drivers/net/wireless/ath/ath9k/recv.c

   1 /*
   2  * Copyright (c) 2008-2011 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 ath_ant_div_comb_alt_check(u8 div_group, int alt_ratio,
  32                                         int curr_main_set, int curr_alt_set,
  33                                         int alt_rssi_avg, int main_rssi_avg)
  34 {
  35         bool result = false;
  36         switch (div_group) {
  37         case 0:
  38                 if (alt_ratio > ATH_ANT_DIV_COMB_ALT_ANT_RATIO)
  39                         result = true;
  40                 break;
  41         case 1:
  42         case 2:
  43                 if ((((curr_main_set == ATH_ANT_DIV_COMB_LNA2) &&
  44                         (curr_alt_set == ATH_ANT_DIV_COMB_LNA1) &&
  45                                 (alt_rssi_avg >= (main_rssi_avg - 5))) ||
  46                         ((curr_main_set == ATH_ANT_DIV_COMB_LNA1) &&
  47                         (curr_alt_set == ATH_ANT_DIV_COMB_LNA2) &&
  48                                 (alt_rssi_avg >= (main_rssi_avg - 2)))) &&
  49                                                         (alt_rssi_avg >= 4))
  50                         result = true;
  51                 else
  52                         result = false;
  53                 break;
  54         }
  55
  56         return result;
  57 }
  58
  59 static inline bool ath9k_check_auto_sleep(struct ath_softc *sc)
  60 {
  61         return sc->ps_enabled &&
  62                (sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_AUTOSLEEP);
  63 }
  64
  65 /*
  66  * Setup and link descriptors.
  67  *
  68  * 11N: we can no longer afford to self link the last descriptor.
  69  * MAC acknowledges BA status as long as it copies frames to host
  70  * buffer (or rx fifo). This can incorrectly acknowledge packets
  71  * to a sender if last desc is self-linked.
  72  */
  73 static void ath_rx_buf_link(struct ath_softc *sc, struct ath_buf *bf)
  74 {
  75         struct ath_hw *ah = sc->sc_ah;
  76         struct ath_common *common = ath9k_hw_common(ah);
  77         struct ath_desc *ds;
  78         struct sk_buff *skb;
  79
  80         ATH_RXBUF_RESET(bf);
  81
  82         ds = bf->bf_desc;
  83         ds->ds_link = 0; /* link to null */
  84         ds->ds_data = bf->bf_buf_addr;
  85
  86         /* virtual addr of the beginning of the buffer. */
  87         skb = bf->bf_mpdu;
  88         BUG_ON(skb == NULL);
  89         ds->ds_vdata = skb->data;
  90
  91         /*
  92          * setup rx descriptors. The rx_bufsize here tells the hardware
  93          * how much data it can DMA to us and that we are prepared
  94          * to process
  95          */
  96         ath9k_hw_setuprxdesc(ah, ds,
  97                              common->rx_bufsize,
  98                              0);
  99
 100         if (sc->rx.rxlink == NULL)
 101                 ath9k_hw_putrxbuf(ah, bf->bf_daddr);
 102         else
 103                 *sc->rx.rxlink = bf->bf_daddr;
 104
 105         sc->rx.rxlink = &ds->ds_link;
 106 }
 107
 108 static void ath_setdefantenna(struct ath_softc *sc, u32 antenna)
 109 {
 110         /* XXX block beacon interrupts */
 111         ath9k_hw_setantenna(sc->sc_ah, antenna);
 112         sc->rx.defant = antenna;
 113         sc->rx.rxotherant = 0;
 114 }
 115
 116 static void ath_opmode_init(struct ath_softc *sc)
 117 {
 118         struct ath_hw *ah = sc->sc_ah;
 119         struct ath_common *common = ath9k_hw_common(ah);
 120
 121         u32 rfilt, mfilt[2];
 122
 123         /* configure rx filter */
 124         rfilt = ath_calcrxfilter(sc);
 125         ath9k_hw_setrxfilter(ah, rfilt);
 126
 127         /* configure bssid mask */
 128         ath_hw_setbssidmask(common);
 129
 130         /* configure operational mode */
 131         ath9k_hw_setopmode(ah);
 132
 133         /* calculate and install multicast filter */
 134         mfilt[0] = mfilt[1] = ~0;
 135         ath9k_hw_setmcastfilter(ah, mfilt[0], mfilt[1]);
 136 }
 137
 138 static bool ath_rx_edma_buf_link(struct ath_softc *sc,
 139                                  enum ath9k_rx_qtype qtype)
 140 {
 141         struct ath_hw *ah = sc->sc_ah;
 142         struct ath_rx_edma *rx_edma;
 143         struct sk_buff *skb;
 144         struct ath_buf *bf;
 145
 146         rx_edma = &sc->rx.rx_edma[qtype];
 147         if (skb_queue_len(&rx_edma->rx_fifo) >= rx_edma->rx_fifo_hwsize)
 148                 return false;
 149
 150         bf = list_first_entry(&sc->rx.rxbuf, struct ath_buf, list);
 151         list_del_init(&bf->list);
 152
 153         skb = bf->bf_mpdu;
 154
 155         ATH_RXBUF_RESET(bf);
 156         memset(skb->data, 0, ah->caps.rx_status_len);
 157         dma_sync_single_for_device(sc->dev, bf->bf_buf_addr,
 158                                 ah->caps.rx_status_len, DMA_TO_DEVICE);
 159
 160         SKB_CB_ATHBUF(skb) = bf;
 161         ath9k_hw_addrxbuf_edma(ah, bf->bf_buf_addr, qtype);
 162         skb_queue_tail(&rx_edma->rx_fifo, skb);
 163
 164         return true;
 165 }
 166
 167 static void ath_rx_addbuffer_edma(struct ath_softc *sc,
 168                                   enum ath9k_rx_qtype qtype, int size)
 169 {
 170         struct ath_common *common = ath9k_hw_common(sc->sc_ah);
