aboutsummaryrefslogtreecommitdiff
path: root/drivers/net/wireless/wl12xx/tx.c
blob: 2019ed9ebfc44cce2127804a4db8a5227cd5d463 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
/*
 * This file is part of wl1271
 *
 * Copyright (C) 2009 Nokia Corporation
 *
 * Contact: Luciano Coelho <luciano.coelho@nokia.com>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * version 2 as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA
 *
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/etherdevice.h>

#include "wl12xx.h"
#include "io.h"
#include "reg.h"
#include "ps.h"
#include "tx.h"

static int wl1271_set_default_wep_key(struct wl1271 *wl, u8 id)
{
	int ret;
	bool is_ap = (wl->bss_type == BSS_TYPE_AP_BSS);

	if (is_ap)
		ret = wl1271_cmd_set_ap_default_wep_key(wl, id);
	else
		ret = wl1271_cmd_set_sta_default_wep_key(wl, id);

	if (ret < 0)
		return ret;

	wl1271_debug(DEBUG_CRYPT, "default wep key idx: %d", (int)id);
	return 0;
}

static int wl1271_alloc_tx_id(struct wl1271 *wl, struct sk_buff *skb)
{
	int id;

	id = find_first_zero_bit(wl->tx_frames_map, ACX_TX_DESCRIPTORS);
	if (id >= ACX_TX_DESCRIPTORS)
		return -EBUSY;

	__set_bit(id, wl->tx_frames_map);
	wl->tx_frames[id] = skb;
	wl->tx_frames_cnt++;
	return id;
}

static void wl1271_free_tx_id(struct wl1271 *wl, int id)
{
	if (__test_and_clear_bit(id, wl->tx_frames_map)) {
		wl->tx_frames[id] = NULL;
		wl->tx_frames_cnt--;
	}
}

static void wl1271_tx_ap_update_inconnection_sta(struct wl1271 *wl,
						 struct sk_buff *skb)
{
	struct ieee80211_hdr *hdr;

	/*
	 * add the station to the known list before transmitting the
	 * authentication response. this way it won't get de-authed by FW
	 * when transmitting too soon.
	 */
	hdr = (struct ieee80211_hdr *)(skb->data +
				       sizeof(struct wl1271_tx_hw_descr));
	if (ieee80211_is_auth(hdr->frame_control))
		wl1271_acx_set_inconnection_sta(wl, hdr->addr1);
}

static void wl1271_tx_regulate_link(struct wl1271 *wl, u8 hlid)
{
	bool fw_ps;
	u8 tx_blks;

	/* only regulate station links */
	if (hlid < WL1271_AP_STA_HLID_START)
		return;

	fw_ps = test_bit(hlid, (unsigned long *)&wl->ap_fw_ps_map);
	tx_blks = wl->links[hlid].allocated_blks;

	/*
	 * if in FW PS and there is enough data in FW we can put the link
	 * into high-level PS and clean out its TX queues.
	 */
	if (fw_ps && tx_blks >= WL1271_PS_STA_MAX_BLOCKS)
		wl1271_ps_link_start(wl, hlid, true);
}

u8 wl1271_tx_get_hlid(struct sk_buff *skb)
{
	struct ieee80211_tx_info *control = IEEE80211_SKB_CB(skb);

	if (control->control.sta) {
		struct wl1271_station *wl_sta;

		wl_sta = (struct wl1271_station *)
				control->control.sta->drv_priv;
		return wl_sta->hlid;
	} else {
		struct ieee80211_hdr *hdr;

		hdr = (struct ieee80211_hdr *)skb->data;
		if (ieee80211_is_mgmt(hdr->frame_control))
			return WL1271_AP_GLOBAL_HLID;
		else
			return WL1271_AP_BROADCAST_HLID;
	}
}

static int wl1271_tx_allocate(struct wl1271 *wl, struct sk_buff *skb, u32 extra,
				u32 buf_offset, u8 hlid)
{
	struct wl1271_tx_hw_descr *desc;
	u32 total_len = skb->len + sizeof(struct wl1271_tx_hw_descr) + extra;
	u32 len;
	u32 total_blocks;
	int id, ret = -EBUSY;
	u32 spare_blocks;

	if (unlikely(wl->quirks & WL12XX_QUIRK_USE_2_SPARE_BLOCKS))
		spare_blocks = 2;
	else
		spare_blocks = 1;

	if (buf_offset + total_len > WL1271_AGGR_BUFFER_SIZE)
		return -EAGAIN;

