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 2007-2009, Intel Corporation
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.
16 #include <linux/ieee80211.h>
17 #include <net/mac80211.h>
18 #include "ieee80211_i.h"
24 * Aggregation on the TX side requires setting the hardware flag
25 * %IEEE80211_HW_AMPDU_AGGREGATION as well as, if present, the @ampdu_queues
26 * hardware parameter to the number of hardware AMPDU queues. If there are no
27 * hardware queues then the driver will (currently) have to do all frame
30 * When TX aggregation is started by some subsystem (usually the rate control
31 * algorithm would be appropriate) by calling the
32 * ieee80211_start_tx_ba_session() function, the driver will be notified via
33 * its @ampdu_action function, with the %IEEE80211_AMPDU_TX_START action.
35 * In response to that, the driver is later required to call the
36 * ieee80211_start_tx_ba_cb() (or ieee80211_start_tx_ba_cb_irqsafe())
37 * function, which will start the aggregation session.
39 * Similarly, when the aggregation session is stopped by
40 * ieee80211_stop_tx_ba_session(), the driver's @ampdu_action function will
41 * be called with the action %IEEE80211_AMPDU_TX_STOP. In this case, the
42 * call must not fail, and the driver must later call ieee80211_stop_tx_ba_cb()
43 * (or ieee80211_stop_tx_ba_cb_irqsafe()).
46 static void ieee80211_send_addba_request(struct ieee80211_sub_if_data *sdata,
47 const u8 *da, u16 tid,
48 u8 dialog_token, u16 start_seq_num,
49 u16 agg_size, u16 timeout)
51 struct ieee80211_local *local = sdata->local;
53 struct ieee80211_mgmt *mgmt;
56 skb = dev_alloc_skb(sizeof(*mgmt) + local->hw.extra_tx_headroom);
59 printk(KERN_ERR "%s: failed to allocate buffer "
60 "for addba request frame\n", sdata->dev->name);
63 skb_reserve(skb, local->hw.extra_tx_headroom);
64 mgmt = (struct ieee80211_mgmt *) skb_put(skb, 24);
66 memcpy(mgmt->da, da, ETH_ALEN);
67 memcpy(mgmt->sa, sdata->dev->dev_addr, ETH_ALEN);
68 if (sdata->vif.type == NL80211_IFTYPE_AP ||
69 sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
70 memcpy(mgmt->bssid, sdata->dev->dev_addr, ETH_ALEN);
71 else if (sdata->vif.type == NL80211_IFTYPE_STATION)
72 memcpy(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN);
74 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
75 IEEE80211_STYPE_ACTION);
77 skb_put(skb, 1 + sizeof(mgmt->u.action.u.addba_req));
79 mgmt->u.action.category = WLAN_CATEGORY_BACK;
80 mgmt->u.action.u.addba_req.action_code = WLAN_ACTION_ADDBA_REQ;
82 mgmt->u.action.u.addba_req.dialog_token = dialog_token;
83 capab = (u16)(1 << 1); /* bit 1 aggregation policy */
84 capab |= (u16)(tid << 2); /* bit 5:2 TID number */
85 capab |= (u16)(agg_size << 6); /* bit 15:6 max size of aggergation */
87 mgmt->u.action.u.addba_req.capab = cpu_to_le16(capab);
89 mgmt->u.action.u.addba_req.timeout = cpu_to_le16(timeout);
90 mgmt->u.action.u.addba_req.start_seq_num =
91 cpu_to_le16(start_seq_num << 4);
93 ieee80211_tx_skb(sdata, skb, 1);
96 void ieee80211_send_bar(struct ieee80211_sub_if_data *sdata, u8 *ra, u16 tid, u16 ssn)
98 struct ieee80211_local *local = sdata->local;
100 struct ieee80211_bar *bar;
103 skb = dev_alloc_skb(sizeof(*bar) + local->hw.extra_tx_headroom);
105 printk(KERN_ERR "%s: failed to allocate buffer for "
106 "bar frame\n", sdata->dev->name);
109 skb_reserve(skb, local->hw.extra_tx_headroom);
110 bar = (struct ieee80211_bar *)skb_put(skb, sizeof(*bar));
111 memset(bar, 0, sizeof(*bar));
112 bar->frame_control = cpu_to_le16(IEEE80211_FTYPE_CTL |
113 IEEE80211_STYPE_BACK_REQ);
114 memcpy(bar->ra, ra, ETH_ALEN);
115 memcpy(bar->ta, sdata->dev->dev_addr, ETH_ALEN);
116 bar_control |= (u16)IEEE80211_BAR_CTRL_ACK_POLICY_NORMAL;
117 bar_control |= (u16)IEEE80211_BAR_CTRL_CBMTID_COMPRESSED_BA;
118 bar_control |= (u16)(tid << 12);
119 bar->control = cpu_to_le16(bar_control);
120 bar->start_seq_num = cpu_to_le16(ssn);
122 ieee80211_tx_skb(sdata, skb, 0);
125 static int ___ieee80211_stop_tx_ba_session(struct sta_info *sta, u16 tid,
126 enum ieee80211_back_parties initiator)
128 struct ieee80211_local *local = sta->local;
132 state = &sta->ampdu_mlme.tid_state_tx[tid];
134 if (local->hw.ampdu_queues) {
137 * Stop the AC queue to avoid issues where we send
138 * unaggregated frames already before the delba.
