carl9170: stop stale uplink BA sessions
[linux-3.10.git] / drivers / net / wireless / ath / carl9170 / tx.c
1 /*
2  * Atheros CARL9170 driver
3  *
4  * 802.11 xmit & status routines
5  *
6  * Copyright 2008, Johannes Berg <johannes@sipsolutions.net>
7  * Copyright 2009, 2010, Christian Lamparter <chunkeey@googlemail.com>
8  *
9  * This program is free software; you can redistribute it and/or modify
10  * it under the terms of the GNU General Public License as published by
11  * the Free Software Foundation; either version 2 of the License, or
12  * (at your option) any later version.
13  *
14  * This program is distributed in the hope that it will be useful,
15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17  * GNU General Public License for more details.
18  *
19  * You should have received a copy of the GNU General Public License
20  * along with this program; see the file COPYING.  If not, see
21  * http://www.gnu.org/licenses/.
22  *
23  * This file incorporates work covered by the following copyright and
24  * permission notice:
25  *    Copyright (c) 2007-2008 Atheros Communications, Inc.
26  *
27  *    Permission to use, copy, modify, and/or distribute this software for any
28  *    purpose with or without fee is hereby granted, provided that the above
29  *    copyright notice and this permission notice appear in all copies.
30  *
31  *    THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
32  *    WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
33  *    MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
34  *    ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
35  *    WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
36  *    ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
37  *    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
38  */
39
40 #include <linux/init.h>
41 #include <linux/slab.h>
42 #include <linux/module.h>
43 #include <linux/etherdevice.h>
44 #include <net/mac80211.h>
45 #include "carl9170.h"
46 #include "hw.h"
47 #include "cmd.h"
48
49 static inline unsigned int __carl9170_get_queue(struct ar9170 *ar,
50                                                 unsigned int queue)
51 {
52         if (unlikely(modparam_noht)) {
53                 return queue;
54         } else {
55                 /*
56                  * This is just another workaround, until
57                  * someone figures out how to get QoS and
58                  * AMPDU to play nicely together.
59                  */
60
61                 return 2;               /* AC_BE */
62         }
63 }
64
65 static inline unsigned int carl9170_get_queue(struct ar9170 *ar,
66                                               struct sk_buff *skb)
67 {
68         return __carl9170_get_queue(ar, skb_get_queue_mapping(skb));
69 }
70
71 static bool is_mem_full(struct ar9170 *ar)
72 {
73         return (DIV_ROUND_UP(IEEE80211_MAX_FRAME_LEN, ar->fw.mem_block_size) >
74                 atomic_read(&ar->mem_free_blocks));
75 }
76
77 static void carl9170_tx_accounting(struct ar9170 *ar, struct sk_buff *skb)
78 {
79         int queue, i;
80         bool mem_full;
81
82         atomic_inc(&ar->tx_total_queued);
83
84         queue = skb_get_queue_mapping(skb);
85         spin_lock_bh(&ar->tx_stats_lock);
86
87         /*
88          * The driver has to accept the frame, regardless if the queue is
89          * full to the brim, or not. We have to do the queuing internally,
90          * since mac80211 assumes that a driver which can operate with
91          * aggregated frames does not reject frames for this reason.
92          */
93         ar->tx_stats[queue].len++;
94         ar->tx_stats[queue].count++;
95
96         mem_full = is_mem_full(ar);
97         for (i = 0; i < ar->hw->queues; i++) {
98                 if (mem_full || ar->tx_stats[i].len >= ar->tx_stats[i].limit) {
99                         ieee80211_stop_queue(ar->hw, i);
100                         ar->queue_stop_timeout[i] = jiffies;
101                 }
102         }
103
104         spin_unlock_bh(&ar->tx_stats_lock);
105 }
106
107 static void carl9170_tx_accounting_free(struct ar9170 *ar, struct sk_buff *skb)
108 {
109         struct ieee80211_tx_info *txinfo;
110         int queue;
111
112         txinfo = IEEE80211_SKB_CB(skb);
113         queue = skb_get_queue_mapping(skb);
114
115         spin_lock_bh(&ar->tx_stats_lock);
116
117         ar->tx_stats[queue].len--;
118
119         if (!is_mem_full(ar)) {
120                 unsigned int i;
121                 for (i = 0; i < ar->hw->queues; i++) {
122                         if (ar->tx_stats[i].len >= CARL9170_NUM_TX_LIMIT_SOFT)
123                                 continue;
124
125                         if (ieee80211_queue_stopped(ar->hw, i)) {
126                                 unsigned long tmp;
127
128                                 tmp = jiffies - ar->queue_stop_timeout[i];
129                                 if (tmp > ar->max_queue_stop_timeout[i])
130                                         ar->max_queue_stop_timeout[i] = tmp;
131                         }
132
133                         ieee80211_wake_queue(ar->hw, i);
134                 }
135         }
136
137         spin_unlock_bh(&ar->tx_stats_lock);
138         if (atomic_dec_and_test(&ar->tx_total_queued))
139                 complete(&ar->tx_flush);
140 }
141
142 static int carl9170_alloc_dev_space(struct ar9170 *ar, struct sk_buff *skb)
143 {
144         struct _carl9170_tx_superframe *super = (void *) skb->data;
145         unsigned int chunks;
146         int cookie = -1;
147
148         atomic_inc(&ar->mem_allocs);
149
150         chunks = DIV_ROUND_UP(skb->len, ar->fw.mem_block_size);
151         if (unlikely(atomic_sub_return(chunks, &ar->mem_free_blocks) < 0)) {
152                 atomic_add(chunks, &ar->mem_free_blocks);
153                 return -ENOSPC;
154         }
155
156         spin_lock_bh(&ar->mem_lock);
157         cookie = bitmap_find_free_region(ar->mem_bitmap, ar->fw.mem_blocks, 0);
158         spin_unlock_bh(&ar->mem_lock);
159
160         if (unlikely(cookie < 0)) {
161                 atomic_add(chunks, &ar->mem_free_blocks);
162                 return -ENOSPC;
163         }
164
165         super = (void *) skb->data;
166
167         /*
168          * Cookie #0 serves two special purposes:
169          *  1. The firmware might use it generate BlockACK frames
170          *     in responds of an incoming BlockAckReqs.
171          *
172          *  2. Prevent double-free bugs.
173          */
174         super->s.cookie = (u8) cookie + 1;
175         return 0;
176 }
177
178 static void carl9170_release_dev_space(struct ar9170 *ar, struct sk_buff *skb)
179 {
180         struct _carl9170_tx_superframe *super = (void *) skb->data;
181         int cookie;
182
183         /* make a local copy of the cookie */
184         cookie = super->s.cookie;
185         /* invalidate cookie */
186         super->s.cookie = 0;
187
188         /*
189          * Do a out-of-bounds check on the cookie:
190          *
191          *  * cookie "0" is reserved and won't be assigned to any
192          *    out-going frame. Internally however, it is used to
193          *    mark no longer/un-accounted frames and serves as a
194          *    cheap way of preventing frames from being freed
195          *    twice by _accident_. NB: There is a tiny race...