	/* allocate free identifier for the packet */
	id = wl1271_alloc_tx_id(wl, skb);
	if (id < 0)
		return id;

	/* approximate the number of blocks required for this packet
	   in the firmware */
	if (wl->block_size)
		len = ALIGN(total_len, wl->block_size);
	else
		len = total_len;

	total_blocks = (len + TX_HW_BLOCK_SIZE - 1) / TX_HW_BLOCK_SIZE +
		spare_blocks;

	if (total_blocks <= wl->tx_blocks_available) {
		desc = (struct wl1271_tx_hw_descr *)skb_push(
			skb, total_len - skb->len);

		/* HW descriptor fields change between wl127x and wl128x */
		if (wl->chip.id == CHIP_ID_1283_PG20) {
			desc->wl128x_mem.total_mem_blocks = total_blocks;
		} else {
			desc->wl127x_mem.extra_blocks = spare_blocks;
			desc->wl127x_mem.total_mem_blocks = total_blocks;
		}

		desc->id = id;

		wl->tx_blocks_available -= total_blocks;

		if (wl->bss_type == BSS_TYPE_AP_BSS)
			wl->links[hlid].allocated_blks += total_blocks;

		ret = 0;

		wl1271_debug(DEBUG_TX,
			     "tx_allocate: size: %d, blocks: %d, id: %d",
			     total_len, total_blocks, id);
	} else {
		wl1271_free_tx_id(wl, id);
	}

	return ret;
}

static void wl1271_tx_fill_hdr(struct wl1271 *wl, struct sk_buff *skb,
			      u32 extra, struct ieee80211_tx_info *control,
			      u8 hlid)
{
	struct timespec ts;
	struct wl1271_tx_hw_descr *desc;
	int aligned_len, ac, rate_idx;
	s64 hosttime;
	u16 tx_attr;

	desc = (struct wl1271_tx_hw_descr *) skb->data;

	/* relocate space for security header */
	if (extra) {
		void *framestart = skb->data + sizeof(*desc);
		u16 fc = *(u16 *)(framestart + extra);
		int hdrlen = ieee80211_hdrlen(cpu_to_le16(fc));
		memmove(framestart, framestart + extra, hdrlen);
	}

	/* configure packet life time */
	getnstimeofday(&ts);
	hosttime = (timespec_to_ns(&ts) >> 10);
	desc->start_time = cpu_to_le32(hosttime - wl->time_offset);

	if (wl->bss_type != BSS_TYPE_AP_BSS)
		desc->life_time = cpu_to_le16(TX_HW_MGMT_PKT_LIFETIME_TU);
	else
		desc->life_time = cpu_to_le16(TX_HW_AP_MODE_PKT_LIFETIME_TU);

	/* queue */
	ac = wl1271_tx_get_queue(skb_get_queue_mapping(skb));
	desc->tid = skb->priority;

	if (skb->pkt_type == TX_PKT_TYPE_DUMMY_REQ) {
		/*
		 * FW expects the dummy packet to have an invalid session id -
		 * any session id that is different than the one set in the join
		 */
		tx_attr = ((~wl->session_counter) <<
			   TX_HW_ATTR_OFST_SESSION_COUNTER) &
			   TX_HW_ATTR_SESSION_COUNTER;

		tx_attr |= TX_HW_ATTR_TX_DUMMY_REQ;
	} else {
		/* configure the tx attributes */
		tx_attr =
			wl->session_counter << TX_HW_ATTR_OFST_SESSION_COUNTER;
	}

	if (wl->bss_type != BSS_TYPE_AP_BSS) {
		desc->aid = hlid;

