summaryrefslogtreecommitdiffstats
path: root/drivers/net/wireless/ath/ath9k/recv.c
blob: fb4ba27d92b7b8010d1d6ce8c5b155635c088fbf (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
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
/*
 * Copyright (c) 2008-2011 Atheros Communications Inc.
 *
 * Permission to use, copy, modify, and/or distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <linux/dma-mapping.h>
#include "ath9k.h"
#include "ar9003_mac.h"

#define SKB_CB_ATHBUF(__skb)	(*((struct ath_rxbuf **)__skb->cb))

static inline bool ath9k_check_auto_sleep(struct ath_softc *sc)
{
	return sc->ps_enabled &&
	       (sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_AUTOSLEEP);
}

/*
 * Setup and link descriptors.
 *
 * 11N: we can no longer afford to self link the last descriptor.
 * MAC acknowledges BA status as long as it copies frames to host
 * buffer (or rx fifo). This can incorrectly acknowledge packets
 * to a sender if last desc is self-linked.
 */
static void ath_rx_buf_link(struct ath_softc *sc, struct ath_rxbuf *bf,
			    bool flush)
{
	struct ath_hw *ah = sc->sc_ah;
	struct ath_common *common = ath9k_hw_common(ah);
	struct ath_desc *ds;
	struct sk_buff *skb;

	ds = bf->bf_desc;
	ds->ds_link = 0; /* link to null */
	ds->ds_data = bf->bf_buf_addr;

	/* virtual addr of the beginning of the buffer. */
	skb = bf->bf_mpdu;
	BUG_ON(skb == NULL);
	ds->ds_vdata = skb->data;

	/*
	 * setup rx descriptors. The rx_bufsize here tells the hardware
	 * how much data it can DMA to us and that we are prepared
	 * to process
	 */
	ath9k_hw_setuprxdesc(ah, ds,
			     common->rx_bufsize,
			     0);

	if (sc->rx.rxlink)
		*sc->rx.rxlink = bf->bf_daddr;
	else if (!flush)
		ath9k_hw_putrxbuf(ah, bf->bf_daddr);

	sc->rx.rxlink = &ds->ds_link;
}

static void ath_rx_buf_relink(struct ath_softc *sc, struct ath_rxbuf *bf,
			      bool flush)
{
	if (sc->rx.buf_hold)
		ath_rx_buf_link(sc, sc->rx.buf_hold, flush);

	sc->rx.buf_hold = bf;
}

static void ath_setdefantenna(struct ath_softc *sc, u32 antenna)
{
	/* XXX block beacon interrupts */
	ath9k_hw_setantenna(sc->sc_ah, antenna);
	sc->rx.defant = antenna;
	sc->rx.rxotherant = 0;
}

static void ath_opmode_init(struct ath_softc *sc)
{
	struct ath_hw *ah = sc->sc_ah;
	struct ath_common *common = ath9k_hw_common(ah);

	u32 rfilt, mfilt[2];

	/* configure rx filter */
	rfilt = ath_calcrxfilter(sc);
	ath9k_hw_setrxfilter(ah, rfilt);

	/* configure bssid mask */
	ath_hw_setbssidmask(common);

	/* configure operational mode */
	ath9k_hw_setopmode(ah);

	/* calculate and install multicast filter */
	mfilt[0] = mfilt[1] = ~0;
	ath9k_hw_setmcastfilter(ah, mfilt[0], mfilt[1]);
}

static bool ath_rx_edma_buf_link(struct ath_softc *sc,
				 enum ath9k_rx_qtype qtype)
{
	struct ath_hw *ah = sc->sc_ah;
	struct ath_rx_edma *rx_edma;
	struct sk_buff *skb;
	struct ath_rxbuf *bf;

	rx_edma = &sc->rx.rx_edma[qtype];
	if (skb_queue_len(&rx_edma->rx_fifo) >= rx_edma->rx_fifo_hwsize)
		return false;

	bf = list_first_entry(&sc->rx.rxbuf, struct ath_rxbuf, list);
	list_del_init(&bf->list);

	skb = bf->bf_mpdu;

	memset(skb->data, 0, ah->caps.rx_status_len);
	dma_sync_single_for_device(sc->dev, bf->bf_buf_addr,
				ah->caps.rx_status_len, DMA_TO_DEVICE);

	SKB_CB_ATHBUF(skb) = bf;
	ath9k_hw_addrxbuf_edma(ah, bf->bf_buf_addr, qtype);
	__skb_queue_tail(&rx_edma->rx_fifo, skb);

	return true;
}

static void ath_rx_addbuffer_edma(struct ath_softc *sc,
				  enum ath9k_rx_qtype qtype)
{
	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
	struct ath_rxbuf *bf, *tbf;

	if (list_empty(&sc->rx.rxbuf)) {
		ath_dbg(common, QUEUE, "No free rx buf available\n");
		return;
	}

	list_for_each_entry_safe(bf, tbf, &sc->rx.rxbuf, list)
		if (!ath_rx_edma_buf_link(sc, qtype))
			break;

