Merge branch 'rbd-sysfs' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph...
[pandora-kernel.git] / drivers / net / wireless / ath / ath9k / recv.c
1 /*
2  * Copyright (c) 2008-2009 Atheros Communications Inc.
3  *
4  * Permission to use, copy, modify, and/or distribute this software for any
5  * purpose with or without fee is hereby granted, provided that the above
6  * copyright notice and this permission notice appear in all copies.
7  *
8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15  */
16
17 #include "ath9k.h"
18 #include "ar9003_mac.h"
19
20 #define SKB_CB_ATHBUF(__skb)    (*((struct ath_buf **)__skb->cb))
21
22 static inline bool ath_is_alt_ant_ratio_better(int alt_ratio, int maxdelta,
23                                                int mindelta, int main_rssi_avg,
24                                                int alt_rssi_avg, int pkt_count)
25 {
26         return (((alt_ratio >= ATH_ANT_DIV_COMB_ALT_ANT_RATIO2) &&
27                 (alt_rssi_avg > main_rssi_avg + maxdelta)) ||
28                 (alt_rssi_avg > main_rssi_avg + mindelta)) && (pkt_count > 50);
29 }
30
31 static inline bool ath9k_check_auto_sleep(struct ath_softc *sc)
32 {
33         return sc->ps_enabled &&
34                (sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_AUTOSLEEP);
35 }
36
37 static struct ieee80211_hw * ath_get_virt_hw(struct ath_softc *sc,
38                                              struct ieee80211_hdr *hdr)
39 {
40         struct ieee80211_hw *hw = sc->pri_wiphy->hw;
41         int i;
42
43         spin_lock_bh(&sc->wiphy_lock);
44         for (i = 0; i < sc->num_sec_wiphy; i++) {
45                 struct ath_wiphy *aphy = sc->sec_wiphy[i];
46                 if (aphy == NULL)
47                         continue;
48                 if (compare_ether_addr(hdr->addr1, aphy->hw->wiphy->perm_addr)
49                     == 0) {
50                         hw = aphy->hw;
51                         break;
52                 }
53         }
54         spin_unlock_bh(&sc->wiphy_lock);
55         return hw;
56 }
57
58 /*
59  * Setup and link descriptors.
60  *
61  * 11N: we can no longer afford to self link the last descriptor.
62  * MAC acknowledges BA status as long as it copies frames to host
63  * buffer (or rx fifo). This can incorrectly acknowledge packets
64  * to a sender if last desc is self-linked.
65  */
66 static void ath_rx_buf_link(struct ath_softc *sc, struct ath_buf *bf)
67 {
68         struct ath_hw *ah = sc->sc_ah;
69         struct ath_common *common = ath9k_hw_common(ah);
70         struct ath_desc *ds;
71         struct sk_buff *skb;
72
73         ATH_RXBUF_RESET(bf);
74
75         ds = bf->bf_desc;
76         ds->ds_link = 0; /* link to null */
77         ds->ds_data = bf->bf_buf_addr;
78
79         /* virtual addr of the beginning of the buffer. */
80         skb = bf->bf_mpdu;
81         BUG_ON(skb == NULL);
82         ds->ds_vdata = skb->data;
83
84         /*
85          * setup rx descriptors. The rx_bufsize here tells the hardware
86          * how much data it can DMA to us and that we are prepared
87          * to process
88          */
89         ath9k_hw_setuprxdesc(ah, ds,
90                              common->rx_bufsize,
91                              0);
92
93         if (sc->rx.rxlink == NULL)
94                 ath9k_hw_putrxbuf(ah, bf->bf_daddr);
95         else
96                 *sc->rx.rxlink = bf->bf_daddr;
97
98         sc->rx.rxlink = &ds->ds_link;
99         ath9k_hw_rxena(ah);
100 }
101
102 static void ath_setdefantenna(struct ath_softc *sc, u32 antenna)
103 {
104         /* XXX block beacon interrupts */
105         ath9k_hw_setantenna(sc->sc_ah, antenna);
106         sc->rx.defant = antenna;
107         sc->rx.rxotherant = 0;
108 }
109
110 static void ath_opmode_init(struct ath_softc *sc)
111 {
112         struct ath_hw *ah = sc->sc_ah;
113         struct ath_common *common = ath9k_hw_common(ah);
114
115         u32 rfilt, mfilt[2];
116
117         /* configure rx filter */
118         rfilt = ath_calcrxfilter(sc);
119         ath9k_hw_setrxfilter(ah, rfilt);
120
121         /* configure bssid mask */
122         ath_hw_setbssidmask(common);
123
124         /* configure operational mode */
125         ath9k_hw_setopmode(ah);
126
127         /* calculate and install multicast filter */
128         mfilt[0] = mfilt[1] = ~0;
129         ath9k_hw_setmcastfilter(ah, mfilt[0], mfilt[1]);
130 }
131
132 static bool ath_rx_edma_buf_link(struct ath_softc *sc,
133                                  enum ath9k_rx_qtype qtype)
134 {
135         struct ath_hw *ah = sc->sc_ah;
136         struct ath_rx_edma *rx_edma;
137         struct sk_buff *skb;
138         struct ath_buf *bf;
139
140         rx_edma = &sc->rx.rx_edma[qtype];
141         if (skb_queue_len(&rx_edma->rx_fifo) >= rx_edma->rx_fifo_hwsize)
142                 return false;
143
144         bf = list_first_entry(&sc->rx.rxbuf, struct ath_buf, list);
145         list_del_init(&bf->list);
146
147         skb = bf->bf_mpdu;
148
149         ATH_RXBUF_RESET(bf);
150         memset(skb->data, 0, ah->caps.rx_status_len);
151         dma_sync_single_for_device(sc->dev, bf->bf_buf_addr,
152                                 ah->caps.rx_status_len, DMA_TO_DEVICE);
153
154         SKB_CB_ATHBUF(skb) = bf;
155         ath9k_hw_addrxbuf_edma(ah, bf->bf_buf_addr, qtype);
156         skb_queue_tail(&rx_edma->rx_fifo, skb);
157
158         return true;
159 }
160
161 static void ath_rx_addbuffer_edma(struct ath_softc *sc,
162                                   enum ath9k_rx_qtype qtype, int size)
163 {
164         struct ath_common *common = ath9k_hw_common(sc->sc_ah);
165         u32 nbuf = 0;
166
167         if (list_empty(&sc->rx.rxbuf)) {
168                 ath_print(common, ATH_DBG_QUEUE, "No free rx buf available\n");
169                 return;
170         }
171
172         while (!list_empty(&sc->rx.rxbuf)) {
173                 nbuf++;
174
175                 if (!ath_rx_edma_buf_link(sc, qtype))
176                         break;
177
178                 if (nbuf >= size)
179                         break;
180         }
181 }
182
183 static void ath_rx_remove_buffer(struct ath_softc *sc,
184                                  enum ath9k_rx_qtype qtype)
185 {
186         struct ath_buf *bf;
187         struct ath_rx_edma *rx_edma;
188         struct sk_buff *skb;
189
190         rx_edma = &sc->rx.rx_edma[qtype];
191
192         while ((skb = skb_dequeue(&rx_edma->rx_fifo)) != NULL) {
193                 bf = SKB_CB_ATHBUF(skb);
194                 BUG_ON(!bf);
195                 list_add_tail(&bf->list, &sc->rx.rxbuf);
196         }
197 }
198
199 static void ath_rx_edma_cleanup(struct ath_softc *sc)
200 {
201         struct ath_buf *bf;
202
203         ath_rx_remove_buffer(sc, ATH9K_RX_QUEUE_LP);
204         ath_rx_remove_buffer(sc, ATH9K_RX_QUEUE_HP);
205
206         list_for_each_entry(bf, &sc->rx.rxbuf, list) {
207                 if (bf->bf_mpdu)
208                         dev_kfree_skb_any(bf->bf_mpdu);
209         }
210
211         INIT_LIST_HEAD(&sc->rx.rxbuf);
212
213         kfree(sc->rx.rx_bufptr);
214         sc->rx.rx_bufptr = NULL;
215 }
216
217 static void ath_rx_edma_init_queue(struct ath_rx_edma *rx_edma, int size)
218 {
219         skb_queue_head_init(&rx_edma->rx_fifo);
220         skb_queue_head_init(&rx_edma->rx_buffers);
221         rx_edma->rx_fifo_hwsize = size;
222 }
223
224 static int ath_rx_edma_init(struct ath_softc *sc, int nbufs)
225 {
226         struct ath_common *common = ath9k_hw_common(sc->sc_ah);
227         struct ath_hw *ah = sc->sc_ah;
228         struct sk_buff *skb;
229         struct ath_buf *bf;
230         int error = 0, i;
231         u32 size;
232
233
234         common->rx_bufsize = roundup(IEEE80211_MAX_MPDU_LEN +
235                                      ah->caps.rx_status_len,
236                                      min(common->cachelsz, (u16)64));
237
238         ath9k_hw_set_rx_bufsize(ah, common->rx_bufsize -
239                                     ah->caps.rx_status_len);
240