		/* if the packets are destined for AP (have a STA entry)
		   send them with AP rate policies, otherwise use default
		   basic rates */
		if (control->control.sta)
			rate_idx = ACX_TX_AP_FULL_RATE;
		else
			rate_idx = ACX_TX_BASIC_RATE;
	} else {
		desc->hlid = hlid;
		switch (hlid) {
		case WL1271_AP_GLOBAL_HLID:
			rate_idx = ACX_TX_AP_MODE_MGMT_RATE;
			break;
		case WL1271_AP_BROADCAST_HLID:
			rate_idx = ACX_TX_AP_MODE_BCST_RATE;
			break;
		default:
			rate_idx = ac;
			break;
		}
	}

	tx_attr |= rate_idx << TX_HW_ATTR_OFST_RATE_POLICY;
	desc->reserved = 0;

	if (wl->block_size) {
		aligned_len = ALIGN(skb->len, wl->block_size);

		desc->wl128x_mem.extra_bytes = aligned_len - skb->len;
		desc->length = cpu_to_le16(aligned_len >> 2);

		wl1271_debug(DEBUG_TX, "tx_fill_hdr: hlid: %d "
			     "tx_attr: 0x%x len: %d life: %d mem: %d",
			     desc->hlid, tx_attr,
			     le16_to_cpu(desc->length),
			     le16_to_cpu(desc->life_time),
			     desc->wl128x_mem.total_mem_blocks);
	} else {
		int pad;

		/* align the length (and store in terms of words) */
		aligned_len = ALIGN(skb->len, WL1271_TX_ALIGN_TO);
		desc->length = cpu_to_le16(aligned_len >> 2);

		/* calculate number of padding bytes */
		pad = aligned_len - skb->len;
		tx_attr |= pad << TX_HW_ATTR_OFST_LAST_WORD_PAD;

		wl1271_debug(DEBUG_TX, "tx_fill_hdr: pad: %d hlid: %d "
			     "tx_attr: 0x%x len: %d life: %d mem: %d", pad,
			     desc->hlid, tx_attr,
			     le16_to_cpu(desc->length),
			     le16_to_cpu(desc->life_time),
			     desc->wl127x_mem.total_mem_blocks);
	}

	desc->tx_attr = cpu_to_le16(tx_attr);
}

/* caller must hold wl->mutex */
static int wl1271_prepare_tx_frame(struct wl1271 *wl, struct sk_buff *skb,
							u32 buf_offset)
{
	struct ieee80211_tx_info *info;
	u32 extra = 0;
	int ret = 0;
	u32 total_len;
	u8 hlid;

	if (!skb)
		return -EINVAL;

	info = IEEE80211_SKB_CB(skb);

	if (info->control.hw_key &&
	    info->control.hw_key->cipher == WLAN_CIPHER_SUITE_TKIP)
		extra = WL1271_TKIP_IV_SPACE;

	if (info->control.hw_key) {
		bool is_wep;
		u8 idx = info->control.hw_key->hw_key_idx;
		u32 cipher = info->control.hw_key->cipher;

		is_wep = (cipher == WLAN_CIPHER_SUITE_WEP40) ||
			 (cipher == WLAN_CIPHER_SUITE_WEP104);

		if (unlikely(is_wep && wl->default_key != idx)) {
			ret = wl1271_set_default_wep_key(wl, idx);
			if (ret < 0)
				return ret;
			wl->default_key = idx;
		}
	}

	if (wl->bss_type == BSS_TYPE_AP_BSS)
		hlid = wl1271_tx_get_hlid(skb);
	else
		hlid = TX_HW_DEFAULT_AID;

	ret = wl1271_tx_allocate(wl, skb, extra, buf_offset, hlid);
	if (ret < 0)
		return ret;

	if (wl->bss_type == BSS_TYPE_AP_BSS) {
		wl1271_tx_ap_update_inconnection_sta(wl, skb);
		wl1271_tx_regulate_link(wl, hlid);
	}

	wl1271_tx_fill_hdr(wl, skb, extra, info, hlid);