}

static void ath_rx_remove_buffer(struct ath_softc *sc,
				 enum ath9k_rx_qtype qtype)
{
	struct ath_rxbuf *bf;
	struct ath_rx_edma *rx_edma;
	struct sk_buff *skb;

	rx_edma = &sc->rx.rx_edma[qtype];

	while ((skb = __skb_dequeue(&rx_edma->rx_fifo)) != NULL) {
		bf = SKB_CB_ATHBUF(skb);
		BUG_ON(!bf);
		list_add_tail(&bf->list, &sc->rx.rxbuf);
	}
}

static void ath_rx_edma_cleanup(struct ath_softc *sc)
{
	struct ath_hw *ah = sc->sc_ah;
	struct ath_common *common = ath9k_hw_common(ah);
	struct ath_rxbuf *bf;

	ath_rx_remove_buffer(sc, ATH9K_RX_QUEUE_LP);
	ath_rx_remove_buffer(sc, ATH9K_RX_QUEUE_HP);

	list_for_each_entry(bf, &sc->rx.rxbuf, list) {
		if (bf->bf_mpdu) {
			dma_unmap_single(sc->dev, bf->bf_buf_addr,
					common->rx_bufsize,
					DMA_BIDIRECTIONAL);
			dev_kfree_skb_any(bf->bf_mpdu);
			bf->bf_buf_addr = 0;
			bf->bf_mpdu = NULL;
		}
	}
}

static void ath_rx_edma_init_queue(struct ath_rx_edma *rx_edma, int size)
{
	__skb_queue_head_init(&rx_edma->rx_fifo);
	rx_edma->rx_fifo_hwsize = size;
}

static int ath_rx_edma_init(struct ath_softc *sc, int nbufs)
{
	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
	struct ath_hw *ah = sc->sc_ah;
	struct sk_buff *skb;
	struct ath_rxbuf *bf;
	int error = 0, i;
	u32 size;

	ath9k_hw_set_rx_bufsize(ah, common->rx_bufsize -
				    ah->caps.rx_status_len);

	ath_rx_edma_init_queue(&sc->rx.rx_edma[ATH9K_RX_QUEUE_LP],
			       ah->caps.rx_lp_qdepth);
	ath_rx_edma_init_queue(&sc->rx.rx_edma[ATH9K_RX_QUEUE_HP],
			       ah->caps.rx_hp_qdepth);

	size = sizeof(struct ath_rxbuf) * nbufs;
	bf = devm_kzalloc(sc->dev, size, GFP_KERNEL);
	if (!bf)
		return -ENOMEM;

	INIT_LIST_HEAD(&sc->rx.rxbuf);

	for (i = 0; i < nbufs; i++, bf++) {
		skb = ath_rxbuf_alloc(common, common->rx_bufsize, GFP_KERNEL);
		if (!skb) {
			error = -ENOMEM;
			goto rx_init_fail;
		}

		memset(skb->data, 0, common->rx_bufsize);
		bf->bf_mpdu = skb;

		bf->bf_buf_addr = dma_map_single(sc->dev, skb->data,
						 common->rx_bufsize,
						 DMA_BIDIRECTIONAL);
		if (unlikely(dma_mapping_error(sc->dev,
						bf->bf_buf_addr))) {
				dev_kfree_skb_any(skb);
				bf->bf_mpdu = NULL;
				bf->bf_buf_addr = 0;
				ath_err(common,
					"dma_mapping_error() on RX init\n");
				error = -ENOMEM;
				goto rx_init_fail;
		}

		list_add_tail(&bf->list, &sc->rx.rxbuf);
	}

	return 0;

rx_init_fail:
	ath_rx_edma_cleanup(sc);
	return error;
}

static void ath_edma_start_recv(struct ath_softc *sc)
{
	ath9k_hw_rxena(sc->sc_ah);
	ath_rx_addbuffer_edma(sc, ATH9K_RX_QUEUE_HP);
	ath_rx_addbuffer_edma(sc, ATH9K_RX_QUEUE_LP);
	ath_opmode_init(sc);
	ath9k_hw_startpcureceive(sc->sc_ah, sc->cur_chan->offchannel);
}

static void ath_edma_stop_recv(struct ath_softc *sc)
{
	ath_rx_remove_buffer(sc, ATH9K_RX_QUEUE_HP);
	ath_rx_remove_buffer(sc, ATH9K_RX_QUEUE_LP);
}

int ath_rx_init(struct ath_softc *sc, int nbufs)
{
	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
	struct sk_buff *skb;
	struct ath_rxbuf *bf;
	int error = 0;

	spin_lock_init(&sc->sc_pcu_lock);

	common->rx_bufsize = IEEE80211_MAX_MPDU_LEN / 2 +
			     sc->sc_ah->caps.rx_status_len;

	if (sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_EDMA)
		return ath_rx_edma_init(sc, nbufs);

	ath_dbg(common, CONFIG, "cachelsz %u rxbufsize %u\n",
		common->cachelsz, common->rx_bufsize);

