 0);
580 #ifdef CONFIG_MAC80211_HT_DEBUG
581                 printk(KERN_DEBUG "BA request denied - HW unavailable for"
582                                         " tid %d\n", tid);
583 #endif /* CONFIG_MAC80211_HT_DEBUG */
584                 *state = HT_AGG_STATE_IDLE;
585                 goto err_unlock_queue;
586         }
587
588         /* Will put all the packets in the new SW queue */
589         ieee80211_requeue(local, ieee802_1d_to_ac[tid]);
590         spin_unlock_bh(&sta->lock);
591
592         /* send an addBA request */
593         sta->ampdu_mlme.dialog_token_allocator++;
594         sta->ampdu_mlme.tid_tx[tid]->dialog_token =
595                         sta->ampdu_mlme.dialog_token_allocator;
596         sta->ampdu_mlme.tid_tx[tid]->ssn = start_seq_num;
597
598
599         ieee80211_send_addba_request(sta->sdata, ra, tid,
600                          sta->ampdu_mlme.tid_tx[tid]->dialog_token,
601                          sta->ampdu_mlme.tid_tx[tid]->ssn,
602                          0x40, 5000);
603         /* activate the timer for the recipient's addBA response */
604         sta->ampdu_mlme.tid_tx[tid]->addba_resp_timer.expires =
605                                 jiffies + ADDBA_RESP_INTERVAL;
606         add_timer(&sta->ampdu_mlme.tid_tx[tid]->addba_resp_timer);
607 #ifdef CONFIG_MAC80211_HT_DEBUG
608         printk(KERN_DEBUG "activated addBA response timer on tid %d\n", tid);
609 #endif
610         goto exit;
611
612 err_unlock_queue:
613         kfree(sta->ampdu_mlme.tid_tx[tid]);
614         sta->ampdu_mlme.tid_tx[tid] = NULL;
615         ret = -EBUSY;
616 err_unlock_sta:
617         spin_unlock_bh(&sta->lock);
618 exit:
619         rcu_read_unlock();
620         return ret;
621 }
622 EXPORT_SYMBOL(ieee80211_start_tx_ba_session);
623
624 int ieee80211_stop_tx_ba_session(struct ieee80211_hw *hw,
625                                  u8 *ra, u16 tid,
626                                  enum ieee80211_back_parties initiator)
627 {
628         struct ieee80211_local *local = hw_to_local(hw);
629         struct sta_info *sta;
630         u8 *state;
631         int ret = 0;
632
633         if (tid >= STA_TID_NUM)
634                 return -EINVAL;
635
636         rcu_read_lock();
637         sta = sta_info_get(local, ra);
638         if (!sta) {
639                 rcu_read_unlock();
640                 return -ENOENT;
641         }
642
643         /* check if the TID is in aggregation */
644         state = &sta->ampdu_mlme.tid_state_tx[tid];
645         spin_lock_bh(&sta->lock);
646
647         if (*state != HT_AGG_STATE_OPERATIONAL) {
648                 ret = -ENOENT;
649                 goto stop_BA_exit;
650         }
651
652 #ifdef CONFIG_MAC80211_HT_DEBUG
653         printk(KERN_DEBUG "Tx BA session stop requested for %pM tid %u\n",
654                ra, tid);
655 #endif /* CONFIG_MAC80211_HT_DEBUG */
656
657         ieee80211_stop_queue(hw, sta->tid_to_tx_q[tid]);
658
659         *state = HT_AGG_STATE_REQ_STOP_BA_MSK |
660                 (initiator << HT_AGG_STATE_INITIATOR_SHIFT);
661
662         if (local->ops->ampdu_action)
663                 ret = local->ops->ampdu_action(hw, IEEE80211_AMPDU_TX_STOP,
664                                                &sta->sta, tid, NULL);
665
666         /* case HW denied going back to legacy */
667         if (ret) {
668                 WARN_ON(ret != -EBUSY);