	/*
	 * The length of each packet is stored in terms of
	 * words. Thus, we must pad the skb data to make sure its
	 * length is aligned.  The number of padding bytes is computed
	 * and set in wl1271_tx_fill_hdr.
	 * In special cases, we want to align to a specific block size
	 * (eg. for wl128x with SDIO we align to 256).
	 */
	if (wl->block_size)
		total_len = ALIGN(skb->len, wl->block_size);
	else
		total_len = ALIGN(skb->len, WL1271_TX_ALIGN_TO);

	memcpy(wl->aggr_buf + buf_offset, skb->data, skb->len);
	memset(wl->aggr_buf + buf_offset + skb->len, 0, total_len - skb->len);

	return total_len;
}

u32 wl1271_tx_enabled_rates_get(struct wl1271 *wl, u32 rate_set)
{
	struct ieee80211_supported_band *band;
	u32 enabled_rates = 0;
	int bit;

	band = wl->hw->wiphy->bands[wl->band];
	for (bit = 0; bit < band->n_bitrates; bit++) {
		if (rate_set & 0x1)
			enabled_rates |= band->bitrates[bit].hw_value;
		rate_set >>= 1;
	}

#ifdef CONFIG_WL12XX_HT
	/* MCS rates indication are on bits 16 - 23 */
	rate_set >>= HW_HT_RATES_OFFSET - band->n_bitrates;

	for (bit = 0; bit < 8; bit++) {
		if (rate_set & 0x1)
			enabled_rates |= (CONF_HW_BIT_RATE_MCS_0 << bit);
		rate_set >>= 1;
	}
#endif

	return enabled_rates;
}

void wl1271_handle_tx_low_watermark(struct wl1271 *wl)
{
	unsigned long flags;

	if (test_bit(WL1271_FLAG_TX_QUEUE_STOPPED, &wl->flags) &&
	    wl->tx_queue_count <= WL1271_TX_QUEUE_LOW_WATERMARK) {
		/* firmware buffer has space, restart queues */
		spin_lock_irqsave(&wl->wl_lock, flags);
		ieee80211_wake_queues(wl->hw);
		clear_bit(WL1271_FLAG_TX_QUEUE_STOPPED, &wl->flags);
		spin_unlock_irqrestore(&wl->wl_lock, flags);
	}
}

static struct sk_buff *wl1271_sta_skb_dequeue(struct wl1271 *wl)
{
	struct sk_buff *skb = NULL;
	unsigned long flags;

	skb = skb_dequeue(&wl->tx_queue[CONF_TX_AC_VO]);
	if (skb)
		goto out;
	skb = skb_dequeue(&wl->tx_queue[CONF_TX_AC_VI]);
	if (skb)
		goto out;
	skb = skb_dequeue(&wl->tx_queue[CONF_TX_AC_BE]);
	if (skb)
		goto out;
	skb = skb_dequeue(&wl->tx_queue[CONF_TX_AC_BK]);

out:
	if (skb) {
		spin_lock_irqsave(&wl->wl_lock, flags);
		wl->tx_queue_count--;
		spin_unlock_irqrestore(&wl->wl_lock, flags);
	}

	return skb;
}

static struct sk_buff *wl1271_ap_skb_dequeue(struct wl1271 *wl)
{
	struct sk_buff *skb = NULL;
	unsigned long flags;
	int i, h, start_hlid;

	/* start from the link after the last one */
	start_hlid = (wl->last_tx_hlid + 1) % AP_MAX_LINKS;

	/* dequeue according to AC, round robin on each link */
	for (i = 0; i < AP_MAX_LINKS; i++) {
		h = (start_hlid + i) % AP_MAX_LINKS;

		skb = skb_dequeue(&wl->links[h].tx_queue[CONF_TX_AC_VO]);
		if (skb)
			goto out;
		skb = skb_dequeue(&wl->links[h].tx_queue[CONF_TX_AC_VI]);
		if (skb)
			goto out;
		skb = skb_dequeue(&wl->links[h].tx_queue[CONF_TX_AC_BE]);
		if (skb)
			goto out;
		skb = skb_dequeue(&wl->links[h].tx_queue[CONF_TX_AC_BK]);
		if (skb)
			goto out;
	}

out:
	if (skb) {
		wl->last_tx_hlid = h;
		spin_lock_irqsave(&wl->wl_lock, flags);
		wl->tx_queue_count--;
		spin_unlock_irqrestore(&wl->wl_lock, flags);
	} else {
		wl->last_tx_hlid = 0;
	}

	return skb;
}

static struct sk_buff *wl1271_skb_dequeue(struct wl1271 *wl)
{
	if (wl->bss_type == BSS_TYPE_AP_BSS)
		return wl1271_ap_skb_dequeue(wl);

	return wl1271_sta_skb_dequeue(wl);
}

static void wl1271_skb_queue_head(struct wl1271 *wl, struct sk_buff *skb)
{
	unsigned long flags;
	int q = wl1271_tx_get_queue(skb_get_queue_mapping(skb));

	if (wl->bss_type == BSS_TYPE_AP_BSS) {
		u8 hlid = wl1271_tx_get_hlid(skb);
		skb_queue_head(&wl->links[hlid].tx_queue[q], skb);