140 ieee80211_stop_queue_by_reason(&local->hw,
141 local->hw.queues + sta->tid_to_tx_q[tid],
142 IEEE80211_QUEUE_STOP_REASON_AGGREGATION);
146 * Pretend the driver woke the queue, just in case
147 * it disabled it before the session was stopped.
149 ieee80211_wake_queue(
150 &local->hw, local->hw.queues + sta->tid_to_tx_q[tid]);
152 *state = HT_AGG_STATE_REQ_STOP_BA_MSK |
153 (initiator << HT_AGG_STATE_INITIATOR_SHIFT);
155 ret = local->ops->ampdu_action(&local->hw, IEEE80211_AMPDU_TX_STOP,
156 &sta->sta, tid, NULL);
158 /* HW shall not deny going back to legacy */
160 *state = HT_AGG_STATE_OPERATIONAL;
167 * After sending add Block Ack request we activated a timer until
168 * add Block Ack response will arrive from the recipient.
169 * If this timer expires sta_addba_resp_timer_expired will be executed.
171 static void sta_addba_resp_timer_expired(unsigned long data)
173 /* not an elegant detour, but there is no choice as the timer passes
174 * only one argument, and both sta_info and TID are needed, so init
175 * flow in sta_info_create gives the TID as data, while the timer_to_id
176 * array gives the sta through container_of */
177 u16 tid = *(u8 *)data;
178 struct sta_info *sta = container_of((void *)data,
179 struct sta_info, timer_to_tid[tid]);
182 state = &sta->ampdu_mlme.tid_state_tx[tid];
184 /* check if the TID waits for addBA response */
185 spin_lock_bh(&sta->lock);
186 if (!(*state & HT_ADDBA_REQUESTED_MSK)) {
187 spin_unlock_bh(&sta->lock);
188 *state = HT_AGG_STATE_IDLE;
189 #ifdef CONFIG_MAC80211_HT_DEBUG
190 printk(KERN_DEBUG "timer expired on tid %d but we are not "
191 "expecting addBA response there", tid);
196 #ifdef CONFIG_MAC80211_HT_DEBUG
197 printk(KERN_DEBUG "addBA response timer expired on tid %d\n", tid);
200 ___ieee80211_stop_tx_ba_session(sta, tid, WLAN_BACK_INITIATOR);
201 spin_unlock_bh(&sta->lock);
204 static inline int ieee80211_ac_from_tid(int tid)
206 return ieee802_1d_to_ac[tid & 7];
209 int ieee80211_start_tx_ba_session(struct ieee80211_hw *hw, u8 *ra, u16 tid)
211 struct ieee80211_local *local = hw_to_local(hw);
212 struct sta_info *sta;
213 struct ieee80211_sub_if_data *sdata;
215 int i, qn = -1, ret = 0;
218 if (WARN_ON(!local->ops->ampdu_action))
221 if ((tid >= STA_TID_NUM) || !(hw->flags & IEEE80211_HW_AMPDU_AGGREGATION))
224 #ifdef CONFIG_MAC80211_HT_DEBUG
225 printk(KERN_DEBUG "Open BA session requested for %pM tid %u\n",
227 #endif /* CONFIG_MAC80211_HT_DEBUG */
229 if (hw->ampdu_queues && ieee80211_ac_from_tid(tid) == 0) {
230 #ifdef CONFIG_MAC80211_HT_DEBUG
231 printk(KERN_DEBUG "rejecting on voice AC\n");
238 sta = sta_info_get(local, ra);
240 #ifdef CONFIG_MAC80211_HT_DEBUG
241 printk(KERN_DEBUG "Could not find the station\n");
248 * The aggregation code is not prepared to handle
249 * anything but STA/AP due to the BSSID handling.