 171         u32 nbuf = 0;
 172
 173         if (list_empty(&sc->rx.rxbuf)) {
 174                 ath_dbg(common, ATH_DBG_QUEUE, "No free rx buf available\n");
 175                 return;
 176         }
 177
 178         while (!list_empty(&sc->rx.rxbuf)) {
 179                 nbuf++;
 180
 181                 if (!ath_rx_edma_buf_link(sc, qtype))
 182                         break;
 183
 184                 if (nbuf >= size)
 185                         break;
 186         }
 187 }
 188
 189 static void ath_rx_remove_buffer(struct ath_softc *sc,
 190                                  enum ath9k_rx_qtype qtype)
 191 {
 192         struct ath_buf *bf;
 193         struct ath_rx_edma *rx_edma;
 194         struct sk_buff *skb;
 195
 196         rx_edma = &sc->rx.rx_edma[qtype];
 197
 198         while ((skb = skb_dequeue(&rx_edma->rx_fifo)) != NULL) {
 199                 bf = SKB_CB_ATHBUF(skb);
 200                 BUG_ON(!bf);
 201                 list_add_tail(&bf->list, &sc->rx.rxbuf);
 202         }
 203 }
 204
 205 static void ath_rx_edma_cleanup(struct ath_softc *sc)
 206 {
 207         struct ath_buf *bf;
 208
 209         ath_rx_remove_buffer(sc, ATH9K_RX_QUEUE_LP);
 210         ath_rx_remove_buffer(sc, ATH9K_RX_QUEUE_HP);
 211
 212         list_for_each_entry(bf, &sc->rx.rxbuf, list) {
 213                 if (bf->bf_mpdu)
 214                         dev_kfree_skb_any(bf->bf_mpdu);
 215         }
 216
 217         INIT_LIST_HEAD(&sc->rx.rxbuf);
 218
 219         kfree(sc->rx.rx_bufptr);
 220         sc->rx.rx_bufptr = NULL;
 221 }
 222
 223 static void ath_rx_edma_init_queue(struct ath_rx_edma *rx_edma, int size)
 224 {
 225         skb_queue_head_init(&rx_edma->rx_fifo);
 226         skb_queue_head_init(&rx_edma->rx_buffers);
 227         rx_edma->rx_fifo_hwsize = size;
 228 }
 229
 230 static int ath_rx_edma_init(struct ath_softc *sc, int nbufs)
 231 {
 232         struct ath_common *common = ath9k_hw_common(sc->sc_ah);
 233         struct ath_hw *ah = sc->sc_ah;
 234         struct sk_buff *skb;
 235         struct ath_buf *bf;
 236         int error = 0, i;
 237         u32 size;
 238
 239         ath9k_hw_set_rx_bufsize(ah, common->rx_bufsize -
 240                                     ah->caps.rx_status_len);
 241
 242         ath_rx_edma_init_queue(&sc->rx.rx_edma[ATH9K_RX_QUEUE_LP],
 243                                ah->caps.rx_lp_qdepth);
 244         ath_rx_edma_init_queue(&sc->rx.rx_edma[ATH9K_RX_QUEUE_HP],
 245                                ah->caps.rx_hp_qdepth);
 246
 247         size = sizeof(struct ath_buf) * nbufs;
 248         bf = kzalloc(size, GFP_KERNEL);
 249         if (!bf)
 250                 return -ENOMEM;
 251
 252         INIT_LIST_HEAD(&sc->rx.rxbuf);
 253         sc->rx.rx_bufptr = bf;
 254
 255         for (i = 0; i < nbufs; i++, bf++) {
 256                 skb = ath_rxbuf_alloc(common, common->rx_bufsize, GFP_KERNEL);
 257                 if (!skb) {
 258                         error = -ENOMEM;
 259                         goto rx_init_fail;
 260                 }
 261
 262                 memset(skb->data, 0, common->rx_bufsize);
 263                 bf->bf_mpdu = skb;
 264
 265                 bf->bf_buf_addr = dma_map_single(sc->dev, skb->data,
 266                                                  common->rx_bufsize,
 267                                                  DMA_BIDIRECTIONAL);
 268                 if (unlikely(dma_mapping_error(sc->dev,
 269                                                 bf->bf_buf_addr))) {
 270                                 dev_kfree_skb_any(skb);
 271                                 bf->bf_mpdu = NULL;
 272                                 bf->bf_buf_addr = 0;
 273                                 ath_err(common,
 274                                         "dma_mapping_error() on RX init\n");
 275                                 error = -ENOMEM;
 276                                 goto rx_init_fail;
 277                 }
 278
 279                 list_add_tail(&bf->list, &sc->rx.rxbuf);
 280         }
 281
 282         return 0;
 283
 284 rx_init_fail:
 285         ath_rx_edma_cleanup(sc);
 286         return error;
 287 }
 288
 289 static void ath_edma_start_recv(struct ath_softc *sc)
 290 {
 291         spin_lock_bh(&sc->rx.rxbuflock);
 292
 293         ath9k_hw_rxena(sc->sc_ah);
 294
 295         ath_rx_addbuffer_edma(sc, ATH9K_RX_QUEUE_HP,
 296                               sc->rx.rx_edma[ATH9K_RX_QUEUE_HP].rx_fifo_hwsize);
 297
 298         ath_rx_addbuffer_edma(sc, ATH9K_RX_QUEUE_LP,
 299                               sc->rx.rx_edma[ATH9K_RX_QUEUE_LP].rx_fifo_hwsize);
 300
 301         ath_opmode_init(sc);
 302
 303         ath9k_hw_startpcureceive(sc->sc_ah, (sc->sc_flags & SC_OP_OFFCHANNEL));
 304
 305         spin_unlock_bh(&sc->rx.rxbuflock);
 306 }
 307
 308 static void ath_edma_stop_recv(struct ath_softc *sc)
 309 {
 310         ath_rx_remove_buffer(sc, ATH9K_RX_QUEUE_HP);
 311         ath_rx_remove_buffer(sc, ATH9K_RX_QUEUE_LP);
 312 }
 313
 314 int ath_rx_init(struct ath_softc *sc, int nbufs)
 315 {
 316         struct ath_common *common = ath9k_hw_common(sc->sc_ah);
 317         struct sk_buff *skb;
 318         struct ath_buf *bf;
 319         int error = 0;