		/* make sure we dequeue the same packet next time */
		wl->last_tx_hlid = (hlid + AP_MAX_LINKS - 1) % AP_MAX_LINKS;
	} else {
		skb_queue_head(&wl->tx_queue[q], skb);
	}

	spin_lock_irqsave(&wl->wl_lock, flags);
	wl->tx_queue_count++;
	spin_unlock_irqrestore(&wl->wl_lock, flags);
}

void wl1271_tx_work_locked(struct wl1271 *wl)
{
	struct sk_buff *skb;
	u32 buf_offset = 0;
	bool sent_packets = false;
	int ret;

	if (unlikely(wl->state == WL1271_STATE_OFF))
		return;

	while ((skb = wl1271_skb_dequeue(wl))) {
		ret = wl1271_prepare_tx_frame(wl, skb, buf_offset);
		if (ret == -EAGAIN) {
			/*
			 * Aggregation buffer is full.
			 * Flush buffer and try again.
			 */
			wl1271_skb_queue_head(wl, skb);
			wl1271_write(wl, WL1271_SLV_MEM_DATA, wl->aggr_buf,
				     buf_offset, true);
			sent_packets = true;
			buf_offset = 0;
			continue;
		} else if (ret == -EBUSY) {
			/*
			 * Firmware buffer is full.
			 * Queue back last skb, and stop aggregating.
			 */
			wl1271_skb_queue_head(wl, skb);
			/* No work left, avoid scheduling redundant tx work */
			set_bit(WL1271_FLAG_FW_TX_BUSY, &wl->flags);
			goto out_ack;
		} else if (ret < 0) {
			dev_kfree_skb(skb);
			goto out_ack;
		}
		buf_offset += ret;
		wl->tx_packets_count++;
	}

out_ack:
	if (buf_offset) {
		wl1271_write(wl, WL1271_SLV_MEM_DATA, wl->aggr_buf,
				buf_offset, true);
		sent_packets = true;
	}
	if (sent_packets) {
		/*
		 * Interrupt the firmware with the new packets. This is only
		 * required for older hardware revisions
		 */
		if (wl->quirks & WL12XX_QUIRK_END_OF_TRANSACTION)
			wl1271_write32(wl, WL1271_HOST_WR_ACCESS,
				       wl->tx_packets_count);

		wl1271_handle_tx_low_watermark(wl);
	}
}

void wl1271_tx_work(struct work_struct *work)
{
	struct wl1271 *wl = container_of(work, struct wl1271, tx_work);
	int ret;

	mutex_lock(&wl->mutex);
	ret = wl1271_ps_elp_wakeup(wl);
	if (ret < 0)
		goto out;

	wl1271_tx_work_locked(wl);

	wl1271_ps_elp_wakeup(wl);
out:
	mutex_unlock(&wl->mutex);
}

static void wl1271_tx_complete_packet(struct wl1271 *wl,
				      struct wl1271_tx_hw_res_descr *result)
{
	struct ieee80211_tx_info *info;
	struct sk_buff *skb;
	int id = result->id;
	int rate = -1;
	u8 retries = 0;

	/* check for id legality */
	if (unlikely(id >= ACX_TX_DESCRIPTORS || wl->tx_frames[id] == NULL)) {
		wl1271_warning("TX result illegal id: %d", id);
		return;
	}

	skb = wl->tx_frames[id];
	info = IEEE80211_SKB_CB(skb);

	if (skb->pkt_type == TX_PKT_TYPE_DUMMY_REQ) {
		dev_kfree_skb(skb);
		wl1271_free_tx_id(wl, id);
		return;
	}

