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 /*
  38  * Setup and link descriptors.
  39  *
  40  * 11N: we can no longer afford to self link the last descriptor.
  41  * MAC acknowledges BA status as long as it copies frames to host
  42  * buffer (or rx fifo). This can incorrectly acknowledge packets
  43  * to a sender if last desc is self-linked.
  44  */
  45 static void ath_rx_buf_link(struct ath_softc *sc, struct ath_buf *bf)
  46 {
  47         struct ath_hw *ah = sc->sc_ah;
  48         struct ath_common *common = ath9k_hw_common(ah);
  49         struct ath_desc *ds;
  50         struct sk_buff *skb;
  51
  52         ATH_RXBUF_RESET(bf);
  53
  54         ds = bf->bf_desc;
  55         ds->ds_link = 0; /* link to null */
  56         ds->ds_data = bf->bf_buf_addr;
  57
  58         /* virtual addr of the beginning of the buffer. */
  59         skb = bf->bf_mpdu;
  60         BUG_ON(skb == NULL);
  61         ds->ds_vdata = skb->data;
  62
  63         /*
  64          * setup rx descriptors. The rx_bufsize here tells the hardware
  65          * how much data it can DMA to us and that we are prepared
  66          * to process
  67          */
  68         ath9k_hw_setuprxdesc(ah, ds,
  69                              common->rx_bufsize,
  70                              0);
  71
  72         if (sc->rx.rxlink == NULL)
  73                 ath9k_hw_putrxbuf(ah, bf->bf_daddr);
  74         else
  75                 *sc->rx.rxlink = bf->bf_daddr;
  76
  77         sc->rx.rxlink = &ds->ds_link;
  78         ath9k_hw_rxena(ah);
  79 }
  80
  81 static void ath_setdefantenna(struct ath_softc *sc, u32 antenna)
  82 {
  83         /* XXX block beacon interrupts */
  84         ath9k_hw_setantenna(sc->sc_ah, antenna);
  85         sc->rx.defant = antenna;
  86         sc->rx.rxotherant = 0;
  87 }
  88
  89 static void ath_opmode_init(struct ath_softc *sc)
  90 {
  91         struct ath_hw *ah = sc->sc_ah;
  92         struct ath_common *common = ath9k_hw_common(ah);
  93
  94         u32 rfilt, mfilt[2];
  95
  96         /* configure rx filter */
  97         rfilt = ath_calcrxfilter(sc);
  98         ath9k_hw_setrxfilter(ah, rfilt);
  99
 100         /* configure bssid mask */
 101         ath_hw_setbssidmask(common);
 102
 103         /* configure operational mode */
 104         ath9k_hw_setopmode(ah);
 105
 106         /* calculate and install multicast filter */
 107         mfilt[0] = mfilt[1] = ~0;
 108         ath9k_hw_setmcastfilter(ah, mfilt[0], mfilt[1]);
 109 }
 110
 111 static bool ath_rx_edma_buf_link(struct ath_softc *sc,
 112                                  enum ath9k_rx_qtype qtype)
 113 {
 114         struct ath_hw *ah = sc->sc_ah;
 115         struct ath_rx_edma *rx_edma;
 116         struct sk_buff *skb;
 117         struct ath_buf *bf;
 118
 119         rx_edma = &sc->rx.rx_edma[qtype];
 120         if (skb_queue_len(&rx_edma->rx_fifo) >= rx_edma->rx_fifo_hwsize)
 121                 return false;
 122
 123         bf = list_first_entry(&sc->rx.rxbuf, struct ath_buf, list);
 124         list_del_init(&bf->list);
 125
 126         skb = bf->bf_mpdu;
 127
 128         ATH_RXBUF_RESET(bf);
 129         memset(skb->data, 0, ah->caps.rx_status_len);
 130         dma_sync_single_for_device(sc->dev, bf->bf_buf_addr,
 131                                 ah->caps.rx_status_len, DMA_TO_DEVICE);
 132
 133         SKB_CB_ATHBUF(skb) = bf;
 134         ath9k_hw_addrxbuf_edma(ah, bf->bf_buf_addr, qtype);
 135         skb_queue_tail(&rx_edma->rx_fifo, skb);
 136
 137         return true;
 138 }
 139
 140 static void ath_rx_addbuffer_edma(struct ath_softc *sc,
 141                                   enum ath9k_rx_qtype qtype, int size)
 142 {
 143         struct ath_common *common = ath9k_hw_common(sc->sc_ah);
 144         u32 nbuf = 0;
 145
 146         if (list_empty(&sc->rx.rxbuf)) {
 147                 ath_dbg(common, ATH_DBG_QUEUE, "No free rx buf available\n");
 148                 return;
 149         }
 150
 151         while (!list_empty(&sc->rx.rxbuf)) {
 152                 nbuf++;
 153
 154                 if (!ath_rx_edma_buf_link(sc, qtype))
 155                         break;
 156
 157                 if (nbuf >= size)
 158                         break;
 159         }
 160 }
 161
 162 static void ath_rx_remove_buffer(struct ath_softc *sc,
 163                                  enum ath9k_rx_qtype qtype)
 164 {
 165         struct ath_buf *bf;
 166         struct ath_rx_edma *rx_edma;
 167         struct sk_buff *skb;
 168
 169         rx_edma = &sc->rx.rx_edma[qtype];
 170
 171         while ((skb = skb_dequeue(&rx_edma->rx_fifo)) != NULL) {
 172                 bf = SKB_CB_ATHBUF(skb);
 173                 BUG_ON(!bf);
 174                 list_add_tail(&bf->list, &sc->rx.rxbuf);
 175         }
 176 }
 177
 178 static void ath_rx_edma_cleanup(struct ath_softc *sc)
 179 {
 180         struct ath_buf *bf;
 181
 182         ath_rx_remove_buffer(sc, ATH9K_RX_QUEUE_LP);
 183         ath_rx_remove_buffer(sc, ATH9K_RX_QUEUE_HP);
 184
 185         list_for_each_entry(bf, &sc->rx.rxbuf, list) {
 186                 if (bf->bf_mpdu)
 187                         dev_kfree_skb_any(bf->bf_mpdu);
 188         }
 189
 190         INIT_LIST_HEAD(&sc->rx.rxbuf);
 191
 192         kfree(sc->rx.rx_bufptr);
 193         sc->rx.rx_bufptr = NULL;
 194 }
 195
 196 static void ath_rx_edma_init_queue(struct ath_rx_edma *rx_edma, int size)
 197 {
 198         skb_queue_head_init(&rx_edma->rx_fifo);
 199         skb_queue_head_init(&rx_edma->rx_buffers);
 200         rx_edma->rx_fifo_hwsize = size;
 201 }
 202
 203 static int ath_rx_edma_init(struct ath_softc *sc, int nbufs)
 204 {
 205         struct ath_common *common = ath9k_hw_common(sc->sc_ah);
 206         struct ath_hw *ah = sc->sc_ah;
 207         struct sk_buff *skb;
 208         struct ath_buf *bf;
 209         int error = 0, i;
 210         u32 size;
 211
 212         ath9k_hw_set_rx_bufsize(ah, common->rx_bufsize -
 213                                     ah->caps.rx_status_len);
 214
 215         ath_rx_edma_init_queue(&sc->rx.rx_edma[ATH9K_RX_QUEUE_LP],
 216                                ah->caps.rx_lp_qdepth);
 217         ath_rx_edma_init_queue(&sc->rx.rx_edma[ATH9K_RX_QUEUE_HP],
 218                                ah->caps.rx_hp_qdepth);
 219
 220         size = sizeof(struct ath_buf) * nbufs;
 221         bf = kzalloc(size, GFP_KERNEL);
 222         if (!bf)
 223                 return -ENOMEM;
 224
 225         INIT_LIST_HEAD(&sc->rx.rxbuf);
 226         sc->rx.rx_bufptr = bf;
 227
 228         for (i = 0; i < nbufs; i++, bf++) {
 229                 skb = ath_rxbuf_alloc(common, common->rx_bufsize, GFP_KERNEL);
 230                 if (!skb) {
 231                         error = -ENOMEM;
 232                         goto rx_init_fail;
 233                 }
 234
 235                 memset(skb->data, 0, common->rx_bufsize);
 236                 bf->bf_mpdu = skb;
 237
 238                 bf->bf_buf_addr = dma_map_single(sc->dev, skb->data,
 239                                                  common->rx_bufsize,
 240                                                  DMA_BIDIRECTIONAL);
 241                 if (unlikely(dma_mapping_error(sc->dev,
 242                                                 bf->bf_buf_addr))) {
 243                                 dev_kfree_skb_any(skb);
 244                                 bf->bf_mpdu = NULL;
 245                                 bf->bf_buf_addr = 0;
 246                                 ath_err(common,
 247                                         "dma_mapping_error() on RX init\n");
 248                                 error = -ENOMEM;
 249                                 goto rx_init_fail;
 250                 }
 251
 252                 list_add_tail(&bf->list, &sc->rx.rxbuf);
 253         }
 254
 255         return 0;
 256
 257 rx_init_fail:
 258         ath_rx_edma_cleanup(sc);
 259         return error;
 260 }
 261
 262 static void ath_edma_start_recv(struct ath_softc *sc)
 263 {
 264         spin_lock_bh(&sc->rx.rxbuflock);
 265
 266         ath9k_hw_rxena(sc->sc_ah);
 267
 268         ath_rx_addbuffer_edma(sc, ATH9K_RX_QUEUE_HP,
 269                               sc->rx.rx_edma[ATH9K_RX_QUEUE_HP].rx_fifo_hwsize);
 270
 271         ath_rx_addbuffer_edma(sc, ATH9K_RX_QUEUE_LP,
 272                               sc->rx.rx_edma[ATH9K_RX_QUEUE_LP].rx_fifo_hwsize);
 273
 274         ath_opmode_init(sc);
 275
 276         ath9k_hw_startpcureceive(sc->sc_ah, (sc->sc_flags & SC_OP_OFFCHANNEL));
 277
 278         spin_unlock_bh(&sc->rx.rxbuflock);
 279 }
 280
 281 static void ath_edma_stop_recv(struct ath_softc *sc)
 282 {
 283         ath_rx_remove_buffer(sc, ATH9K_RX_QUEUE_HP);
 284         ath_rx_remove_buffer(sc, ATH9K_RX_QUEUE_LP);
 285 }
 286
 287 int ath_rx_init(struct ath_softc *sc, int nbufs)
 288 {
 289         struct ath_common *common = ath9k_hw_common(sc->sc_ah);
 290         struct sk_buff *skb;
 291         struct ath_buf *bf;
 292         int error = 0;
 293
 294         spin_lock_init(&sc->sc_pcu_lock);
 295         sc->sc_flags &= ~SC_OP_RXFLUSH;
 296         spin_lock_init(&sc->rx.rxbuflock);
 297
 298         common->rx_bufsize = IEEE80211_MAX_MPDU_LEN / 2 +
 299                              sc->sc_ah->caps.rx_status_len;
 300
 301         if (sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_EDMA) {
 302                 return ath_rx_edma_init(sc, nbufs);
 303         } else {
 304                 ath_dbg(common, ATH_DBG_CONFIG, "cachelsz %u rxbufsize %u\n",
 305                         common->cachelsz, common->rx_bufsize);
 306
 307                 /* Initialize rx descriptors */
 308
 309                 error = ath_descdma_setup(sc, &sc->rx.rxdma, &sc->rx.rxbuf,
 310                                 "rx", nbufs, 1, 0);
 311                 if (error != 0) {
 312                         ath_err(common,