	/* Initialize rx descriptors */

	error = ath_descdma_setup(sc, &sc->rx.rxdma, &sc->rx.rxbuf,
				  "rx", nbufs, 1, 0);
	if (error != 0) {
		ath_err(common,
			"failed to allocate rx descriptors: %d\n",
			error);
		goto err;
	}

	list_for_each_entry(bf, &sc->rx.rxbuf, list) {
		skb = ath_rxbuf_alloc(common, common->rx_bufsize,
				      GFP_KERNEL);
		if (skb == NULL) {
			error = -ENOMEM;
			goto err;
		}

		bf->bf_mpdu = skb;
		bf->bf_buf_addr = dma_map_single(sc->dev, skb->data,
						 common->rx_bufsize,
						 DMA_FROM_DEVICE);
		if (unlikely(dma_mapping_error(sc->dev,
					       bf->bf_buf_addr))) {
			dev_kfree_skb_any(skb);
			bf->bf_mpdu = NULL;
			bf->bf_buf_addr = 0;
			ath_err(common,
				"dma_mapping_error() on RX init\n");
			error = -ENOMEM;
			goto err;
		}
	}
	sc->rx.rxlink = NULL;
err:
	if (error)
		ath_rx_cleanup(sc);

	return error;
}

void ath_rx_cleanup(struct ath_softc *sc)
{
	struct ath_hw *ah = sc->sc_ah;
	struct ath_common *common = ath9k_hw_common(ah);
	struct sk_buff *skb;
	struct ath_rxbuf *bf;

	if (sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_EDMA) {
		ath_rx_edma_cleanup(sc);
		return;
	}

	list_for_each_entry(bf, &sc->rx.rxbuf, list) {
		skb = bf->bf_mpdu;
		if (skb) {
			dma_unmap_single(sc->dev, bf->bf_buf_addr,
					 common->rx_bufsize,
					 DMA_FROM_DEVICE);
			dev_kfree_skb(skb);
			bf->bf_buf_addr = 0;
			bf->bf_mpdu = NULL;
		}
	}
}

/*
 * Calculate the receive filter according to the
 * operating mode and state:
 *
 * o always accept unicast, broadcast, and multicast traffic
 * o maintain current state of phy error reception (the hal
 *   may enable phy error frames for noise immunity work)
 * o probe request frames are accepted only when operating in
 *   hostap, adhoc, or monitor modes
 * o enable promiscuous mode according to the interface state
 * o accept beacons:
 *   - when operating in adhoc mode so the 802.11 layer creates
 *     node table entries for peers,
 *   - when operating in station mode for collecting rssi data when
 *     the station is otherwise quiet, or
 *   - when operating as a repeater so we see repeater-sta beacons
 *   - when scanning
 */

u32 ath_calcrxfilter(struct ath_softc *sc)
{
	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
	u32 rfilt;

	if (IS_ENABLED(CONFIG_ATH9K_TX99))
		return 0;

	rfilt = ATH9K_RX_FILTER_UCAST | ATH9K_RX_FILTER_BCAST
		| ATH9K_RX_FILTER_MCAST;

	/* if operating on a DFS channel, enable radar pulse detection */
	if (sc->hw->conf.radar_enabled)
		rfilt |= ATH9K_RX_FILTER_PHYRADAR | ATH9K_RX_FILTER_PHYERR;

	spin_lock_bh(&sc->chan_lock);

	if (sc->cur_chan->rxfilter & FIF_PROBE_REQ)
		rfilt |= ATH9K_RX_FILTER_PROBEREQ;

	if (sc->sc_ah->is_monitoring)
		rfilt |= ATH9K_RX_FILTER_PROM;

	if ((sc->cur_chan->rxfilter & FIF_CONTROL) ||
	    sc->sc_ah->dynack.enabled)
		rfilt |= ATH9K_RX_FILTER_CONTROL;

	if ((sc->sc_ah->opmode == NL80211_IFTYPE_STATION) &&
	    (sc->cur_chan->nvifs <= 1) &&
	    !(sc->cur_chan->rxfilter & FIF_BCN_PRBRESP_PROMISC))
		rfilt |= ATH9K_RX_FILTER_MYBEACON;
	else if (sc->sc_ah->opmode != NL80211_IFTYPE_OCB)
		rfilt |= ATH9K_RX_FILTER_BEACON;

	if ((sc->sc_ah->opmode == NL80211_IFTYPE_AP) ||
	    (sc->cur_chan->rxfilter & FIF_PSPOLL))
		rfilt |= ATH9K_RX_FILTER_PSPOLL;

	if (sc->cur_chandef.width != NL80211_CHAN_WIDTH_20_NOHT)
		rfilt |= ATH9K_RX_FILTER_COMP_BAR;

	if (sc->cur_chan->nvifs > 1 || (sc->cur_chan->rxfilter & FIF_OTHER_BSS)) {
		/* This is needed for older chips */
		if (sc->sc_ah->hw_version.macVersion <= AR_SREV_VERSION_9160)
			rfilt |= ATH9K_RX_FILTER_PROM;
		rfilt |= ATH9K_RX_FILTER_MCAST_BCAST_ALL;
	}

	if (AR_SREV_9550(sc->sc_ah) || AR_SREV_9531(sc->sc_ah) ||
	    AR_SREV_9561(sc->sc_ah))
		rfilt |= ATH9K_RX_FILTER_4ADDRESS;

	if (AR_SREV_9462(sc->sc_ah) || AR_SREV_9565(sc->sc_ah))
		rfilt |= ATH9K_RX_FILTER_CONTROL_WRAPPER;

	if (ath9k_is_chanctx_enabled() &&
	    test_bit(ATH_OP_SCANNING, &common->op_flags))
		rfilt |= ATH9K_RX_FILTER_BEACON;

	spin_unlock_bh(&sc->chan_lock);

	return rfilt;