	/* update the TX status info */
	if (result->status == TX_SUCCESS) {
		if (!(info->flags & IEEE80211_TX_CTL_NO_ACK))
			info->flags |= IEEE80211_TX_STAT_ACK;
		rate = wl1271_rate_to_idx(result->rate_class_index, wl->band);
		retries = result->ack_failures;
	} else if (result->status == TX_RETRY_EXCEEDED) {
		wl->stats.excessive_retries++;
		retries = result->ack_failures;
	}

	info->status.rates[0].idx = rate;
	info->status.rates[0].count = retries;
	info->status.rates[0].flags = 0;
	info->status.ack_signal = -1;

	wl->stats.retry_count += result->ack_failures;

	/* update security sequence number */
	wl->tx_security_seq += (result->lsb_security_sequence_number -
				wl->tx_security_last_seq);
	wl->tx_security_last_seq = result->lsb_security_sequence_number;

	/* remove private header from packet */
	skb_pull(skb, sizeof(struct wl1271_tx_hw_descr));

	/* remove TKIP header space if present */
	if (info->control.hw_key &&
	    info->control.hw_key->cipher == WLAN_CIPHER_SUITE_TKIP) {
		int hdrlen = ieee80211_get_hdrlen_from_skb(skb);
		memmove(skb->data + WL1271_TKIP_IV_SPACE, skb->data, hdrlen);
		skb_pull(skb, WL1271_TKIP_IV_SPACE);
	}

	wl1271_debug(DEBUG_TX, "tx status id %u skb 0x%p failures %u rate 0x%x"
		     " status 0x%x",
		     result->id, skb, result->ack_failures,
		     result->rate_class_index, result->status);

	/* return the packet to the stack */
	skb_queue_tail(&wl->deferred_tx_queue, skb);
	ieee80211_queue_work(wl->hw, &wl->netstack_work);
	wl1271_free_tx_id(wl, result->id);
}

/* Called upon reception of a TX complete interrupt */
void wl1271_tx_complete(struct wl1271 *wl)
{
	struct wl1271_acx_mem_map *memmap =
		(struct wl1271_acx_mem_map *)wl->target_mem_map;
	u32 count, fw_counter;
	u32 i;

	/* read the tx results from the chipset */
	wl1271_read(wl, le32_to_cpu(memmap->tx_result),
		    wl->tx_res_if, sizeof(*wl->tx_res_if), false);
	fw_counter = le32_to_cpu(wl->tx_res_if->tx_result_fw_counter);

	/* write host counter to chipset (to ack) */
	wl1271_write32(wl, le32_to_cpu(memmap->tx_result) +
		       offsetof(struct wl1271_tx_hw_res_if,
				tx_result_host_counter), fw_counter);

	count = fw_counter - wl->tx_results_count;
	wl1271_debug(DEBUG_TX, "tx_complete received, packets: %d", count);

	/* verify that the result buffer is not getting overrun */
	if (unlikely(count > TX_HW_RESULT_QUEUE_LEN))
		wl1271_warning("TX result overflow from chipset: %d", count);

	/* process the results */
	for (i = 0; i < count; i++) {
		struct wl1271_tx_hw_res_descr *result;
		u8 offset = wl->tx_results_count & TX_HW_RESULT_QUEUE_LEN_MASK;

		/* process the packet */
		result =  &(wl->tx_res_if->tx_results_queue[offset]);
		wl1271_tx_complete_packet(wl, result);

		wl->tx_results_count++;
	}
}

void wl1271_tx_reset_link_queues(struct wl1271 *wl, u8 hlid)
{
	struct sk_buff *skb;
	int i, total = 0;
	unsigned long flags;
	struct ieee80211_tx_info *info;

	for (i = 0; i < NUM_TX_QUEUES; i++) {
		while ((skb = skb_dequeue(&wl->links[hlid].tx_queue[i]))) {
			wl1271_debug(DEBUG_TX, "link freeing skb 0x%p", skb);
			info = IEEE80211_SKB_CB(skb);
			info->status.rates[0].idx = -1;
			info->status.rates[0].count = 0;
			ieee80211_tx_status(wl->hw, skb);
			total++;
		}
	}

	spin_lock_irqsave(&wl->wl_lock, flags);
	wl->tx_queue_count -= total;
	spin_unlock_irqrestore(&wl->wl_lock, flags);

	wl1271_handle_tx_low_watermark(wl);
}

/* caller must hold wl->mutex */
void wl1271_tx_reset(struct wl1271 *wl)
{
	int i;
	struct sk_buff *skb;
	struct ieee80211_tx_info *info;