250 * IBSS could work in the code but isn't supported
251 * by drivers or the standard.
253 if (sta->sdata->vif.type != NL80211_IFTYPE_STATION &&
254 sta->sdata->vif.type != NL80211_IFTYPE_AP_VLAN &&
255 sta->sdata->vif.type != NL80211_IFTYPE_AP) {
260 if (test_sta_flags(sta, WLAN_STA_SUSPEND)) {
261 #ifdef CONFIG_MAC80211_HT_DEBUG
262 printk(KERN_DEBUG "Suspend in progress. "
263 "Denying BA session request\n");
269 spin_lock_bh(&sta->lock);
273 /* we have tried too many times, receiver does not want A-MPDU */
274 if (sta->ampdu_mlme.addba_req_num[tid] > HT_AGG_MAX_RETRIES) {
279 state = &sta->ampdu_mlme.tid_state_tx[tid];
280 /* check if the TID is not in aggregation flow already */
281 if (*state != HT_AGG_STATE_IDLE) {
282 #ifdef CONFIG_MAC80211_HT_DEBUG
283 printk(KERN_DEBUG "BA request denied - session is not "
284 "idle on tid %u\n", tid);
285 #endif /* CONFIG_MAC80211_HT_DEBUG */
290 if (hw->ampdu_queues) {
291 spin_lock(&local->queue_stop_reason_lock);
292 /* reserve a new queue for this session */
293 for (i = 0; i < local->hw.ampdu_queues; i++) {
294 if (local->ampdu_ac_queue[i] < 0) {
296 local->ampdu_ac_queue[qn] =
297 ieee80211_ac_from_tid(tid);
301 spin_unlock(&local->queue_stop_reason_lock);
304 #ifdef CONFIG_MAC80211_HT_DEBUG
305 printk(KERN_DEBUG "BA request denied - "
306 "queue unavailable for tid %d\n", tid);
307 #endif /* CONFIG_MAC80211_HT_DEBUG */
313 * If we successfully allocate the session, we can't have
314 * anything going on on the queue this TID maps into, so
315 * stop it for now. This is a "virtual" stop using the same
316 * mechanism that drivers will use.
318 * XXX: queue up frames for this session in the sta_info
319 * struct instead to avoid hitting all other STAs.