241         ath_rx_edma_init_queue(&sc->rx.rx_edma[ATH9K_RX_QUEUE_LP],
242                                ah->caps.rx_lp_qdepth);
243         ath_rx_edma_init_queue(&sc->rx.rx_edma[ATH9K_RX_QUEUE_HP],
244                                ah->caps.rx_hp_qdepth);
245
246         size = sizeof(struct ath_buf) * nbufs;
247         bf = kzalloc(size, GFP_KERNEL);
248         if (!bf)
249                 return -ENOMEM;
250
251         INIT_LIST_HEAD(&sc->rx.rxbuf);
252         sc->rx.rx_bufptr = bf;
253
254         for (i = 0; i < nbufs; i++, bf++) {
255                 skb = ath_rxbuf_alloc(common, common->rx_bufsize, GFP_KERNEL);
256                 if (!skb) {
257                         error = -ENOMEM;
258                         goto rx_init_fail;
259                 }
260
261                 memset(skb->data, 0, common->rx_bufsize);
262                 bf->bf_mpdu = skb;
263
264                 bf->bf_buf_addr = dma_map_single(sc->dev, skb->data,
265                                                  common->rx_bufsize,
266                                                  DMA_BIDIRECTIONAL);
267                 if (unlikely(dma_mapping_error(sc->dev,
268                                                 bf->bf_buf_addr))) {
269                                 dev_kfree_skb_any(skb);
270                                 bf->bf_mpdu = NULL;
271                                 bf->bf_buf_addr = 0;
272                                 ath_print(common, ATH_DBG_FATAL,
273                                         "dma_mapping_error() on RX init\n");
274                                 error = -ENOMEM;
275                                 goto rx_init_fail;
276                 }
277
278                 list_add_tail(&bf->list, &sc->rx.rxbuf);
279         }
280
281         return 0;
282
283 rx_init_fail:
284         ath_rx_edma_cleanup(sc);
285         return error;
286 }
287
288 static void ath_edma_start_recv(struct ath_softc *sc)
289 {
290         spin_lock_bh(&sc->rx.rxbuflock);
291
292         ath9k_hw_rxena(sc->sc_ah);
293
294         ath_rx_addbuffer_edma(sc, ATH9K_RX_QUEUE_HP,
295                               sc->rx.rx_edma[ATH9K_RX_QUEUE_HP].rx_fifo_hwsize);
296
297         ath_rx_addbuffer_edma(sc, ATH9K_RX_QUEUE_LP,
298                               sc->rx.rx_edma[ATH9K_RX_QUEUE_LP].rx_fifo_hwsize);
299
300         ath_opmode_init(sc);
301
302         ath9k_hw_startpcureceive(sc->sc_ah, (sc->sc_flags & SC_OP_OFFCHANNEL));
303
304         spin_unlock_bh(&sc->rx.rxbuflock);
305 }
306
307 static void ath_edma_stop_recv(struct ath_softc *sc)
308 {
309         ath_rx_remove_buffer(sc, ATH9K_RX_QUEUE_HP);
310         ath_rx_remove_buffer(sc, ATH9K_RX_QUEUE_LP);
311 }
312
313 int ath_rx_init(struct ath_softc *sc, int nbufs)
314 {
315         struct ath_common *common = ath9k_hw_common(sc->sc_ah);
316         struct sk_buff *skb;
317         struct ath_buf *bf;
318         int error = 0;
319
320         spin_lock_init(&sc->rx.pcu_lock);
321         sc->sc_flags &= ~SC_OP_RXFLUSH;
322         spin_lock_init(&sc->rx.rxbuflock);
323
324         if (sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_EDMA) {
325                 return ath_rx_edma_init(sc, nbufs);
326         } else {
327                 common->rx_bufsize = roundup(IEEE80211_MAX_MPDU_LEN,
328                                 min(common->cachelsz, (u16)64));
329
330                 ath_print(common, ATH_DBG_CONFIG, "cachelsz %u rxbufsize %u\n",
331                                 common->cachelsz, common->rx_bufsize);
332
333                 /* Initialize rx descriptors */
334
335                 error = ath_descdma_setup(sc, &sc->rx.rxdma, &sc->rx.rxbuf,
336                                 "rx", nbufs, 1, 0);
337                 if (error != 0) {
338                         ath_print(common, ATH_DBG_FATAL,
339                                   "failed to allocate rx descriptors: %d\n",
340                                   error);
341                         goto err;
342                 }
343
344                 list_for_each_entry(bf, &sc->rx.rxbuf, list) {
345                         skb = ath_rxbuf_alloc(common, common->rx_bufsize,
346                                               GFP_KERNEL);
347                         if (skb == NULL) {
348                                 error = -ENOMEM;
349                                 goto err;
350                         }
351
352                         bf->bf_mpdu = skb;
353                         bf->bf_buf_addr = dma_map_single(sc->dev, skb->data,
354                                         common->rx_bufsize,
355                                         DMA_FROM_DEVICE);
356                         if (unlikely(dma_mapping_error(sc->dev,
357                                                         bf->bf_buf_addr))) {
358                                 dev_kfree_skb_any(skb);
359                                 bf->bf_mpdu = NULL;
360                                 bf->bf_buf_addr = 0;
361                                 ath_print(common, ATH_DBG_FATAL,
362                                           "dma_mapping_error() on RX init\n");
363                                 error = -ENOMEM;
364                                 goto err;
365                         }
366                 }
367                 sc->rx.rxlink = NULL;
368         }
369
370 err:
371         if (error)
372                 ath_rx_cleanup(sc);
373
374         return error;
375 }
376
377 void ath_rx_cleanup(struct ath_softc *sc)
378 {
379         struct ath_hw *ah = sc->sc_ah;
380         struct ath_common *common = ath9k_hw_common(ah);
381         struct sk_buff *skb;
382         struct ath_buf *bf;
383
384         if (sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_EDMA) {
385                 ath_rx_edma_cleanup(sc);
386                 return;
387         } else {
388                 list_for_each_entry(bf, &sc->rx.rxbuf, list) {
389                         skb = bf->bf_mpdu;
390                         if (skb) {
391                                 dma_unmap_single(sc->dev, bf->bf_buf_addr,
392                                                 common->rx_bufsize,
393                                                 DMA_FROM_DEVICE);
394                                 dev_kfree_skb(skb);
395                                 bf->bf_buf_addr = 0;
396                                 bf->bf_mpdu = NULL;
397                         }
398                 }
399
400                 if (sc->rx.rxdma.dd_desc_len != 0)
401                         ath_descdma_cleanup(sc, &sc->rx.rxdma, &sc->rx.rxbuf);
402         }
403 }
404
405 /*
406  * Calculate the receive filter according to the
407  * operating mode and state:
408  *
409  * o always accept unicast, broadcast, and multicast traffic
410  * o maintain current state of phy error reception (the hal
411  *   may enable phy error frames for noise immunity work)
412  * o probe request frames are accepted only when operating in
413  *   hostap, adhoc, or monitor modes
414  * o enable promiscuous mode according to the interface state
415  * o accept beacons:
416  *   - when operating in adhoc mode so the 802.11 layer creates
417  *     node table entries for peers,
418  *   - when operating in station mode for collecting rssi data when
419  *     the station is otherwise quiet, or
420  *   - when operating as a repeater so we see repeater-sta beacons
421  *   - when scanning
422  */
423
424 u32 ath_calcrxfilter(struct ath_softc *sc)
425 {
426 #define RX_FILTER_PRESERVE (ATH9K_RX_FILTER_PHYERR | ATH9K_RX_FILTER_PHYRADAR)
427
428         u32 rfilt;
429
430         rfilt = (ath9k_hw_getrxfilter(sc->sc_ah) & RX_FILTER_PRESERVE)
431                 | ATH9K_RX_FILTER_UCAST | ATH9K_RX_FILTER_BCAST
432                 | ATH9K_RX_FILTER_MCAST;
433
434         if (sc->rx.rxfilter & FIF_PROBE_REQ)
435                 rfilt |= ATH9K_RX_FILTER_PROBEREQ;
436
437         /*
438          * Set promiscuous mode when FIF_PROMISC_IN_BSS is enabled for station
439          * mode interface or when in monitor mode. AP mode does not need this
440          * since it receives all in-BSS frames anyway.