 320
 321         spin_lock_init(&sc->sc_pcu_lock);
 322         sc->sc_flags &= ~SC_OP_RXFLUSH;
 323         spin_lock_init(&sc->rx.rxbuflock);
 324
 325         common->rx_bufsize = IEEE80211_MAX_MPDU_LEN / 2 +
 326                              sc->sc_ah->caps.rx_status_len;
 327
 328         if (sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_EDMA) {
 329                 return ath_rx_edma_init(sc, nbufs);
 330         } else {
 331                 ath_dbg(common, ATH_DBG_CONFIG, "cachelsz %u rxbufsize %u\n",
 332                         common->cachelsz, common->rx_bufsize);
 333
 334                 /* Initialize rx descriptors */
 335
 336                 error = ath_descdma_setup(sc, &sc->rx.rxdma, &sc->rx.rxbuf,
 337                                 "rx", nbufs, 1, 0);
 338                 if (error != 0) {
 339                         ath_err(common,
 340                                 "failed to allocate rx descriptors: %d\n",
 341                                 error);
 342                         goto err;
 343                 }
 344
 345                 list_for_each_entry(bf, &sc->rx.rxbuf, list) {
 346                         skb = ath_rxbuf_alloc(common, common->rx_bufsize,
 347                                               GFP_KERNEL);
 348                         if (skb == NULL) {
 349                                 error = -ENOMEM;
 350                                 goto err;
 351                         }
 352
 353                         bf->bf_mpdu = skb;
 354                         bf->bf_buf_addr = dma_map_single(sc->dev, skb->data,
 355                                         common->rx_bufsize,
 356                                         DMA_FROM_DEVICE);
 357                         if (unlikely(dma_mapping_error(sc->dev,
 358                                                         bf->bf_buf_addr))) {
 359                                 dev_kfree_skb_any(skb);
 360                                 bf->bf_mpdu = NULL;
 361                                 bf->bf_buf_addr = 0;
 362                                 ath_err(common,
 363                                         "dma_mapping_error() on RX init\n");
 364                                 error = -ENOMEM;
 365                                 goto err;
 366                         }
 367                 }
 368                 sc->rx.rxlink = NULL;
 369         }
 370
 371 err:
 372         if (error)
 373                 ath_rx_cleanup(sc);
 374
 375         return error;
 376 }
 377
 378 void ath_rx_cleanup(struct ath_softc *sc)
 379 {
 380         struct ath_hw *ah = sc->sc_ah;
 381         struct ath_common *common = ath9k_hw_common(ah);
 382         struct sk_buff *skb;
 383         struct ath_buf *bf;
 384
 385         if (sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_EDMA) {
 386                 ath_rx_edma_cleanup(sc);
 387                 return;
 388         } else {
 389                 list_for_each_entry(bf, &sc->rx.rxbuf, list) {
 390                         skb = bf->bf_mpdu;
 391                         if (skb) {
 392                                 dma_unmap_single(sc->dev, bf->bf_buf_addr,
 393                                                 common->rx_bufsize,
 394                                                 DMA_FROM_DEVICE);
 395                                 dev_kfree_skb(skb);
 396                                 bf->bf_buf_addr = 0;
 397                                 bf->bf_mpdu = NULL;
 398                         }
 399                 }
 400
 401                 if (sc->rx.rxdma.dd_desc_len != 0)
 402                         ath_descdma_cleanup(sc, &sc->rx.rxdma, &sc->rx.rxbuf);
 403         }
 404 }
 405
 406 /*
 407  * Calculate the receive filter according to the
 408  * operating mode and state:
 409  *
 410  * o always accept unicast, broadcast, and multicast traffic
 411  * o maintain current state of phy error reception (the hal
 412  *   may enable phy error frames for noise immunity work)
 413  * o probe request frames are accepted only when operating in
 414  *   hostap, adhoc, or monitor modes
 415  * o enable promiscuous mode according to the interface state
 416  * o accept beacons:
 417  *   - when operating in adhoc mode so the 802.11 layer creates
 418  *     node table entries for peers,
 419  *   - when operating in station mode for collecting rssi data when
 420  *     the station is otherwise quiet, or
 421  *   - when operating as a repeater so we see repeater-sta beacons
 422  *   - when scanning
 423  */
 424
 425 u32 ath_calcrxfilter(struct ath_softc *sc)
 426 {
 427 #define RX_FILTER_PRESERVE (ATH9K_RX_FILTER_PHYERR | ATH9K_RX_FILTER_PHYRADAR)
 428
 429         u32 rfilt;
 430
 431         rfilt = (ath9k_hw_getrxfilter(sc->sc_ah) & RX_FILTER_PRESERVE)
 432                 | ATH9K_RX_FILTER_UCAST | ATH9K_RX_FILTER_BCAST
 433                 | ATH9K_RX_FILTER_MCAST;
 434
 435         if (sc->rx.rxfilter & FIF_PROBE_REQ)
 436                 rfilt |= ATH9K_RX_FILTER_PROBEREQ;
 437
 438         /*
 439          * Set promiscuous mode when FIF_PROMISC_IN_BSS is enabled for station
 440          * mode interface or when in monitor mode. AP mode does not need this
 441          * since it receives all in-BSS frames anyway.