196          *
197          *  * obviously, cookie number is limited by the amount
198          *    of available memory blocks, so the number can
199          *    never execeed the mem_blocks count.
200          */
201         if (unlikely(WARN_ON_ONCE(cookie == 0) ||
202             WARN_ON_ONCE(cookie > ar->fw.mem_blocks)))
203                 return;
204
205         atomic_add(DIV_ROUND_UP(skb->len, ar->fw.mem_block_size),
206                    &ar->mem_free_blocks);
207
208         spin_lock_bh(&ar->mem_lock);
209         bitmap_release_region(ar->mem_bitmap, cookie - 1, 0);
210         spin_unlock_bh(&ar->mem_lock);
211 }
212
213 /* Called from any context */
214 static void carl9170_tx_release(struct kref *ref)
215 {
216         struct ar9170 *ar;
217         struct carl9170_tx_info *arinfo;
218         struct ieee80211_tx_info *txinfo;
219         struct sk_buff *skb;
220
221         arinfo = container_of(ref, struct carl9170_tx_info, ref);
222         txinfo = container_of((void *) arinfo, struct ieee80211_tx_info,
223                               rate_driver_data);
224         skb = container_of((void *) txinfo, struct sk_buff, cb);
225
226         ar = arinfo->ar;
227         if (WARN_ON_ONCE(!ar))
228                 return;
229
230         BUILD_BUG_ON(
231             offsetof(struct ieee80211_tx_info, status.ampdu_ack_len) != 23);
232
233         memset(&txinfo->status.ampdu_ack_len, 0,
234                sizeof(struct ieee80211_tx_info) -
235                offsetof(struct ieee80211_tx_info, status.ampdu_ack_len));
236
237         if (atomic_read(&ar->tx_total_queued))
238                 ar->tx_schedule = true;
239
240         if (txinfo->flags & IEEE80211_TX_CTL_AMPDU) {
241                 if (!atomic_read(&ar->tx_ampdu_upload))
242                         ar->tx_ampdu_schedule = true;
243
244                 if (txinfo->flags & IEEE80211_TX_STAT_AMPDU) {
245                         txinfo->status.ampdu_len = txinfo->pad[0];
246                         txinfo->status.ampdu_ack_len = txinfo->pad[1];
247                         txinfo->pad[0] = txinfo->pad[1] = 0;
248                 } else if (txinfo->flags & IEEE80211_TX_STAT_ACK) {
249                         /*
250                          * drop redundant tx_status reports:
251                          *
252                          * 1. ampdu_ack_len of the final tx_status does
253                          *    include the feedback of this particular frame.
254                          *
255                          * 2. tx_status_irqsafe only queues up to 128
256                          *    tx feedback reports and discards the rest.
257                          *
258                          * 3. minstrel_ht is picky, it only accepts
259                          *    reports of frames with the TX_STATUS_AMPDU flag.
260                          */
261
262                         dev_kfree_skb_any(skb);
263                         return;
264                 } else {
265                         /*
266                          * Frame has failed, but we want to keep it in
267                          * case it was lost due to a power-state
268                          * transition.
269                          */
270                 }
271         }
272
273         skb_pull(skb, sizeof(struct _carl9170_tx_superframe));
274         ieee80211_tx_status_irqsafe(ar->hw, skb);
275 }
276
277 void carl9170_tx_get_skb(struct sk_buff *skb)
278 {
279         struct carl9170_tx_info *arinfo = (void *)
280                 (IEEE80211_SKB_CB(skb))->rate_driver_data;
281         kref_get(&arinfo->ref);
282 }
283
284 int carl9170_tx_put_skb(struct sk_buff *skb)
285 {
286         struct carl9170_tx_info *arinfo = (void *)
287                 (IEEE80211_SKB_CB(skb))->rate_driver_data;
288
289         return kref_put(&arinfo->ref, carl9170_tx_release);
290 }
291
292 /* Caller must hold the tid_info->lock & rcu_read_lock */
293 static void carl9170_tx_shift_bm(struct ar9170 *ar,
294         struct carl9170_sta_tid *tid_info, u16 seq)
295 {
296         u16 off;
297
298         off = SEQ_DIFF(seq, tid_info->bsn);
299
300         if (WARN_ON_ONCE(off >= CARL9170_BAW_BITS))
301                 return;
302
303         /*
304          * Sanity check. For each MPDU we set the bit in bitmap and
305          * clear it once we received the tx_status.
306          * But if the bit is already cleared then we've been bitten
307          * by a bug.
308          */
309         WARN_ON_ONCE(!test_and_clear_bit(off, tid_info->bitmap));
310
311         off = SEQ_DIFF(tid_info->snx, tid_info->bsn);
312         if (WARN_ON_ONCE(off >= CARL9170_BAW_BITS))
313                 return;
314
315         if (!bitmap_empty(tid_info->bitmap, off))
316                 off = find_first_bit(tid_info->bitmap, off);
317
318         tid_info->bsn += off;
319         tid_info->bsn &= 0x0fff;
320
321         bitmap_shift_right(tid_info->bitmap, tid_info->bitmap,
322                            off, CARL9170_BAW_BITS);
323 }
324
325 static void carl9170_tx_status_process_ampdu(struct ar9170 *ar,
326         struct sk_buff *skb, struct ieee80211_tx_info *txinfo)
327 {
328         struct _carl9170_tx_superframe *super = (void *) skb->data;
329         struct ieee80211_hdr *hdr = (void *) super->frame_data;
330         struct ieee80211_tx_info *tx_info;
331         struct carl9170_tx_info *ar_info;
332         struct carl9170_sta_info *sta_info;
333         struct ieee80211_sta *sta;
334         struct carl9170_sta_tid *tid_info;
335         struct ieee80211_vif *vif;
336         unsigned int vif_id;
337         u8 tid;
338
339         if (!(txinfo->flags & IEEE80211_TX_CTL_AMPDU) ||
340             txinfo->flags & IEEE80211_TX_CTL_INJECTED)
341                 return;
342
343         tx_info = IEEE80211_SKB_CB(skb);
344         ar_info = (void *) tx_info->rate_driver_data;
345
346         vif_id = (super->s.misc & CARL9170_TX_SUPER_MISC_VIF_ID) >>
347                  CARL9170_TX_SUPER_MISC_VIF_ID_S;
348
349         if (WARN_ON_ONCE(vif_id >= AR9170_MAX_VIRTUAL_MAC))
350                 return;
351
352         rcu_read_lock();
353         vif = rcu_dereference(ar->vif_priv[vif_id].vif);
354         if (unlikely(!vif))
355                 goto out_rcu;
356
357         /*
358          * Normally we should use wrappers like ieee80211_get_DA to get
359          * the correct peer ieee80211_sta.