441          */
442         if (((sc->sc_ah->opmode != NL80211_IFTYPE_AP) &&
443              (sc->rx.rxfilter & FIF_PROMISC_IN_BSS)) ||
444             (sc->sc_ah->is_monitoring))
445                 rfilt |= ATH9K_RX_FILTER_PROM;
446
447         if (sc->rx.rxfilter & FIF_CONTROL)
448                 rfilt |= ATH9K_RX_FILTER_CONTROL;
449
450         if ((sc->sc_ah->opmode == NL80211_IFTYPE_STATION) &&
451             (sc->nvifs <= 1) &&
452             !(sc->rx.rxfilter & FIF_BCN_PRBRESP_PROMISC))
453                 rfilt |= ATH9K_RX_FILTER_MYBEACON;
454         else
455                 rfilt |= ATH9K_RX_FILTER_BEACON;
456
457         if ((AR_SREV_9280_20_OR_LATER(sc->sc_ah) ||
458             AR_SREV_9285_12_OR_LATER(sc->sc_ah)) &&
459             (sc->sc_ah->opmode == NL80211_IFTYPE_AP) &&
460             (sc->rx.rxfilter & FIF_PSPOLL))
461                 rfilt |= ATH9K_RX_FILTER_PSPOLL;
462
463         if (conf_is_ht(&sc->hw->conf))
464                 rfilt |= ATH9K_RX_FILTER_COMP_BAR;
465
466         if (sc->sec_wiphy || (sc->nvifs > 1) ||
467             (sc->rx.rxfilter & FIF_OTHER_BSS)) {
468                 /* The following may also be needed for other older chips */
469                 if (sc->sc_ah->hw_version.macVersion == AR_SREV_VERSION_9160)
470                         rfilt |= ATH9K_RX_FILTER_PROM;
471                 rfilt |= ATH9K_RX_FILTER_MCAST_BCAST_ALL;
472         }
473
474         return rfilt;
475
476 #undef RX_FILTER_PRESERVE
477 }
478
479 int ath_startrecv(struct ath_softc *sc)
480 {
481         struct ath_hw *ah = sc->sc_ah;
482         struct ath_buf *bf, *tbf;
483
484         if (ah->caps.hw_caps & ATH9K_HW_CAP_EDMA) {
485                 ath_edma_start_recv(sc);
486                 return 0;
487         }
488
489         spin_lock_bh(&sc->rx.rxbuflock);
490         if (list_empty(&sc->rx.rxbuf))
491                 goto start_recv;
492
493         sc->rx.rxlink = NULL;
494         list_for_each_entry_safe(bf, tbf, &sc->rx.rxbuf, list) {
495                 ath_rx_buf_link(sc, bf);
496         }
497
498         /* We could have deleted elements so the list may be empty now */
499         if (list_empty(&sc->rx.rxbuf))
500                 goto start_recv;
501
502         bf = list_first_entry(&sc->rx.rxbuf, struct ath_buf, list);
503         ath9k_hw_putrxbuf(ah, bf->bf_daddr);
504         ath9k_hw_rxena(ah);
505
506 start_recv:
507         ath_opmode_init(sc);
508         ath9k_hw_startpcureceive(ah, (sc->sc_flags & SC_OP_OFFCHANNEL));
509
510         spin_unlock_bh(&sc->rx.rxbuflock);
511
512         return 0;
513 }
514
515 bool ath_stoprecv(struct ath_softc *sc)
516 {
517         struct ath_hw *ah = sc->sc_ah;
518         bool stopped;
519
520         spin_lock_bh(&sc->rx.rxbuflock);
521         ath9k_hw_abortpcurecv(ah);
522         ath9k_hw_setrxfilter(ah, 0);
523         stopped = ath9k_hw_stopdmarecv(ah);
524
525         if (sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_EDMA)
526                 ath_edma_stop_recv(sc);
527         else
528                 sc->rx.rxlink = NULL;
529         spin_unlock_bh(&sc->rx.rxbuflock);
530
531         return stopped;
532 }
533
534 void ath_flushrecv(struct ath_softc *sc)
535 {
536         sc->sc_flags |= SC_OP_RXFLUSH;
537         if (sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_EDMA)
538                 ath_rx_tasklet(sc, 1, true);
539         ath_rx_tasklet(sc, 1, false);
540         sc->sc_flags &= ~SC_OP_RXFLUSH;
541 }
542
543 static bool ath_beacon_dtim_pending_cab(struct sk_buff *skb)
544 {
545         /* Check whether the Beacon frame has DTIM indicating buffered bc/mc */
546         struct ieee80211_mgmt *mgmt;
547         u8 *pos, *end, id, elen;
548         struct ieee80211_tim_ie *tim;
549
550         mgmt = (struct ieee80211_mgmt *)skb->data;
551         pos = mgmt->u.beacon.variable;
552         end = skb->data + skb->len;
553
554         while (pos + 2 < end) {
555                 id = *pos++;
556                 elen = *pos++;
557                 if (pos + elen > end)
558                         break;
559
560                 if (id == WLAN_EID_TIM) {
561                         if (elen < sizeof(*tim))
562                                 break;
563                         tim = (struct ieee80211_tim_ie *) pos;
564                         if (tim->dtim_count != 0)
565                                 break;
566                         return tim->bitmap_ctrl & 0x01;
567                 }
568
569                 pos += elen;
570         }
571
572         return false;
573 }
574
575 static void ath_rx_ps_beacon(struct ath_softc *sc, struct sk_buff *skb)
576 {
577         struct ieee80211_mgmt *mgmt;
578         struct ath_common *common = ath9k_hw_common(sc->sc_ah);
579
580         if (skb->len < 24 + 8 + 2 + 2)
581                 return;
582
583         mgmt = (struct ieee80211_mgmt *)skb->data;
584         if (memcmp(common->curbssid, mgmt->bssid, ETH_ALEN) != 0)
585                 return; /* not from our current AP */
586
587         sc->ps_flags &= ~PS_WAIT_FOR_BEACON;
588
589         if (sc->ps_flags & PS_BEACON_SYNC) {
590                 sc->ps_flags &= ~PS_BEACON_SYNC;
591                 ath_print(common, ATH_DBG_PS,
592                           "Reconfigure Beacon timers based on "
593                           "timestamp from the AP\n");
594                 ath_beacon_config(sc, NULL);
595         }
596
597         if (ath_beacon_dtim_pending_cab(skb)) {
598                 /*
599                  * Remain awake waiting for buffered broadcast/multicast
600                  * frames. If the last broadcast/multicast frame is not
601                  * received properly, the next beacon frame will work as
602                  * a backup trigger for returning into NETWORK SLEEP state,
603                  * so we are waiting for it as well.
604                  */
605                 ath_print(common, ATH_DBG_PS, "Received DTIM beacon indicating "
606                           "buffered broadcast/multicast frame(s)\n");
607                 sc->ps_flags |= PS_WAIT_FOR_CAB | PS_WAIT_FOR_BEACON;
608                 return;
609         }
610
611         if (sc->ps_flags & PS_WAIT_FOR_CAB) {
612                 /*
613                  * This can happen if a broadcast frame is dropped or the AP
614                  * fails to send a frame indicating that all CAB frames have
615                  * been delivered.
616                  */
617                 sc->ps_flags &= ~PS_WAIT_FOR_CAB;
618                 ath_print(common, ATH_DBG_PS,
619                           "PS wait for CAB frames timed out\n");
620         }
621 }
622
623 static void ath_rx_ps(struct ath_softc *sc, struct sk_buff *skb)
624 {
625         struct ieee80211_hdr *hdr;
626         struct ath_common *common = ath9k_hw_common(sc->sc_ah);
627
628         hdr = (struct ieee80211_hdr *)skb->data;
629
630         /* Process Beacon and CAB receive in PS state */
631         if (((sc->ps_flags & PS_WAIT_FOR_BEACON) || ath9k_check_auto_sleep(sc))
632             && ieee80211_is_beacon(hdr->frame_control))
633                 ath_rx_ps_beacon(sc, skb);
634         else if ((sc->ps_flags & PS_WAIT_FOR_CAB) &&
635                  (ieee80211_is_data(hdr->frame_control) ||
636                   ieee80211_is_action(hdr->frame_control)) &&
637                  is_multicast_ether_addr(hdr->addr1) &&
638                  !ieee80211_has_moredata(hdr->frame_control)) {
639                 /*
640                  * No more broadcast/multicast frames to be received at this
641                  * point.
642                  */
643                 sc->ps_flags &= ~(PS_WAIT_FOR_CAB | PS_WAIT_FOR_BEACON);
644                 ath_print(common, ATH_DBG_PS,
645                           "All PS CAB frames received, back to sleep\n");
646         } else if ((sc->ps_flags & PS_WAIT_FOR_PSPOLL_DATA) &&
647                    !is_multicast_ether_addr(hdr->addr1) &&
648                    !ieee80211_has_morefrags(hdr->frame_control)) {
649                 sc->ps_flags &= ~PS_WAIT_FOR_PSPOLL_DATA;
650                 ath_print(common, ATH_DBG_PS,
651                           "Going back to sleep after having received "
652                           "PS-Poll data (0x%lx)\n",
653                         sc->ps_flags & (PS_WAIT_FOR_BEACON |
654                                         PS_WAIT_FOR_CAB |
655                                         PS_WAIT_FOR_PSPOLL_DATA |
656                                         PS_WAIT_FOR_TX_ACK));
657         }
658 }
659
660 static void ath_rx_send_to_mac80211(struct ieee80211_hw *hw,
661                                     struct ath_softc *sc, struct sk_buff *skb,
662                                     struct ieee80211_rx_status *rxs)
663 {
664         struct ieee80211_hdr *hdr;
665
666         hdr = (struct ieee80211_hdr *)skb->data;
667
668         /* Send the frame to mac80211 */
669         if (is_multicast_ether_addr(hdr->addr1)) {
670                 int i;
671                 /*
672                  * Deliver broadcast/multicast frames to all suitable
673                  * virtual wiphys.
674                  */
675                 /* TODO: filter based on channel configuration */
676                 for (i = 0; i < sc->num_sec_wiphy; i++) {
677                         struct ath_wiphy *aphy = sc->sec_wiphy[i];
678                         struct sk_buff *nskb;
679                         if (aphy == NULL)
680                                 continue;
681                         nskb = skb_copy(skb, GFP_ATOMIC);
682                         if (!nskb)
683                                 continue;
684                         ieee80211_rx(aphy->hw, nskb);
685                 }
686                 ieee80211_rx(sc->hw, skb);
687         } else
688                 /* Deliver unicast frames based on receiver address */
689                 ieee80211_rx(hw, skb);
690 }
691
692 static bool ath_edma_get_buffers(struct ath_softc *sc,
693                                  enum ath9k_rx_qtype qtype)
694 {
695         struct ath_rx_edma *rx_edma = &sc->rx.rx_edma[qtype];
696         struct ath_hw *ah = sc->sc_ah;
697         struct ath_common *common = ath9k_hw_common(ah);
698         struct sk_buff *skb;
699         struct ath_buf *bf;
700         int ret;
701
702         skb = skb_peek(&rx_edma->rx_fifo);
703         if (!skb)
704                 return false;
705
706         bf = SKB_CB_ATHBUF(skb);
707         BUG_ON(!bf);
708
709         dma_sync_single_for_cpu(sc->dev, bf->bf_buf_addr,
710                                 common->rx_bufsize, DMA_FROM_DEVICE);
711
712         ret = ath9k_hw_process_rxdesc_edma(ah, NULL, skb->data);
713         if (ret == -EINPROGRESS) {
714                 /*let device gain the buffer again*/
715                 dma_sync_single_for_device(sc->dev, bf->bf_buf_addr,
716                                 common->rx_bufsize, DMA_FROM_DEVICE);
717                 return false;
718         }
719
720         __skb_unlink(skb, &rx_edma->rx_fifo);
721         if (ret == -EINVAL) {
722                 /* corrupt descriptor, skip this one and the following one */
723                 list_add_tail(&bf->list, &sc->rx.rxbuf);
724                 ath_rx_edma_buf_link(sc, qtype);
725                 skb = skb_peek(&rx_edma->rx_fifo);
726                 if (!skb)
727                         return true;
728
729                 bf = SKB_CB_ATHBUF(skb);
730                 BUG_ON(!bf);
731
732                 __skb_unlink(skb, &rx_edma->rx_fifo);
733                 list_add_tail(&bf->list, &sc->rx.rxbuf);
734                 ath_rx_edma_buf_link(sc, qtype);
735                 return true;
736         }
737         skb_queue_tail(&rx_edma->rx_buffers, skb);
738
739         return true;
740 }
741
742 static struct ath_buf *ath_edma_get_next_rx_buf(struct ath_softc *sc,
743                                                 struct ath_rx_status *rs,
744                                                 enum ath9k_rx_qtype qtype)
745 {
746         struct ath_rx_edma *rx_edma = &sc->rx.rx_edma[qtype];
747         struct sk_buff *skb;
748         struct ath_buf *bf;
749
750         while (ath_edma_get_buffers(sc, qtype));
751         skb = __skb_dequeue(&rx_edma->rx_buffers);
752         if (!skb)
753                 return NULL;
754
755         bf = SKB_CB_ATHBUF(skb);
756         ath9k_hw_process_rxdesc_edma(sc->sc_ah, rs, skb->data);
757         return bf;
758 }
759
760 static struct ath_buf *ath_get_next_rx_buf(struct ath_softc *sc,
761                                            struct ath_rx_status *rs)
762 {
763         struct ath_hw *ah = sc->sc_ah;
764         struct ath_common *common = ath9k_hw_common(ah);
765         struct ath_desc *ds;
766         struct ath_buf *bf;
767         int ret;
768
769         if (list_empty(&sc->rx.rxbuf)) {
770                 sc->rx.rxlink = NULL;
771                 return NULL;
772         }
773
774         bf = list_first_entry(&sc->rx.rxbuf, struct ath_buf, list);
775         ds = bf->bf_desc;
776
777         /*
778          * Must provide the virtual address of the current
779          * descriptor, the physical address, and the virtual
780          * address of the next descriptor in the h/w chain.