}

void ath_startrecv(struct ath_softc *sc)
{
	struct ath_hw *ah = sc->sc_ah;
	struct ath_rxbuf *bf, *tbf;

	if (ah->caps.hw_caps & ATH9K_HW_CAP_EDMA) {
		ath_edma_start_recv(sc);
		return;
	}

	if (list_empty(&sc->rx.rxbuf))
		goto start_recv;

	sc->rx.buf_hold = NULL;
	sc->rx.rxlink = NULL;
	list_for_each_entry_safe(bf, tbf, &sc->rx.rxbuf, list) {
		ath_rx_buf_link(sc, bf, false);
	}

	/* We could have deleted elements so the list may be empty now */
	if (list_empty(&sc->rx.rxbuf))
		goto start_recv;

	bf = list_first_entry(&sc->rx.rxbuf, struct ath_rxbuf, list);
	ath9k_hw_putrxbuf(ah, bf->bf_daddr);
	ath9k_hw_rxena(ah);

start_recv:
	ath_opmode_init(sc);
	ath9k_hw_startpcureceive(ah, sc->cur_chan->offchannel);
}

static void ath_flushrecv(struct ath_softc *sc)
{
	if (sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_EDMA)
		ath_rx_tasklet(sc, 1, true);
	ath_rx_tasklet(sc, 1, false);
}

bool ath_stoprecv(struct ath_softc *sc)
{
	struct ath_hw *ah = sc->sc_ah;
	bool stopped, reset = false;

	ath9k_hw_abortpcurecv(ah);
	ath9k_hw_setrxfilter(ah, 0);
	stopped = ath9k_hw_stopdmarecv(ah, &reset);

	ath_flushrecv(sc);

	if (sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_EDMA)
		ath_edma_stop_recv(sc);
	else
		sc->rx.rxlink = NULL;

	if (!(ah->ah_flags & AH_UNPLUGGED) &&
	    unlikely(!stopped)) {
		ath_dbg(ath9k_hw_common(sc->sc_ah), RESET,
			"Failed to stop Rx DMA\n");
		RESET_STAT_INC(sc, RESET_RX_DMA_ERROR);
	}
	return stopped && !reset;
}

static bool ath_beacon_dtim_pending_cab(struct sk_buff *skb)
{
	/* Check whether the Beacon frame has DTIM indicating buffered bc/mc */
	struct ieee80211_mgmt *mgmt;
	u8 *pos, *end, id, elen;
	struct ieee80211_tim_ie *tim;

	mgmt = (struct ieee80211_mgmt *)skb->data;
	pos = mgmt->u.beacon.variable;
	end = skb->data + skb->len;

	while (pos + 2 < end) {
		id = *pos++;
		elen = *pos++;
		if (pos + elen > end)
			break;

		if (id == WLAN_EID_TIM) {
			if (elen < sizeof(*tim))
				break;
			tim = (struct ieee80211_tim_ie *) pos;
			if (tim->dtim_count != 0)
				break;
			return tim->bitmap_ctrl & 0x01;
		}

		pos += elen;
	}

	return false;
}

static void ath_rx_ps_beacon(struct ath_softc *sc, struct sk_buff *skb)
{
	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
	bool skip_beacon = false;

	if (skb->len < 24 + 8 + 2 + 2)
		return;

	sc->ps_flags &= ~PS_WAIT_FOR_BEACON;

	if (sc->ps_flags & PS_BEACON_SYNC) {
		sc->ps_flags &= ~PS_BEACON_SYNC;
		ath_dbg(common, PS,
			"Reconfigure beacon timers based on synchronized timestamp\n");

#ifdef CONFIG_ATH9K_CHANNEL_CONTEXT
		if (ath9k_is_chanctx_enabled()) {
			if (sc->cur_chan == &sc->offchannel.chan)
				skip_beacon = true;
		}
#endif

		if (!skip_beacon &&
		    !(WARN_ON_ONCE(sc->cur_chan->beacon.beacon_interval == 0)))
			ath9k_set_beacon(sc);

		ath9k_p2p_beacon_sync(sc);
	}

	if (ath_beacon_dtim_pending_cab(skb)) {
		/*
		 * Remain awake waiting for buffered broadcast/multicast
		 * frames. If the last broadcast/multicast frame is not
		 * received properly, the next beacon frame will work as
		 * a backup trigger for returning into NETWORK SLEEP state,
		 * so we are waiting for it as well.
		 */
		ath_dbg(common, PS,
			"Received DTIM beacon indicating buffered broadcast/multicast frame(s)\n");
		sc->ps_flags |= PS_WAIT_FOR_CAB | PS_WAIT_FOR_BEACON;
		return;
	}

	if (sc->ps_flags & PS_WAIT_FOR_CAB) {
		/*
		 * This can happen if a broadcast frame is dropped or the AP
		 * fails to send a frame indicating that all CAB frames have
		 * been delivered.
		 */
		sc->ps_flags &= ~PS_WAIT_FOR_CAB;
		ath_dbg(common, PS, "PS wait for CAB frames timed out\n");
	}
}

static void ath_rx_ps(struct ath_softc *sc, struct sk_buff *skb, bool mybeacon)
{
	struct ieee80211_hdr *hdr;
	struct ath_common *common = ath9k_hw_common(sc->sc_ah);

	hdr = (struct ieee80211_hdr *)skb->data;