 313                                 "failed to allocate rx descriptors: %d\n",
 314                                 error);
 315                         goto err;
 316                 }
 317
 318                 list_for_each_entry(bf, &sc->rx.rxbuf, list) {
 319                         skb = ath_rxbuf_alloc(common, common->rx_bufsize,
 320                                               GFP_KERNEL);
 321                         if (skb == NULL) {
 322                                 error = -ENOMEM;
 323                                 goto err;
 324                         }
 325
 326                         bf->bf_mpdu = skb;
 327                         bf->bf_buf_addr = dma_map_single(sc->dev, skb->data,
 328                                         common->rx_bufsize,
 329                                         DMA_FROM_DEVICE);
 330                         if (unlikely(dma_mapping_error(sc->dev,
 331                                                         bf->bf_buf_addr))) {
 332                                 dev_kfree_skb_any(skb);
 333                                 bf->bf_mpdu = NULL;
 334                                 bf->bf_buf_addr = 0;
 335                                 ath_err(common,
 336                                         "dma_mapping_error() on RX init\n");
 337                                 error = -ENOMEM;
 338                                 goto err;
 339                         }
 340                 }
 341                 sc->rx.rxlink = NULL;
 342         }
 343
 344 err:
 345         if (error)
 346                 ath_rx_cleanup(sc);
 347
 348         return error;
 349 }
 350
 351 void ath_rx_cleanup(struct ath_softc *sc)
 352 {
 353         struct ath_hw *ah = sc->sc_ah;
 354         struct ath_common *common = ath9k_hw_common(ah);
 355         struct sk_buff *skb;
 356         struct ath_buf *bf;
 357
 358         if (sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_EDMA) {
 359                 ath_rx_edma_cleanup(sc);
 360                 return;
 361         } else {
 362                 list_for_each_entry(bf, &sc->rx.rxbuf, list) {
 363                         skb = bf->bf_mpdu;
 364                         if (skb) {
 365                                 dma_unmap_single(sc->dev, bf->bf_buf_addr,
 366                                                 common->rx_bufsize,
 367                                                 DMA_FROM_DEVICE);
 368                                 dev_kfree_skb(skb);
 369                                 bf->bf_buf_addr = 0;
 370                                 bf->bf_mpdu = NULL;
 371                         }
 372                 }
 373
 374                 if (sc->rx.rxdma.dd_desc_len != 0)
 375                         ath_descdma_cleanup(sc, &sc->rx.rxdma, &sc->rx.rxbuf);
 376         }
 377 }
 378
 379 /*
 380  * Calculate the receive filter according to the
 381  * operating mode and state:
 382  *
 383  * o always accept unicast, broadcast, and multicast traffic
 384  * o maintain current state of phy error reception (the hal
 385  *   may enable phy error frames for noise immunity work)
 386  * o probe request frames are accepted only when operating in
 387  *   hostap, adhoc, or monitor modes
 388  * o enable promiscuous mode according to the interface state
 389  * o accept beacons:
 390  *   - when operating in adhoc mode so the 802.11 layer creates
 391  *     node table entries for peers,
 392  *   - when operating in station mode for collecting rssi data when
 393  *     the station is otherwise quiet, or
 394  *   - when operating as a repeater so we see repeater-sta beacons
 395  *   - when scanning
 396  */
 397
 398 u32 ath_calcrxfilter(struct ath_softc *sc)
 399 {
 400 #define RX_FILTER_PRESERVE (ATH9K_RX_FILTER_PHYERR | ATH9K_RX_FILTER_PHYRADAR)
 401
 402         u32 rfilt;
 403
 404         rfilt = (ath9k_hw_getrxfilter(sc->sc_ah) & RX_FILTER_PRESERVE)
 405                 | ATH9K_RX_FILTER_UCAST | ATH9K_RX_FILTER_BCAST
 406                 | ATH9K_RX_FILTER_MCAST;
 407
 408         if (sc->rx.rxfilter & FIF_PROBE_REQ)
 409                 rfilt |= ATH9K_RX_FILTER_PROBEREQ;
 410
 411         /*
 412          * Set promiscuous mode when FIF_PROMISC_IN_BSS is enabled for station
 413          * mode interface or when in monitor mode. AP mode does not need this
 414          * since it receives all in-BSS frames anyway.
 415          */
 416         if (sc->sc_ah->is_monitoring)
 417                 rfilt |= ATH9K_RX_FILTER_PROM;
 418
 419         if (sc->rx.rxfilter & FIF_CONTROL)
 420                 rfilt |= ATH9K_RX_FILTER_CONTROL;
 421
 422         if ((sc->sc_ah->opmode == NL80211_IFTYPE_STATION) &&
 423             (sc->nvifs <= 1) &&
 424             !(sc->rx.rxfilter & FIF_BCN_PRBRESP_PROMISC))
 425                 rfilt |= ATH9K_RX_FILTER_MYBEACON;
 426         else
 427                 rfilt |= ATH9K_RX_FILTER_BEACON;
 428
 429         if ((AR_SREV_9280_20_OR_LATER(sc->sc_ah) ||
 430             AR_SREV_9285_12_OR_LATER(sc->sc_ah)) &&
 431             (sc->sc_ah->opmode == NL80211_IFTYPE_AP) &&
 432             (sc->rx.rxfilter & FIF_PSPOLL))
 433                 rfilt |= ATH9K_RX_FILTER_PSPOLL;
 434
 435         if (conf_is_ht(&sc->hw->conf))
 436                 rfilt |= ATH9K_RX_FILTER_COMP_BAR;
 437
 438         if (sc->nvifs > 1 || (sc->rx.rxfilter & FIF_OTHER_BSS)) {
 439                 /* The following may also be needed for other older chips */
 440                 if (sc->sc_ah->hw_version.macVersion == AR_SREV_VERSION_9160)
 441                         rfilt |= ATH9K_RX_FILTER_PROM;
 442                 rfilt |= ATH9K_RX_FILTER_MCAST_BCAST_ALL;
 443         }
 444
 445         return rfilt;
 446
 447 #undef RX_FILTER_PRESERVE
 448 }
 449
 450 int ath_startrecv(struct ath_softc *sc)
 451 {
 452         struct ath_hw *ah = sc->sc_ah;
 453         struct ath_buf *bf, *tbf;
 454
 455         if (ah->caps.hw_caps & ATH9K_HW_CAP_EDMA) {
 456                 ath_edma_start_recv(sc);
 457                 return 0;
 458         }
 459
 460         spin_lock_bh(&sc->rx.rxbuflock);
 461         if (list_empty(&sc->rx.rxbuf))
 462                 goto start_recv;
 463
 464         sc->rx.rxlink = NULL;
 465         list_for_each_entry_safe(bf, tbf, &sc->rx.rxbuf, list) {
 466                 ath_rx_buf_link(sc, bf);
 467         }
 468
 469         /* We could have deleted elements so the list may be empty now */
 470         if (list_empty(&sc->rx.rxbuf))
 471                 goto start_recv;
 472
 473         bf = list_first_entry(&sc->rx.rxbuf, struct ath_buf, list);
 474         ath9k_hw_putrxbuf(ah, bf->bf_daddr);
 475         ath9k_hw_rxena(ah);
 476
 477 start_recv:
 478         ath_opmode_init(sc);
 479         ath9k_hw_startpcureceive(ah, (sc->sc_flags & SC_OP_OFFCHANNEL));
 480
 481         spin_unlock_bh(&sc->rx.rxbuflock);
 482
 483         return 0;
 484 }
 485
 486 bool ath_stoprecv(struct ath_softc *sc)
 487 {
 488         struct ath_hw *ah = sc->sc_ah;
 489         bool stopped, reset = false;
 490
 491         spin_lock_bh(&sc->rx.rxbuflock);
 492         ath9k_hw_abortpcurecv(ah);
 493         ath9k_hw_setrxfilter(ah, 0);
 494         stopped = ath9k_hw_stopdmarecv(ah, &reset);
 495
 496         if (sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_EDMA)
 497                 ath_edma_stop_recv(sc);
 498         else
 499                 sc->rx.rxlink = NULL;
 500         spin_unlock_bh(&sc->rx.rxbuflock);
 501
 502         if (!(ah->ah_flags & AH_UNPLUGGED) &&
 503             unlikely(!stopped)) {
 504                 ath_err(ath9k_hw_common(sc->sc_ah),
 505                         "Could not stop RX, we could be "
 506                         "confusing the DMA engine when we start RX up\n");
 507                 ATH_DBG_WARN_ON_ONCE(!stopped);
 508         }
 509         return stopped || reset;
 510 }
 511
 512 void ath_flushrecv(struct ath_softc *sc)
 513 {
 514         sc->sc_flags |= SC_OP_RXFLUSH;
 515         if (sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_EDMA)
 516                 ath_rx_tasklet(sc, 1, true);
 517         ath_rx_tasklet(sc, 1, false);
 518         sc->sc_flags &= ~SC_OP_RXFLUSH;
 519 }
 520
 521 static bool ath_beacon_dtim_pending_cab(struct sk_buff *skb)
 522 {
 523         /* Check whether the Beacon frame has DTIM indicating buffered bc/mc */
 524         struct ieee80211_mgmt *mgmt;
 525         u8 *pos, *end, id, elen;
 526         struct ieee80211_tim_ie *tim;
 527
 528         mgmt = (struct ieee80211_mgmt *)skb->data;
 529         pos = mgmt->u.beacon.variable;
 530         end = skb->data + skb->len;
 531
 532         while (pos + 2 < end) {
 533                 id = *pos++;
 534                 elen = *pos++;
 535                 if (pos + elen > end)
 536                         break;
 537
 538                 if (id == WLAN_EID_TIM) {
 539                         if (elen < sizeof(*tim))
 540                                 break;
 541                         tim = (struct ieee80211_tim_ie *) pos;
 542                         if (tim->dtim_count != 0)
 543                                 break;
 544                         return tim->bitmap_ctrl & 0x01;
 545                 }
 546
 547                 pos += elen;
 548         }
 549
 550         return false;
 551 }
 552
 553 static void ath_rx_ps_beacon(struct ath_softc *sc, struct sk_buff *skb)
 554 {
 555         struct ieee80211_mgmt *mgmt;
 556         struct ath_common *common = ath9k_hw_common(sc->sc_ah);
 557
 558         if (skb->len < 24 + 8 + 2 + 2)
 559                 return;
 560
 561         mgmt = (struct ieee80211_mgmt *)skb->data;
 562         if (memcmp(common->curbssid, mgmt->bssid, ETH_ALEN) != 0) {
 563                 /* TODO:  This doesn't work well if you have stations
 564                  * associated to two different APs because curbssid
 565                  * is just the last AP that any of the stations associated
 566                  * with.