781          * This allows the HAL to look ahead to see if the
782          * hardware is done with a descriptor by checking the
783          * done bit in the following descriptor and the address
784          * of the current descriptor the DMA engine is working
785          * on.  All this is necessary because of our use of
786          * a self-linked list to avoid rx overruns.
787          */
788         ret = ath9k_hw_rxprocdesc(ah, ds, rs, 0);
789         if (ret == -EINPROGRESS) {
790                 struct ath_rx_status trs;
791                 struct ath_buf *tbf;
792                 struct ath_desc *tds;
793
794                 memset(&trs, 0, sizeof(trs));
795                 if (list_is_last(&bf->list, &sc->rx.rxbuf)) {
796                         sc->rx.rxlink = NULL;
797                         return NULL;
798                 }
799
800                 tbf = list_entry(bf->list.next, struct ath_buf, list);
801
802                 /*
803                  * On some hardware the descriptor status words could
804                  * get corrupted, including the done bit. Because of
805                  * this, check if the next descriptor's done bit is
806                  * set or not.
807                  *
808                  * If the next descriptor's done bit is set, the current
809                  * descriptor has been corrupted. Force s/w to discard
810                  * this descriptor and continue...
811                  */
812
813                 tds = tbf->bf_desc;
814                 ret = ath9k_hw_rxprocdesc(ah, tds, &trs, 0);
815                 if (ret == -EINPROGRESS)
816                         return NULL;
817         }
818
819         if (!bf->bf_mpdu)
820                 return bf;
821
822         /*
823          * Synchronize the DMA transfer with CPU before
824          * 1. accessing the frame
825          * 2. requeueing the same buffer to h/w
826          */
827         dma_sync_single_for_cpu(sc->dev, bf->bf_buf_addr,
828                         common->rx_bufsize,
829                         DMA_FROM_DEVICE);
830
831         return bf;
832 }
833
834 /* Assumes you've already done the endian to CPU conversion */
835 static bool ath9k_rx_accept(struct ath_common *common,
836                             struct ieee80211_hdr *hdr,
837                             struct ieee80211_rx_status *rxs,
838                             struct ath_rx_status *rx_stats,
839                             bool *decrypt_error)
840 {
841         struct ath_hw *ah = common->ah;
842         __le16 fc;
843         u8 rx_status_len = ah->caps.rx_status_len;
844
845         fc = hdr->frame_control;
846
847         if (!rx_stats->rs_datalen)
848                 return false;
849         /*
850          * rs_status follows rs_datalen so if rs_datalen is too large
851          * we can take a hint that hardware corrupted it, so ignore
852          * those frames.
853          */
854         if (rx_stats->rs_datalen > (common->rx_bufsize - rx_status_len))
855                 return false;
856
857         /*
858          * rs_more indicates chained descriptors which can be used
859          * to link buffers together for a sort of scatter-gather
860          * operation.
861          * reject the frame, we don't support scatter-gather yet and
862          * the frame is probably corrupt anyway
863          */
864         if (rx_stats->rs_more)
865                 return false;
866
867         /*
868          * The rx_stats->rs_status will not be set until the end of the
869          * chained descriptors so it can be ignored if rs_more is set. The
870          * rs_more will be false at the last element of the chained
871          * descriptors.
872          */
873         if (rx_stats->rs_status != 0) {
874                 if (rx_stats->rs_status & ATH9K_RXERR_CRC)
875                         rxs->flag |= RX_FLAG_FAILED_FCS_CRC;
876                 if (rx_stats->rs_status & ATH9K_RXERR_PHY)
877                         return false;
878
879                 if (rx_stats->rs_status & ATH9K_RXERR_DECRYPT) {
880                         *decrypt_error = true;
881                 } else if (rx_stats->rs_status & ATH9K_RXERR_MIC) {
882                         /*
883                          * The MIC error bit is only valid if the frame
884                          * is not a control frame or fragment, and it was
885                          * decrypted using a valid TKIP key.
886                          */
887                         if (!ieee80211_is_ctl(fc) &&
888                             !ieee80211_has_morefrags(fc) &&
889                             !(le16_to_cpu(hdr->seq_ctrl) & IEEE80211_SCTL_FRAG) &&
890                             test_bit(rx_stats->rs_keyix, common->tkip_keymap))
891                                 rxs->flag |= RX_FLAG_MMIC_ERROR;
892                         else
893                                 rx_stats->rs_status &= ~ATH9K_RXERR_MIC;
894                 }
895                 /*
896                  * Reject error frames with the exception of
897                  * decryption and MIC failures. For monitor mode,
898                  * we also ignore the CRC error.
899                  */
900                 if (ah->is_monitoring) {
901                         if (rx_stats->rs_status &
902                             ~(ATH9K_RXERR_DECRYPT | ATH9K_RXERR_MIC |
903                               ATH9K_RXERR_CRC))
904                                 return false;
905                 } else {
906                         if (rx_stats->rs_status &
907                             ~(ATH9K_RXERR_DECRYPT | ATH9K_RXERR_MIC)) {
908                                 return false;
909                         }
910                 }
911         }
912         return true;
913 }
914
915 static int ath9k_process_rate(struct ath_common *common,
916                               struct ieee80211_hw *hw,
917                               struct ath_rx_status *rx_stats,
918                               struct ieee80211_rx_status *rxs)
919 {
920         struct ieee80211_supported_band *sband;
921         enum ieee80211_band band;
922         unsigned int i = 0;
923
924         band = hw->conf.channel->band;
925         sband = hw->wiphy->bands[band];
926
927         if (rx_stats->rs_rate & 0x80) {
928                 /* HT rate */
929                 rxs->flag |= RX_FLAG_HT;
930                 if (rx_stats->rs_flags & ATH9K_RX_2040)
931                         rxs->flag |= RX_FLAG_40MHZ;
932                 if (rx_stats->rs_flags & ATH9K_RX_GI)
933                         rxs->flag |= RX_FLAG_SHORT_GI;
934                 rxs->rate_idx = rx_stats->rs_rate & 0x7f;
935                 return 0;
936         }
937
938         for (i = 0; i < sband->n_bitrates; i++) {
939                 if (sband->bitrates[i].hw_value == rx_stats->rs_rate) {
940                         rxs->rate_idx = i;
941                         return 0;
942                 }
943                 if (sband->bitrates[i].hw_value_short == rx_stats->rs_rate) {
944                         rxs->flag |= RX_FLAG_SHORTPRE;
945                         rxs->rate_idx = i;
946                         return 0;
947                 }
948         }
949
950         /*
951          * No valid hardware bitrate found -- we should not get here
952          * because hardware has already validated this frame as OK.
953          */
954         ath_print(common, ATH_DBG_XMIT, "unsupported hw bitrate detected "
955                   "0x%02x using 1 Mbit\n", rx_stats->rs_rate);
956
957         return -EINVAL;
958 }
959
960 static void ath9k_process_rssi(struct ath_common *common,
961                                struct ieee80211_hw *hw,
962                                struct ieee80211_hdr *hdr,
963                                struct ath_rx_status *rx_stats)
964 {
965         struct ath_hw *ah = common->ah;
966         struct ieee80211_sta *sta;
967         struct ath_node *an;
968         int last_rssi = ATH_RSSI_DUMMY_MARKER;
969         __le16 fc;
970
971         fc = hdr->frame_control;
972
973         rcu_read_lock();
974         /*
975          * XXX: use ieee80211_find_sta! This requires quite a bit of work
976          * under the current ath9k virtual wiphy implementation as we have
977          * no way of tying a vif to wiphy. Typically vifs are attached to
978          * at least one sdata of a wiphy on mac80211 but with ath9k virtual
979          * wiphy you'd have to iterate over every wiphy and each sdata.