 442          */
 443         if (sc->sc_ah->is_monitoring)
 444                 rfilt |= ATH9K_RX_FILTER_PROM;
 445
 446         if (sc->rx.rxfilter & FIF_CONTROL)
 447                 rfilt |= ATH9K_RX_FILTER_CONTROL;
 448
 449         if ((sc->sc_ah->opmode == NL80211_IFTYPE_STATION) &&
 450             (sc->nvifs <= 1) &&
 451             !(sc->rx.rxfilter & FIF_BCN_PRBRESP_PROMISC))
 452                 rfilt |= ATH9K_RX_FILTER_MYBEACON;
 453         else
 454                 rfilt |= ATH9K_RX_FILTER_BEACON;
 455
 456         if ((sc->sc_ah->opmode == NL80211_IFTYPE_AP) ||
 457             (sc->rx.rxfilter & FIF_PSPOLL))
 458                 rfilt |= ATH9K_RX_FILTER_PSPOLL;
 459
 460         if (conf_is_ht(&sc->hw->conf))
 461                 rfilt |= ATH9K_RX_FILTER_COMP_BAR;
 462
 463         if (sc->nvifs > 1 || (sc->rx.rxfilter & FIF_OTHER_BSS)) {
 464                 /* The following may also be needed for other older chips */
 465                 if (sc->sc_ah->hw_version.macVersion == AR_SREV_VERSION_9160)
 466                         rfilt |= ATH9K_RX_FILTER_PROM;
 467                 rfilt |= ATH9K_RX_FILTER_MCAST_BCAST_ALL;
 468         }
 469
 470         return rfilt;
 471
 472 #undef RX_FILTER_PRESERVE
 473 }
 474
 475 int ath_startrecv(struct ath_softc *sc)
 476 {
 477         struct ath_hw *ah = sc->sc_ah;
 478         struct ath_buf *bf, *tbf;
 479
 480         if (ah->caps.hw_caps & ATH9K_HW_CAP_EDMA) {
 481                 ath_edma_start_recv(sc);
 482                 return 0;
 483         }
 484
 485         spin_lock_bh(&sc->rx.rxbuflock);
 486         if (list_empty(&sc->rx.rxbuf))
 487                 goto start_recv;
 488
 489         sc->rx.rxlink = NULL;
 490         list_for_each_entry_safe(bf, tbf, &sc->rx.rxbuf, list) {
 491                 ath_rx_buf_link(sc, bf);
 492         }
 493
 494         /* We could have deleted elements so the list may be empty now */
 495         if (list_empty(&sc->rx.rxbuf))
 496                 goto start_recv;
 497
 498         bf = list_first_entry(&sc->rx.rxbuf, struct ath_buf, list);
 499         ath9k_hw_putrxbuf(ah, bf->bf_daddr);
 500         ath9k_hw_rxena(ah);
 501
 502 start_recv:
 503         ath_opmode_init(sc);
 504         ath9k_hw_startpcureceive(ah, (sc->sc_flags & SC_OP_OFFCHANNEL));
 505
 506         spin_unlock_bh(&sc->rx.rxbuflock);
 507
 508         return 0;
 509 }
 510
 511 bool ath_stoprecv(struct ath_softc *sc)
 512 {
 513         struct ath_hw *ah = sc->sc_ah;
 514         bool stopped, reset = false;
 515
 516         spin_lock_bh(&sc->rx.rxbuflock);
 517         ath9k_hw_abortpcurecv(ah);
 518         ath9k_hw_setrxfilter(ah, 0);
 519         stopped = ath9k_hw_stopdmarecv(ah, &reset);
 520
 521         if (sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_EDMA)
 522                 ath_edma_stop_recv(sc);
 523         else
 524                 sc->rx.rxlink = NULL;
 525         spin_unlock_bh(&sc->rx.rxbuflock);
 526
 527         if (!(ah->ah_flags & AH_UNPLUGGED) &&
 528             unlikely(!stopped)) {
 529                 ath_err(ath9k_hw_common(sc->sc_ah),
 530                         "Could not stop RX, we could be "
 531                         "confusing the DMA engine when we start RX up\n");
 532                 ATH_DBG_WARN_ON_ONCE(!stopped);
 533         }
 534         return stopped && !reset;
 535 }
 536
 537 void ath_flushrecv(struct ath_softc *sc)
 538 {
 539         sc->sc_flags |= SC_OP_RXFLUSH;
 540         if (sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_EDMA)
 541                 ath_rx_tasklet(sc, 1, true);
 542         ath_rx_tasklet(sc, 1, false);
 543         sc->sc_flags &= ~SC_OP_RXFLUSH;
 544 }
 545
 546 static bool ath_beacon_dtim_pending_cab(struct sk_buff *skb)
 547 {
 548         /* Check whether the Beacon frame has DTIM indicating buffered bc/mc */
 549         struct ieee80211_mgmt *mgmt;
 550         u8 *pos, *end, id, elen;
 551         struct ieee80211_tim_ie *tim;
 552
 553         mgmt = (struct ieee80211_mgmt *)skb->data;
 554         pos = mgmt->u.beacon.variable;
 555         end = skb->data + skb->len;
 556
 557         while (pos + 2 < end) {
 558                 id = *pos++;
 559                 elen = *pos++;
 560                 if (pos + elen > end)
 561                         break;
 562
 563                 if (id == WLAN_EID_TIM) {
 564                         if (elen < sizeof(*tim))
 565                                 break;
 566                         tim = (struct ieee80211_tim_ie *) pos;
 567                         if (tim->dtim_count != 0)
 568                                 break;
 569                         return tim->bitmap_ctrl & 0x01;
 570                 }
 571
 572                 pos += elen;
 573         }
 574
 575         return false;
 576 }
 577
 578 static void ath_rx_ps_beacon(struct ath_softc *sc, struct sk_buff *skb)
 579 {
 580         struct ieee80211_mgmt *mgmt;
 581         struct ath_common *common = ath9k_hw_common(sc->sc_ah);
 582
 583         if (skb->len < 24 + 8 + 2 + 2)
 584                 return;
 585
 586         mgmt = (struct ieee80211_mgmt *)skb->data;
 587         if (memcmp(common->curbssid, mgmt->bssid, ETH_ALEN) != 0) {
 588                 /* TODO:  This doesn't work well if you have stations
 589                  * associated to two different APs because curbssid
 590                  * is just the last AP that any of the stations associated
 591                  * with.
 592                  */
 593                 return; /* not from our current AP */
 594         }
 595
 596         sc->ps_flags &= ~PS_WAIT_FOR_BEACON;
 597
 598         if (sc->ps_flags & PS_BEACON_SYNC) {
 599                 sc->ps_flags &= ~PS_BEACON_SYNC;
 600                 ath_dbg(common, ATH_DBG_PS,
 601                         "Reconfigure Beacon timers based on timestamp from the AP\n");
 602                 ath_set_beacon(sc);
 603                 sc->ps_flags &= ~PS_TSFOOR_SYNC;
 604         }
 605
 606         if (ath_beacon_dtim_pending_cab(skb)) {
 607                 /*
 608                  * Remain awake waiting for buffered broadcast/multicast
 609                  * frames. If the last broadcast/multicast frame is not
 610                  * received properly, the next beacon frame will work as
 611                  * a backup trigger for returning into NETWORK SLEEP state,
 612                  * so we are waiting for it as well.