 567                  */
 568                 return; /* not from our current AP */
 569         }
 570
 571         sc->ps_flags &= ~PS_WAIT_FOR_BEACON;
 572
 573         if (sc->ps_flags & PS_BEACON_SYNC) {
 574                 sc->ps_flags &= ~PS_BEACON_SYNC;
 575                 ath_dbg(common, ATH_DBG_PS,
 576                         "Reconfigure Beacon timers based on timestamp from the AP\n");
 577                 ath_beacon_config(sc, NULL);
 578         }
 579
 580         if (ath_beacon_dtim_pending_cab(skb)) {
 581                 /*
 582                  * Remain awake waiting for buffered broadcast/multicast
 583                  * frames. If the last broadcast/multicast frame is not
 584                  * received properly, the next beacon frame will work as
 585                  * a backup trigger for returning into NETWORK SLEEP state,
 586                  * so we are waiting for it as well.
 587                  */
 588                 ath_dbg(common, ATH_DBG_PS,
 589                         "Received DTIM beacon indicating buffered broadcast/multicast frame(s)\n");
 590                 sc->ps_flags |= PS_WAIT_FOR_CAB | PS_WAIT_FOR_BEACON;
 591                 return;
 592         }
 593
 594         if (sc->ps_flags & PS_WAIT_FOR_CAB) {
 595                 /*
 596                  * This can happen if a broadcast frame is dropped or the AP
 597                  * fails to send a frame indicating that all CAB frames have
 598                  * been delivered.
 599                  */
 600                 sc->ps_flags &= ~PS_WAIT_FOR_CAB;
 601                 ath_dbg(common, ATH_DBG_PS,
 602                         "PS wait for CAB frames timed out\n");
 603         }
 604 }
 605
 606 static void ath_rx_ps(struct ath_softc *sc, struct sk_buff *skb)
 607 {
 608         struct ieee80211_hdr *hdr;
 609         struct ath_common *common = ath9k_hw_common(sc->sc_ah);
 610
 611         hdr = (struct ieee80211_hdr *)skb->data;
 612
 613         /* Process Beacon and CAB receive in PS state */
 614         if (((sc->ps_flags & PS_WAIT_FOR_BEACON) || ath9k_check_auto_sleep(sc))
 615             && ieee80211_is_beacon(hdr->frame_control))
 616                 ath_rx_ps_beacon(sc, skb);
 617         else if ((sc->ps_flags & PS_WAIT_FOR_CAB) &&
 618                  (ieee80211_is_data(hdr->frame_control) ||
 619                   ieee80211_is_action(hdr->frame_control)) &&
 620                  is_multicast_ether_addr(hdr->addr1) &&
 621                  !ieee80211_has_moredata(hdr->frame_control)) {
 622                 /*
 623                  * No more broadcast/multicast frames to be received at this
 624                  * point.
 625                  */
 626                 sc->ps_flags &= ~(PS_WAIT_FOR_CAB | PS_WAIT_FOR_BEACON);
 627                 ath_dbg(common, ATH_DBG_PS,
 628                         "All PS CAB frames received, back to sleep\n");
 629         } else if ((sc->ps_flags & PS_WAIT_FOR_PSPOLL_DATA) &&
 630                    !is_multicast_ether_addr(hdr->addr1) &&
 631                    !ieee80211_has_morefrags(hdr->frame_control)) {
 632                 sc->ps_flags &= ~PS_WAIT_FOR_PSPOLL_DATA;
 633                 ath_dbg(common, ATH_DBG_PS,
 634                         "Going back to sleep after having received PS-Poll data (0x%lx)\n",
 635                         sc->ps_flags & (PS_WAIT_FOR_BEACON |
 636                                         PS_WAIT_FOR_CAB |
 637                                         PS_WAIT_FOR_PSPOLL_DATA |
 638                                         PS_WAIT_FOR_TX_ACK));
 639         }
 640 }
 641
 642 static bool ath_edma_get_buffers(struct ath_softc *sc,
 643                                  enum ath9k_rx_qtype qtype)
 644 {
 645         struct ath_rx_edma *rx_edma = &sc->rx.rx_edma[qtype];
 646         struct ath_hw *ah = sc->sc_ah;
 647         struct ath_common *common = ath9k_hw_common(ah);
 648         struct sk_buff *skb;
 649         struct ath_buf *bf;
 650         int ret;
 651
 652         skb = skb_peek(&rx_edma->rx_fifo);
 653         if (!skb)
 654                 return false;
 655
 656         bf = SKB_CB_ATHBUF(skb);
 657         BUG_ON(!bf);
 658
 659         dma_sync_single_for_cpu(sc->dev, bf->bf_buf_addr,
 660                                 common->rx_bufsize, DMA_FROM_DEVICE);
 661
 662         ret = ath9k_hw_process_rxdesc_edma(ah, NULL, skb->data);
 663         if (ret == -EINPROGRESS) {
 664                 /*let device gain the buffer again*/
 665                 dma_sync_single_for_device(sc->dev, bf->bf_buf_addr,
 666                                 common->rx_bufsize, DMA_FROM_DEVICE);
 667                 return false;
 668         }
 669
 670         __skb_unlink(skb, &rx_edma->rx_fifo);
 671         if (ret == -EINVAL) {
 672                 /* corrupt descriptor, skip this one and the following one */
 673                 list_add_tail(&bf->list, &sc->rx.rxbuf);
 674                 ath_rx_edma_buf_link(sc, qtype);
 675                 skb = skb_peek(&rx_edma->rx_fifo);
 676                 if (!skb)
 677                         return true;
 678
 679                 bf = SKB_CB_ATHBUF(skb);
 680                 BUG_ON(!bf);
 681
 682                 __skb_unlink(skb, &rx_edma->rx_fifo);
 683                 list_add_tail(&bf->list, &sc->rx.rxbuf);
 684                 ath_rx_edma_buf_link(sc, qtype);
 685                 return true;
 686         }
 687         skb_queue_tail(&rx_edma->rx_buffers, skb);
 688
 689         return true;
 690 }
 691
 692 static struct ath_buf *ath_edma_get_next_rx_buf(struct ath_softc *sc,
 693                                                 struct ath_rx_status *rs,
 694                                                 enum ath9k_rx_qtype qtype)
 695 {
 696         struct ath_rx_edma *rx_edma = &sc->rx.rx_edma[qtype];
 697         struct sk_buff *skb;
 698         struct ath_buf *bf;
 699
 700         while (ath_edma_get_buffers(sc, qtype));
 701         skb = __skb_dequeue(&rx_edma->rx_buffers);
 702         if (!skb)
 703                 return NULL;
 704
 705         bf = SKB_CB_ATHBUF(skb);
 706         ath9k_hw_process_rxdesc_edma(sc->sc_ah, rs, skb->data);
 707         return bf;
 708 }
 709
 710 static struct ath_buf *ath_get_next_rx_buf(struct ath_softc *sc,
 711                                            struct ath_rx_status *rs)
 712 {
 713         struct ath_hw *ah = sc->sc_ah;
 714         struct ath_common *common = ath9k_hw_common(ah);
 715         struct ath_desc *ds;
 716         struct ath_buf *bf;
 717         int ret;
 718
 719         if (list_empty(&sc->rx.rxbuf)) {
 720                 sc->rx.rxlink = NULL;
 721                 return NULL;
 722         }
 723
 724         bf = list_first_entry(&sc->rx.rxbuf, struct ath_buf, list);
 725         ds = bf->bf_desc;
 726
 727         /*
 728          * Must provide the virtual address of the current
 729          * descriptor, the physical address, and the virtual
 730          * address of the next descriptor in the h/w chain.