980          */
981         if (is_multicast_ether_addr(hdr->addr1))
982                 sta = ieee80211_find_sta_by_ifaddr(hw, hdr->addr2, NULL);
983         else
984                 sta = ieee80211_find_sta_by_ifaddr(hw, hdr->addr2, hdr->addr1);
985
986         if (sta) {
987                 an = (struct ath_node *) sta->drv_priv;
988                 if (rx_stats->rs_rssi != ATH9K_RSSI_BAD &&
989                    !rx_stats->rs_moreaggr)
990                         ATH_RSSI_LPF(an->last_rssi, rx_stats->rs_rssi);
991                 last_rssi = an->last_rssi;
992         }
993         rcu_read_unlock();
994
995         if (likely(last_rssi != ATH_RSSI_DUMMY_MARKER))
996                 rx_stats->rs_rssi = ATH_EP_RND(last_rssi,
997                                               ATH_RSSI_EP_MULTIPLIER);
998         if (rx_stats->rs_rssi < 0)
999                 rx_stats->rs_rssi = 0;
1000
1001         /* Update Beacon RSSI, this is used by ANI. */
1002         if (ieee80211_is_beacon(fc))
1003                 ah->stats.avgbrssi = rx_stats->rs_rssi;
1004 }
1005
1006 /*
1007  * For Decrypt or Demic errors, we only mark packet status here and always push
1008  * up the frame up to let mac80211 handle the actual error case, be it no
1009  * decryption key or real decryption error. This let us keep statistics there.
1010  */
1011 static int ath9k_rx_skb_preprocess(struct ath_common *common,
1012                                    struct ieee80211_hw *hw,
1013                                    struct ieee80211_hdr *hdr,
1014                                    struct ath_rx_status *rx_stats,
1015                                    struct ieee80211_rx_status *rx_status,
1016                                    bool *decrypt_error)
1017 {
1018         memset(rx_status, 0, sizeof(struct ieee80211_rx_status));
1019
1020         /*
1021          * everything but the rate is checked here, the rate check is done
1022          * separately to avoid doing two lookups for a rate for each frame.
1023          */
1024         if (!ath9k_rx_accept(common, hdr, rx_status, rx_stats, decrypt_error))
1025                 return -EINVAL;
1026
1027         ath9k_process_rssi(common, hw, hdr, rx_stats);
1028
1029         if (ath9k_process_rate(common, hw, rx_stats, rx_status))
1030                 return -EINVAL;
1031
1032         rx_status->band = hw->conf.channel->band;
1033         rx_status->freq = hw->conf.channel->center_freq;
1034         rx_status->signal = ATH_DEFAULT_NOISE_FLOOR + rx_stats->rs_rssi;
1035         rx_status->antenna = rx_stats->rs_antenna;
1036         rx_status->flag |= RX_FLAG_TSFT;
1037
1038         return 0;
1039 }
1040
1041 static void ath9k_rx_skb_postprocess(struct ath_common *common,
1042                                      struct sk_buff *skb,
1043                                      struct ath_rx_status *rx_stats,
1044                                      struct ieee80211_rx_status *rxs,
1045                                      bool decrypt_error)
1046 {
1047         struct ath_hw *ah = common->ah;
1048         struct ieee80211_hdr *hdr;
1049         int hdrlen, padpos, padsize;
1050         u8 keyix;
1051         __le16 fc;
1052
1053         /* see if any padding is done by the hw and remove it */
1054         hdr = (struct ieee80211_hdr *) skb->data;
1055         hdrlen = ieee80211_get_hdrlen_from_skb(skb);
1056         fc = hdr->frame_control;
1057         padpos = ath9k_cmn_padpos(hdr->frame_control);
1058
1059         /* The MAC header is padded to have 32-bit boundary if the
1060          * packet payload is non-zero. The general calculation for
1061          * padsize would take into account odd header lengths:
1062          * padsize = (4 - padpos % 4) % 4; However, since only
1063          * even-length headers are used, padding can only be 0 or 2
1064          * bytes and we can optimize this a bit. In addition, we must
1065          * not try to remove padding from short control frames that do
1066          * not have payload. */
1067         padsize = padpos & 3;
1068         if (padsize && skb->len>=padpos+padsize+FCS_LEN) {
1069                 memmove(skb->data + padsize, skb->data, padpos);
1070                 skb_pull(skb, padsize);
1071         }
1072
1073         keyix = rx_stats->rs_keyix;
1074
1075         if (!(keyix == ATH9K_RXKEYIX_INVALID) && !decrypt_error &&
1076             ieee80211_has_protected(fc)) {
1077                 rxs->flag |= RX_FLAG_DECRYPTED;
1078         } else if (ieee80211_has_protected(fc)
1079                    && !decrypt_error && skb->len >= hdrlen + 4) {
1080                 keyix = skb->data[hdrlen + 3] >> 6;
1081
1082                 if (test_bit(keyix, common->keymap))
1083                         rxs->flag |= RX_FLAG_DECRYPTED;
1084         }
1085         if (ah->sw_mgmt_crypto &&
1086             (rxs->flag & RX_FLAG_DECRYPTED) &&
1087             ieee80211_is_mgmt(fc))
1088                 /* Use software decrypt for management frames. */
1089                 rxs->flag &= ~RX_FLAG_DECRYPTED;
1090 }
1091
1092 static void ath_lnaconf_alt_good_scan(struct ath_ant_comb *antcomb,
1093                                       struct ath_hw_antcomb_conf ant_conf,
1094                                       int main_rssi_avg)
1095 {
1096         antcomb->quick_scan_cnt = 0;
1097
1098         if (ant_conf.main_lna_conf == ATH_ANT_DIV_COMB_LNA2)
1099                 antcomb->rssi_lna2 = main_rssi_avg;
1100         else if (ant_conf.main_lna_conf == ATH_ANT_DIV_COMB_LNA1)
1101                 antcomb->rssi_lna1 = main_rssi_avg;
1102
1103         switch ((ant_conf.main_lna_conf << 4) | ant_conf.alt_lna_conf) {
1104         case (0x10): /* LNA2 A-B */
1105                 antcomb->main_conf = ATH_ANT_DIV_COMB_LNA1_MINUS_LNA2;
1106                 antcomb->first_quick_scan_conf =
1107                         ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2;
1108                 antcomb->second_quick_scan_conf = ATH_ANT_DIV_COMB_LNA1;
1109                 break;
1110         case (0x20): /* LNA1 A-B */
1111                 antcomb->main_conf = ATH_ANT_DIV_COMB_LNA1_MINUS_LNA2;
1112                 antcomb->first_quick_scan_conf =
1113                         ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2;
1114                 antcomb->second_quick_scan_conf = ATH_ANT_DIV_COMB_LNA2;
1115                 break;
1116         case (0x21): /* LNA1 LNA2 */
1117                 antcomb->main_conf = ATH_ANT_DIV_COMB_LNA2;
1118                 antcomb->first_quick_scan_conf =
1119                         ATH_ANT_DIV_COMB_LNA1_MINUS_LNA2;
1120                 antcomb->second_quick_scan_conf =
1121                         ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2;
1122                 break;
1123         case (0x12): /* LNA2 LNA1 */
1124                 antcomb->main_conf = ATH_ANT_DIV_COMB_LNA1;
1125                 antcomb->first_quick_scan_conf =
1126                         ATH_ANT_DIV_COMB_LNA1_MINUS_LNA2;
1127                 antcomb->second_quick_scan_conf =
1128                         ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2;
1129                 break;
1130         case (0x13): /* LNA2 A+B */
1131                 antcomb->main_conf = ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2;
1132                 antcomb->first_quick_scan_conf =
1133                         ATH_ANT_DIV_COMB_LNA1_MINUS_LNA2;
1134                 antcomb->second_quick_scan_conf = ATH_ANT_DIV_COMB_LNA1;
1135                 break;
1136         case (0x23): /* LNA1 A+B */
1137                 antcomb->main_conf = ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2;
1138                 antcomb->first_quick_scan_conf =
1139                         ATH_ANT_DIV_COMB_LNA1_MINUS_LNA2;
1140                 antcomb->second_quick_scan_conf = ATH_ANT_DIV_COMB_LNA2;
1141                 break;
1142         default:
1143                 break;
1144         }
1145 }
1146
1147 static void ath_select_ant_div_from_quick_scan(struct ath_ant_comb *antcomb,
1148                                 struct ath_hw_antcomb_conf *div_ant_conf,
1149                                 int main_rssi_avg, int alt_rssi_avg,
1150                                 int alt_ratio)
1151 {
1152         /* alt_good */
1153         switch (antcomb->quick_scan_cnt) {
1154         case 0:
1155                 /* set alt to main, and alt to first conf */
1156                 div_ant_conf->main_lna_conf = antcomb->main_conf;
1157                 div_ant_conf->alt_lna_conf = antcomb->first_quick_scan_conf;
1158                 break;
1159         case 1:
1160                 /* set alt to main, and alt to first conf */
1161                 div_ant_conf->main_lna_conf = antcomb->main_conf;
1162                 div_ant_conf->alt_lna_conf = antcomb->second_quick_scan_conf;
1163                 antcomb->rssi_first = main_rssi_avg;
1164                 antcomb->rssi_second = alt_rssi_avg;
1165
1166                 if (antcomb->main_conf == ATH_ANT_DIV_COMB_LNA1) {
1167                         /* main is LNA1 */
1168                         if (ath_is_alt_ant_ratio_better(alt_ratio,
1169                                                 ATH_ANT_DIV_COMB_LNA1_DELTA_HI,
1170                                                 ATH_ANT_DIV_COMB_LNA1_DELTA_LOW,
1171                                                 main_rssi_avg, alt_rssi_avg,
1172                                                 antcomb->total_pkt_count))
1173                                 antcomb->first_ratio = true;
1174                         else
1175                                 antcomb->first_ratio = false;
1176                 } else if (antcomb->main_conf == ATH_ANT_DIV_COMB_LNA2) {
1177                         if (ath_is_alt_ant_ratio_better(alt_ratio,
1178                                                 ATH_ANT_DIV_COMB_LNA1_DELTA_MID,
1179                                                 ATH_ANT_DIV_COMB_LNA1_DELTA_LOW,
1180                                                 main_rssi_avg, alt_rssi_avg,
1181                                                 antcomb->total_pkt_count))
1182                                 antcomb->first_ratio = true;
1183                         else
1184                                 antcomb->first_ratio = false;
1185                 } else {