 613                  */
 614                 ath_dbg(common, ATH_DBG_PS,
 615                         "Received DTIM beacon indicating buffered broadcast/multicast frame(s)\n");
 616                 sc->ps_flags |= PS_WAIT_FOR_CAB | PS_WAIT_FOR_BEACON;
 617                 return;
 618         }
 619
 620         if (sc->ps_flags & PS_WAIT_FOR_CAB) {
 621                 /*
 622                  * This can happen if a broadcast frame is dropped or the AP
 623                  * fails to send a frame indicating that all CAB frames have
 624                  * been delivered.
 625                  */
 626                 sc->ps_flags &= ~PS_WAIT_FOR_CAB;
 627                 ath_dbg(common, ATH_DBG_PS,
 628                         "PS wait for CAB frames timed out\n");
 629         }
 630 }
 631
 632 static void ath_rx_ps(struct ath_softc *sc, struct sk_buff *skb)
 633 {
 634         struct ieee80211_hdr *hdr;
 635         struct ath_common *common = ath9k_hw_common(sc->sc_ah);
 636
 637         hdr = (struct ieee80211_hdr *)skb->data;
 638
 639         /* Process Beacon and CAB receive in PS state */
 640         if (((sc->ps_flags & PS_WAIT_FOR_BEACON) || ath9k_check_auto_sleep(sc))
 641             && ieee80211_is_beacon(hdr->frame_control))
 642                 ath_rx_ps_beacon(sc, skb);
 643         else if ((sc->ps_flags & PS_WAIT_FOR_CAB) &&
 644                  (ieee80211_is_data(hdr->frame_control) ||
 645                   ieee80211_is_action(hdr->frame_control)) &&
 646                  is_multicast_ether_addr(hdr->addr1) &&
 647                  !ieee80211_has_moredata(hdr->frame_control)) {
 648                 /*
 649                  * No more broadcast/multicast frames to be received at this
 650                  * point.
 651                  */
 652                 sc->ps_flags &= ~(PS_WAIT_FOR_CAB | PS_WAIT_FOR_BEACON);
 653                 ath_dbg(common, ATH_DBG_PS,
 654                         "All PS CAB frames received, back to sleep\n");
 655         } else if ((sc->ps_flags & PS_WAIT_FOR_PSPOLL_DATA) &&
 656                    !is_multicast_ether_addr(hdr->addr1) &&
 657                    !ieee80211_has_morefrags(hdr->frame_control)) {
 658                 sc->ps_flags &= ~PS_WAIT_FOR_PSPOLL_DATA;
 659                 ath_dbg(common, ATH_DBG_PS,
 660                         "Going back to sleep after having received PS-Poll data (0x%lx)\n",
 661                         sc->ps_flags & (PS_WAIT_FOR_BEACON |
 662                                         PS_WAIT_FOR_CAB |
 663                                         PS_WAIT_FOR_PSPOLL_DATA |
 664                                         PS_WAIT_FOR_TX_ACK));
 665         }
 666 }
 667
 668 static bool ath_edma_get_buffers(struct ath_softc *sc,
 669                                  enum ath9k_rx_qtype qtype)
 670 {
 671         struct ath_rx_edma *rx_edma = &sc->rx.rx_edma[qtype];
 672         struct ath_hw *ah = sc->sc_ah;
 673         struct ath_common *common = ath9k_hw_common(ah);
 674         struct sk_buff *skb;
 675         struct ath_buf *bf;
 676         int ret;
 677
 678         skb = skb_peek(&rx_edma->rx_fifo);
 679         if (!skb)
 680                 return false;
 681
 682         bf = SKB_CB_ATHBUF(skb);
 683         BUG_ON(!bf);
 684
 685         dma_sync_single_for_cpu(sc->dev, bf->bf_buf_addr,
 686                                 common->rx_bufsize, DMA_FROM_DEVICE);
 687
 688         ret = ath9k_hw_process_rxdesc_edma(ah, NULL, skb->data);
 689         if (ret == -EINPROGRESS) {
 690                 /*let device gain the buffer again*/
 691                 dma_sync_single_for_device(sc->dev, bf->bf_buf_addr,
 692                                 common->rx_bufsize, DMA_FROM_DEVICE);
 693                 return false;
 694         }
 695
 696         __skb_unlink(skb, &rx_edma->rx_fifo);
 697         if (ret == -EINVAL) {
 698                 /* corrupt descriptor, skip this one and the following one */
 699                 list_add_tail(&bf->list, &sc->rx.rxbuf);
 700                 ath_rx_edma_buf_link(sc, qtype);
 701                 skb = skb_peek(&rx_edma->rx_fifo);
 702                 if (!skb)
 703                         return true;
 704
 705                 bf = SKB_CB_ATHBUF(skb);
 706                 BUG_ON(!bf);
 707
 708                 __skb_unlink(skb, &rx_edma->rx_fifo);
 709                 list_add_tail(&bf->list, &sc->rx.rxbuf);
 710                 ath_rx_edma_buf_link(sc, qtype);
 711                 return true;
 712         }
 713         skb_queue_tail(&rx_edma->rx_buffers, skb);
 714
 715         return true;
 716 }
 717
 718 static struct ath_buf *ath_edma_get_next_rx_buf(struct ath_softc *sc,
 719                                                 struct ath_rx_status *rs,
 720                                                 enum ath9k_rx_qtype qtype)
 721 {
 722         struct ath_rx_edma *rx_edma = &sc->rx.rx_edma[qtype];
 723         struct sk_buff *skb;
 724         struct ath_buf *bf;
 725
 726         while (ath_edma_get_buffers(sc, qtype));
 727         skb = __skb_dequeue(&rx_edma->rx_buffers);
 728         if (!skb)
 729                 return NULL;
 730
 731         bf = SKB_CB_ATHBUF(skb);
 732         ath9k_hw_process_rxdesc_edma(sc->sc_ah, rs, skb->data);
 733         return bf;
 734 }
 735
 736 static struct ath_buf *ath_get_next_rx_buf(struct ath_softc *sc,
 737                                            struct ath_rx_status *rs)
 738 {
 739         struct ath_hw *ah = sc->sc_ah;
 740         struct ath_common *common = ath9k_hw_common(ah);
 741         struct ath_desc *ds;
 742         struct ath_buf *bf;
 743         int ret;
 744
 745         if (list_empty(&sc->rx.rxbuf)) {
 746                 sc->rx.rxlink = NULL;
 747                 return NULL;
 748         }
 749
 750         bf = list_first_entry(&sc->rx.rxbuf, struct ath_buf, list);
 751         ds = bf->bf_desc;
 752
 753         /*
 754          * Must provide the virtual address of the current
 755          * descriptor, the physical address, and the virtual
 756          * address of the next descriptor in the h/w chain.