 731          * This allows the HAL to look ahead to see if the
 732          * hardware is done with a descriptor by checking the
 733          * done bit in the following descriptor and the address
 734          * of the current descriptor the DMA engine is working
 735          * on.  All this is necessary because of our use of
 736          * a self-linked list to avoid rx overruns.
 737          */
 738         ret = ath9k_hw_rxprocdesc(ah, ds, rs, 0);
 739         if (ret == -EINPROGRESS) {
 740                 struct ath_rx_status trs;
 741                 struct ath_buf *tbf;
 742                 struct ath_desc *tds;
 743
 744                 memset(&trs, 0, sizeof(trs));
 745                 if (list_is_last(&bf->list, &sc->rx.rxbuf)) {
 746                         sc->rx.rxlink = NULL;
 747                         return NULL;
 748                 }
 749
 750                 tbf = list_entry(bf->list.next, struct ath_buf, list);
 751
 752                 /*
 753                  * On some hardware the descriptor status words could
 754                  * get corrupted, including the done bit. Because of
 755                  * this, check if the next descriptor's done bit is
 756                  * set or not.
 757                  *
 758                  * If the next descriptor's done bit is set, the current
 759                  * descriptor has been corrupted. Force s/w to discard
 760                  * this descriptor and continue...
 761                  */
 762
 763                 tds = tbf->bf_desc;
 764                 ret = ath9k_hw_rxprocdesc(ah, tds, &trs, 0);
 765                 if (ret == -EINPROGRESS)
 766                         return NULL;
 767         }
 768
 769         if (!bf->bf_mpdu)
 770                 return bf;
 771
 772         /*
 773          * Synchronize the DMA transfer with CPU before
 774          * 1. accessing the frame
 775          * 2. requeueing the same buffer to h/w
 776          */
 777         dma_sync_single_for_cpu(sc->dev, bf->bf_buf_addr,
 778                         common->rx_bufsize,
 779                         DMA_FROM_DEVICE);
 780
 781         return bf;
 782 }
 783
 784 /* Assumes you've already done the endian to CPU conversion */
 785 static bool ath9k_rx_accept(struct ath_common *common,
 786                             struct ieee80211_hdr *hdr,
 787                             struct ieee80211_rx_status *rxs,
 788                             struct ath_rx_status *rx_stats,
 789                             bool *decrypt_error)
 790 {
 791 #define is_mc_or_valid_tkip_keyix ((is_mc ||                    \
 792                 (rx_stats->rs_keyix != ATH9K_RXKEYIX_INVALID && \
 793                 test_bit(rx_stats->rs_keyix, common->tkip_keymap))))
 794
 795         struct ath_hw *ah = common->ah;
 796         __le16 fc;
 797         u8 rx_status_len = ah->caps.rx_status_len;
 798
 799         fc = hdr->frame_control;
 800
 801         if (!rx_stats->rs_datalen)
 802                 return false;
 803         /*
 804          * rs_status follows rs_datalen so if rs_datalen is too large
 805          * we can take a hint that hardware corrupted it, so ignore
 806          * those frames.
 807          */
 808         if (rx_stats->rs_datalen > (common->rx_bufsize - rx_status_len))
 809                 return false;
 810
 811         /* Only use error bits from the last fragment */
 812         if (rx_stats->rs_more)
 813                 return true;
 814
 815         /*
 816          * The rx_stats->rs_status will not be set until the end of the
 817          * chained descriptors so it can be ignored if rs_more is set. The
 818          * rs_more will be false at the last element of the chained
 819          * descriptors.
 820          */
 821         if (rx_stats->rs_status != 0) {
 822                 if (rx_stats->rs_status & ATH9K_RXERR_CRC)
 823                         rxs->flag |= RX_FLAG_FAILED_FCS_CRC;
 824                 if (rx_stats->rs_status & ATH9K_RXERR_PHY)
 825                         return false;
 826
 827                 if (rx_stats->rs_status & ATH9K_RXERR_DECRYPT) {
 828                         *decrypt_error = true;
 829                 } else if (rx_stats->rs_status & ATH9K_RXERR_MIC) {
 830                         bool is_mc;
 831                         /*
 832                          * The MIC error bit is only valid if the frame
 833                          * is not a control frame or fragment, and it was
 834                          * decrypted using a valid TKIP key.
 835                          */
 836                         is_mc = !!is_multicast_ether_addr(hdr->addr1);
 837
 838                         if (!ieee80211_is_ctl(fc) &&
 839                             !ieee80211_has_morefrags(fc) &&
 840                             !(le16_to_cpu(hdr->seq_ctrl) & IEEE80211_SCTL_FRAG) &&
 841                             is_mc_or_valid_tkip_keyix)
 842                                 rxs->flag |= RX_FLAG_MMIC_ERROR;
 843                         else
 844                                 rx_stats->rs_status &= ~ATH9K_RXERR_MIC;
 845                 }
 846                 /*
 847                  * Reject error frames with the exception of
 848                  * decryption and MIC failures. For monitor mode,
 849                  * we also ignore the CRC error.
 850                  */
 851                 if (ah->is_monitoring) {
 852                         if (rx_stats->rs_status &
 853                             ~(ATH9K_RXERR_DECRYPT | ATH9K_RXERR_MIC |
 854                               ATH9K_RXERR_CRC))
 855                                 return false;
 856                 } else {
 857                         if (rx_stats->rs_status &
 858                             ~(ATH9K_RXERR_DECRYPT | ATH9K_RXERR_MIC)) {
 859                                 return false;
 860                         }
 861                 }
 862         }
 863         return true;
 864 }
 865
 866 static int ath9k_process_rate(struct ath_common *common,
 867                               struct ieee80211_hw *hw,
 868                               struct ath_rx_status *rx_stats,
 869                               struct ieee80211_rx_status *rxs)
 870 {
 871         struct ieee80211_supported_band *sband;
 872         enum ieee80211_band band;
 873         unsigned int i = 0;
 874
 875         band = hw->conf.channel->band;
 876         sband = hw->wiphy->bands[band];
 877
 878         if (rx_stats->rs_rate & 0x80) {
 879                 /* HT rate */
 880                 rxs->flag |= RX_FLAG_HT;
 881                 if (rx_stats->rs_flags & ATH9K_RX_2040)
 882                         rxs->flag |= RX_FLAG_40MHZ;
 883                 if (rx_stats->rs_flags & ATH9K_RX_GI)
 884                         rxs->flag |= RX_FLAG_SHORT_GI;
 885                 rxs->rate_idx = rx_stats->rs_rate & 0x7f;
 886                 return 0;
 887         }
 888
 889         for (i = 0; i < sband->n_bitrates; i++) {
 890                 if (sband->bitrates[i].hw_value == rx_stats->rs_rate) {
 891                         rxs->rate_idx = i;
 892                         return 0;
 893                 }
 894                 if (sband->bitrates[i].hw_value_short == rx_stats->rs_rate) {
 895                         rxs->flag |= RX_FLAG_SHORTPRE;
 896                         rxs->rate_idx = i;
 897                         return 0;
 898                 }
 899         }
 900
 901         /*
 902          * No valid hardware bitrate found -- we should not get here
 903          * because hardware has already validated this frame as OK.
 904          */
 905         ath_dbg(common, ATH_DBG_XMIT,
 906                 "unsupported hw bitrate detected 0x%02x using 1 Mbit\n",
 907                 rx_stats->rs_rate);
 908
 909         return -EINVAL;
 910 }
 911
 912 static void ath9k_process_rssi(struct ath_common *common,
 913                                struct ieee80211_hw *hw,
 914                                struct ieee80211_hdr *hdr,
 915                                struct ath_rx_status *rx_stats)
 916 {
 917         struct ath_softc *sc = hw->priv;
 918         struct ath_hw *ah = common->ah;
 919         int last_rssi;
 920         __le16 fc;
 921
 922         if (ah->opmode != NL80211_IFTYPE_STATION)
 923                 return;
 924
 925         fc = hdr->frame_control;
 926         if (!ieee80211_is_beacon(fc) ||
 927             compare_ether_addr(hdr->addr3, common->curbssid)) {
 928                 /* TODO:  This doesn't work well if you have stations
 929                  * associated to two different APs because curbssid
 930                  * is just the last AP that any of the stations associated
 931                  * with.
 932                  */
 933                 return;
 934         }
 935
 936         if (rx_stats->rs_rssi != ATH9K_RSSI_BAD && !rx_stats->rs_moreaggr)
 937                 ATH_RSSI_LPF(sc->last_rssi, rx_stats->rs_rssi);
 938
 939         last_rssi = sc->last_rssi;
 940         if (likely(last_rssi != ATH_RSSI_DUMMY_MARKER))
 941                 rx_stats->rs_rssi = ATH_EP_RND(last_rssi,
 942                                               ATH_RSSI_EP_MULTIPLIER);
 943         if (rx_stats->rs_rssi < 0)
 944                 rx_stats->rs_rssi = 0;
 945
 946         /* Update Beacon RSSI, this is used by ANI. */
 947         ah->stats.avgbrssi = rx_stats->rs_rssi;
 948 }
 949
 950 /*
 951  * For Decrypt or Demic errors, we only mark packet status here and always push
 952  * up the frame up to let mac80211 handle the actual error case, be it no
 953  * decryption key or real decryption error. This let us keep statistics there.
 954  */
 955 static int ath9k_rx_skb_preprocess(struct ath_common *common,
 956                                    struct ieee80211_hw *hw,
 957                                    struct ieee80211_hdr *hdr,
 958                                    struct ath_rx_status *rx_stats,
 959                                    struct ieee80211_rx_status *rx_status,
 960                                    bool *decrypt_error)
 961 {
 962         memset(rx_status, 0, sizeof(struct ieee80211_rx_status));
 963
 964         /*
 965          * everything but the rate is checked here, the rate check is done
 966          * separately to avoid doing two lookups for a rate for each frame.