	/* Process Beacon and CAB receive in PS state */
	if (((sc->ps_flags & PS_WAIT_FOR_BEACON) || ath9k_check_auto_sleep(sc))
	    && mybeacon) {
		ath_rx_ps_beacon(sc, skb);
	} else if ((sc->ps_flags & PS_WAIT_FOR_CAB) &&
		   (ieee80211_is_data(hdr->frame_control) ||
		    ieee80211_is_action(hdr->frame_control)) &&
		   is_multicast_ether_addr(hdr->addr1) &&
		   !ieee80211_has_moredata(hdr->frame_control)) {
		/*
		 * No more broadcast/multicast frames to be received at this
		 * point.
		 */
		sc->ps_flags &= ~(PS_WAIT_FOR_CAB | PS_WAIT_FOR_BEACON);
		ath_dbg(common, PS,
			"All PS CAB frames received, back to sleep\n");
	} else if ((sc->ps_flags & PS_WAIT_FOR_PSPOLL_DATA) &&
		   !is_multicast_ether_addr(hdr->addr1) &&
		   !ieee80211_has_morefrags(hdr->frame_control)) {
		sc->ps_flags &= ~PS_WAIT_FOR_PSPOLL_DATA;
		ath_dbg(common, PS,
			"Going back to sleep after having received PS-Poll data (0x%lx)\n",
			sc->ps_flags & (PS_WAIT_FOR_BEACON |
					PS_WAIT_FOR_CAB |
					PS_WAIT_FOR_PSPOLL_DATA |
					PS_WAIT_FOR_TX_ACK));
	}
}

static bool ath_edma_get_buffers(struct ath_softc *sc,
				 enum ath9k_rx_qtype qtype,
				 struct ath_rx_status *rs,
				 struct ath_rxbuf **dest)
{
	struct ath_rx_edma *rx_edma = &sc->rx.rx_edma[qtype];
	struct ath_hw *ah = sc->sc_ah;
	struct ath_common *common = ath9k_hw_common(ah);
	struct sk_buff *skb;
	struct ath_rxbuf *bf;
	int ret;

	skb = skb_peek(&rx_edma->rx_fifo);
	if (!skb)
		return false;

	bf = SKB_CB_ATHBUF(skb);
	BUG_ON(!bf);

	dma_sync_single_for_cpu(sc->dev, bf->bf_buf_addr,
				common->rx_bufsize, DMA_FROM_DEVICE);

	ret = ath9k_hw_process_rxdesc_edma(ah, rs, skb->data);
	if (ret == -EINPROGRESS) {
		/*let device gain the buffer again*/
		dma_sync_single_for_device(sc->dev, bf->bf_buf_addr,
				common->rx_bufsize, DMA_FROM_DEVICE);
		return false;
	}

	__skb_unlink(skb, &rx_edma->rx_fifo);
	if (ret == -EINVAL) {
		/* corrupt descriptor, skip this one and the following one */
		list_add_tail(&bf->list, &sc->rx.rxbuf);
		ath_rx_edma_buf_link(sc, qtype);

		skb = skb_peek(&rx_edma->rx_fifo);
		if (skb) {
			bf = SKB_CB_ATHBUF(skb);
			BUG_ON(!bf);

			__skb_unlink(skb, &rx_edma->rx_fifo);
			list_add_tail(&bf->list, &sc->rx.rxbuf);
			ath_rx_edma_buf_link(sc, qtype);
		}

		bf = NULL;
	}

	*dest = bf;
	return true;
}

static struct ath_rxbuf *ath_edma_get_next_rx_buf(struct ath_softc *sc,
						struct ath_rx_status *rs,
						enum ath9k_rx_qtype qtype)
{
	struct ath_rxbuf *bf = NULL;

	while (ath_edma_get_buffers(sc, qtype, rs, &bf)) {
		if (!bf)
			continue;

		return bf;
	}
	return NULL;
}

static struct ath_rxbuf *ath_get_next_rx_buf(struct ath_softc *sc,
					   struct ath_rx_status *rs)
{
	struct ath_hw *ah = sc->sc_ah;
	struct ath_common *common = ath9k_hw_common(ah);
	struct ath_desc *ds;
	struct ath_rxbuf *bf;
	int ret;

	if (list_empty(&sc->rx.rxbuf)) {
		sc->rx.rxlink = NULL;
		return NULL;
	}

	bf = list_first_entry(&sc->rx.rxbuf, struct ath_rxbuf, list);
	if (bf == sc->rx.buf_hold)
		return NULL;

	ds = bf->bf_desc;

	/*
	 * Must provide the virtual address of the current
	 * descriptor, the physical address, and the virtual
	 * address of the next descriptor in the h/w chain.
	 * This allows the HAL to look ahead to see if the
	 * hardware is done with a descriptor by checking the
	 * done bit in the following descriptor and the address
	 * of the current descriptor the DMA engine is working
	 * on.  All this is necessary because of our use of
	 * a self-linked list to avoid rx overruns.
	 */
	ret = ath9k_hw_rxprocdesc(ah, ds, rs);
	if (ret == -EINPROGRESS) {
		struct ath_rx_status trs;
		struct ath_rxbuf *tbf;
		struct ath_desc *tds;

		memset(&trs, 0, sizeof(trs));
		if (list_is_last(&bf->list, &sc->rx.rxbuf)) {
			sc->rx.rxlink = NULL;
			return NULL;
		}

		tbf = list_entry(bf->list.next, struct ath_rxbuf, list);