669                 *state = HT_AGG_STATE_OPERATIONAL;
670                 ieee80211_wake_queue(hw, sta->tid_to_tx_q[tid]);
671                 goto stop_BA_exit;
672         }
673
674 stop_BA_exit:
675         spin_unlock_bh(&sta->lock);
676         rcu_read_unlock();
677         return ret;
678 }
679 EXPORT_SYMBOL(ieee80211_stop_tx_ba_session);
680
681 void ieee80211_start_tx_ba_cb(struct ieee80211_hw *hw, u8 *ra, u16 tid)
682 {
683         struct ieee80211_local *local = hw_to_local(hw);
684         struct sta_info *sta;
685         u8 *state;
686
687         if (tid >= STA_TID_NUM) {
688 #ifdef CONFIG_MAC80211_HT_DEBUG
689                 printk(KERN_DEBUG "Bad TID value: tid = %d (>= %d)\n",
690                                 tid, STA_TID_NUM);
691 #endif
692                 return;
693         }
694
695         rcu_read_lock();
696         sta = sta_info_get(local, ra);
697         if (!sta) {
698                 rcu_read_unlock();
699 #ifdef CONFIG_MAC80211_HT_DEBUG
700                 printk(KERN_DEBUG "Could not find station: %pM\n", ra);
701 #endif
702                 return;
703         }
704
705         state = &sta->ampdu_mlme.tid_state_tx[tid];
706         spin_lock_bh(&sta->lock);
707
708         if (!(*state & HT_ADDBA_REQUESTED_MSK)) {
709 #ifdef CONFIG_MAC80211_HT_DEBUG
710                 printk(KERN_DEBUG "addBA was not requested yet, state is %d\n",
711                                 *state);
712 #endif
713                 spin_unlock_bh(&sta->lock);
714                 rcu_read_unlock();
715                 return;
716         }
717
718         WARN_ON_ONCE(*state & HT_ADDBA_DRV_READY_MSK);
719
720         *state |= HT_ADDBA_DRV_READY_MSK;
721
722         if (*state == HT_AGG_STATE_OPERATIONAL) {
723 #ifdef CONFIG_MAC80211_HT_DEBUG
724                 printk(KERN_DEBUG "Aggregation is on for tid %d \n", tid);
725 #endif
726                 ieee80211_wake_queue(hw, sta->tid_to_tx_q[tid]);
727         }
728         spin_unlock_bh(&sta->lock);
729         rcu_read_unlock();
730 }
731 EXPORT_SYMBOL(ieee80211_start_tx_ba_cb);
732
733 void ieee80211_stop_tx_ba_cb(struct ieee80211_hw *hw, u8 *ra, u8 tid)
734 {
735         struct ieee80211_local *local = hw_to_local(hw);
736         struct sta_info *sta;
737         u8 *state;
738         int agg_queue;
739
740         if (tid >= STA_TID_NUM) {
741 #ifdef CONFIG_MAC80211_HT_DEBUG
742                 printk(KERN_DEBUG "Bad TID value: tid = %d (>= %d)\n",
743                                 tid, STA_TID_NUM);
744 #endif
745                 return;
746         }
747
748 #ifdef CONFIG_MAC80211_HT_DEBUG
749         printk(KERN_DEBUG "Stopping Tx BA session for %pM tid %d\n",
750                ra, tid);
751 #endif /* CONFIG_MAC80211_HT_DEBUG */
752
753         rcu_read_lock();
754         sta = sta_info_get(local, ra);
755         if (!sta) {
756 #ifdef CONFIG_MAC80211_HT_DEBUG
757                 printk(KERN_DEBUG "Could not find station: %pM\n", ra);
758 #endif
759                 rcu_read_unlock();
760                 return;
761         }
762         state = &sta->ampdu_mlme.tid_state_tx[tid];
763
764         /* NOTE: no need to use sta->lock in this state check, as
765          * ieee80211_stop_tx_ba_session will let only one stop call to
766          * pass through per sta/tid
767          */
768         if ((*state & HT_AGG_STATE_REQ_STOP_BA_MSK) == 0) {