360          *
361          * But there is a problem with indirect traffic (broadcasts, or
362          * data which is designated for other stations) in station mode.
363          * The frame will be directed to the AP for distribution and not
364          * to the actual destination.
365          */
366         sta = ieee80211_find_sta(vif, hdr->addr1);
367         if (unlikely(!sta))
368                 goto out_rcu;
369
370         tid = get_tid_h(hdr);
371
372         sta_info = (void *) sta->drv_priv;
373         tid_info = rcu_dereference(sta_info->agg[tid]);
374         if (!tid_info)
375                 goto out_rcu;
376
377         spin_lock_bh(&tid_info->lock);
378         if (likely(tid_info->state >= CARL9170_TID_STATE_IDLE))
379                 carl9170_tx_shift_bm(ar, tid_info, get_seq_h(hdr));
380
381         if (sta_info->stats[tid].clear) {
382                 sta_info->stats[tid].clear = false;
383                 sta_info->stats[tid].ampdu_len = 0;
384                 sta_info->stats[tid].ampdu_ack_len = 0;
385         }
386
387         sta_info->stats[tid].ampdu_len++;
388         if (txinfo->status.rates[0].count == 1)
389                 sta_info->stats[tid].ampdu_ack_len++;
390
391         if (super->f.mac_control & cpu_to_le16(AR9170_TX_MAC_IMM_BA)) {
392                 txinfo->pad[0] = sta_info->stats[tid].ampdu_len;
393                 txinfo->pad[1] = sta_info->stats[tid].ampdu_ack_len;
394                 txinfo->flags |= IEEE80211_TX_STAT_AMPDU;
395                 sta_info->stats[tid].clear = true;
396         }
397         spin_unlock_bh(&tid_info->lock);
398
399 out_rcu:
400         rcu_read_unlock();
401 }
402
403 void carl9170_tx_status(struct ar9170 *ar, struct sk_buff *skb,
404                         const bool success)
405 {
406         struct ieee80211_tx_info *txinfo;
407
408         carl9170_tx_accounting_free(ar, skb);
409
410         txinfo = IEEE80211_SKB_CB(skb);
411
412         if (success)
413                 txinfo->flags |= IEEE80211_TX_STAT_ACK;
414         else
415                 ar->tx_ack_failures++;
416
417         if (txinfo->flags & IEEE80211_TX_CTL_AMPDU)
418                 carl9170_tx_status_process_ampdu(ar, skb, txinfo);
419
420         carl9170_tx_put_skb(skb);
421 }
422
423 /* This function may be called form any context */
424 void carl9170_tx_callback(struct ar9170 *ar, struct sk_buff *skb)
425 {
426         struct ieee80211_tx_info *txinfo = IEEE80211_SKB_CB(skb);
427
428         atomic_dec(&ar->tx_total_pending);
429
430         if (txinfo->flags & IEEE80211_TX_CTL_AMPDU)
431                 atomic_dec(&ar->tx_ampdu_upload);
432
433         if (carl9170_tx_put_skb(skb))
434                 tasklet_hi_schedule(&ar->usb_tasklet);
435 }
436
437 static struct sk_buff *carl9170_get_queued_skb(struct ar9170 *ar, u8 cookie,
438                                                struct sk_buff_head *queue)
439 {
440         struct sk_buff *skb;
441
442         spin_lock_bh(&queue->lock);
443         skb_queue_walk(queue, skb) {
444                 struct _carl9170_tx_superframe *txc = (void *) skb->data;
445
446                 if (txc->s.cookie != cookie)
447                         continue;
448
449                 __skb_unlink(skb, queue);
450                 spin_unlock_bh(&queue->lock);
451
452                 carl9170_release_dev_space(ar, skb);
453                 return skb;
454         }
455         spin_unlock_bh(&queue->lock);
456
457         return NULL;
458 }
459
460 static void carl9170_tx_fill_rateinfo(struct ar9170 *ar, unsigned int rix,
461         unsigned int tries, struct ieee80211_tx_info *txinfo)
462 {
463         unsigned int i;
464
465         for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) {
466                 if (txinfo->status.rates[i].idx < 0)
467                         break;
468
469                 if (i == rix) {
470                         txinfo->status.rates[i].count = tries;
471                         i++;
472                         break;
473                 }
474         }
475
476         for (; i < IEEE80211_TX_MAX_RATES; i++) {
477                 txinfo->status.rates[i].idx = -1;
478                 txinfo->status.rates[i].count = 0;
479         }
480 }
481
482 static void carl9170_check_queue_stop_timeout(struct ar9170 *ar)
483 {
484         int i;
485         struct sk_buff *skb;
486         struct ieee80211_tx_info *txinfo;
487         struct carl9170_tx_info *arinfo;
488         bool restart = false;
489
490         for (i = 0; i < ar->hw->queues; i++) {
491                 spin_lock_bh(&ar->tx_status[i].lock);
492
493                 skb = skb_peek(&ar->tx_status[i]);
494
495                 if (!skb)
496                         goto next;
497
498                 txinfo = IEEE80211_SKB_CB(skb);
499                 arinfo = (void *) txinfo->rate_driver_data;
500
501                 if (time_is_before_jiffies(arinfo->timeout +
502                     msecs_to_jiffies(CARL9170_QUEUE_STUCK_TIMEOUT)) == true)
503                         restart = true;
504
505 next:
506                 spin_unlock_bh(&ar->tx_status[i].lock);
507         }
508
509         if (restart) {
510                 /*
511                  * At least one queue has been stuck for long enough.
512                  * Give the device a kick and hope it gets back to
513                  * work.
514                  *
515                  * possible reasons may include:
516                  *  - frames got lost/corrupted (bad connection to the device)
517                  *  - stalled rx processing/usb controller hiccups
518                  *  - firmware errors/bugs
519                  *  - every bug you can think of.
520                  *  - all bugs you can't...
521                  *  - ...