		/*
		 * On some hardware the descriptor status words could
		 * get corrupted, including the done bit. Because of
		 * this, check if the next descriptor's done bit is
		 * set or not.
		 *
		 * If the next descriptor's done bit is set, the current
		 * descriptor has been corrupted. Force s/w to discard
		 * this descriptor and continue...
		 */

		tds = tbf->bf_desc;
		ret = ath9k_hw_rxprocdesc(ah, tds, &trs);
		if (ret == -EINPROGRESS)
			return NULL;

		/*
		 * Re-check previous descriptor, in case it has been filled
		 * in the mean time.
		 */
		ret = ath9k_hw_rxprocdesc(ah, ds, rs);
		if (ret == -EINPROGRESS) {
			/*
			 * mark descriptor as zero-length and set the 'more'
			 * flag to ensure that both buffers get discarded
			 */
			rs->rs_datalen = 0;
			rs->rs_more = true;
		}
	}

	list_del(&bf->list);
	if (!bf->bf_mpdu)
		return bf;

	/*
	 * Synchronize the DMA transfer with CPU before
	 * 1. accessing the frame
	 * 2. requeueing the same buffer to h/w
	 */
	dma_sync_single_for_cpu(sc->dev, bf->bf_buf_addr,
			common->rx_bufsize,
			DMA_FROM_DEVICE);

	return bf;
}

static void ath9k_process_tsf(struct ath_rx_status *rs,
			      struct ieee80211_rx_status *rxs,
			      u64 tsf)
{
	u32 tsf_lower = tsf & 0xffffffff;

	rxs->mactime = (tsf & ~0xffffffffULL) | rs->rs_tstamp;
	if (rs->rs_tstamp > tsf_lower &&
	    unlikely(rs->rs_tstamp - tsf_lower > 0x10000000))
		rxs->mactime -= 0x100000000ULL;

	if (rs->rs_tstamp < tsf_lower &&
	    unlikely(tsf_lower - rs->rs_tstamp > 0x10000000))
		rxs->mactime += 0x100000000ULL;
}

/*
 * For Decrypt or Demic errors, we only mark packet status here and always push
 * up the frame up to let mac80211 handle the actual error case, be it no
 * decryption key or real decryption error. This let us keep statistics there.
 */
static int ath9k_rx_skb_preprocess(struct ath_softc *sc,
				   struct sk_buff *skb,
				   struct ath_rx_status *rx_stats,
				   struct ieee80211_rx_status *rx_status,
				   bool *decrypt_error, u64 tsf)
{
	struct ieee80211_hw *hw = sc->hw;
	struct ath_hw *ah = sc->sc_ah;
	struct ath_common *common = ath9k_hw_common(ah);
	struct ieee80211_hdr *hdr;
	bool discard_current = sc->rx.discard_next;

	/*
	 * Discard corrupt descriptors which are marked in
	 * ath_get_next_rx_buf().
	 */
	if (discard_current)
		goto corrupt;

	sc->rx.discard_next = false;

	/*
	 * Discard zero-length packets.
	 */
	if (!rx_stats->rs_datalen) {
		RX_STAT_INC(rx_len_err);
		goto corrupt;
	}

	/*
	 * rs_status follows rs_datalen so if rs_datalen is too large
	 * we can take a hint that hardware corrupted it, so ignore
	 * those frames.
	 */
	if (rx_stats->rs_datalen > (common->rx_bufsize - ah->caps.rx_status_len)) {
		RX_STAT_INC(rx_len_err);
		goto corrupt;
	}

	/* Only use status info from the last fragment */
	if (rx_stats->rs_more)
		return 0;

	/*
	 * Return immediately if the RX descriptor has been marked
	 * as corrupt based on the various error bits.
	 *
	 * This is different from the other corrupt descriptor
	 * condition handled above.
	 */
	if (rx_stats->rs_status & ATH9K_RXERR_CORRUPT_DESC)
		goto corrupt;

	hdr = (struct ieee80211_hdr *) (skb->data + ah->caps.rx_status_len);

	ath9k_process_tsf(rx_stats, rx_status, tsf);
	ath_debug_stat_rx(sc, rx_stats);

	/*
	 * Process PHY errors and return so that the packet
	 * can be dropped.
	 */
	if (rx_stats->rs_status & ATH9K_RXERR_PHY) {
		/*
		 * DFS and spectral are mutually exclusive
		 *
		 * Since some chips use PHYERR_RADAR as indication for both, we
		 * need to double check which feature is enabled to prevent
		 * feeding spectral or dfs-detector with wrong frames.
		 */
		if (hw->conf.radar_enabled) {
			ath9k_dfs_process_phyerr(sc, hdr, rx_stats,
						 rx_status->mactime);
		} else if (sc->spec_priv.spectral_mode != SPECTRAL_DISABLED &&
			   ath_cmn_process_fft(&sc->spec_priv, hdr, rx_stats,
					       rx_status->mactime)) {
			RX_STAT_INC(rx_spectral);
		}
		return -EINVAL;
	}