1186                         if ((((alt_ratio >= ATH_ANT_DIV_COMB_ALT_ANT_RATIO2) &&
1187                             (alt_rssi_avg > main_rssi_avg +
1188                             ATH_ANT_DIV_COMB_LNA1_DELTA_HI)) ||
1189                             (alt_rssi_avg > main_rssi_avg)) &&
1190                             (antcomb->total_pkt_count > 50))
1191                                 antcomb->first_ratio = true;
1192                         else
1193                                 antcomb->first_ratio = false;
1194                 }
1195                 break;
1196         case 2:
1197                 antcomb->alt_good = false;
1198                 antcomb->scan_not_start = false;
1199                 antcomb->scan = false;
1200                 antcomb->rssi_first = main_rssi_avg;
1201                 antcomb->rssi_third = alt_rssi_avg;
1202
1203                 if (antcomb->second_quick_scan_conf == ATH_ANT_DIV_COMB_LNA1)
1204                         antcomb->rssi_lna1 = alt_rssi_avg;
1205                 else if (antcomb->second_quick_scan_conf ==
1206                          ATH_ANT_DIV_COMB_LNA2)
1207                         antcomb->rssi_lna2 = alt_rssi_avg;
1208                 else if (antcomb->second_quick_scan_conf ==
1209                          ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2) {
1210                         if (antcomb->main_conf == ATH_ANT_DIV_COMB_LNA2)
1211                                 antcomb->rssi_lna2 = main_rssi_avg;
1212                         else if (antcomb->main_conf == ATH_ANT_DIV_COMB_LNA1)
1213                                 antcomb->rssi_lna1 = main_rssi_avg;
1214                 }
1215
1216                 if (antcomb->rssi_lna2 > antcomb->rssi_lna1 +
1217                     ATH_ANT_DIV_COMB_LNA1_LNA2_SWITCH_DELTA)
1218                         div_ant_conf->main_lna_conf = ATH_ANT_DIV_COMB_LNA2;
1219                 else
1220                         div_ant_conf->main_lna_conf = ATH_ANT_DIV_COMB_LNA1;
1221
1222                 if (antcomb->main_conf == ATH_ANT_DIV_COMB_LNA1) {
1223                         if (ath_is_alt_ant_ratio_better(alt_ratio,
1224                                                 ATH_ANT_DIV_COMB_LNA1_DELTA_HI,
1225                                                 ATH_ANT_DIV_COMB_LNA1_DELTA_LOW,
1226                                                 main_rssi_avg, alt_rssi_avg,
1227                                                 antcomb->total_pkt_count))
1228                                 antcomb->second_ratio = true;
1229                         else
1230                                 antcomb->second_ratio = false;
1231                 } else if (antcomb->main_conf == ATH_ANT_DIV_COMB_LNA2) {
1232                         if (ath_is_alt_ant_ratio_better(alt_ratio,
1233                                                 ATH_ANT_DIV_COMB_LNA1_DELTA_MID,
1234                                                 ATH_ANT_DIV_COMB_LNA1_DELTA_LOW,
1235                                                 main_rssi_avg, alt_rssi_avg,
1236                                                 antcomb->total_pkt_count))
1237                                 antcomb->second_ratio = true;
1238                         else
1239                                 antcomb->second_ratio = false;
1240                 } else {
1241                         if ((((alt_ratio >= ATH_ANT_DIV_COMB_ALT_ANT_RATIO2) &&
1242                             (alt_rssi_avg > main_rssi_avg +
1243                             ATH_ANT_DIV_COMB_LNA1_DELTA_HI)) ||
1244                             (alt_rssi_avg > main_rssi_avg)) &&
1245                             (antcomb->total_pkt_count > 50))
1246                                 antcomb->second_ratio = true;
1247                         else
1248                                 antcomb->second_ratio = false;
1249                 }
1250
1251                 /* set alt to the conf with maximun ratio */
1252                 if (antcomb->first_ratio && antcomb->second_ratio) {
1253                         if (antcomb->rssi_second > antcomb->rssi_third) {
1254                                 /* first alt*/
1255                                 if ((antcomb->first_quick_scan_conf ==
1256                                     ATH_ANT_DIV_COMB_LNA1) ||
1257                                     (antcomb->first_quick_scan_conf ==
1258                                     ATH_ANT_DIV_COMB_LNA2))
1259                                         /* Set alt LNA1 or LNA2*/
1260                                         if (div_ant_conf->main_lna_conf ==
1261                                             ATH_ANT_DIV_COMB_LNA2)
1262                                                 div_ant_conf->alt_lna_conf =
1263                                                         ATH_ANT_DIV_COMB_LNA1;
1264                                         else
1265                                                 div_ant_conf->alt_lna_conf =
1266                                                         ATH_ANT_DIV_COMB_LNA2;
1267                                 else
1268                                         /* Set alt to A+B or A-B */
1269                                         div_ant_conf->alt_lna_conf =
1270                                                 antcomb->first_quick_scan_conf;
1271                         } else if ((antcomb->second_quick_scan_conf ==
1272                                    ATH_ANT_DIV_COMB_LNA1) ||
1273                                    (antcomb->second_quick_scan_conf ==
1274                                    ATH_ANT_DIV_COMB_LNA2)) {
1275                                 /* Set alt LNA1 or LNA2 */
1276                                 if (div_ant_conf->main_lna_conf ==
1277                                     ATH_ANT_DIV_COMB_LNA2)
1278                                         div_ant_conf->alt_lna_conf =
1279                                                 ATH_ANT_DIV_COMB_LNA1;
1280                                 else
1281                                         div_ant_conf->alt_lna_conf =
1282                                                 ATH_ANT_DIV_COMB_LNA2;
1283                         } else {
1284                                 /* Set alt to A+B or A-B */
1285                                 div_ant_conf->alt_lna_conf =
1286                                         antcomb->second_quick_scan_conf;
1287                         }
1288                 } else if (antcomb->first_ratio) {
1289                         /* first alt */
1290                         if ((antcomb->first_quick_scan_conf ==
1291                             ATH_ANT_DIV_COMB_LNA1) ||
1292                             (antcomb->first_quick_scan_conf ==
1293                             ATH_ANT_DIV_COMB_LNA2))
1294                                         /* Set alt LNA1 or LNA2 */
1295                                 if (div_ant_conf->main_lna_conf ==
1296                                     ATH_ANT_DIV_COMB_LNA2)
1297                                         div_ant_conf->alt_lna_conf =
1298                                                         ATH_ANT_DIV_COMB_LNA1;
1299                                 else
1300                                         div_ant_conf->alt_lna_conf =
1301                                                         ATH_ANT_DIV_COMB_LNA2;
1302                         else
1303                                 /* Set alt to A+B or A-B */
1304                                 div_ant_conf->alt_lna_conf =
1305                                                 antcomb->first_quick_scan_conf;
1306                 } else if (antcomb->second_ratio) {
1307                                 /* second alt */
1308                         if ((antcomb->second_quick_scan_conf ==
1309                             ATH_ANT_DIV_COMB_LNA1) ||
1310                             (antcomb->second_quick_scan_conf ==
1311                             ATH_ANT_DIV_COMB_LNA2))
1312                                 /* Set alt LNA1 or LNA2 */
1313                                 if (div_ant_conf->main_lna_conf ==
1314                                     ATH_ANT_DIV_COMB_LNA2)
1315                                         div_ant_conf->alt_lna_conf =
1316                                                 ATH_ANT_DIV_COMB_LNA1;
1317                                 else
1318                                         div_ant_conf->alt_lna_conf =
1319                                                 ATH_ANT_DIV_COMB_LNA2;
1320                         else
1321                                 /* Set alt to A+B or A-B */
1322                                 div_ant_conf->alt_lna_conf =
1323                                                 antcomb->second_quick_scan_conf;
1324                 } else {
1325                         /* main is largest */
1326                         if ((antcomb->main_conf == ATH_ANT_DIV_COMB_LNA1) ||
1327                             (antcomb->main_conf == ATH_ANT_DIV_COMB_LNA2))
1328                                 /* Set alt LNA1 or LNA2 */
1329                                 if (div_ant_conf->main_lna_conf ==
1330                                     ATH_ANT_DIV_COMB_LNA2)
1331                                         div_ant_conf->alt_lna_conf =
1332                                                         ATH_ANT_DIV_COMB_LNA1;
1333                                 else
1334                                         div_ant_conf->alt_lna_conf =
1335                                                         ATH_ANT_DIV_COMB_LNA2;
1336                         else
1337                                 /* Set alt to A+B or A-B */
1338                                 div_ant_conf->alt_lna_conf = antcomb->main_conf;
1339                 }
1340                 break;
1341         default:
1342                 break;
1343         }
1344 }
1345
1346 static void ath_ant_div_conf_fast_divbias(struct ath_hw_antcomb_conf *ant_conf)
1347 {
1348         /* Adjust the fast_div_bias based on main and alt lna conf */
1349         switch ((ant_conf->main_lna_conf << 4) | ant_conf->alt_lna_conf) {
1350         case (0x01): /* A-B LNA2 */
1351                 ant_conf->fast_div_bias = 0x3b;
1352                 break;
1353         case (0x02): /* A-B LNA1 */
1354                 ant_conf->fast_div_bias = 0x3d;
1355                 break;
1356         case (0x03): /* A-B A+B */