 757          * This allows the HAL to look ahead to see if the
 758          * hardware is done with a descriptor by checking the
 759          * done bit in the following descriptor and the address
 760          * of the current descriptor the DMA engine is working
 761          * on.  All this is necessary because of our use of
 762          * a self-linked list to avoid rx overruns.
 763          */
 764         ret = ath9k_hw_rxprocdesc(ah, ds, rs, 0);
 765         if (ret == -EINPROGRESS) {
 766                 struct ath_rx_status trs;
 767                 struct ath_buf *tbf;
 768                 struct ath_desc *tds;
 769
 770                 memset(&trs, 0, sizeof(trs));
 771                 if (list_is_last(&bf->list, &sc->rx.rxbuf)) {
 772                         sc->rx.rxlink = NULL;
 773                         return NULL;
 774                 }
 775
 776                 tbf = list_entry(bf->list.next, struct ath_buf, list);
 777
 778                 /*
 779                  * On some hardware the descriptor status words could
 780                  * get corrupted, including the done bit. Because of
 781                  * this, check if the next descriptor's done bit is
 782                  * set or not.
 783                  *
 784                  * If the next descriptor's done bit is set, the current
 785                  * descriptor has been corrupted. Force s/w to discard
 786                  * this descriptor and continue...
 787                  */
 788
 789                 tds = tbf->bf_desc;
 790                 ret = ath9k_hw_rxprocdesc(ah, tds, &trs, 0);
 791                 if (ret == -EINPROGRESS)
 792                         return NULL;
 793         }
 794
 795         if (!bf->bf_mpdu)
 796                 return bf;
 797
 798         /*
 799          * Synchronize the DMA transfer with CPU before
 800          * 1. accessing the frame
 801          * 2. requeueing the same buffer to h/w
 802          */
 803         dma_sync_single_for_cpu(sc->dev, bf->bf_buf_addr,
 804                         common->rx_bufsize,
 805                         DMA_FROM_DEVICE);
 806
 807         return bf;
 808 }
 809
 810 /* Assumes you've already done the endian to CPU conversion */
 811 static bool ath9k_rx_accept(struct ath_common *common,
 812                             struct ieee80211_hdr *hdr,
 813                             struct ieee80211_rx_status *rxs,
 814                             struct ath_rx_status *rx_stats,
 815                             bool *decrypt_error)
 816 {
 817         bool is_mc, is_valid_tkip, strip_mic, mic_error;
 818         struct ath_hw *ah = common->ah;
 819         __le16 fc;
 820         u8 rx_status_len = ah->caps.rx_status_len;
 821
 822         fc = hdr->frame_control;
 823
 824         is_mc = !!is_multicast_ether_addr(hdr->addr1);
 825         is_valid_tkip = rx_stats->rs_keyix != ATH9K_RXKEYIX_INVALID &&
 826                 test_bit(rx_stats->rs_keyix, common->tkip_keymap);
 827         strip_mic = is_valid_tkip && !(rx_stats->rs_status &
 828                 (ATH9K_RXERR_DECRYPT | ATH9K_RXERR_CRC | ATH9K_RXERR_MIC));
 829
 830         if (!rx_stats->rs_datalen)
 831                 return false;
 832         /*
 833          * rs_status follows rs_datalen so if rs_datalen is too large
 834          * we can take a hint that hardware corrupted it, so ignore
 835          * those frames.
 836          */
 837         if (rx_stats->rs_datalen > (common->rx_bufsize - rx_status_len))
 838                 return false;
 839
 840         /* Only use error bits from the last fragment */
 841         if (rx_stats->rs_more)
 842                 return true;
 843
 844         mic_error = is_valid_tkip && !ieee80211_is_ctl(fc) &&
 845                 !ieee80211_has_morefrags(fc) &&
 846                 !(le16_to_cpu(hdr->seq_ctrl) & IEEE80211_SCTL_FRAG) &&
 847                 (rx_stats->rs_status & ATH9K_RXERR_MIC);
 848
 849         /*
 850          * The rx_stats->rs_status will not be set until the end of the
 851          * chained descriptors so it can be ignored if rs_more is set. The
 852          * rs_more will be false at the last element of the chained
 853          * descriptors.
 854          */
 855         if (rx_stats->rs_status != 0) {
 856                 if (rx_stats->rs_status & ATH9K_RXERR_CRC) {
 857                         rxs->flag |= RX_FLAG_FAILED_FCS_CRC;
 858                         mic_error = false;
 859                 }
 860                 if (rx_stats->rs_status & ATH9K_RXERR_PHY)
 861                         return false;
 862
 863                 if (rx_stats->rs_status & ATH9K_RXERR_DECRYPT) {
 864                         *decrypt_error = true;
 865                         mic_error = false;
 866                 }
 867
 868                 /*
 869                  * Reject error frames with the exception of
 870                  * decryption and MIC failures. For monitor mode,
 871                  * we also ignore the CRC error.
 872                  */
 873                 if (ah->is_monitoring) {
 874                         if (rx_stats->rs_status &
 875                             ~(ATH9K_RXERR_DECRYPT | ATH9K_RXERR_MIC |
 876                               ATH9K_RXERR_CRC))
 877                                 return false;
 878                 } else {
 879                         if (rx_stats->rs_status &
 880                             ~(ATH9K_RXERR_DECRYPT | ATH9K_RXERR_MIC)) {
 881                                 return false;
 882                         }
 883                 }
 884         }
 885
 886         /*
 887          * For unicast frames the MIC error bit can have false positives,
 888          * so all MIC error reports need to be validated in software.
 889          * False negatives are not common, so skip software verification
 890          * if the hardware considers the MIC valid.