321 ieee80211_stop_queue_by_reason(
322 &local->hw, hw->queues + qn,
323 IEEE80211_QUEUE_STOP_REASON_AGGREGATION);
326 /* prepare A-MPDU MLME for Tx aggregation */
327 sta->ampdu_mlme.tid_tx[tid] =
328 kmalloc(sizeof(struct tid_ampdu_tx), GFP_ATOMIC);
329 if (!sta->ampdu_mlme.tid_tx[tid]) {
330 #ifdef CONFIG_MAC80211_HT_DEBUG
332 printk(KERN_ERR "allocate tx mlme to tid %d failed\n",
336 goto err_return_queue;
340 sta->ampdu_mlme.tid_tx[tid]->addba_resp_timer.function =
341 sta_addba_resp_timer_expired;
342 sta->ampdu_mlme.tid_tx[tid]->addba_resp_timer.data =
343 (unsigned long)&sta->timer_to_tid[tid];
344 init_timer(&sta->ampdu_mlme.tid_tx[tid]->addba_resp_timer);
346 /* Ok, the Addba frame hasn't been sent yet, but if the driver calls the
347 * call back right away, it must see that the flow has begun */
348 *state |= HT_ADDBA_REQUESTED_MSK;
350 start_seq_num = sta->tid_seq[tid];
352 ret = local->ops->ampdu_action(hw, IEEE80211_AMPDU_TX_START,
353 &sta->sta, tid, &start_seq_num);
356 #ifdef CONFIG_MAC80211_HT_DEBUG
357 printk(KERN_DEBUG "BA request denied - HW unavailable for"
359 #endif /* CONFIG_MAC80211_HT_DEBUG */
360 *state = HT_AGG_STATE_IDLE;
363 sta->tid_to_tx_q[tid] = qn;
365 spin_unlock_bh(&sta->lock);
367 /* send an addBA request */
368 sta->ampdu_mlme.dialog_token_allocator++;
369 sta->ampdu_mlme.tid_tx[tid]->dialog_token =
370 sta->ampdu_mlme.dialog_token_allocator;
371 sta->ampdu_mlme.tid_tx[tid]->ssn = start_seq_num;
373 ieee80211_send_addba_request(sta->sdata, ra, tid,
374 sta->ampdu_mlme.tid_tx[tid]->dialog_token,
375 sta->ampdu_mlme.tid_tx[tid]->ssn,
377 /* activate the timer for the recipient's addBA response */
378 sta->ampdu_mlme.tid_tx[tid]->addba_resp_timer.expires =
379 jiffies + ADDBA_RESP_INTERVAL;
380 add_timer(&sta->ampdu_mlme.tid_tx[tid]->addba_resp_timer);
381 #ifdef CONFIG_MAC80211_HT_DEBUG
382 printk(KERN_DEBUG "activated addBA response timer on tid %d\n", tid);
387 kfree(sta->ampdu_mlme.tid_tx[tid]);
388 sta->ampdu_mlme.tid_tx[tid] = NULL;
391 /* We failed, so start queue again right away. */
392 ieee80211_wake_queue_by_reason(hw, hw->queues + qn,
393 IEEE80211_QUEUE_STOP_REASON_AGGREGATION);
394 /* give queue back to pool */
395 spin_lock(&local->queue_stop_reason_lock);
396 local->ampdu_ac_queue[qn] = -1;
397 spin_unlock(&local->queue_stop_reason_lock);
400 spin_unlock_bh(&sta->lock);
405 EXPORT_SYMBOL(ieee80211_start_tx_ba_session);
407 static void ieee80211_agg_tx_operational(struct ieee80211_local *local,
408 struct sta_info *sta, u16 tid)
410 #ifdef CONFIG_MAC80211_HT_DEBUG
411 printk(KERN_DEBUG "Aggregation is on for tid %d \n", tid);
414 if (local->hw.ampdu_queues) {
416 * Wake up the A-MPDU queue, we stopped it earlier,
417 * this will in turn wake the entire AC.
419 ieee80211_wake_queue_by_reason(&local->hw,
420 local->hw.queues + sta->tid_to_tx_q[tid],
421 IEEE80211_QUEUE_STOP_REASON_AGGREGATION);
424 local->ops->ampdu_action(&local->hw, IEEE80211_AMPDU_TX_OPERATIONAL,
425 &sta->sta, tid, NULL);
428 void ieee80211_start_tx_ba_cb(struct ieee80211_hw *hw, u8 *ra, u16 tid)
430 struct ieee80211_local *local = hw_to_local(hw);
431 struct sta_info *sta;
434 if (tid >= STA_TID_NUM) {
435 #ifdef CONFIG_MAC80211_HT_DEBUG
436 printk(KERN_DEBUG "Bad TID value: tid = %d (>= %d)\n",
443 sta = sta_info_get(local, ra);
446 #ifdef CONFIG_MAC80211_HT_DEBUG