1357                 ant_conf->fast_div_bias = 0x1;
1358                 break;
1359         case (0x10): /* LNA2 A-B */
1360                 ant_conf->fast_div_bias = 0x7;
1361                 break;
1362         case (0x12): /* LNA2 LNA1 */
1363                 ant_conf->fast_div_bias = 0x2;
1364                 break;
1365         case (0x13): /* LNA2 A+B */
1366                 ant_conf->fast_div_bias = 0x7;
1367                 break;
1368         case (0x20): /* LNA1 A-B */
1369                 ant_conf->fast_div_bias = 0x6;
1370                 break;
1371         case (0x21): /* LNA1 LNA2 */
1372                 ant_conf->fast_div_bias = 0x0;
1373                 break;
1374         case (0x23): /* LNA1 A+B */
1375                 ant_conf->fast_div_bias = 0x6;
1376                 break;
1377         case (0x30): /* A+B A-B */
1378                 ant_conf->fast_div_bias = 0x1;
1379                 break;
1380         case (0x31): /* A+B LNA2 */
1381                 ant_conf->fast_div_bias = 0x3b;
1382                 break;
1383         case (0x32): /* A+B LNA1 */
1384                 ant_conf->fast_div_bias = 0x3d;
1385                 break;
1386         default:
1387                 break;
1388         }
1389 }
1390
1391 /* Antenna diversity and combining */
1392 static void ath_ant_comb_scan(struct ath_softc *sc, struct ath_rx_status *rs)
1393 {
1394         struct ath_hw_antcomb_conf div_ant_conf;
1395         struct ath_ant_comb *antcomb = &sc->ant_comb;
1396         int alt_ratio = 0, alt_rssi_avg = 0, main_rssi_avg = 0, curr_alt_set;
1397         int curr_main_set, curr_bias;
1398         int main_rssi = rs->rs_rssi_ctl0;
1399         int alt_rssi = rs->rs_rssi_ctl1;
1400         int rx_ant_conf,  main_ant_conf;
1401         bool short_scan = false;
1402
1403         rx_ant_conf = (rs->rs_rssi_ctl2 >> ATH_ANT_RX_CURRENT_SHIFT) &
1404                        ATH_ANT_RX_MASK;
1405         main_ant_conf = (rs->rs_rssi_ctl2 >> ATH_ANT_RX_MAIN_SHIFT) &
1406                          ATH_ANT_RX_MASK;
1407
1408         /* Record packet only when alt_rssi is positive */
1409         if (alt_rssi > 0) {
1410                 antcomb->total_pkt_count++;
1411                 antcomb->main_total_rssi += main_rssi;
1412                 antcomb->alt_total_rssi  += alt_rssi;
1413                 if (main_ant_conf == rx_ant_conf)
1414                         antcomb->main_recv_cnt++;
1415                 else
1416                         antcomb->alt_recv_cnt++;
1417         }
1418
1419         /* Short scan check */
1420         if (antcomb->scan && antcomb->alt_good) {
1421                 if (time_after(jiffies, antcomb->scan_start_time +
1422                     msecs_to_jiffies(ATH_ANT_DIV_COMB_SHORT_SCAN_INTR)))
1423                         short_scan = true;
1424                 else
1425                         if (antcomb->total_pkt_count ==
1426                             ATH_ANT_DIV_COMB_SHORT_SCAN_PKTCOUNT) {
1427                                 alt_ratio = ((antcomb->alt_recv_cnt * 100) /
1428                                             antcomb->total_pkt_count);
1429                                 if (alt_ratio < ATH_ANT_DIV_COMB_ALT_ANT_RATIO)
1430                                         short_scan = true;
1431                         }
1432         }
1433
1434         if (((antcomb->total_pkt_count < ATH_ANT_DIV_COMB_MAX_PKTCOUNT) ||
1435             rs->rs_moreaggr) && !short_scan)
1436                 return;
1437
1438         if (antcomb->total_pkt_count) {
1439                 alt_ratio = ((antcomb->alt_recv_cnt * 100) /
1440                              antcomb->total_pkt_count);
1441                 main_rssi_avg = (antcomb->main_total_rssi /
1442                                  antcomb->total_pkt_count);
1443                 alt_rssi_avg = (antcomb->alt_total_rssi /
1444                                  antcomb->total_pkt_count);
1445         }
1446
1447
1448         ath9k_hw_antdiv_comb_conf_get(sc->sc_ah, &div_ant_conf);
1449         curr_alt_set = div_ant_conf.alt_lna_conf;
1450         curr_main_set = div_ant_conf.main_lna_conf;
1451         curr_bias = div_ant_conf.fast_div_bias;
1452
1453         antcomb->count++;
1454
1455         if (antcomb->count == ATH_ANT_DIV_COMB_MAX_COUNT) {
1456                 if (alt_ratio > ATH_ANT_DIV_COMB_ALT_ANT_RATIO) {
1457                         ath_lnaconf_alt_good_scan(antcomb, div_ant_conf,
1458                                                   main_rssi_avg);
1459                         antcomb->alt_good = true;
1460                 } else {
1461                         antcomb->alt_good = false;
1462                 }
1463
1464                 antcomb->count = 0;
1465                 antcomb->scan = true;
1466                 antcomb->scan_not_start = true;
1467         }
1468
1469         if (!antcomb->scan) {
1470                 if (alt_ratio > ATH_ANT_DIV_COMB_ALT_ANT_RATIO) {
1471                         if (curr_alt_set == ATH_ANT_DIV_COMB_LNA2) {
1472                                 /* Switch main and alt LNA */
1473                                 div_ant_conf.main_lna_conf =
1474                                                 ATH_ANT_DIV_COMB_LNA2;
1475                                 div_ant_conf.alt_lna_conf  =
1476                                                 ATH_ANT_DIV_COMB_LNA1;
1477                         } else if (curr_alt_set == ATH_ANT_DIV_COMB_LNA1) {
1478                                 div_ant_conf.main_lna_conf =
1479                                                 ATH_ANT_DIV_COMB_LNA1;
1480                                 div_ant_conf.alt_lna_conf  =
1481                                                 ATH_ANT_DIV_COMB_LNA2;
1482                         }
1483
1484                         goto div_comb_done;
1485                 } else if ((curr_alt_set != ATH_ANT_DIV_COMB_LNA1) &&
1486                            (curr_alt_set != ATH_ANT_DIV_COMB_LNA2)) {
1487                         /* Set alt to another LNA */
1488                         if (curr_main_set == ATH_ANT_DIV_COMB_LNA2)
1489                                 div_ant_conf.alt_lna_conf =
1490                                                 ATH_ANT_DIV_COMB_LNA1;
1491                         else if (curr_main_set == ATH_ANT_DIV_COMB_LNA1)
1492                                 div_ant_conf.alt_lna_conf =
1493                                                 ATH_ANT_DIV_COMB_LNA2;
1494
1495                         goto div_comb_done;
1496                 }
1497
1498                 if ((alt_rssi_avg < (main_rssi_avg +
1499                     ATH_ANT_DIV_COMB_LNA1_LNA2_DELTA)))
1500                         goto div_comb_done;
1501         }
1502
1503         if (!antcomb->scan_not_start) {
1504                 switch (curr_alt_set) {
1505                 case ATH_ANT_DIV_COMB_LNA2:
1506                         antcomb->rssi_lna2 = alt_rssi_avg;
1507                         antcomb->rssi_lna1 = main_rssi_avg;
1508                         antcomb->scan = true;
1509                         /* set to A+B */
1510                         div_ant_conf.main_lna_conf =
1511                                 ATH_ANT_DIV_COMB_LNA1;
1512                         div_ant_conf.alt_lna_conf  =
1513                                 ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2;
1514                         break;
1515                 case ATH_ANT_DIV_COMB_LNA1:
1516                         antcomb->rssi_lna1 = alt_rssi_avg;
1517                         antcomb->rssi_lna2 = main_rssi_avg;
1518                         antcomb->scan = true;
1519                         /* set to A+B */
1520                         div_ant_conf.main_lna_conf = ATH_ANT_DIV_COMB_LNA2;
1521                         div_ant_conf.alt_lna_conf  =
1522                                 ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2;
1523                         break;
1524                 case ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2:
1525                         antcomb->rssi_add = alt_rssi_avg;
1526                         antcomb->scan = true;
1527                         /* set to A-B */
1528                         div_ant_conf.alt_lna_conf =
1529                                 ATH_ANT_DIV_COMB_LNA1_MINUS_LNA2;
1530                         break;
1531                 case ATH_ANT_DIV_COMB_LNA1_MINUS_LNA2:
1532                         antcomb->rssi_sub = alt_rssi_avg;
1533                         antcomb->scan = false;
1534                         if (antcomb->rssi_lna2 >
1535                             (antcomb->rssi_lna1 +
1536                             ATH_ANT_DIV_COMB_LNA1_LNA2_SWITCH_DELTA)) {
1537                                 /* use LNA2 as main LNA */
1538                                 if ((antcomb->rssi_add > antcomb->rssi_lna1) &&
1539                                     (antcomb->rssi_add > antcomb->rssi_sub)) {
1540                                         /* set to A+B */
1541                                         div_ant_conf.main_lna_conf =
1542                                                 ATH_ANT_DIV_COMB_LNA2;
1543                                         div_ant_conf.alt_lna_conf  =
1544                                                 ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2;
1545                                 } else if (antcomb->rssi_sub >
1546                                            antcomb->rssi_lna1) {
1547                                         /* set to A-B */
1548                                         div_ant_conf.main_lna_conf =
1549                                                 ATH_ANT_DIV_COMB_LNA2;
1550                                         div_ant_conf.alt_lna_conf =
1551                                                 ATH_ANT_DIV_COMB_LNA1_MINUS_LNA2;
1552                                 } else {
1553                                         /* set to LNA1 */
1554                                         div_ant_conf.main_lna_conf =
1555                                                 ATH_ANT_DIV_COMB_LNA2;
1556                                         div_ant_conf.alt_lna_conf =
1557                                                 ATH_ANT_DIV_COMB_LNA1;
1558                                 }
1559                         } else {
1560                                 /* use LNA1 as main LNA */