	/*
	 * everything but the rate is checked here, the rate check is done
	 * separately to avoid doing two lookups for a rate for each frame.
	 */
	spin_lock_bh(&sc->chan_lock);
	if (!ath9k_cmn_rx_accept(common, hdr, rx_status, rx_stats, decrypt_error,
				 sc->cur_chan->rxfilter)) {
		spin_unlock_bh(&sc->chan_lock);
		return -EINVAL;
	}
	spin_unlock_bh(&sc->chan_lock);

	if (ath_is_mybeacon(common, hdr)) {
		RX_STAT_INC(rx_beacons);
		rx_stats->is_mybeacon = true;
	}

	/*
	 * This shouldn't happen, but have a safety check anyway.
	 */
	if (WARN_ON(!ah->curchan))
		return -EINVAL;

	if (ath9k_cmn_process_rate(common, hw, rx_stats, rx_status)) {
		/*
		 * No valid hardware bitrate found -- we should not get here
		 * because hardware has already validated this frame as OK.
		 */
		ath_dbg(common, ANY, "unsupported hw bitrate detected 0x%02x using 1 Mbit\n",
			rx_stats->rs_rate);
		RX_STAT_INC(rx_rate_err);
		return -EINVAL;
	}

	if (ath9k_is_chanctx_enabled()) {
		if (rx_stats->is_mybeacon)
			ath_chanctx_beacon_recv_ev(sc,
					   ATH_CHANCTX_EVENT_BEACON_RECEIVED);
	}

	ath9k_cmn_process_rssi(common, hw, rx_stats, rx_status);

	rx_status->band = ah->curchan->chan->band;
	rx_status->freq = ah->curchan->chan->center_freq;
	rx_status->antenna = rx_stats->rs_antenna;
	rx_status->flag |= RX_FLAG_MACTIME_END;

#ifdef CONFIG_ATH9K_BTCOEX_SUPPORT
	if (ieee80211_is_data_present(hdr->frame_control) &&
	    !ieee80211_is_qos_nullfunc(hdr->frame_control))
		sc->rx.num_pkts++;
#endif

	return 0;

corrupt:
	sc->rx.discard_next = rx_stats->rs_more;
	return -EINVAL;
}

/*
 * Run the LNA combining algorithm only in these cases:
 *
 * Standalone WLAN cards with both LNA/Antenna diversity
 * enabled in the EEPROM.
 *
 * WLAN+BT cards which are in the supported card list
 * in ath_pci_id_table and the user has loaded the
 * driver with "bt_ant_diversity" set to true.
 */
static void ath9k_antenna_check(struct ath_softc *sc,
				struct ath_rx_status *rs)
{
	struct ath_hw *ah = sc->sc_ah;
	struct ath9k_hw_capabilities *pCap = &ah->caps;
	struct ath_common *common = ath9k_hw_common(ah);

	if (!(ah->caps.hw_caps & ATH9K_HW_CAP_ANT_DIV_COMB))
		return;

	/*
	 * Change the default rx antenna if rx diversity
	 * chooses the other antenna 3 times in a row.
	 */
	if (sc->rx.defant != rs->rs_antenna) {
		if (++sc->rx.rxotherant >= 3)
			ath_setdefantenna(sc, rs->rs_antenna);
	} else {
		sc->rx.rxotherant = 0;
	}

	if (pCap->hw_caps & ATH9K_HW_CAP_BT_ANT_DIV) {
		if (common->bt_ant_diversity)
			ath_ant_comb_scan(sc, rs);
	} else {
		ath_ant_comb_scan(sc, rs);
	}
}

static void ath9k_apply_ampdu_details(struct ath_softc *sc,
	struct ath_rx_status *rs, struct ieee80211_rx_status *rxs)
{
	if (rs->rs_isaggr) {
		rxs->flag |= RX_FLAG_AMPDU_DETAILS | RX_FLAG_AMPDU_LAST_KNOWN;

		rxs->ampdu_reference = sc->rx.ampdu_ref;

		if (!rs->rs_moreaggr) {
			rxs->flag |= RX_FLAG_AMPDU_IS_LAST;
			sc->rx.ampdu_ref++;
		}

		if (rs->rs_flags & ATH9K_RX_DELIM_CRC_PRE)
			rxs->flag |= RX_FLAG_AMPDU_DELIM_CRC_ERROR;
	}
}

int ath_rx_tasklet(struct ath_softc *sc, int flush, bool hp)
{
	struct ath_rxbuf *bf;
	struct sk_buff *skb = NULL, *requeue_skb, *hdr_skb;
	struct ieee80211_rx_status *rxs;
	struct ath_hw *ah = sc->sc_ah;
	struct ath_common *common = ath9k_hw_common(ah);
	struct ieee80211_hw *hw = sc->hw;
	int retval;
	struct ath_rx_status rs;
	enum ath9k_rx_qtype qtype;
	bool edma = !!(ah->caps.hw_caps & ATH9K_HW_CAP_EDMA);
	int dma_type;
	u64 tsf = 0;
	unsigned long flags;
	dma_addr_t new_buf_addr;
	unsigned int budget = 512;
	struct ieee80211_hdr *hdr;

	if (edma)
		dma_type = DMA_BIDIRECTIONAL;
	else
		dma_type = DMA_FROM_DEVICE;

	qtype = hp ? ATH9K_RX_QUEUE_HP : ATH9K_RX_QUEUE_LP;

	tsf = ath9k_hw_gettsf64(ah);

	do {
		bool decrypt_error = false;

		memset(&rs, 0, sizeof(rs));
		if (edma)
			bf = ath_edma_get_next_rx_buf(sc, &rs, qtype);
		else
			bf = ath_get_next_rx_buf(sc, &rs);

		if (!bf)
			break;

		skb = bf->bf_mpdu;
		if (!skb)
			continue;