447 printk(KERN_DEBUG "Could not find station: %pM\n", ra);
452 state = &sta->ampdu_mlme.tid_state_tx[tid];
453 spin_lock_bh(&sta->lock);
455 if (WARN_ON(!(*state & HT_ADDBA_REQUESTED_MSK))) {
456 #ifdef CONFIG_MAC80211_HT_DEBUG
457 printk(KERN_DEBUG "addBA was not requested yet, state is %d\n",
460 spin_unlock_bh(&sta->lock);
465 if (WARN_ON(*state & HT_ADDBA_DRV_READY_MSK))
468 *state |= HT_ADDBA_DRV_READY_MSK;
470 if (*state == HT_AGG_STATE_OPERATIONAL)
471 ieee80211_agg_tx_operational(local, sta, tid);
474 spin_unlock_bh(&sta->lock);
477 EXPORT_SYMBOL(ieee80211_start_tx_ba_cb);
479 void ieee80211_start_tx_ba_cb_irqsafe(struct ieee80211_hw *hw,
480 const u8 *ra, u16 tid)
482 struct ieee80211_local *local = hw_to_local(hw);
483 struct ieee80211_ra_tid *ra_tid;
484 struct sk_buff *skb = dev_alloc_skb(0);
486 if (unlikely(!skb)) {
487 #ifdef CONFIG_MAC80211_HT_DEBUG
489 printk(KERN_WARNING "%s: Not enough memory, "
490 "dropping start BA session", skb->dev->name);
494 ra_tid = (struct ieee80211_ra_tid *) &skb->cb;
495 memcpy(&ra_tid->ra, ra, ETH_ALEN);
498 skb->pkt_type = IEEE80211_ADDBA_MSG;
499 skb_queue_tail(&local->skb_queue, skb);
500 tasklet_schedule(&local->tasklet);
502 EXPORT_SYMBOL(ieee80211_start_tx_ba_cb_irqsafe);
504 int __ieee80211_stop_tx_ba_session(struct sta_info *sta, u16 tid,
505 enum ieee80211_back_parties initiator)
510 /* check if the TID is in aggregation */
511 state = &sta->ampdu_mlme.tid_state_tx[tid];
512 spin_lock_bh(&sta->lock);
514 if (*state != HT_AGG_STATE_OPERATIONAL) {
519 #ifdef CONFIG_MAC80211_HT_DEBUG
520 printk(KERN_DEBUG "Tx BA session stop requested for %pM tid %u\n",
522 #endif /* CONFIG_MAC80211_HT_DEBUG */
524 ret = ___ieee80211_stop_tx_ba_session(sta, tid, initiator);
527 spin_unlock_bh(&sta->lock);
531 int ieee80211_stop_tx_ba_session(struct ieee80211_hw *hw,
533 enum ieee80211_back_parties initiator)
535 struct ieee80211_local *local = hw_to_local(hw);
536 struct sta_info *sta;
539 if (WARN_ON(!local->ops->ampdu_action))
542 if (tid >= STA_TID_NUM)
546 sta = sta_info_get(local, ra);
552 ret = __ieee80211_stop_tx_ba_session(sta, tid, initiator);
556 EXPORT_SYMBOL(ieee80211_stop_tx_ba_session);
558 void ieee80211_stop_tx_ba_cb(struct ieee80211_hw *hw, u8 *ra, u8 tid)
560 struct ieee80211_local *local = hw_to_local(hw);
561 struct sta_info *sta;
564 if (tid >= STA_TID_NUM) {
565 #ifdef CONFIG_MAC80211_HT_DEBUG
566 printk(KERN_DEBUG "Bad TID value: tid = %d (>= %d)\n",
572 #ifdef CONFIG_MAC80211_HT_DEBUG
573 printk(KERN_DEBUG "Stopping Tx BA session for %pM tid %d\n",
575 #endif /* CONFIG_MAC80211_HT_DEBUG */
578 sta = sta_info_get(local, ra);
580 #ifdef CONFIG_MAC80211_HT_DEBUG
581 printk(KERN_DEBUG "Could not find station: %pM\n", ra);
586 state = &sta->ampdu_mlme.tid_state_tx[tid];
588 /* NOTE: no need to use sta->lock in this state check, as
589 * ieee80211_stop_tx_ba_session will let only one stop call to
590 * pass through per sta/tid
592 if ((*state & HT_AGG_STATE_REQ_STOP_BA_MSK) == 0) {
593 #ifdef CONFIG_MAC80211_HT_DEBUG
594 printk(KERN_DEBUG "unexpected callback to A-MPDU stop\n");
600 if (*state & HT_AGG_STATE_INITIATOR_MSK)
601 ieee80211_send_delba(sta->sdata, ra, tid,
602 WLAN_BACK_INITIATOR, WLAN_REASON_QSTA_NOT_USE);
604 spin_lock_bh(&sta->lock);
606 if (*state & HT_AGG_STATE_INITIATOR_MSK &&
609 * Wake up this queue, we stopped it earlier,
610 * this will in turn wake the entire AC.