	/* TX failure */
	if (wl->bss_type == BSS_TYPE_AP_BSS) {
		for (i = 0; i < AP_MAX_LINKS; i++) {
			wl1271_tx_reset_link_queues(wl, i);
			wl->links[i].allocated_blks = 0;
			wl->links[i].prev_freed_blks = 0;
		}

		wl->last_tx_hlid = 0;
	} else {
		for (i = 0; i < NUM_TX_QUEUES; i++) {
			while ((skb = skb_dequeue(&wl->tx_queue[i]))) {
				wl1271_debug(DEBUG_TX, "freeing skb 0x%p",
					     skb);

				if (skb->pkt_type == TX_PKT_TYPE_DUMMY_REQ) {
					dev_kfree_skb(skb);
				} else {
					info = IEEE80211_SKB_CB(skb);
					info->status.rates[0].idx = -1;
					info->status.rates[0].count = 0;
					ieee80211_tx_status(wl->hw, skb);
				}
			}
		}
	}

	wl->tx_queue_count = 0;

	/*
	 * Make sure the driver is at a consistent state, in case this
	 * function is called from a context other than interface removal.
	 */
	wl1271_handle_tx_low_watermark(wl);

	for (i = 0; i < ACX_TX_DESCRIPTORS; i++) {
		if (wl->tx_frames[i] == NULL)
			continue;

		skb = wl->tx_frames[i];
		wl1271_free_tx_id(wl, i);
		wl1271_debug(DEBUG_TX, "freeing skb 0x%p", skb);

		if (skb->pkt_type == TX_PKT_TYPE_DUMMY_REQ) {
			dev_kfree_skb(skb);
		} else {
			/*
			 * Remove private headers before passing the skb to
			 * mac80211
			 */
			info = IEEE80211_SKB_CB(skb);
			skb_pull(skb, sizeof(struct wl1271_tx_hw_descr));
			if (info->control.hw_key &&
			    info->control.hw_key->cipher ==
			    WLAN_CIPHER_SUITE_TKIP) {
				int hdrlen = ieee80211_get_hdrlen_from_skb(skb);
				memmove(skb->data + WL1271_TKIP_IV_SPACE,
					skb->data, hdrlen);
				skb_pull(skb, WL1271_TKIP_IV_SPACE);
			}

			info->status.rates[0].idx = -1;
			info->status.rates[0].count = 0;

			ieee80211_tx_status(wl->hw, skb);
		}
	}
}

#define WL1271_TX_FLUSH_TIMEOUT 500000

/* caller must *NOT* hold wl->mutex */
void wl1271_tx_flush(struct wl1271 *wl)
{
	unsigned long timeout;
	timeout = jiffies + usecs_to_jiffies(WL1271_TX_FLUSH_TIMEOUT);

	while (!time_after(jiffies, timeout)) {
		mutex_lock(&wl->mutex);
		wl1271_debug(DEBUG_TX, "flushing tx buffer: %d %d",
			     wl->tx_frames_cnt, wl->tx_queue_count);
		if ((wl->tx_frames_cnt == 0) && (wl->tx_queue_count == 0)) {
			mutex_unlock(&wl->mutex);
			return;
		}
		mutex_unlock(&wl->mutex);
		msleep(1);
	}

	wl1271_warning("Unable to flush all TX buffers, timed out.");
}

u32 wl1271_tx_min_rate_get(struct wl1271 *wl)
{
	int i;
	u32 rate = 0;

	if (!wl->basic_rate_set) {
		WARN_ON(1);
		wl->basic_rate_set = wl->conf.tx.basic_rate;
	}

	for (i = 0; !rate; i++) {
		if ((wl->basic_rate_set >> i) & 0x1)
			rate = 1 << i;
	}

	return rate;
}