 967          */
 968         if (!ath9k_rx_accept(common, hdr, rx_status, rx_stats, decrypt_error))
 969                 return -EINVAL;
 970
 971         /* Only use status info from the last fragment */
 972         if (rx_stats->rs_more)
 973                 return 0;
 974
 975         ath9k_process_rssi(common, hw, hdr, rx_stats);
 976
 977         if (ath9k_process_rate(common, hw, rx_stats, rx_status))
 978                 return -EINVAL;
 979
 980         rx_status->band = hw->conf.channel->band;
 981         rx_status->freq = hw->conf.channel->center_freq;
 982         rx_status->signal = ATH_DEFAULT_NOISE_FLOOR + rx_stats->rs_rssi;
 983         rx_status->antenna = rx_stats->rs_antenna;
 984         rx_status->flag |= RX_FLAG_MACTIME_MPDU;
 985
 986         return 0;
 987 }
 988
 989 static void ath9k_rx_skb_postprocess(struct ath_common *common,
 990                                      struct sk_buff *skb,
 991                                      struct ath_rx_status *rx_stats,
 992                                      struct ieee80211_rx_status *rxs,
 993                                      bool decrypt_error)
 994 {
 995         struct ath_hw *ah = common->ah;
 996         struct ieee80211_hdr *hdr;
 997         int hdrlen, padpos, padsize;
 998         u8 keyix;
 999         __le16 fc;
1000
1001         /* see if any padding is done by the hw and remove it */
1002         hdr = (struct ieee80211_hdr *) skb->data;
1003         hdrlen = ieee80211_get_hdrlen_from_skb(skb);
1004         fc = hdr->frame_control;
1005         padpos = ath9k_cmn_padpos(hdr->frame_control);
1006
1007         /* The MAC header is padded to have 32-bit boundary if the
1008          * packet payload is non-zero. The general calculation for
1009          * padsize would take into account odd header lengths:
1010          * padsize = (4 - padpos % 4) % 4; However, since only
1011          * even-length headers are used, padding can only be 0 or 2
1012          * bytes and we can optimize this a bit. In addition, we must
1013          * not try to remove padding from short control frames that do
1014          * not have payload. */
1015         padsize = padpos & 3;
1016         if (padsize && skb->len>=padpos+padsize+FCS_LEN) {
1017                 memmove(skb->data + padsize, skb->data, padpos);
1018                 skb_pull(skb, padsize);
1019         }
1020
1021         keyix = rx_stats->rs_keyix;
1022
1023         if (!(keyix == ATH9K_RXKEYIX_INVALID) && !decrypt_error &&
1024             ieee80211_has_protected(fc)) {
1025                 rxs->flag |= RX_FLAG_DECRYPTED;
1026         } else if (ieee80211_has_protected(fc)
1027                    && !decrypt_error && skb->len >= hdrlen + 4) {
1028                 keyix = skb->data[hdrlen + 3] >> 6;
1029
1030                 if (test_bit(keyix, common->keymap))
1031                         rxs->flag |= RX_FLAG_DECRYPTED;
1032         }
1033         if (ah->sw_mgmt_crypto &&
1034             (rxs->flag & RX_FLAG_DECRYPTED) &&
1035             ieee80211_is_mgmt(fc))
1036                 /* Use software decrypt for management frames. */
1037                 rxs->flag &= ~RX_FLAG_DECRYPTED;
1038 }
1039
1040 static void ath_lnaconf_alt_good_scan(struct ath_ant_comb *antcomb,
1041                                       struct ath_hw_antcomb_conf ant_conf,
1042                                       int main_rssi_avg)
1043 {
1044         antcomb->quick_scan_cnt = 0;
1045
1046         if (ant_conf.main_lna_conf == ATH_ANT_DIV_COMB_LNA2)
1047                 antcomb->rssi_lna2 = main_rssi_avg;
1048         else if (ant_conf.main_lna_conf == ATH_ANT_DIV_COMB_LNA1)
1049                 antcomb->rssi_lna1 = main_rssi_avg;
1050
1051         switch ((ant_conf.main_lna_conf << 4) | ant_conf.alt_lna_conf) {
1052         case (0x10): /* LNA2 A-B */
1053                 antcomb->main_conf = ATH_ANT_DIV_COMB_LNA1_MINUS_LNA2;
1054                 antcomb->first_quick_scan_conf =
1055                         ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2;
1056                 antcomb->second_quick_scan_conf = ATH_ANT_DIV_COMB_LNA1;
1057                 break;
1058         case (0x20): /* LNA1 A-B */
1059                 antcomb->main_conf = ATH_ANT_DIV_COMB_LNA1_MINUS_LNA2;
1060                 antcomb->first_quick_scan_conf =
1061                         ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2;
1062                 antcomb->second_quick_scan_conf = ATH_ANT_DIV_COMB_LNA2;
1063                 break;
1064         case (0x21): /* LNA1 LNA2 */
1065                 antcomb->main_conf = ATH_ANT_DIV_COMB_LNA2;
1066                 antcomb->first_quick_scan_conf =
1067                         ATH_ANT_DIV_COMB_LNA1_MINUS_LNA2;
1068                 antcomb->second_quick_scan_conf =
1069                         ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2;
1070                 break;
1071         case (0x12): /* LNA2 LNA1 */
1072                 antcomb->main_conf = ATH_ANT_DIV_COMB_LNA1;
1073                 antcomb->first_quick_scan_conf =
1074                         ATH_ANT_DIV_COMB_LNA1_MINUS_LNA2;
1075                 antcomb->second_quick_scan_conf =
1076                         ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2;
1077                 break;
1078         case (0x13): /* LNA2 A+B */
1079                 antcomb->main_conf = ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2;
1080                 antcomb->first_quick_scan_conf =
1081                         ATH_ANT_DIV_COMB_LNA1_MINUS_LNA2;
1082                 antcomb->second_quick_scan_conf = ATH_ANT_DIV_COMB_LNA1;
1083                 break;
1084         case (0x23): /* LNA1 A+B */
1085                 antcomb->main_conf = ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2;
1086                 antcomb->first_quick_scan_conf =
1087                         ATH_ANT_DIV_COMB_LNA1_MINUS_LNA2;
1088                 antcomb->second_quick_scan_conf = ATH_ANT_DIV_COMB_LNA2;
1089                 break;
1090         default:
1091                 break;
1092         }
1093 }
1094
1095 static void ath_select_ant_div_from_quick_scan(struct ath_ant_comb *antcomb,
1096                                 struct ath_hw_antcomb_conf *div_ant_conf,
1097                                 int main_rssi_avg, int alt_rssi_avg,
1098                                 int alt_ratio)
1099 {
1100         /* alt_good */
1101         switch (antcomb->quick_scan_cnt) {
1102         case 0:
1103                 /* set alt to main, and alt to first conf */
1104                 div_ant_conf->main_lna_conf = antcomb->main_conf;
1105                 div_ant_conf->alt_lna_conf = antcomb->first_quick_scan_conf;
1106                 break;
1107         case 1:
1108                 /* set alt to main, and alt to first conf */
1109                 div_ant_conf->main_lna_conf = antcomb->main_conf;
1110                 div_ant_conf->alt_lna_conf = antcomb->second_quick_scan_conf;
1111                 antcomb->rssi_first = main_rssi_avg;
1112                 antcomb->rssi_second = alt_rssi_avg;
1113
1114                 if (antcomb->main_conf == ATH_ANT_DIV_COMB_LNA1) {
1115                         /* main is LNA1 */
1116                         if (ath_is_alt_ant_ratio_better(alt_ratio,
1117                                                 ATH_ANT_DIV_COMB_LNA1_DELTA_HI,
1118                                                 ATH_ANT_DIV_COMB_LNA1_DELTA_LOW,
1119                                                 main_rssi_avg, alt_rssi_avg,
1120                                                 antcomb->total_pkt_count))
1121                                 antcomb->first_ratio = true;
1122                         else
1123                                 antcomb->first_ratio = false;
1124                 } else if (antcomb->main_conf == ATH_ANT_DIV_COMB_LNA2) {
1125                         if (ath_is_alt_ant_ratio_better(alt_ratio,
1126                                                 ATH_ANT_DIV_COMB_LNA1_DELTA_MID,
1127                                                 ATH_ANT_DIV_COMB_LNA1_DELTA_LOW,
1128                                                 main_rssi_avg, alt_rssi_avg,
1129                                                 antcomb->total_pkt_count))
1130                                 antcomb->first_ratio = true;
1131                         else
1132                                 antcomb->first_ratio = false;
1133                 } else {
1134                         if ((((alt_ratio >= ATH_ANT_DIV_COMB_ALT_ANT_RATIO2) &&
1135                             (alt_rssi_avg > main_rssi_avg +
1136                             ATH_ANT_DIV_COMB_LNA1_DELTA_HI)) ||
1137                             (alt_rssi_avg > main_rssi_avg)) &&
1138                             (antcomb->total_pkt_count > 50))
1139                                 antcomb->first_ratio = true;
1140                         else
1141                                 antcomb->first_ratio = false;
1142                 }
1143                 break;
1144         case 2:
1145                 antcomb->alt_good = false;
1146                 antcomb->scan_not_start = false;
1147                 antcomb->scan = false;
1148                 antcomb->rssi_first = main_rssi_avg;
1149                 antcomb->rssi_third = alt_rssi_avg;
1150
1151                 if (antcomb->second_quick_scan_conf == ATH_ANT_DIV_COMB_LNA1)
1152                         antcomb->rssi_lna1 = alt_rssi_avg;
1153                 else if (antcomb->second_quick_scan_conf ==
1154                          ATH_ANT_DIV_COMB_LNA2)
1155                         antcomb->rssi_lna2 = alt_rssi_avg;
1156                 else if (antcomb->second_quick_scan_conf ==
1157                          ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2) {
1158                         if (antcomb->main_conf == ATH_ANT_DIV_COMB_LNA2)
1159                                 antcomb->rssi_lna2 = main_rssi_avg;
1160                         else if (antcomb->main_conf == ATH_ANT_DIV_COMB_LNA1)
1161                                 antcomb->rssi_lna1 = main_rssi_avg;
1162                 }
1163
1164                 if (antcomb->rssi_lna2 > antcomb->rssi_lna1 +
1165                     ATH_ANT_DIV_COMB_LNA1_LNA2_SWITCH_DELTA)
1166                         div_ant_conf->main_lna_conf = ATH_ANT_DIV_COMB_LNA2;
1167                 else
1168                         div_ant_conf->main_lna_conf = ATH_ANT_DIV_COMB_LNA1;
1169
1170                 if (antcomb->main_conf == ATH_ANT_DIV_COMB_LNA1) {
1171                         if (ath_is_alt_ant_ratio_better(alt_ratio,
1172                                                 ATH_ANT_DIV_COMB_LNA1_DELTA_HI,
1173                                                 ATH_ANT_DIV_COMB_LNA1_DELTA_LOW,
1174                                                 main_rssi_avg, alt_rssi_avg,
1175                                                 antcomb->total_pkt_count))
1176                                 antcomb->second_ratio = true;
1177                         else