1561                                 if ((antcomb->rssi_add > antcomb->rssi_lna2) &&
1562                                     (antcomb->rssi_add > antcomb->rssi_sub)) {
1563                                         /* set to A+B */
1564                                         div_ant_conf.main_lna_conf =
1565                                                 ATH_ANT_DIV_COMB_LNA1;
1566                                         div_ant_conf.alt_lna_conf  =
1567                                                 ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2;
1568                                 } else if (antcomb->rssi_sub >
1569                                            antcomb->rssi_lna1) {
1570                                         /* set to A-B */
1571                                         div_ant_conf.main_lna_conf =
1572                                                 ATH_ANT_DIV_COMB_LNA1;
1573                                         div_ant_conf.alt_lna_conf =
1574                                                 ATH_ANT_DIV_COMB_LNA1_MINUS_LNA2;
1575                                 } else {
1576                                         /* set to LNA2 */
1577                                         div_ant_conf.main_lna_conf =
1578                                                 ATH_ANT_DIV_COMB_LNA1;
1579                                         div_ant_conf.alt_lna_conf =
1580                                                 ATH_ANT_DIV_COMB_LNA2;
1581                                 }
1582                         }
1583                         break;
1584                 default:
1585                         break;
1586                 }
1587         } else {
1588                 if (!antcomb->alt_good) {
1589                         antcomb->scan_not_start = false;
1590                         /* Set alt to another LNA */
1591                         if (curr_main_set == ATH_ANT_DIV_COMB_LNA2) {
1592                                 div_ant_conf.main_lna_conf =
1593                                                 ATH_ANT_DIV_COMB_LNA2;
1594                                 div_ant_conf.alt_lna_conf =
1595                                                 ATH_ANT_DIV_COMB_LNA1;
1596                         } else if (curr_main_set == ATH_ANT_DIV_COMB_LNA1) {
1597                                 div_ant_conf.main_lna_conf =
1598                                                 ATH_ANT_DIV_COMB_LNA1;
1599                                 div_ant_conf.alt_lna_conf =
1600                                                 ATH_ANT_DIV_COMB_LNA2;
1601                         }
1602                         goto div_comb_done;
1603                 }
1604         }
1605
1606         ath_select_ant_div_from_quick_scan(antcomb, &div_ant_conf,
1607                                            main_rssi_avg, alt_rssi_avg,
1608                                            alt_ratio);
1609
1610         antcomb->quick_scan_cnt++;
1611
1612 div_comb_done:
1613         ath_ant_div_conf_fast_divbias(&div_ant_conf);
1614
1615         ath9k_hw_antdiv_comb_conf_set(sc->sc_ah, &div_ant_conf);
1616
1617         antcomb->scan_start_time = jiffies;
1618         antcomb->total_pkt_count = 0;
1619         antcomb->main_total_rssi = 0;
1620         antcomb->alt_total_rssi = 0;
1621         antcomb->main_recv_cnt = 0;
1622         antcomb->alt_recv_cnt = 0;
1623 }
1624
1625 int ath_rx_tasklet(struct ath_softc *sc, int flush, bool hp)
1626 {
1627         struct ath_buf *bf;
1628         struct sk_buff *skb = NULL, *requeue_skb;
1629         struct ieee80211_rx_status *rxs;
1630         struct ath_hw *ah = sc->sc_ah;
1631         struct ath_common *common = ath9k_hw_common(ah);
1632         /*
1633          * The hw can techncically differ from common->hw when using ath9k
1634          * virtual wiphy so to account for that we iterate over the active
1635          * wiphys and find the appropriate wiphy and therefore hw.
1636          */
1637         struct ieee80211_hw *hw = NULL;
1638         struct ieee80211_hdr *hdr;
1639         int retval;
1640         bool decrypt_error = false;
1641         struct ath_rx_status rs;
1642         enum ath9k_rx_qtype qtype;
1643         bool edma = !!(ah->caps.hw_caps & ATH9K_HW_CAP_EDMA);
1644         int dma_type;
1645         u8 rx_status_len = ah->caps.rx_status_len;
1646         u64 tsf = 0;
1647         u32 tsf_lower = 0;
1648         unsigned long flags;
1649
1650         if (edma)
1651                 dma_type = DMA_BIDIRECTIONAL;
1652         else
1653                 dma_type = DMA_FROM_DEVICE;
1654
1655         qtype = hp ? ATH9K_RX_QUEUE_HP : ATH9K_RX_QUEUE_LP;
1656         spin_lock_bh(&sc->rx.rxbuflock);
1657
1658         tsf = ath9k_hw_gettsf64(ah);
1659         tsf_lower = tsf & 0xffffffff;
1660
1661         do {
1662                 /* If handling rx interrupt and flush is in progress => exit */
1663                 if ((sc->sc_flags & SC_OP_RXFLUSH) && (flush == 0))
1664                         break;
1665
1666                 memset(&rs, 0, sizeof(rs));
1667                 if (edma)
1668                         bf = ath_edma_get_next_rx_buf(sc, &rs, qtype);
1669                 else
1670                         bf = ath_get_next_rx_buf(sc, &rs);
1671
1672                 if (!bf)
1673                         break;
1674
1675                 skb = bf->bf_mpdu;
1676                 if (!skb)
1677                         continue;
1678
1679                 hdr = (struct ieee80211_hdr *) (skb->data + rx_status_len);
1680                 rxs =  IEEE80211_SKB_RXCB(skb);
1681
1682                 hw = ath_get_virt_hw(sc, hdr);
1683
1684                 ath_debug_stat_rx(sc, &rs);
1685
1686                 /*
1687                  * If we're asked to flush receive queue, directly
1688                  * chain it back at the queue without processing it.
1689                  */
1690                 if (flush)
1691                         goto requeue;
1692
1693                 retval = ath9k_rx_skb_preprocess(common, hw, hdr, &rs,
1694                                                  rxs, &decrypt_error);
1695                 if (retval)
1696                         goto requeue;
1697
1698                 rxs->mactime = (tsf & ~0xffffffffULL) | rs.rs_tstamp;
1699                 if (rs.rs_tstamp > tsf_lower &&
1700                     unlikely(rs.rs_tstamp - tsf_lower > 0x10000000))
1701                         rxs->mactime -= 0x100000000ULL;
1702
1703                 if (rs.rs_tstamp < tsf_lower &&
1704                     unlikely(tsf_lower - rs.rs_tstamp > 0x10000000))
1705                         rxs->mactime += 0x100000000ULL;
1706
1707                 /* Ensure we always have an skb to requeue once we are done
1708                  * processing the current buffer's skb */
1709                 requeue_skb = ath_rxbuf_alloc(common, common->rx_bufsize, GFP_ATOMIC);
1710
1711                 /* If there is no memory we ignore the current RX'd frame,
1712                  * tell hardware it can give us a new frame using the old
1713                  * skb and put it at the tail of the sc->rx.rxbuf list for
1714                  * processing. */
1715                 if (!requeue_skb)
1716                         goto requeue;
1717
1718                 /* Unmap the frame */
1719                 dma_unmap_single(sc->dev, bf->bf_buf_addr,
1720                                  common->rx_bufsize,
1721                                  dma_type);
1722
1723                 skb_put(skb, rs.rs_datalen + ah->caps.rx_status_len);
1724                 if (ah->caps.rx_status_len)
1725                         skb_pull(skb, ah->caps.rx_status_len);
1726
1727                 ath9k_rx_skb_postprocess(common, skb, &rs,
1728                                          rxs, decrypt_error);
1729
1730                 /* We will now give hardware our shiny new allocated skb */
1731                 bf->bf_mpdu = requeue_skb;
1732                 bf->bf_buf_addr = dma_map_single(sc->dev, requeue_skb->data,
1733                                                  common->rx_bufsize,
1734                                                  dma_type);
1735                 if (unlikely(dma_mapping_error(sc->dev,
1736                           bf->bf_buf_addr))) {
1737                         dev_kfree_skb_any(requeue_skb);
1738                         bf->bf_mpdu = NULL;
1739                         bf->bf_buf_addr = 0;
1740                         ath_print(common, ATH_DBG_FATAL,
1741                                   "dma_mapping_error() on RX\n");
1742                         ath_rx_send_to_mac80211(hw, sc, skb, rxs);
1743                         break;
1744                 }
1745
1746                 /*
1747                  * change the default rx antenna if rx diversity chooses the
1748                  * other antenna 3 times in a row.
1749                  */
1750                 if (sc->rx.defant != rs.rs_antenna) {
1751                         if (++sc->rx.rxotherant >= 3)
1752                                 ath_setdefantenna(sc, rs.rs_antenna);
1753                 } else {
1754                         sc->rx.rxotherant = 0;
1755                 }
1756
1757                 spin_lock_irqsave(&sc->sc_pm_lock, flags);
1758                 if (unlikely(ath9k_check_auto_sleep(sc) ||
1759                              (sc->ps_flags & (PS_WAIT_FOR_BEACON |
1760                                               PS_WAIT_FOR_CAB |
1761                                               PS_WAIT_FOR_PSPOLL_DATA))))
1762                         ath_rx_ps(sc, skb);
1763                 spin_unlock_irqrestore(&sc->sc_pm_lock, flags);
1764
1765                 if (ah->caps.hw_caps & ATH9K_HW_CAP_ANT_DIV_COMB)
1766                         ath_ant_comb_scan(sc, &rs);
1767
1768                 ath_rx_send_to_mac80211(hw, sc, skb, rxs);
1769
1770 requeue:
1771                 if (edma) {
1772                         list_add_tail(&bf->list, &sc->rx.rxbuf);
1773                         ath_rx_edma_buf_link(sc, qtype);
1774                 } else {
1775                         list_move_tail(&bf->list, &sc->rx.rxbuf);
1776                         ath_rx_buf_link(sc, bf);
1777                 }
1778         } while (1);
1779
1780         spin_unlock_bh(&sc->rx.rxbuflock);
1781
1782         return 0;
1783 }