522                  */
523                 carl9170_restart(ar, CARL9170_RR_STUCK_TX);
524         }
525 }
526
527 static void carl9170_tx_ampdu_timeout(struct ar9170 *ar)
528 {
529         struct carl9170_sta_tid *iter;
530         struct sk_buff *skb;
531         struct ieee80211_tx_info *txinfo;
532         struct carl9170_tx_info *arinfo;
533         struct _carl9170_tx_superframe *super;
534         struct ieee80211_sta *sta;
535         struct ieee80211_vif *vif;
536         struct ieee80211_hdr *hdr;
537         unsigned int vif_id;
538
539         rcu_read_lock();
540         list_for_each_entry_rcu(iter, &ar->tx_ampdu_list, list) {
541                 if (iter->state < CARL9170_TID_STATE_IDLE)
542                         continue;
543
544                 spin_lock_bh(&iter->lock);
545                 skb = skb_peek(&iter->queue);
546                 if (!skb)
547                         goto unlock;
548
549                 txinfo = IEEE80211_SKB_CB(skb);
550                 arinfo = (void *)txinfo->rate_driver_data;
551                 if (time_is_after_jiffies(arinfo->timeout +
552                     msecs_to_jiffies(CARL9170_QUEUE_TIMEOUT)))
553                         goto unlock;
554
555                 super = (void *) skb->data;
556                 hdr = (void *) super->frame_data;
557
558                 vif_id = (super->s.misc & CARL9170_TX_SUPER_MISC_VIF_ID) >>
559                          CARL9170_TX_SUPER_MISC_VIF_ID_S;
560
561                 if (WARN_ON(vif_id >= AR9170_MAX_VIRTUAL_MAC))
562                         goto unlock;
563
564                 vif = rcu_dereference(ar->vif_priv[vif_id].vif);
565                 if (WARN_ON(!vif))
566                         goto unlock;
567
568                 sta = ieee80211_find_sta(vif, hdr->addr1);
569                 if (WARN_ON(!sta))
570                         goto unlock;
571
572                 ieee80211_stop_tx_ba_session(sta, iter->tid);
573 unlock:
574                 spin_unlock_bh(&iter->lock);
575
576         }
577         rcu_read_unlock();
578 }
579
580 void carl9170_tx_janitor(struct work_struct *work)
581 {
582         struct ar9170 *ar = container_of(work, struct ar9170,
583                                          tx_janitor.work);
584         if (!IS_STARTED(ar))
585                 return;
586
587         ar->tx_janitor_last_run = jiffies;
588
589         carl9170_check_queue_stop_timeout(ar);
590         carl9170_tx_ampdu_timeout(ar);
591
592         if (!atomic_read(&ar->tx_total_queued))
593                 return;
594
595         ieee80211_queue_delayed_work(ar->hw, &ar->tx_janitor,
596                 msecs_to_jiffies(CARL9170_TX_TIMEOUT));
597 }
598
599 static void __carl9170_tx_process_status(struct ar9170 *ar,
600         const uint8_t cookie, const uint8_t info)
601 {
602         struct sk_buff *skb;
603         struct ieee80211_tx_info *txinfo;
604         struct carl9170_tx_info *arinfo;
605         unsigned int r, t, q;
606         bool success = true;
607
608         q = ar9170_qmap[info & CARL9170_TX_STATUS_QUEUE];
609
610         skb = carl9170_get_queued_skb(ar, cookie, &ar->tx_status[q]);
611         if (!skb) {
612                 /*
613                  * We have lost the race to another thread.
614                  */
615
616                 return ;
617         }
618
619         txinfo = IEEE80211_SKB_CB(skb);
620         arinfo = (void *) txinfo->rate_driver_data;
621
622         if (!(info & CARL9170_TX_STATUS_SUCCESS))
623                 success = false;
624
625         r = (info & CARL9170_TX_STATUS_RIX) >> CARL9170_TX_STATUS_RIX_S;
626         t = (info & CARL9170_TX_STATUS_TRIES) >> CARL9170_TX_STATUS_TRIES_S;
627
628         carl9170_tx_fill_rateinfo(ar, r, t, txinfo);
629         carl9170_tx_status(ar, skb, success);
630 }
631
632 void carl9170_tx_process_status(struct ar9170 *ar,
633                                 const struct carl9170_rsp *cmd)
634 {
635         unsigned int i;
636
637         for (i = 0;  i < cmd->hdr.ext; i++) {
638                 if (WARN_ON(i > ((cmd->hdr.len / 2) + 1))) {
639                         print_hex_dump_bytes("UU:", DUMP_PREFIX_NONE,
640                                              (void *) cmd, cmd->hdr.len + 4);
641                         break;
642                 }
643
644                 __carl9170_tx_process_status(ar, cmd->_tx_status[i].cookie,
645                                              cmd->_tx_status[i].info);
646         }
647 }
648
649 static __le32 carl9170_tx_physet(struct ar9170 *ar,
650         struct ieee80211_tx_info *info, struct ieee80211_tx_rate *txrate)
651 {
652         struct ieee80211_rate *rate = NULL;
653         u32 power, chains;
654         __le32 tmp;
655
656         tmp = cpu_to_le32(0);
657
658         if (txrate->flags & IEEE80211_TX_RC_40_MHZ_WIDTH)
659                 tmp |= cpu_to_le32(AR9170_TX_PHY_BW_40MHZ <<
660                         AR9170_TX_PHY_BW_S);
661         /* this works because 40 MHz is 2 and dup is 3 */
662         if (txrate->flags & IEEE80211_TX_RC_DUP_DATA)
663                 tmp |= cpu_to_le32(AR9170_TX_PHY_BW_40MHZ_DUP <<
664                         AR9170_TX_PHY_BW_S);
665
666         if (txrate->flags & IEEE80211_TX_RC_SHORT_GI)
667                 tmp |= cpu_to_le32(AR9170_TX_PHY_SHORT_GI);
668
669         if (txrate->flags & IEEE80211_TX_RC_MCS) {
670                 u32 r = txrate->idx;
671                 u8 *txpower;
672
673                 /* heavy clip control */
674                 tmp |= cpu_to_le32((r & 0x7) <<
675                         AR9170_TX_PHY_TX_HEAVY_CLIP_S);
676
677                 if (txrate->flags & IEEE80211_TX_RC_40_MHZ_WIDTH) {
678                         if (info->band == IEEE80211_BAND_5GHZ)
679                                 txpower = ar->power_5G_ht40;
680                         else
681                                 txpower = ar->power_2G_ht40;
682                 } else {
683                         if (info->band == IEEE80211_BAND_5GHZ)
684                                 txpower = ar->power_5G_ht20;
685                         else
686                                 txpower = ar->power_2G_ht20;
687                 }
688
689                 power = txpower[r & 7];
690
691                 /* +1 dBm for HT40 */
692                 if (txrate->flags & IEEE80211_TX_RC_40_MHZ_WIDTH)
693                         power += 2;
694
695                 r <<= AR9170_TX_PHY_MCS_S;
696                 BUG_ON(r & ~AR9170_TX_PHY_MCS);
697
698                 tmp |= cpu_to_le32(r & AR9170_TX_PHY_MCS);
699                 tmp |= cpu_to_le32(AR9170_TX_PHY_MOD_HT);
700
701                 /*
702                  * green field preamble does not work.