612 ieee80211_wake_queue_by_reason(hw,
613 hw->queues + sta->tid_to_tx_q[tid],
614 IEEE80211_QUEUE_STOP_REASON_AGGREGATION);
617 *state = HT_AGG_STATE_IDLE;
618 sta->ampdu_mlme.addba_req_num[tid] = 0;
619 kfree(sta->ampdu_mlme.tid_tx[tid]);
620 sta->ampdu_mlme.tid_tx[tid] = NULL;
621 spin_unlock_bh(&sta->lock);
625 EXPORT_SYMBOL(ieee80211_stop_tx_ba_cb);
627 void ieee80211_stop_tx_ba_cb_irqsafe(struct ieee80211_hw *hw,
628 const u8 *ra, u16 tid)
630 struct ieee80211_local *local = hw_to_local(hw);
631 struct ieee80211_ra_tid *ra_tid;
632 struct sk_buff *skb = dev_alloc_skb(0);
634 if (unlikely(!skb)) {
635 #ifdef CONFIG_MAC80211_HT_DEBUG
637 printk(KERN_WARNING "%s: Not enough memory, "
638 "dropping stop BA session", skb->dev->name);
642 ra_tid = (struct ieee80211_ra_tid *) &skb->cb;
643 memcpy(&ra_tid->ra, ra, ETH_ALEN);
646 skb->pkt_type = IEEE80211_DELBA_MSG;
647 skb_queue_tail(&local->skb_queue, skb);
648 tasklet_schedule(&local->tasklet);
650 EXPORT_SYMBOL(ieee80211_stop_tx_ba_cb_irqsafe);
653 void ieee80211_process_addba_resp(struct ieee80211_local *local,
654 struct sta_info *sta,
655 struct ieee80211_mgmt *mgmt,
661 capab = le16_to_cpu(mgmt->u.action.u.addba_resp.capab);
662 tid = (capab & IEEE80211_ADDBA_PARAM_TID_MASK) >> 2;
664 state = &sta->ampdu_mlme.tid_state_tx[tid];
666 spin_lock_bh(&sta->lock);
668 if (!(*state & HT_ADDBA_REQUESTED_MSK)) {
669 spin_unlock_bh(&sta->lock);
673 if (mgmt->u.action.u.addba_resp.dialog_token !=
674 sta->ampdu_mlme.tid_tx[tid]->dialog_token) {
675 spin_unlock_bh(&sta->lock);
676 #ifdef CONFIG_MAC80211_HT_DEBUG
677 printk(KERN_DEBUG "wrong addBA response token, tid %d\n", tid);
678 #endif /* CONFIG_MAC80211_HT_DEBUG */
682 del_timer_sync(&sta->ampdu_mlme.tid_tx[tid]->addba_resp_timer);
683 #ifdef CONFIG_MAC80211_HT_DEBUG
684 printk(KERN_DEBUG "switched off addBA timer for tid %d \n", tid);
685 #endif /* CONFIG_MAC80211_HT_DEBUG */
686 if (le16_to_cpu(mgmt->u.action.u.addba_resp.status)
687 == WLAN_STATUS_SUCCESS) {
688 u8 curstate = *state;
690 *state |= HT_ADDBA_RECEIVED_MSK;
692 if (*state != curstate && *state == HT_AGG_STATE_OPERATIONAL)
693 ieee80211_agg_tx_operational(local, sta, tid);
695 sta->ampdu_mlme.addba_req_num[tid] = 0;
697 sta->ampdu_mlme.addba_req_num[tid]++;
698 ___ieee80211_stop_tx_ba_session(sta, tid, WLAN_BACK_INITIATOR);
700 spin_unlock_bh(&sta->lock);