769 #ifdef CONFIG_MAC80211_HT_DEBUG
770                 printk(KERN_DEBUG "unexpected callback to A-MPDU stop\n");
771 #endif
772                 rcu_read_unlock();
773                 return;
774         }
775
776         if (*state & HT_AGG_STATE_INITIATOR_MSK)
777                 ieee80211_send_delba(sta->sdata, ra, tid,
778                         WLAN_BACK_INITIATOR, WLAN_REASON_QSTA_NOT_USE);
779
780         agg_queue = sta->tid_to_tx_q[tid];
781
782         ieee80211_ht_agg_queue_remove(local, sta, tid, 1);
783
784         /* We just requeued the all the frames that were in the
785          * removed queue, and since we might miss a softirq we do
786          * netif_schedule_queue.  ieee80211_wake_queue is not used
787          * here as this queue is not necessarily stopped
788          */
789         netif_schedule_queue(netdev_get_tx_queue(local->mdev, agg_queue));
790         spin_lock_bh(&sta->lock);
791         *state = HT_AGG_STATE_IDLE;
792         sta->ampdu_mlme.addba_req_num[tid] = 0;
793         kfree(sta->ampdu_mlme.tid_tx[tid]);
794         sta->ampdu_mlme.tid_tx[tid] = NULL;
795         spin_unlock_bh(&sta->lock);
796
797         rcu_read_unlock();
798 }
799 EXPORT_SYMBOL(ieee80211_stop_tx_ba_cb);
800
801 void ieee80211_start_tx_ba_cb_irqsafe(struct ieee80211_hw *hw,
802                                       const u8 *ra, u16 tid)
803 {
804         struct ieee80211_local *local = hw_to_local(hw);
805         struct ieee80211_ra_tid *ra_tid;
806         struct sk_buff *skb = dev_alloc_skb(0);
807
808         if (unlikely(!skb)) {
809 #ifdef CONFIG_MAC80211_HT_DEBUG
810                 if (net_ratelimit())
811                         printk(KERN_WARNING "%s: Not enough memory, "
812                                "dropping start BA session", skb->dev->name);
813 #endif
814                 return;
815         }
816         ra_tid = (struct ieee80211_ra_tid *) &skb->cb;
817         memcpy(&ra_tid->ra, ra, ETH_ALEN);
818         ra_tid->tid = tid;
819
820         skb->pkt_type = IEEE80211_ADDBA_MSG;
821         skb_queue_tail(&local->skb_queue, skb);
822         tasklet_schedule(&local->tasklet);
823 }
824 EXPORT_SYMBOL(ieee80211_start_tx_ba_cb_irqsafe);
825
826 void ieee80211_stop_tx_ba_cb_irqsafe(struct ieee80211_hw *hw,
827                                      const u8 *ra, u16 tid)
828 {
829         struct ieee80211_local *local = hw_to_local(hw);
830         struct ieee80211_ra_tid *ra_tid;
831         struct sk_buff *skb = dev_alloc_skb(0);
832
833         if (unlikely(!skb)) {
834 #ifdef CONFIG_MAC80211_HT_DEBUG
835                 if (net_ratelimit())
836                         printk(KERN_WARNING "%s: Not enough memory, "
837                                "dropping stop BA session", skb->dev->name);
838 #endif
839                 return;
840         }
841         ra_tid = (struct ieee80211_ra_tid *) &skb->cb;
842         memcpy(&ra_tid->ra, ra, ETH_ALEN);
843         ra_tid->tid = tid;
844
845         skb->pkt_type = IEEE80211_DELBA_MSG;
846         skb_queue_tail(&local->skb_queue, skb);
847         tasklet_schedule(&local->tasklet);
848 }
849 EXPORT_SYMBOL(ieee80211_stop_tx_ba_cb_irqsafe);
850
851 /*
852  * After accepting the AddBA Request we activated a timer,
853  * resetting it after each frame that arrives from the originator.
854  * if this timer expires ieee80211_sta_stop_rx_ba_session will be executed.