1178                                 antcomb->second_ratio = false;
1179                 } else if (antcomb->main_conf == ATH_ANT_DIV_COMB_LNA2) {
1180                         if (ath_is_alt_ant_ratio_better(alt_ratio,
1181                                                 ATH_ANT_DIV_COMB_LNA1_DELTA_MID,
1182                                                 ATH_ANT_DIV_COMB_LNA1_DELTA_LOW,
1183                                                 main_rssi_avg, alt_rssi_avg,
1184                                                 antcomb->total_pkt_count))
1185                                 antcomb->second_ratio = true;
1186                         else
1187                                 antcomb->second_ratio = false;
1188                 } else {
1189                         if ((((alt_ratio >= ATH_ANT_DIV_COMB_ALT_ANT_RATIO2) &&
1190                             (alt_rssi_avg > main_rssi_avg +
1191                             ATH_ANT_DIV_COMB_LNA1_DELTA_HI)) ||
1192                             (alt_rssi_avg > main_rssi_avg)) &&
1193                             (antcomb->total_pkt_count > 50))
1194                                 antcomb->second_ratio = true;
1195                         else
1196                                 antcomb->second_ratio = false;
1197                 }
1198
1199                 /* set alt to the conf with maximun ratio */
1200                 if (antcomb->first_ratio && antcomb->second_ratio) {
1201                         if (antcomb->rssi_second > antcomb->rssi_third) {
1202                                 /* first alt*/
1203                                 if ((antcomb->first_quick_scan_conf ==
1204                                     ATH_ANT_DIV_COMB_LNA1) ||
1205                                     (antcomb->first_quick_scan_conf ==
1206                                     ATH_ANT_DIV_COMB_LNA2))
1207                                         /* Set alt LNA1 or LNA2*/
1208                                         if (div_ant_conf->main_lna_conf ==
1209                                             ATH_ANT_DIV_COMB_LNA2)
1210                                                 div_ant_conf->alt_lna_conf =
1211                                                         ATH_ANT_DIV_COMB_LNA1;
1212                                         else
1213                                                 div_ant_conf->alt_lna_conf =
1214                                                         ATH_ANT_DIV_COMB_LNA2;
1215                                 else
1216                                         /* Set alt to A+B or A-B */
1217                                         div_ant_conf->alt_lna_conf =
1218                                                 antcomb->first_quick_scan_conf;
1219                         } else if ((antcomb->second_quick_scan_conf ==
1220                                    ATH_ANT_DIV_COMB_LNA1) ||
1221                                    (antcomb->second_quick_scan_conf ==
1222                                    ATH_ANT_DIV_COMB_LNA2)) {
1223                                 /* Set alt LNA1 or LNA2 */
1224                                 if (div_ant_conf->main_lna_conf ==
1225                                     ATH_ANT_DIV_COMB_LNA2)
1226                                         div_ant_conf->alt_lna_conf =
1227                                                 ATH_ANT_DIV_COMB_LNA1;
1228                                 else
1229                                         div_ant_conf->alt_lna_conf =
1230                                                 ATH_ANT_DIV_COMB_LNA2;
1231                         } else {
1232                                 /* Set alt to A+B or A-B */
1233                                 div_ant_conf->alt_lna_conf =
1234                                         antcomb->second_quick_scan_conf;
1235                         }
1236                 } else if (antcomb->first_ratio) {
1237                         /* first alt */
1238                         if ((antcomb->first_quick_scan_conf ==
1239                             ATH_ANT_DIV_COMB_LNA1) ||
1240                             (antcomb->first_quick_scan_conf ==
1241                             ATH_ANT_DIV_COMB_LNA2))
1242                                         /* Set alt LNA1 or LNA2 */
1243                                 if (div_ant_conf->main_lna_conf ==
1244                                     ATH_ANT_DIV_COMB_LNA2)
1245                                         div_ant_conf->alt_lna_conf =
1246                                                         ATH_ANT_DIV_COMB_LNA1;
1247                                 else
1248                                         div_ant_conf->alt_lna_conf =
1249                                                         ATH_ANT_DIV_COMB_LNA2;
1250                         else
1251                                 /* Set alt to A+B or A-B */
1252                                 div_ant_conf->alt_lna_conf =
1253                                                 antcomb->first_quick_scan_conf;
1254                 } else if (antcomb->second_ratio) {
1255                                 /* second alt */
1256                         if ((antcomb->second_quick_scan_conf ==
1257                             ATH_ANT_DIV_COMB_LNA1) ||
1258                             (antcomb->second_quick_scan_conf ==
1259                             ATH_ANT_DIV_COMB_LNA2))
1260                                 /* Set alt LNA1 or LNA2 */
1261                                 if (div_ant_conf->main_lna_conf ==
1262                                     ATH_ANT_DIV_COMB_LNA2)
1263                                         div_ant_conf->alt_lna_conf =
1264                                                 ATH_ANT_DIV_COMB_LNA1;
1265                                 else
1266                                         div_ant_conf->alt_lna_conf =
1267                                                 ATH_ANT_DIV_COMB_LNA2;
1268                         else
1269                                 /* Set alt to A+B or A-B */
1270                                 div_ant_conf->alt_lna_conf =
1271                                                 antcomb->second_quick_scan_conf;
1272                 } else {
1273                         /* main is largest */
1274                         if ((antcomb->main_conf == ATH_ANT_DIV_COMB_LNA1) ||
1275                             (antcomb->main_conf == ATH_ANT_DIV_COMB_LNA2))
1276                                 /* Set alt LNA1 or LNA2 */
1277                                 if (div_ant_conf->main_lna_conf ==
1278                                     ATH_ANT_DIV_COMB_LNA2)
1279                                         div_ant_conf->alt_lna_conf =
1280                                                         ATH_ANT_DIV_COMB_LNA1;
1281                                 else
1282                                         div_ant_conf->alt_lna_conf =
1283                                                         ATH_ANT_DIV_COMB_LNA2;
1284                         else
1285                                 /* Set alt to A+B or A-B */
1286                                 div_ant_conf->alt_lna_conf = antcomb->main_conf;
1287                 }
1288                 break;
1289         default:
1290                 break;
1291         }
1292 }
1293
1294 static void ath_ant_div_conf_fast_divbias(struct ath_hw_antcomb_conf *ant_conf)
1295 {
1296         /* Adjust the fast_div_bias based on main and alt lna conf */
1297         switch ((ant_conf->main_lna_conf << 4) | ant_conf->alt_lna_conf) {
1298         case (0x01): /* A-B LNA2 */
1299                 ant_conf->fast_div_bias = 0x3b;
1300                 break;
1301         case (0x02): /* A-B LNA1 */
1302                 ant_conf->fast_div_bias = 0x3d;
1303                 break;
1304         case (0x03): /* A-B A+B */
1305                 ant_conf->fast_div_bias = 0x1;
1306                 break;
1307         case (0x10): /* LNA2 A-B */
1308                 ant_conf->fast_div_bias = 0x7;
1309                 break;
1310         case (0x12): /* LNA2 LNA1 */
1311                 ant_conf->fast_div_bias = 0x2;
1312                 break;
1313         case (0x13): /* LNA2 A+B */
1314                 ant_conf->fast_div_bias = 0x7;
1315                 break;
1316         case (0x20): /* LNA1 A-B */
1317                 ant_conf->fast_div_bias = 0x6;
1318                 break;
1319         case (0x21): /* LNA1 LNA2 */
1320                 ant_conf->fast_div_bias = 0x0;
1321                 break;
1322         case (0x23): /* LNA1 A+B */
1323                 ant_conf->fast_div_bias = 0x6;
1324                 break;
1325         case (0x30): /* A+B A-B */
1326                 ant_conf->fast_div_bias = 0x1;
1327                 break;
1328         case (0x31): /* A+B LNA2 */
1329                 ant_conf->fast_div_bias = 0x3b;
1330                 break;
1331         case (0x32): /* A+B LNA1 */
1332                 ant_conf->fast_div_bias = 0x3d;
1333                 break;
1334         default:
1335                 break;
1336         }
1337 }
1338
1339 /* Antenna diversity and combining */
1340 static void ath_ant_comb_scan(struct ath_softc *sc, struct ath_rx_status *rs)
1341 {
1342         struct ath_hw_antcomb_conf div_ant_conf;
1343         struct ath_ant_comb *antcomb = &sc->ant_comb;
1344         int alt_ratio = 0, alt_rssi_avg = 0, main_rssi_avg = 0, curr_alt_set;
1345         int curr_main_set, curr_bias;
1346         int main_rssi = rs->rs_rssi_ctl0;
1347         int alt_rssi = rs->rs_rssi_ctl1;
1348         int rx_ant_conf,  main_ant_conf;
1349         bool short_scan = false;
1350
1351         rx_ant_conf = (rs->rs_rssi_ctl2 >> ATH_ANT_RX_CURRENT_SHIFT) &
1352                        ATH_ANT_RX_MASK;
1353         main_ant_conf = (rs->rs_rssi_ctl2 >> ATH_ANT_RX_MAIN_SHIFT) &
1354                          ATH_ANT_RX_MASK;
1355
1356         /* Record packet only when alt_rssi is positive */
1357         if (alt_rssi > 0) {
1358                 antcomb->total_pkt_count++;
1359                 antcomb->main_total_rssi += main_rssi;
1360                 antcomb->alt_total_rssi  += alt_rssi;
1361                 if (main_ant_conf == rx_ant_conf)
1362                         antcomb->main_recv_cnt++;
1363                 else
1364                         antcomb->alt_recv_cnt++;
1365         }
1366
1367         /* Short scan check */
1368         if (antcomb->scan && antcomb->alt_good) {
1369                 if (time_after(jiffies, antcomb->scan_start_time +
1370                     msecs_to_jiffies(ATH_ANT_DIV_COMB_SHORT_SCAN_INTR)))
1371                         short_scan = true;
1372                 else
1373                         if (antcomb->total_pkt_count ==
1374                             ATH_ANT_DIV_COMB_SHORT_SCAN_PKTCOUNT) {
1375                                 alt_ratio = ((antcomb->alt_recv_cnt * 100) /
1376                                             antcomb->total_pkt_count);
1377                                 if (alt_ratio < ATH_ANT_DIV_COMB_ALT_ANT_RATIO)
1378                                         short_scan = true;