 891          */
 892         if (strip_mic)
 893                 rxs->flag |= RX_FLAG_MMIC_STRIPPED;
 894         else if (is_mc && mic_error)
 895                 rxs->flag |= RX_FLAG_MMIC_ERROR;
 896
 897         return true;
 898 }
 899
 900 static int ath9k_process_rate(struct ath_common *common,
 901                               struct ieee80211_hw *hw,
 902                               struct ath_rx_status *rx_stats,
 903                               struct ieee80211_rx_status *rxs)
 904 {
 905         struct ieee80211_supported_band *sband;
 906         enum ieee80211_band band;
 907         unsigned int i = 0;
 908
 909         band = hw->conf.channel->band;
 910         sband = hw->wiphy->bands[band];
 911
 912         if (rx_stats->rs_rate & 0x80) {
 913                 /* HT rate */
 914                 rxs->flag |= RX_FLAG_HT;
 915                 if (rx_stats->rs_flags & ATH9K_RX_2040)
 916                         rxs->flag |= RX_FLAG_40MHZ;
 917                 if (rx_stats->rs_flags & ATH9K_RX_GI)
 918                         rxs->flag |= RX_FLAG_SHORT_GI;
 919                 rxs->rate_idx = rx_stats->rs_rate & 0x7f;
 920                 return 0;
 921         }
 922
 923         for (i = 0; i < sband->n_bitrates; i++) {
 924                 if (sband->bitrates[i].hw_value == rx_stats->rs_rate) {
 925                         rxs->rate_idx = i;
 926                         return 0;
 927                 }
 928                 if (sband->bitrates[i].hw_value_short == rx_stats->rs_rate) {
 929                         rxs->flag |= RX_FLAG_SHORTPRE;
 930                         rxs->rate_idx = i;
 931                         return 0;
 932                 }
 933         }
 934
 935         /*
 936          * No valid hardware bitrate found -- we should not get here
 937          * because hardware has already validated this frame as OK.
 938          */
 939         ath_dbg(common, ATH_DBG_XMIT,
 940                 "unsupported hw bitrate detected 0x%02x using 1 Mbit\n",
 941                 rx_stats->rs_rate);
 942
 943         return -EINVAL;
 944 }
 945
 946 static void ath9k_process_rssi(struct ath_common *common,
 947                                struct ieee80211_hw *hw,
 948                                struct ieee80211_hdr *hdr,
 949                                struct ath_rx_status *rx_stats)
 950 {
 951         struct ath_softc *sc = hw->priv;
 952         struct ath_hw *ah = common->ah;
 953         int last_rssi;
 954         __le16 fc;
 955
 956         if ((ah->opmode != NL80211_IFTYPE_STATION) &&
 957             (ah->opmode != NL80211_IFTYPE_ADHOC))
 958                 return;
 959
 960         fc = hdr->frame_control;
 961         if (!ieee80211_is_beacon(fc) ||
 962             compare_ether_addr(hdr->addr3, common->curbssid)) {
 963                 /* TODO:  This doesn't work well if you have stations
 964                  * associated to two different APs because curbssid
 965                  * is just the last AP that any of the stations associated
 966                  * with.
 967                  */
 968                 return;
 969         }
 970
 971         if (rx_stats->rs_rssi != ATH9K_RSSI_BAD && !rx_stats->rs_moreaggr)
 972                 ATH_RSSI_LPF(sc->last_rssi, rx_stats->rs_rssi);
 973
 974         last_rssi = sc->last_rssi;
 975         if (likely(last_rssi != ATH_RSSI_DUMMY_MARKER))
 976                 rx_stats->rs_rssi = ATH_EP_RND(last_rssi,
 977                                               ATH_RSSI_EP_MULTIPLIER);
 978         if (rx_stats->rs_rssi < 0)
 979                 rx_stats->rs_rssi = 0;
 980
 981         /* Update Beacon RSSI, this is used by ANI. */
 982         ah->stats.avgbrssi = rx_stats->rs_rssi;
 983 }
 984
 985 /*
 986  * For Decrypt or Demic errors, we only mark packet status here and always push
 987  * up the frame up to let mac80211 handle the actual error case, be it no
 988  * decryption key or real decryption error. This let us keep statistics there.
 989  */
 990 static int ath9k_rx_skb_preprocess(struct ath_common *common,
 991                                    struct ieee80211_hw *hw,
 992                                    struct ieee80211_hdr *hdr,
 993                                    struct ath_rx_status *rx_stats,
 994                                    struct ieee80211_rx_status *rx_status,
 995                                    bool *decrypt_error)
 996 {
 997         memset(rx_status, 0, sizeof(struct ieee80211_rx_status));
 998
 999         /*
1000          * everything but the rate is checked here, the rate check is done
1001          * separately to avoid doing two lookups for a rate for each frame.