855  */
856 static void sta_rx_agg_session_timer_expired(unsigned long data)
857 {
858         /* not an elegant detour, but there is no choice as the timer passes
859          * only one argument, and various sta_info are needed here, so init
860          * flow in sta_info_create gives the TID as data, while the timer_to_id
861          * array gives the sta through container_of */
862         u8 *ptid = (u8 *)data;
863         u8 *timer_to_id = ptid - *ptid;
864         struct sta_info *sta = container_of(timer_to_id, struct sta_info,
865                                          timer_to_tid[0]);
866
867 #ifdef CONFIG_MAC80211_HT_DEBUG
868         printk(KERN_DEBUG "rx session timer expired on tid %d\n", (u16)*ptid);
869 #endif
870         ieee80211_sta_stop_rx_ba_session(sta->sdata, sta->sta.addr,
871                                          (u16)*ptid, WLAN_BACK_TIMER,
872                                          WLAN_REASON_QSTA_TIMEOUT);
873 }
874
875 void ieee80211_process_addba_request(struct ieee80211_local *local,
876                                      struct sta_info *sta,
877                                      struct ieee80211_mgmt *mgmt,
878                                      size_t len)
879 {
880         struct ieee80211_hw *hw = &local->hw;
881         struct ieee80211_conf *conf = &hw->conf;
882         struct tid_ampdu_rx *tid_agg_rx;
883         u16 capab, tid, timeout, ba_policy, buf_size, start_seq_num, status;
884         u8 dialog_token;
885         int ret = -EOPNOTSUPP;
886
887         /* extract session parameters from addba request frame */
888         dialog_token = mgmt->u.action.u.addba_req.dialog_token;
889         timeout = le16_to_cpu(mgmt->u.action.u.addba_req.timeout);
890         start_seq_num =
891                 le16_to_cpu(mgmt->u.action.u.addba_req.start_seq_num) >> 4;
892
893         capab = le16_to_cpu(mgmt->u.action.u.addba_req.capab);
894         ba_policy = (capab & IEEE80211_ADDBA_PARAM_POLICY_MASK) >> 1;
895         tid = (capab & IEEE80211_ADDBA_PARAM_TID_MASK) >> 2;
896         buf_size = (capab & IEEE80211_ADDBA_PARAM_BUF_SIZE_MASK) >> 6;
897
898         status = WLAN_STATUS_REQUEST_DECLINED;
899
900         /* sanity check for incoming parameters:
901          * check if configuration can support the BA policy
902          * and if buffer size does not exceeds max value */
903         if (((ba_policy != 1)
904                 && (!(conf->ht_cap.cap & IEEE80211_HT_CAP_DELAY_BA)))
905                 || (buf_size > IEEE80211_MAX_AMPDU_BUF)) {
906                 status = WLAN_STATUS_INVALID_QOS_PARAM;
907 #ifdef CONFIG_MAC80211_HT_DEBUG
908                 if (net_ratelimit())
909                         printk(KERN_DEBUG "AddBA Req with bad params from "
910                                 "%pM on tid %u. policy %d, buffer size %d\n",
911                                 mgmt->sa, tid, ba_policy,
912                                 buf_size);
913 #endif /* CONFIG_MAC80211_HT_DEBUG */
914                 goto end_no_lock;
915         }
916         /* determine default buffer size */
917         if (buf_size == 0) {
918                 struct ieee80211_supported_band *sband;
919
920                 sband = local->hw.wiphy->bands[conf->channel->band];
921                 buf_size = IEEE80211_MIN_AMPDU_BUF;
922                 buf_size = buf_size << sband->ht_cap.ampdu_factor;
923         }
924
925
926         /* examine state machine */
927         spin_lock_bh(&sta->lock);
928
929         if (sta->ampdu_mlme.tid_state_rx[tid] != HT_AGG_STATE_IDLE) {
930 #ifdef CONFIG_MAC80211_HT_DEBUG
931                 if (net_ratelimit())
932                         printk(KERN_DEBUG "unexpected AddBA Req from "
933                                 "%pM on tid %u\n",
934                                 mgmt->sa, tid);
935 #endif /* CONFIG_MAC80211_HT_DEBUG */
936                 goto end;
937         }
938
939         /* prepare A-MPDU MLME for Rx aggregation */
940         sta->ampdu_mlme.tid_rx[tid] =
941                         kmalloc(sizeof(struct tid_ampdu_rx), GFP_ATOMIC);
942         if (!sta->ampdu_mlme.tid_rx[tid]) {
943 #ifdef CONFIG_MAC80211_HT_DEBUG
944                 if (net_ratelimit())
945                         printk(KERN_ERR "allocate rx mlme to tid %d failed\n",