703                  *
704                  * if (txrate->flags & IEEE80211_TX_RC_GREEN_FIELD)
705                  * tmp |= cpu_to_le32(AR9170_TX_PHY_GREENFIELD);
706                  */
707         } else {
708                 u8 *txpower;
709                 u32 mod;
710                 u32 phyrate;
711                 u8 idx = txrate->idx;
712
713                 if (info->band != IEEE80211_BAND_2GHZ) {
714                         idx += 4;
715                         txpower = ar->power_5G_leg;
716                         mod = AR9170_TX_PHY_MOD_OFDM;
717                 } else {
718                         if (idx < 4) {
719                                 txpower = ar->power_2G_cck;
720                                 mod = AR9170_TX_PHY_MOD_CCK;
721                         } else {
722                                 mod = AR9170_TX_PHY_MOD_OFDM;
723                                 txpower = ar->power_2G_ofdm;
724                         }
725                 }
726
727                 rate = &__carl9170_ratetable[idx];
728
729                 phyrate = rate->hw_value & 0xF;
730                 power = txpower[(rate->hw_value & 0x30) >> 4];
731                 phyrate <<= AR9170_TX_PHY_MCS_S;
732
733                 tmp |= cpu_to_le32(mod);
734                 tmp |= cpu_to_le32(phyrate);
735
736                 /*
737                  * short preamble seems to be broken too.
738                  *
739                  * if (txrate->flags & IEEE80211_TX_RC_USE_SHORT_PREAMBLE)
740                  *      tmp |= cpu_to_le32(AR9170_TX_PHY_SHORT_PREAMBLE);
741                  */
742         }
743         power <<= AR9170_TX_PHY_TX_PWR_S;
744         power &= AR9170_TX_PHY_TX_PWR;
745         tmp |= cpu_to_le32(power);
746
747         /* set TX chains */
748         if (ar->eeprom.tx_mask == 1) {
749                 chains = AR9170_TX_PHY_TXCHAIN_1;
750         } else {
751                 chains = AR9170_TX_PHY_TXCHAIN_2;
752
753                 /* >= 36M legacy OFDM - use only one chain */
754                 if (rate && rate->bitrate >= 360 &&
755                     !(txrate->flags & IEEE80211_TX_RC_MCS))
756                         chains = AR9170_TX_PHY_TXCHAIN_1;
757         }
758         tmp |= cpu_to_le32(chains << AR9170_TX_PHY_TXCHAIN_S);
759
760         return tmp;
761 }
762
763 static bool carl9170_tx_rts_check(struct ar9170 *ar,
764                                   struct ieee80211_tx_rate *rate,
765                                   bool ampdu, bool multi)
766 {
767         switch (ar->erp_mode) {
768         case CARL9170_ERP_AUTO:
769                 if (ampdu)
770                         break;
771
772         case CARL9170_ERP_MAC80211:
773                 if (!(rate->flags & IEEE80211_TX_RC_USE_RTS_CTS))
774                         break;
775
776         case CARL9170_ERP_RTS:
777                 if (likely(!multi))
778                         return true;
779
780         default:
781                 break;
782         }
783
784         return false;
785 }
786
787 static bool carl9170_tx_cts_check(struct ar9170 *ar,
788                                   struct ieee80211_tx_rate *rate)
789 {
790         switch (ar->erp_mode) {
791         case CARL9170_ERP_AUTO:
792         case CARL9170_ERP_MAC80211:
793                 if (!(rate->flags & IEEE80211_TX_RC_USE_CTS_PROTECT))
794                         break;
795
796         case CARL9170_ERP_CTS:
797                 return true;
798
799         default:
800                 break;
801         }
802
803         return false;
804 }
805
806 static int carl9170_tx_prepare(struct ar9170 *ar, struct sk_buff *skb)
807 {
808         struct ieee80211_hdr *hdr;
809         struct _carl9170_tx_superframe *txc;
810         struct carl9170_vif_info *cvif;
811         struct ieee80211_tx_info *info;
812         struct ieee80211_tx_rate *txrate;
813         struct ieee80211_sta *sta;
814         struct carl9170_tx_info *arinfo;
815         unsigned int hw_queue;
816         int i;
817         __le16 mac_tmp;
818         u16 len;
819         bool ampdu, no_ack;
820
821         BUILD_BUG_ON(sizeof(*arinfo) > sizeof(info->rate_driver_data));
822         BUILD_BUG_ON(sizeof(struct _carl9170_tx_superdesc) !=
823                      CARL9170_TX_SUPERDESC_LEN);
824
825         BUILD_BUG_ON(sizeof(struct _ar9170_tx_hwdesc) !=
826                      AR9170_TX_HWDESC_LEN);
827
828         BUILD_BUG_ON(IEEE80211_TX_MAX_RATES < CARL9170_TX_MAX_RATES);
829
830         BUILD_BUG_ON(AR9170_MAX_VIRTUAL_MAC >
831                 ((CARL9170_TX_SUPER_MISC_VIF_ID >>
832                  CARL9170_TX_SUPER_MISC_VIF_ID_S) + 1));
833
834         hw_queue = ar9170_qmap[carl9170_get_queue(ar, skb)];
835
836         hdr = (void *)skb->data;
837         info = IEEE80211_SKB_CB(skb);
838         len = skb->len;
839
840         /*
841          * Note: If the frame was sent through a monitor interface,
842          * the ieee80211_vif pointer can be NULL.