		/*
		 * Take frame header from the first fragment and RX status from
		 * the last one.
		 */
		if (sc->rx.frag)
			hdr_skb = sc->rx.frag;
		else
			hdr_skb = skb;

		rxs = IEEE80211_SKB_RXCB(hdr_skb);
		memset(rxs, 0, sizeof(struct ieee80211_rx_status));

		retval = ath9k_rx_skb_preprocess(sc, hdr_skb, &rs, rxs,
						 &decrypt_error, tsf);
		if (retval)
			goto requeue_drop_frag;

		/* Ensure we always have an skb to requeue once we are done
		 * processing the current buffer's skb */
		requeue_skb = ath_rxbuf_alloc(common, common->rx_bufsize, GFP_ATOMIC);

		/* If there is no memory we ignore the current RX'd frame,
		 * tell hardware it can give us a new frame using the old
		 * skb and put it at the tail of the sc->rx.rxbuf list for
		 * processing. */
		if (!requeue_skb) {
			RX_STAT_INC(rx_oom_err);
			goto requeue_drop_frag;
		}

		/* We will now give hardware our shiny new allocated skb */
		new_buf_addr = dma_map_single(sc->dev, requeue_skb->data,
					      common->rx_bufsize, dma_type);
		if (unlikely(dma_mapping_error(sc->dev, new_buf_addr))) {
			dev_kfree_skb_any(requeue_skb);
			goto requeue_drop_frag;
		}

		/* Unmap the frame */
		dma_unmap_single(sc->dev, bf->bf_buf_addr,
				 common->rx_bufsize, dma_type);

		bf->bf_mpdu = requeue_skb;
		bf->bf_buf_addr = new_buf_addr;

		skb_put(skb, rs.rs_datalen + ah->caps.rx_status_len);
		if (ah->caps.rx_status_len)
			skb_pull(skb, ah->caps.rx_status_len);

		if (!rs.rs_more)
			ath9k_cmn_rx_skb_postprocess(common, hdr_skb, &rs,
						     rxs, decrypt_error);

		if (rs.rs_more) {
			RX_STAT_INC(rx_frags);
			/*
			 * rs_more indicates chained descriptors which can be
			 * used to link buffers together for a sort of
			 * scatter-gather operation.
			 */
			if (sc->rx.frag) {
				/* too many fragments - cannot handle frame */
				dev_kfree_skb_any(sc->rx.frag);
				dev_kfree_skb_any(skb);
				RX_STAT_INC(rx_too_many_frags_err);
				skb = NULL;
			}
			sc->rx.frag = skb;
			goto requeue;
		}

		if (sc->rx.frag) {
			int space = skb->len - skb_tailroom(hdr_skb);

			if (pskb_expand_head(hdr_skb, 0, space, GFP_ATOMIC) < 0) {
				dev_kfree_skb(skb);
				RX_STAT_INC(rx_oom_err);
				goto requeue_drop_frag;
			}

			sc->rx.frag = NULL;

			skb_copy_from_linear_data(skb, skb_put(hdr_skb, skb->len),
						  skb->len);
			dev_kfree_skb_any(skb);
			skb = hdr_skb;
		}

		if (rxs->flag & RX_FLAG_MMIC_STRIPPED)
			skb_trim(skb, skb->len - 8);

		spin_lock_irqsave(&sc->sc_pm_lock, flags);
		if ((sc->ps_flags & (PS_WAIT_FOR_BEACON |
				     PS_WAIT_FOR_CAB |
				     PS_WAIT_FOR_PSPOLL_DATA)) ||
		    ath9k_check_auto_sleep(sc))
			ath_rx_ps(sc, skb, rs.is_mybeacon);
		spin_unlock_irqrestore(&sc->sc_pm_lock, flags);

		ath9k_antenna_check(sc, &rs);
		ath9k_apply_ampdu_details(sc, &rs, rxs);
		ath_debug_rate_stats(sc, &rs, skb);

		hdr = (struct ieee80211_hdr *)skb->data;
		if (ieee80211_is_ack(hdr->frame_control))
			ath_dynack_sample_ack_ts(sc->sc_ah, skb, rs.rs_tstamp);

		ieee80211_rx(hw, skb);

requeue_drop_frag:
		if (sc->rx.frag) {
			dev_kfree_skb_any(sc->rx.frag);
			sc->rx.frag = NULL;
		}
requeue:
		list_add_tail(&bf->list, &sc->rx.rxbuf);

		if (!edma) {
			ath_rx_buf_relink(sc, bf, flush);
			if (!flush)
				ath9k_hw_rxena(ah);
		} else if (!flush) {
			ath_rx_edma_buf_link(sc, qtype);
		}

		if (!budget--)
			break;
	} while (1);

	if (!(ah->imask & ATH9K_INT_RXEOL)) {
		ah->imask |= (ATH9K_INT_RXEOL | ATH9K_INT_RXORN);
		ath9k_hw_set_interrupts(ah);
	}

	return 0;
}