946                                         tid);
947 #endif
948                 goto end;
949         }
950         /* rx timer */
951         sta->ampdu_mlme.tid_rx[tid]->session_timer.function =
952                                 sta_rx_agg_session_timer_expired;
953         sta->ampdu_mlme.tid_rx[tid]->session_timer.data =
954                                 (unsigned long)&sta->timer_to_tid[tid];
955         init_timer(&sta->ampdu_mlme.tid_rx[tid]->session_timer);
956
957         tid_agg_rx = sta->ampdu_mlme.tid_rx[tid];
958
959         /* prepare reordering buffer */
960         tid_agg_rx->reorder_buf =
961                 kmalloc(buf_size * sizeof(struct sk_buff *), GFP_ATOMIC);
962         if (!tid_agg_rx->reorder_buf) {
963 #ifdef CONFIG_MAC80211_HT_DEBUG
964                 if (net_ratelimit())
965                         printk(KERN_ERR "can not allocate reordering buffer "
966                                "to tid %d\n", tid);
967 #endif
968                 kfree(sta->ampdu_mlme.tid_rx[tid]);
969                 goto end;
970         }
971         memset(tid_agg_rx->reorder_buf, 0,
972                 buf_size * sizeof(struct sk_buff *));
973
974         if (local->ops->ampdu_action)
975                 ret = local->ops->ampdu_action(hw, IEEE80211_AMPDU_RX_START,
976                                                &sta->sta, tid, &start_seq_num);
977 #ifdef CONFIG_MAC80211_HT_DEBUG
978         printk(KERN_DEBUG "Rx A-MPDU request on tid %d result %d\n", tid, ret);
979 #endif /* CONFIG_MAC80211_HT_DEBUG */
980
981         if (ret) {
982                 kfree(tid_agg_rx->reorder_buf);
983                 kfree(tid_agg_rx);
984                 sta->ampdu_mlme.tid_rx[tid] = NULL;
985                 goto end;
986         }
987
988         /* change state and send addba resp */
989         sta->ampdu_mlme.tid_state_rx[tid] = HT_AGG_STATE_OPERATIONAL;
990         tid_agg_rx->dialog_token = dialog_token;
991         tid_agg_rx->ssn = start_seq_num;
992         tid_agg_rx->head_seq_num = start_seq_num;
993         tid_agg_rx->buf_size = buf_size;
994         tid_agg_rx->timeout = timeout;
995         tid_agg_rx->stored_mpdu_num = 0;
996         status = WLAN_STATUS_SUCCESS;
997 end:
998         spin_unlock_bh(&sta->lock);
999
1000 end_no_lock:
1001         ieee80211_send_addba_resp(sta->sdata, sta->sta.addr, tid,
1002                                   dialog_token, status, 1, buf_size, timeout);
1003 }
1004
1005 void ieee80211_process_addba_resp(struct ieee80211_local *local,
1006                                   struct sta_info *sta,
1007                                   struct ieee80211_mgmt *mgmt,
1008                                   size_t len)
1009 {
1010         struct ieee80211_hw *hw = &local->hw;
1011         u16 capab;
1012         u16 tid;
1013         u8 *state;
1014
1015         capab = le16_to_cpu(mgmt->u.action.u.addba_resp.capab);
1016         tid = (capab & IEEE80211_ADDBA_PARAM_TID_MASK) >> 2;
1017
1018         state = &sta->ampdu_mlme.tid_state_tx[tid];
1019
1020         spin_lock_bh(&sta->lock);
1021
1022         if (!(*state & HT_ADDBA_REQUESTED_MSK)) {
1023                 spin_unlock_bh(&sta->lock);
1024                 return;
1025         }
1026
1027         if (mgmt->u.action.u.addba_resp.dialog_token !=
1028                 sta->ampdu_mlme.tid_tx[tid]->dialog_token) {
1029                 spin_unlock_bh(&sta->lock);
1030 #ifdef CONFIG_MAC80211_HT_DEBUG
1031                 printk(KERN_DEBUG "wrong addBA response token, tid %d\n", tid);
1032 #endif /* CONFIG_MAC80211_HT_DEBUG */
1033                 return;
1034         }
1035
1036         del_timer_sync(&sta->ampdu_mlme.tid_tx[tid]->addba_resp_timer);
1037 #ifdef CONFIG_MAC80211_HT_DEBUG
1038         printk(KERN_DEBUG "switched off addBA timer for tid %d \n", tid);
1039 #endif /* CONFIG_MAC80211_HT_DEBUG */
1040         if (le16_to_cpu(mgmt->u.action.u.addba_resp.status)
1041                         == WLAN_STATUS_SUCCESS) {
1042                 *state |= HT_ADDBA_RECEIVED_MSK;
1043                 sta->ampdu_mlme.addba_req_num[tid] = 0;
1044
1045                 if (*state == HT_AGG_STATE_OPERATIONAL)
1046                         ieee80211_wake_queue(hw, sta->tid_to_tx_q[tid]);
1047
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 }