1379                         }
1380         }
1381
1382         if (((antcomb->total_pkt_count < ATH_ANT_DIV_COMB_MAX_PKTCOUNT) ||
1383             rs->rs_moreaggr) && !short_scan)
1384                 return;
1385
1386         if (antcomb->total_pkt_count) {
1387                 alt_ratio = ((antcomb->alt_recv_cnt * 100) /
1388                              antcomb->total_pkt_count);
1389                 main_rssi_avg = (antcomb->main_total_rssi /
1390                                  antcomb->total_pkt_count);
1391                 alt_rssi_avg = (antcomb->alt_total_rssi /
1392                                  antcomb->total_pkt_count);
1393         }
1394
1395
1396         ath9k_hw_antdiv_comb_conf_get(sc->sc_ah, &div_ant_conf);
1397         curr_alt_set = div_ant_conf.alt_lna_conf;
1398         curr_main_set = div_ant_conf.main_lna_conf;
1399         curr_bias = div_ant_conf.fast_div_bias;
1400
1401         antcomb->count++;
1402
1403         if (antcomb->count == ATH_ANT_DIV_COMB_MAX_COUNT) {
1404                 if (alt_ratio > ATH_ANT_DIV_COMB_ALT_ANT_RATIO) {
1405                         ath_lnaconf_alt_good_scan(antcomb, div_ant_conf,
1406                                                   main_rssi_avg);
1407                         antcomb->alt_good = true;
1408                 } else {
1409                         antcomb->alt_good = false;
1410                 }
1411
1412                 antcomb->count = 0;
1413                 antcomb->scan = true;
1414                 antcomb->scan_not_start = true;
1415         }
1416
1417         if (!antcomb->scan) {
1418                 if (alt_ratio > ATH_ANT_DIV_COMB_ALT_ANT_RATIO) {
1419                         if (curr_alt_set == ATH_ANT_DIV_COMB_LNA2) {
1420                                 /* Switch main and alt LNA */
1421                                 div_ant_conf.main_lna_conf =
1422                                                 ATH_ANT_DIV_COMB_LNA2;
1423                                 div_ant_conf.alt_lna_conf  =
1424                                                 ATH_ANT_DIV_COMB_LNA1;
1425                         } else if (curr_alt_set == ATH_ANT_DIV_COMB_LNA1) {
1426                                 div_ant_conf.main_lna_conf =
1427                                                 ATH_ANT_DIV_COMB_LNA1;
1428                                 div_ant_conf.alt_lna_conf  =
1429                                                 ATH_ANT_DIV_COMB_LNA2;
1430                         }
1431
1432                         goto div_comb_done;
1433                 } else if ((curr_alt_set != ATH_ANT_DIV_COMB_LNA1) &&
1434                            (curr_alt_set != ATH_ANT_DIV_COMB_LNA2)) {
1435                         /* Set alt to another LNA */
1436                         if (curr_main_set == ATH_ANT_DIV_COMB_LNA2)
1437                                 div_ant_conf.alt_lna_conf =
1438                                                 ATH_ANT_DIV_COMB_LNA1;
1439                         else if (curr_main_set == ATH_ANT_DIV_COMB_LNA1)
1440                                 div_ant_conf.alt_lna_conf =
1441                                                 ATH_ANT_DIV_COMB_LNA2;
1442
1443                         goto div_comb_done;
1444                 }
1445
1446                 if ((alt_rssi_avg < (main_rssi_avg +
1447                     ATH_ANT_DIV_COMB_LNA1_LNA2_DELTA)))
1448                         goto div_comb_done;
1449         }
1450
1451         if (!antcomb->scan_not_start) {
1452                 switch (curr_alt_set) {
1453                 case ATH_ANT_DIV_COMB_LNA2:
1454                         antcomb->rssi_lna2 = alt_rssi_avg;
1455                         antcomb->rssi_lna1 = main_rssi_avg;
1456                         antcomb->scan = true;
1457                         /* set to A+B */
1458                         div_ant_conf.main_lna_conf =
1459                                 ATH_ANT_DIV_COMB_LNA1;
1460                         div_ant_conf.alt_lna_conf  =
1461                                 ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2;
1462                         break;
1463                 case ATH_ANT_DIV_COMB_LNA1:
1464                         antcomb->rssi_lna1 = alt_rssi_avg;
1465                         antcomb->rssi_lna2 = main_rssi_avg;
1466                         antcomb->scan = true;
1467                         /* set to A+B */
1468                         div_ant_conf.main_lna_conf = ATH_ANT_DIV_COMB_LNA2;
1469                         div_ant_conf.alt_lna_conf  =
1470                                 ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2;
1471                         break;
1472                 case ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2:
1473                         antcomb->rssi_add = alt_rssi_avg;
1474                         antcomb->scan = true;
1475                         /* set to A-B */
1476                         div_ant_conf.alt_lna_conf =
1477                                 ATH_ANT_DIV_COMB_LNA1_MINUS_LNA2;
1478                         break;
1479                 case ATH_ANT_DIV_COMB_LNA1_MINUS_LNA2:
1480                         antcomb->rssi_sub = alt_rssi_avg;
1481                         antcomb->scan = false;
1482                         if (antcomb->rssi_lna2 >
1483                             (antcomb->rssi_lna1 +
1484                             ATH_ANT_DIV_COMB_LNA1_LNA2_SWITCH_DELTA)) {
1485                                 /* use LNA2 as main LNA */
1486                                 if ((antcomb->rssi_add > antcomb->rssi_lna1) &&
1487                                     (antcomb->rssi_add > antcomb->rssi_sub)) {
1488                                         /* set to A+B */
1489                                         div_ant_conf.main_lna_conf =
1490                                                 ATH_ANT_DIV_COMB_LNA2;
1491                                         div_ant_conf.alt_lna_conf  =
1492                                                 ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2;
1493                                 } else if (antcomb->rssi_sub >
1494                                            antcomb->rssi_lna1) {
1495                                         /* set to A-B */
1496                                         div_ant_conf.main_lna_conf =
1497                                                 ATH_ANT_DIV_COMB_LNA2;
1498                                         div_ant_conf.alt_lna_conf =
1499                                                 ATH_ANT_DIV_COMB_LNA1_MINUS_LNA2;
1500                                 } else {
1501                                         /* set to LNA1 */
1502                                         div_ant_conf.main_lna_conf =
1503                                                 ATH_ANT_DIV_COMB_LNA2;
1504                                         div_ant_conf.alt_lna_conf =
1505                                                 ATH_ANT_DIV_COMB_LNA1;
1506                                 }
1507                         } else {
1508                                 /* use LNA1 as main LNA */
1509                                 if ((antcomb->rssi_add > antcomb->rssi_lna2) &&
1510                                     (antcomb->rssi_add > antcomb->rssi_sub)) {
1511                                         /* set to A+B */
1512                                         div_ant_conf.main_lna_conf =
1513                                                 ATH_ANT_DIV_COMB_LNA1;
1514                                         div_ant_conf.alt_lna_conf  =
1515                                                 ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2;
1516                                 } else if (antcomb->rssi_sub >
1517                                            antcomb->rssi_lna1) {
1518                                         /* set to A-B */
1519                                         div_ant_conf.main_lna_conf =
1520                                                 ATH_ANT_DIV_COMB_LNA1;
1521                                         div_ant_conf.alt_lna_conf =
1522                                                 ATH_ANT_DIV_COMB_LNA1_MINUS_LNA2;
1523                                 } else {
1524                                         /* set to LNA2 */
1525                                         div_ant_conf.main_lna_conf =
1526                                                 ATH_ANT_DIV_COMB_LNA1;
1527                                         div_ant_conf.alt_lna_conf =
1528                                                 ATH_ANT_DIV_COMB_LNA2;
1529                                 }
1530                         }
1531                         break;
1532                 default:
1533                         break;
1534                 }
1535         } else {
1536                 if (!antcomb->alt_good) {
1537                         antcomb->scan_not_start = false;
1538                         /* Set alt to another LNA */
1539                         if (curr_main_set == ATH_ANT_DIV_COMB_LNA2) {
1540                                 div_ant_conf.main_lna_conf =
1541                                                 ATH_ANT_DIV_COMB_LNA2;
1542                                 div_ant_conf.alt_lna_conf =
1543                                                 ATH_ANT_DIV_COMB_LNA1;
1544                         } else if (curr_main_set == ATH_ANT_DIV_COMB_LNA1) {
1545                                 div_ant_conf.main_lna_conf =
1546                                                 ATH_ANT_DIV_COMB_LNA1;
1547                                 div_ant_conf.alt_lna_conf =
1548                                                 ATH_ANT_DIV_COMB_LNA2;
1549                         }
1550                         goto div_comb_done;
1551                 }
1552         }
1553
1554         ath_select_ant_div_from_quick_scan(antcomb, &div_ant_conf,
1555                                            main_rssi_avg, alt_rssi_avg,
1556                                            alt_ratio);
1557
1558         antcomb->quick_scan_cnt++;
1559
1560 div_comb_done:
1561         ath_ant_div_conf_fast_divbias(&div_ant_conf);
1562
1563         ath9k_hw_antdiv_comb_conf_set(sc->sc_ah, &div_ant_conf);
1564
1565         antcomb->scan_start_time = jiffies;
1566         antcomb->total_pkt_count = 0;
1567         antcomb->main_total_rssi = 0;
1568         antcomb->alt_total_rssi = 0;
1569         antcomb->main_recv_cnt = 0;
1570         antcomb->alt_recv_cnt = 0;
1571 }
1572
1573 int ath_rx_tasklet(struct ath_softc *sc, int flush, bool hp)
1574 {
1575         struct ath_buf *bf;
1576         struct sk_buff *skb = NULL, *requeue_skb, *hdr_skb;
1577         struct ieee80211_rx_status *rxs;
1578         struct ath_hw *ah = sc->sc_ah;
1579         struct ath_common *common = ath9k_hw_common(ah);
1580         /*
1581          * The hw can technically differ from common->hw when using ath9k
1582          * virtual wiphy so to account for that we iterate over the active
1583          * wiphys and find the appropriate wiphy and therefore hw.