843          */
844         if (likely(info->control.vif))
845                 cvif = (void *) info->control.vif->drv_priv;
846         else
847                 cvif = NULL;
848
849         sta = info->control.sta;
850
851         txc = (void *)skb_push(skb, sizeof(*txc));
852         memset(txc, 0, sizeof(*txc));
853
854         SET_VAL(CARL9170_TX_SUPER_MISC_QUEUE, txc->s.misc, hw_queue);
855
856         if (likely(cvif))
857                 SET_VAL(CARL9170_TX_SUPER_MISC_VIF_ID, txc->s.misc, cvif->id);
858
859         if (unlikely(info->flags & IEEE80211_TX_CTL_SEND_AFTER_DTIM))
860                 txc->s.misc |= CARL9170_TX_SUPER_MISC_CAB;
861
862         if (unlikely(ieee80211_is_probe_resp(hdr->frame_control)))
863                 txc->s.misc |= CARL9170_TX_SUPER_MISC_FILL_IN_TSF;
864
865         mac_tmp = cpu_to_le16(AR9170_TX_MAC_HW_DURATION |
866                               AR9170_TX_MAC_BACKOFF);
867         mac_tmp |= cpu_to_le16((hw_queue << AR9170_TX_MAC_QOS_S) &&
868                                AR9170_TX_MAC_QOS);
869
870         no_ack = !!(info->flags & IEEE80211_TX_CTL_NO_ACK);
871         if (unlikely(no_ack))
872                 mac_tmp |= cpu_to_le16(AR9170_TX_MAC_NO_ACK);
873
874         if (info->control.hw_key) {
875                 len += info->control.hw_key->icv_len;
876
877                 switch (info->control.hw_key->cipher) {
878                 case WLAN_CIPHER_SUITE_WEP40:
879                 case WLAN_CIPHER_SUITE_WEP104:
880                 case WLAN_CIPHER_SUITE_TKIP:
881                         mac_tmp |= cpu_to_le16(AR9170_TX_MAC_ENCR_RC4);
882                         break;
883                 case WLAN_CIPHER_SUITE_CCMP:
884                         mac_tmp |= cpu_to_le16(AR9170_TX_MAC_ENCR_AES);
885                         break;
886                 default:
887                         WARN_ON(1);
888                         goto err_out;
889                 }
890         }
891
892         ampdu = !!(info->flags & IEEE80211_TX_CTL_AMPDU);
893         if (ampdu) {
894                 unsigned int density, factor;
895
896                 if (unlikely(!sta || !cvif))
897                         goto err_out;
898
899                 factor = min_t(unsigned int, 1u,
900                          info->control.sta->ht_cap.ampdu_factor);
901
902                 density = info->control.sta->ht_cap.ampdu_density;
903
904                 if (density) {
905                         /*
906                          * Watch out!
907                          *
908                          * Otus uses slightly different density values than
909                          * those from the 802.11n spec.
910                          */
911
912                         density = max_t(unsigned int, density + 1, 7u);
913                 }
914
915                 SET_VAL(CARL9170_TX_SUPER_AMPDU_DENSITY,
916                         txc->s.ampdu_settings, density);
917
918                 SET_VAL(CARL9170_TX_SUPER_AMPDU_FACTOR,
919                         txc->s.ampdu_settings, factor);
920
921                 for (i = 0; i < CARL9170_TX_MAX_RATES; i++) {
922                         txrate = &info->control.rates[i];
923                         if (txrate->idx >= 0) {
924                                 txc->s.ri[i] =
925                                         CARL9170_TX_SUPER_RI_AMPDU;
926
927                                 if (WARN_ON(!(txrate->flags &
928                                               IEEE80211_TX_RC_MCS))) {
929                                         /*
930                                          * Not sure if it's even possible
931                                          * to aggregate non-ht rates with
932                                          * this HW.
933                                          */
934                                         goto err_out;
935                                 }
936                                 continue;
937                         }
938
939                         txrate->idx = 0;
940                         txrate->count = ar->hw->max_rate_tries;
941                 }
942
943                 mac_tmp |= cpu_to_le16(AR9170_TX_MAC_AGGR);
944         }
945
946         /*
947          * NOTE: For the first rate, the ERP & AMPDU flags are directly
948          * taken from mac_control. For all fallback rate, the firmware
949          * updates the mac_control flags from the rate info field.
950          */
951         for (i = 1; i < CARL9170_TX_MAX_RATES; i++) {
952                 txrate = &info->control.rates[i];
953                 if (txrate->idx < 0)
954                         break;
955
956                 SET_VAL(CARL9170_TX_SUPER_RI_TRIES, txc->s.ri[i],
957                         txrate->count);
958
959                 if (carl9170_tx_rts_check(ar, txrate, ampdu, no_ack))
960                         txc->s.ri[i] |= (AR9170_TX_MAC_PROT_RTS <<
961                                 CARL9170_TX_SUPER_RI_ERP_PROT_S);
962                 else if (carl9170_tx_cts_check(ar, txrate))
963                         txc->s.ri[i] |= (AR9170_TX_MAC_PROT_CTS <<
964                                 CARL9170_TX_SUPER_RI_ERP_PROT_S);
965
966                 txc->s.rr[i - 1] = carl9170_tx_physet(ar, info, txrate);
967         }
968
969         txrate = &info->control.rates[0];
970         SET_VAL(CARL9170_TX_SUPER_RI_TRIES, txc->s.ri[0], txrate->count);
971
972         if (carl9170_tx_rts_check(ar, txrate, ampdu, no_ack))
973                 mac_tmp |= cpu_to_le16(AR9170_TX_MAC_PROT_RTS);
974         else if (carl9170_tx_cts_check(ar, txrate))
975                 mac_tmp |= cpu_to_le16(AR9170_TX_MAC_PROT_CTS);
976
977         txc->s.len = cpu_to_le16(skb->len);
978         txc->f.length = cpu_to_le16(len + FCS_LEN);
979         txc->f.mac_control = mac_tmp;
980         txc->f.phy_control = carl9170_tx_physet(ar, info, txrate);
981
982         arinfo = (void *)info->rate_driver_data;
983         arinfo->timeout = jiffies;
984         arinfo->ar = ar;
985         kref_init(&arinfo->ref);
986         return 0;
987
988 err_out:
989         skb_pull(skb, sizeof(*txc));
990         return -EINVAL;
991 }
992
993 static void carl9170_set_immba(struct ar9170 *ar, struct sk_buff *skb)
994 {
995         struct _carl9170_tx_superframe *super;
996
997         super = (void *) skb->data;
998         super->f.mac_control |= cpu_to_le16(AR9170_TX_MAC_IMM_BA);
999 }
1000
1001 static void carl9170_set_ampdu_params(struct ar9170 *ar, struct sk_buff *skb)
1002 {
1003         struct _carl9170_tx_superframe *super;
1004         int tmp;
1005
1006         super = (void *) skb->data;
1007
1008         tmp = (super->s.ampdu_settings & CARL9170_TX_SUPER_AMPDU_DENSITY) <<
1009                 CARL9170_TX_SUPER_AMPDU_DENSITY_S;
1010
1011         /*
1012          * If you haven't noticed carl9170_tx_prepare has already filled
1013          * in all ampdu spacing & factor parameters.
1014          * Now it's the time to check whenever the settings have to be
1015          * updated by the firmware, or if everything is still the same.
1016          *
1017          * There's no sane way to handle different density values with
1018          * this hardware, so we may as well just do the compare in the
1019          * driver.