1584          */
1585         struct ieee80211_hw *hw = sc->hw;
1586         struct ieee80211_hdr *hdr;
1587         int retval;
1588         bool decrypt_error = false;
1589         struct ath_rx_status rs;
1590         enum ath9k_rx_qtype qtype;
1591         bool edma = !!(ah->caps.hw_caps & ATH9K_HW_CAP_EDMA);
1592         int dma_type;
1593         u8 rx_status_len = ah->caps.rx_status_len;
1594         u64 tsf = 0;
1595         u32 tsf_lower = 0;
1596         unsigned long flags;
1597
1598         if (edma)
1599                 dma_type = DMA_BIDIRECTIONAL;
1600         else
1601                 dma_type = DMA_FROM_DEVICE;
1602
1603         qtype = hp ? ATH9K_RX_QUEUE_HP : ATH9K_RX_QUEUE_LP;
1604         spin_lock_bh(&sc->rx.rxbuflock);
1605
1606         tsf = ath9k_hw_gettsf64(ah);
1607         tsf_lower = tsf & 0xffffffff;
1608
1609         do {
1610                 /* If handling rx interrupt and flush is in progress => exit */
1611                 if ((sc->sc_flags & SC_OP_RXFLUSH) && (flush == 0))
1612                         break;
1613
1614                 memset(&rs, 0, sizeof(rs));
1615                 if (edma)
1616                         bf = ath_edma_get_next_rx_buf(sc, &rs, qtype);
1617                 else
1618                         bf = ath_get_next_rx_buf(sc, &rs);
1619
1620                 if (!bf)
1621                         break;
1622
1623                 skb = bf->bf_mpdu;
1624                 if (!skb)
1625                         continue;
1626
1627                 /*
1628                  * Take frame header from the first fragment and RX status from
1629                  * the last one.
1630                  */
1631                 if (sc->rx.frag)
1632                         hdr_skb = sc->rx.frag;
1633                 else
1634                         hdr_skb = skb;
1635
1636                 hdr = (struct ieee80211_hdr *) (hdr_skb->data + rx_status_len);
1637                 rxs = IEEE80211_SKB_RXCB(hdr_skb);
1638
1639                 ath_debug_stat_rx(sc, &rs);
1640
1641                 /*
1642                  * If we're asked to flush receive queue, directly
1643                  * chain it back at the queue without processing it.
1644                  */
1645                 if (flush)
1646                         goto requeue_drop_frag;
1647
1648                 retval = ath9k_rx_skb_preprocess(common, hw, hdr, &rs,
1649                                                  rxs, &decrypt_error);
1650                 if (retval)
1651                         goto requeue_drop_frag;
1652
1653                 rxs->mactime = (tsf & ~0xffffffffULL) | rs.rs_tstamp;
1654                 if (rs.rs_tstamp > tsf_lower &&
1655                     unlikely(rs.rs_tstamp - tsf_lower > 0x10000000))
1656                         rxs->mactime -= 0x100000000ULL;
1657
1658                 if (rs.rs_tstamp < tsf_lower &&
1659                     unlikely(tsf_lower - rs.rs_tstamp > 0x10000000))
1660                         rxs->mactime += 0x100000000ULL;
1661
1662                 /* Ensure we always have an skb to requeue once we are done
1663                  * processing the current buffer's skb */
1664                 requeue_skb = ath_rxbuf_alloc(common, common->rx_bufsize, GFP_ATOMIC);
1665
1666                 /* If there is no memory we ignore the current RX'd frame,
1667                  * tell hardware it can give us a new frame using the old
1668                  * skb and put it at the tail of the sc->rx.rxbuf list for
1669                  * processing. */
1670                 if (!requeue_skb)
1671                         goto requeue_drop_frag;
1672
1673                 /* Unmap the frame */
1674                 dma_unmap_single(sc->dev, bf->bf_buf_addr,
1675                                  common->rx_bufsize,
1676                                  dma_type);
1677
1678                 skb_put(skb, rs.rs_datalen + ah->caps.rx_status_len);
1679                 if (ah->caps.rx_status_len)
1680                         skb_pull(skb, ah->caps.rx_status_len);
1681
1682                 if (!rs.rs_more)
1683                         ath9k_rx_skb_postprocess(common, hdr_skb, &rs,
1684                                                  rxs, decrypt_error);
1685
1686                 /* We will now give hardware our shiny new allocated skb */
1687                 bf->bf_mpdu = requeue_skb;
1688                 bf->bf_buf_addr = dma_map_single(sc->dev, requeue_skb->data,
1689                                                  common->rx_bufsize,
1690                                                  dma_type);
1691                 if (unlikely(dma_mapping_error(sc->dev,
1692                           bf->bf_buf_addr))) {
1693                         dev_kfree_skb_any(requeue_skb);
1694                         bf->bf_mpdu = NULL;
1695                         bf->bf_buf_addr = 0;
1696                         ath_err(common, "dma_mapping_error() on RX\n");
1697                         ieee80211_rx(hw, skb);
1698                         break;
1699                 }
1700
1701                 if (rs.rs_more) {
1702                         /*
1703                          * rs_more indicates chained descriptors which can be
1704                          * used to link buffers together for a sort of
1705                          * scatter-gather operation.
1706                          */
1707                         if (sc->rx.frag) {
1708                                 /* too many fragments - cannot handle frame */
1709                                 dev_kfree_skb_any(sc->rx.frag);
1710                                 dev_kfree_skb_any(skb);
1711                                 skb = NULL;
1712                         }
1713                         sc->rx.frag = skb;
1714                         goto requeue;
1715                 }
1716
1717                 if (sc->rx.frag) {
1718                         int space = skb->len - skb_tailroom(hdr_skb);
1719
1720                         sc->rx.frag = NULL;
1721
1722                         if (pskb_expand_head(hdr_skb, 0, space, GFP_ATOMIC) < 0) {
1723                                 dev_kfree_skb(skb);
1724                                 goto requeue_drop_frag;
1725                         }
1726
1727                         skb_copy_from_linear_data(skb, skb_put(hdr_skb, skb->len),
1728                                                   skb->len);
1729                         dev_kfree_skb_any(skb);
1730                         skb = hdr_skb;
1731                 }
1732
1733                 /*
1734                  * change the default rx antenna if rx diversity chooses the
1735                  * other antenna 3 times in a row.
1736                  */
1737                 if (sc->rx.defant != rs.rs_antenna) {
1738                         if (++sc->rx.rxotherant >= 3)
1739                                 ath_setdefantenna(sc, rs.rs_antenna);
1740                 } else {
1741                         sc->rx.rxotherant = 0;
1742                 }
1743
1744                 spin_lock_irqsave(&sc->sc_pm_lock, flags);
1745
1746                 if ((sc->ps_flags & (PS_WAIT_FOR_BEACON |
1747                                               PS_WAIT_FOR_CAB |
1748                                               PS_WAIT_FOR_PSPOLL_DATA)) ||
1749                                         unlikely(ath9k_check_auto_sleep(sc)))
1750                         ath_rx_ps(sc, skb);
1751                 spin_unlock_irqrestore(&sc->sc_pm_lock, flags);
1752
1753                 if (ah->caps.hw_caps & ATH9K_HW_CAP_ANT_DIV_COMB)
1754                         ath_ant_comb_scan(sc, &rs);
1755
1756                 ieee80211_rx(hw, skb);
1757
1758 requeue_drop_frag:
1759                 if (sc->rx.frag) {
1760                         dev_kfree_skb_any(sc->rx.frag);
1761                         sc->rx.frag = NULL;
1762                 }
1763 requeue:
1764                 if (edma) {
1765                         list_add_tail(&bf->list, &sc->rx.rxbuf);
1766                         ath_rx_edma_buf_link(sc, qtype);
1767                 } else {
1768                         list_move_tail(&bf->list, &sc->rx.rxbuf);
1769                         ath_rx_buf_link(sc, bf);
1770                 }
1771         } while (1);
1772
1773         spin_unlock_bh(&sc->rx.rxbuflock);
1774
1775         return 0;
1776 }