1020          */
1021
1022         if (tmp != ar->current_density) {
1023                 ar->current_density = tmp;
1024                 super->s.ampdu_settings |=
1025                         CARL9170_TX_SUPER_AMPDU_COMMIT_DENSITY;
1026         }
1027
1028         tmp = (super->s.ampdu_settings & CARL9170_TX_SUPER_AMPDU_FACTOR) <<
1029                 CARL9170_TX_SUPER_AMPDU_FACTOR_S;
1030
1031         if (tmp != ar->current_factor) {
1032                 ar->current_factor = tmp;
1033                 super->s.ampdu_settings |=
1034                         CARL9170_TX_SUPER_AMPDU_COMMIT_FACTOR;
1035         }
1036 }
1037
1038 static bool carl9170_tx_rate_check(struct ar9170 *ar, struct sk_buff *_dest,
1039                                    struct sk_buff *_src)
1040 {
1041         struct _carl9170_tx_superframe *dest, *src;
1042
1043         dest = (void *) _dest->data;
1044         src = (void *) _src->data;
1045
1046         /*
1047          * The mac80211 rate control algorithm expects that all MPDUs in
1048          * an AMPDU share the same tx vectors.
1049          * This is not really obvious right now, because the hardware
1050          * does the AMPDU setup according to its own rulebook.
1051          * Our nicely assembled, strictly monotonic increasing mpdu
1052          * chains will be broken up, mashed back together...
1053          */
1054
1055         return (dest->f.phy_control == src->f.phy_control);
1056 }
1057
1058 static void carl9170_tx_ampdu(struct ar9170 *ar)
1059 {
1060         struct sk_buff_head agg;
1061         struct carl9170_sta_tid *tid_info;
1062         struct sk_buff *skb, *first;
1063         unsigned int i = 0, done_ampdus = 0;
1064         u16 seq, queue, tmpssn;
1065
1066         atomic_inc(&ar->tx_ampdu_scheduler);
1067         ar->tx_ampdu_schedule = false;
1068
1069         if (atomic_read(&ar->tx_ampdu_upload))
1070                 return;
1071
1072         if (!ar->tx_ampdu_list_len)
1073                 return;
1074
1075         __skb_queue_head_init(&agg);
1076
1077         rcu_read_lock();
1078         tid_info = rcu_dereference(ar->tx_ampdu_iter);
1079         if (WARN_ON_ONCE(!tid_info)) {
1080                 rcu_read_unlock();
1081                 return;
1082         }
1083
1084 retry:
1085         list_for_each_entry_continue_rcu(tid_info, &ar->tx_ampdu_list, list) {
1086                 i++;
1087
1088                 if (tid_info->state < CARL9170_TID_STATE_PROGRESS)
1089                         continue;
1090
1091                 queue = TID_TO_WME_AC(tid_info->tid);
1092
1093                 spin_lock_bh(&tid_info->lock);
1094                 if (tid_info->state != CARL9170_TID_STATE_XMIT)
1095                         goto processed;
1096
1097                 tid_info->counter++;
1098                 first = skb_peek(&tid_info->queue);
1099                 tmpssn = carl9170_get_seq(first);
1100                 seq = tid_info->snx;
1101
1102                 if (unlikely(tmpssn != seq)) {
1103                         tid_info->state = CARL9170_TID_STATE_IDLE;
1104
1105                         goto processed;
1106                 }
1107
1108                 while ((skb = skb_peek(&tid_info->queue))) {
1109                         /* strict 0, 1, ..., n - 1, n frame sequence order */
1110                         if (unlikely(carl9170_get_seq(skb) != seq))
1111                                 break;
1112
1113                         /* don't upload more than AMPDU FACTOR allows. */
1114                         if (unlikely(SEQ_DIFF(tid_info->snx, tid_info->bsn) >=
1115                             (tid_info->max - 1)))
1116                                 break;
1117
1118                         if (!carl9170_tx_rate_check(ar, skb, first))
1119                                 break;
1120
1121                         atomic_inc(&ar->tx_ampdu_upload);
1122                         tid_info->snx = seq = SEQ_NEXT(seq);
1123                         __skb_unlink(skb, &tid_info->queue);
1124
1125                         __skb_queue_tail(&agg, skb);
1126
1127                         if (skb_queue_len(&agg) >= CARL9170_NUM_TX_AGG_MAX)
1128                                 break;
1129                 }
1130
1131                 if (skb_queue_empty(&tid_info->queue) ||
1132                     carl9170_get_seq(skb_peek(&tid_info->queue)) !=
1133                     tid_info->snx) {
1134                         /*
1135                          * stop TID, if A-MPDU frames are still missing,
1136                          * or whenever the queue is empty.
1137                          */
1138
1139                         tid_info->state = CARL9170_TID_STATE_IDLE;
1140                 }
1141                 done_ampdus++;
1142
1143 processed:
1144                 spin_unlock_bh(&tid_info->lock);
1145
1146                 if (skb_queue_empty(&agg))
1147                         continue;
1148
1149                 /* apply ampdu spacing & factor settings */
1150                 carl9170_set_ampdu_params(ar, skb_peek(&agg));
1151
1152                 /* set aggregation push bit */
1153                 carl9170_set_immba(ar, skb_peek_tail(&agg));
1154
1155                 spin_lock_bh(&ar->tx_pending[queue].lock);
1156                 skb_queue_splice_tail_init(&agg, &ar->tx_pending[queue]);
1157                 spin_unlock_bh(&ar->tx_pending[queue].lock);
1158                 ar->tx_schedule = true;
1159         }
1160         if ((done_ampdus++ == 0) && (i++ == 0))
1161                 goto retry;
1162
1163         rcu_assign_pointer(ar->tx_ampdu_iter, tid_info);
1164         rcu_read_unlock();
1165 }
1166
1167 static struct sk_buff *carl9170_tx_pick_skb(struct ar9170 *ar,
1168                                             struct sk_buff_head *queue)
1169 {
1170         struct sk_buff *skb;
1171         struct ieee80211_tx_info *info;
1172         struct carl9170_tx_info *arinfo;
1173
1174         BUILD_BUG_ON(sizeof(*arinfo) > sizeof(info->rate_driver_data));
1175
1176         spin_lock_bh(&queue->lock);
1177         skb = skb_peek(queue);
1178         if (unlikely(!skb))
1179                 goto err_unlock;
1180
1181         if (carl9170_alloc_dev_space(ar, skb))
1182                 goto err_unlock;
1183
1184         __skb_unlink(skb, queue);
1185         spin_unlock_bh(&queue->lock);
1186
1187         info = IEEE80211_SKB_CB(skb);
1188         arinfo = (void *) info->rate_driver_data;
1189
1190         arinfo->timeout = jiffies;
1191
1192         /*
1193          * increase ref count to "2".
1194          * Ref counting is the easiest way to solve the race between
1195          * the the urb's completion routine: carl9170_tx_callback and
1196          * wlan tx status functions: carl9170_tx_status/janitor.
1197          */
1198         carl9170_tx_get_skb(skb);
1199
1200         return skb;
1201
1202 err_unlock:
1203         spin_unlock_bh(&queue->lock);
1204         return NULL;
1205 }
1206
1207 void carl9170_tx_drop(struct ar9170 *ar, struct sk_buff *skb)
1208 {
1209         struct _carl9170_tx_superframe *super;
1210         uint8_t q = 0;
1211
1212         ar->tx_dropped++;
1213
1214         super = (void *)skb->data;
1215         SET_VAL(CARL9170_TX_SUPER_MISC_QUEUE, q,
1216                 ar9170_qmap[carl9170_get_queue(ar, skb)]);
1217         __carl9170_tx_process_status(ar, super->s.cookie, q);
1218 }
1219
1220 static void carl9170_tx(struct ar9170 *ar)
1221 {
1222         struct sk_buff *skb;
1223         unsigned int i, q;
1224         bool schedule_garbagecollector = false;
1225
1226         ar->tx_schedule = false;
1227
1228         if (unlikely(!IS_STARTED(ar)))
1229                 return;
1230
1231         carl9170_usb_handle_tx_err(ar);
1232
1233         for (i = 0; i < ar->hw->queues; i++) {
1234                 while (!skb_queue_empty(&ar->tx_pending[i])) {
1235                         skb = carl9170_tx_pick_skb(ar, &ar->tx_pending[i]);
1236                         if (unlikely(!skb))
1237                                 break;
1238
1239                         atomic_inc(&ar->tx_total_pending);
1240
1241                         q = __carl9170_get_queue(ar, i);
1242                         /*
1243                          * NB: tx_status[i] vs. tx_status[q],
1244                          * TODO: Move into pick_skb or alloc_dev_space.
1245                          */
1246                         skb_queue_tail(&ar->tx_status[q], skb);
1247
1248                         carl9170_usb_tx(ar, skb);
1249                         schedule_garbagecollector = true;
1250                 }
1251         }
1252
1253         if (!schedule_garbagecollector)
1254                 return;
1255
1256         ieee80211_queue_delayed_work(ar->hw, &ar->tx_janitor,
1257                 msecs_to_jiffies(CARL9170_TX_TIMEOUT));
1258 }
1259
1260 static bool carl9170_tx_ampdu_queue(struct ar9170 *ar,
1261         struct ieee80211_sta *sta, struct sk_buff *skb)
1262 {
1263         struct carl9170_sta_info *sta_info;
1264         struct carl9170_sta_tid *agg;
1265         struct sk_buff *iter;
1266         unsigned int max;
1267         u16 tid, seq, qseq, off;
1268         bool run = false;
1269
1270         tid = carl9170_get_tid(skb);
1271         seq = carl9170_get_seq(skb);
1272         sta_info = (void *) sta->drv_priv;
1273
1274         rcu_read_lock();
1275         agg = rcu_dereference(sta_info->agg[tid]);
1276         max = sta_info->ampdu_max_len;
1277
1278         if (!agg)
1279                 goto err_unlock_rcu;
1280
1281         spin_lock_bh(&agg->lock);
1282         if (unlikely(agg->state < CARL9170_TID_STATE_IDLE))
1283                 goto err_unlock;
1284
1285         /* check if sequence is within the BA window */
1286         if (unlikely(!BAW_WITHIN(agg->bsn, CARL9170_BAW_BITS, seq)))
1287                 goto err_unlock;
1288
1289         if (WARN_ON_ONCE(!BAW_WITHIN(agg->snx, CARL9170_BAW_BITS, seq)))
1290                 goto err_unlock;
1291
1292         off = SEQ_DIFF(seq, agg->bsn);
1293         if (WARN_ON_ONCE(test_and_set_bit(off, agg->bitmap)))
1294                 goto err_unlock;
1295
1296         if (likely(BAW_WITHIN(agg->hsn, CARL9170_BAW_BITS, seq))) {
1297                 __skb_queue_tail(&agg->queue, skb);
1298                 agg->hsn = seq;
1299                 goto queued;
1300         }
1301
1302         skb_queue_reverse_walk(&agg->queue, iter) {
1303                 qseq = carl9170_get_seq(iter);
1304
1305                 if (BAW_WITHIN(qseq, CARL9170_BAW_BITS, seq)) {
1306                         __skb_queue_after(&agg->queue, iter, skb);
1307                         goto queued;
1308                 }
1309         }
1310
1311         __skb_queue_head(&agg->queue, skb);
1312 queued:
1313
1314         if (unlikely(agg->state != CARL9170_TID_STATE_XMIT)) {
1315                 if (agg->snx == carl9170_get_seq(skb_peek(&agg->queue))) {
1316                         agg->state = CARL9170_TID_STATE_XMIT;
1317                         run = true;
1318                 }
1319         }
1320
1321         spin_unlock_bh(&agg->lock);
1322         rcu_read_unlock();
1323
1324         return run;
1325
1326 err_unlock:
1327         spin_unlock_bh(&agg->lock);
1328
1329 err_unlock_rcu:
1330         rcu_read_unlock();
1331         carl9170_tx_status(ar, skb, false);
1332         ar->tx_dropped++;
1333         return false;
1334 }
1335
1336 int carl9170_op_tx(struct ieee80211_hw *hw, struct sk_buff *skb)
1337 {
1338         struct ar9170 *ar = hw->priv;
1339         struct ieee80211_tx_info *info;
1340         struct ieee80211_sta *sta;
1341         bool run;
1342
1343         if (unlikely(!IS_STARTED(ar)))
1344                 goto err_free;
1345
1346         info = IEEE80211_SKB_CB(skb);
1347         sta = info->control.sta;
1348
1349         if (unlikely(carl9170_tx_prepare(ar, skb)))
1350                 goto err_free;
1351
1352         carl9170_tx_accounting(ar, skb);
1353         /*
1354          * from now on, one has to use carl9170_tx_status to free
1355          * all ressouces which are associated with the frame.
1356          */
1357
1358         if (info->flags & IEEE80211_TX_CTL_AMPDU) {
1359                 if (WARN_ON_ONCE(!sta))
1360                         goto err_free;
1361
1362                 run = carl9170_tx_ampdu_queue(ar, sta, skb);
1363                 if (run)
1364                         carl9170_tx_ampdu(ar);
1365
1366         } else {
1367                 unsigned int queue = skb_get_queue_mapping(skb);
1368
1369                 skb_queue_tail(&ar->tx_pending[queue], skb);
1370         }
1371
1372         carl9170_tx(ar);
1373         return NETDEV_TX_OK;
1374
1375 err_free:
1376         ar->tx_dropped++;
1377         dev_kfree_skb_any(skb);
1378         return NETDEV_TX_OK;
1379 }
1380
1381 void carl9170_tx_scheduler(struct ar9170 *ar)
1382 {
1383
1384         if (ar->tx_ampdu_schedule)
1385                 carl9170_tx_ampdu(ar);
1386
1387         if (ar->tx_schedule)
1388                 carl9170_tx(ar);
1389 }