1002          */
1003         if (!ath9k_rx_accept(common, hdr, rx_status, rx_stats, decrypt_error))
1004                 return -EINVAL;
1005
1006         /* Only use status info from the last fragment */
1007         if (rx_stats->rs_more)
1008                 return 0;
1009
1010         ath9k_process_rssi(common, hw, hdr, rx_stats);
1011
1012         if (ath9k_process_rate(common, hw, rx_stats, rx_status))
1013                 return -EINVAL;
1014
1015         rx_status->band = hw->conf.channel->band;
1016         rx_status->freq = hw->conf.channel->center_freq;
1017         rx_status->signal = ATH_DEFAULT_NOISE_FLOOR + rx_stats->rs_rssi;
1018         rx_status->antenna = rx_stats->rs_antenna;
1019         rx_status->flag |= RX_FLAG_MACTIME_MPDU;
1020
1021         return 0;
1022 }
1023
1024 static void ath9k_rx_skb_postprocess(struct ath_common *common,
1025                                      struct sk_buff *skb,
1026                                      struct ath_rx_status *rx_stats,
1027                                      struct ieee80211_rx_status *rxs,
1028                                      bool decrypt_error)
1029 {
1030         struct ath_hw *ah = common->ah;
1031         struct ieee80211_hdr *hdr;
1032         int hdrlen, padpos, padsize;
1033         u8 keyix;
1034         __le16 fc;
1035
1036         /* see if any padding is done by the hw and remove it */
1037         hdr = (struct ieee80211_hdr *) skb->data;
1038         hdrlen = ieee80211_get_hdrlen_from_skb(skb);
1039         fc = hdr->frame_control;
1040         padpos = ath9k_cmn_padpos(hdr->frame_control);
1041
1042         /* The MAC header is padded to have 32-bit boundary if the
1043          * packet payload is non-zero. The general calculation for
1044          * padsize would take into account odd header lengths:
1045          * padsize = (4 - padpos % 4) % 4; However, since only
1046          * even-length headers are used, padding can only be 0 or 2
1047          * bytes and we can optimize this a bit. In addition, we must
1048          * not try to remove padding from short control frames that do
1049          * not have payload. */
1050         padsize = padpos & 3;
1051         if (padsize && skb->len>=padpos+padsize+FCS_LEN) {
1052                 memmove(skb->data + padsize, skb->data, padpos);
1053                 skb_pull(skb, padsize);
1054         }
1055
1056         keyix = rx_stats->rs_keyix;
1057
1058         if (!(keyix == ATH9K_RXKEYIX_INVALID) && !decrypt_error &&
1059             ieee80211_has_protected(fc)) {
1060                 rxs->flag |= RX_FLAG_DECRYPTED;
1061         } else if (ieee80211_has_protected(fc)
1062                    && !decrypt_error && skb->len >= hdrlen + 4) {
1063                 keyix = skb->data[hdrlen + 3] >> 6;
1064
1065                 if (test_bit(keyix, common->keymap))
1066                         rxs->flag |= RX_FLAG_DECRYPTED;
1067         }
1068         if (ah->sw_mgmt_crypto &&
1069             (rxs->flag & RX_FLAG_DECRYPTED) &&
1070             ieee80211_is_mgmt(fc))
1071                 /* Use software decrypt for management frames. */
1072                 rxs->flag &= ~RX_FLAG_DECRYPTED;
1073 }
1074
1075 static void ath_lnaconf_alt_good_scan(struct ath_ant_comb *antcomb,
1076                                       struct ath_hw_antcomb_conf ant_conf,
1077                                       int main_rssi_avg)
1078 {
1079         antcomb->quick_scan_cnt = 0;
1080
1081         if (ant_conf.main_lna_conf == ATH_ANT_DIV_COMB_LNA2)
1082                 antcomb->rssi_lna2 = main_rssi_avg;
1083         else if (ant_conf.main_lna_conf == ATH_ANT_DIV_COMB_LNA1)
1084                 antcomb->rssi_lna1 = main_rssi_avg;
1085
1086         switch ((ant_conf.main_lna_conf << 4) | ant_conf.alt_lna_conf) {
1087         case 0x10: /* LNA2 A-B */
1088                 antcomb->main_conf = ATH_ANT_DIV_COMB_LNA1_MINUS_LNA2;
1089                 antcomb->first_quick_scan_conf =
1090                         ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2;
1091                 antcomb->second_quick_scan_conf = ATH_ANT_DIV_COMB_LNA1;
1092                 break;
1093         case 0x20: /* LNA1 A-B */
1094                 antcomb->main_conf = ATH_ANT_DIV_COMB_LNA1_MINUS_LNA2;
1095                 antcomb->first_quick_scan_conf =
1096                         ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2;
1097                 antcomb->second_quick_scan_conf = ATH_ANT_DIV_COMB_LNA2;
1098                 break;
1099         case 0x21: /* LNA1 LNA2 */
1100                 antcomb->main_conf = ATH_ANT_DIV_COMB_LNA2;
1101                 antcomb->first_quick_scan_conf =
1102                         ATH_ANT_DIV_COMB_LNA1_MINUS_LNA2;
1103                 antcomb->second_quick_scan_conf =
1104                         ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2;
1105                 break;
1106         case 0x12: /* LNA2 LNA1 */
1107                 antcomb->main_conf = ATH_ANT_DIV_COMB_LNA1;
1108                 antcomb->first_quick_scan_conf =
1109                         ATH_ANT_DIV_COMB_LNA1_MINUS_LNA2;
1110                 antcomb->second_quick_scan_conf =
1111                         ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2;
1112                 break;
1113         case 0x13: /* LNA2 A+B */
1114                 antcomb->main_conf = ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2;
1115                 antcomb->first_quick_scan_conf =
1116                         ATH_ANT_DIV_COMB_LNA1_MINUS_LNA2;
1117                 antcomb->second_quick_scan_conf = ATH_ANT_DIV_COMB_LNA1;
1118                 break;
1119         case 0x23: /* LNA1 A+B */
1120                 antcomb->main_conf = ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2;
1121                 antcomb->first_quick_scan_conf =
1122                         ATH_ANT_DIV_COMB_LNA1_MINUS_LNA2;
1123                 antcomb->second_quick_scan_conf = ATH_ANT_DIV_COMB_LNA2;
1124                 break;
1125         default:
1126                 break;
1127         }
1128 }
1129
1130 static void ath_select_ant_div_from_quick_scan(struct ath_ant_comb *antcomb,
1131                                 struct ath_hw_antcomb_conf *div_ant_conf,
1132                                 int main_rssi_avg, int alt_rssi_avg,
1133                                 int alt_ratio)
1134 {
1135         /* alt_good */
1136         switch (antcomb->quick_scan_cnt) {
1137         case 0:
1138                 /* set alt to main, and alt to first conf */
1139                 div_ant_conf->main_lna_conf = antcomb->main_conf;
1140                 div_ant_conf->alt_lna_conf = antcomb->first_quick_scan_conf;
1141                 break;
1142         case 1:
1143                 /* set alt to main, and alt to first conf */
1144                 div_ant_conf->main_lna_conf = antcomb->main_conf;
1145                 div_ant_conf->alt_lna_conf = antcomb->second_quick_scan_conf;
1146                 antcomb->rssi_first = main_rssi_avg;
1147                 antcomb->rssi_second = alt_rssi_avg;
1148
1149                 if (antcomb->main_conf == ATH_ANT_DIV_COMB_LNA1) {
1150                         /* main is LNA1 */
1151                         if (ath_is_alt_ant_ratio_better(alt_ratio,
1152                                                 ATH_ANT_DIV_COMB_LNA1_DELTA_HI,
1153                                                 ATH_ANT_DIV_COMB_LNA1_DELTA_LOW,
1154                                                 main_rssi_avg, alt_rssi_avg,
1155                                                 antcomb->total_pkt_count))
1156                                 antcomb->first_ratio = true;
1157                         else
1158                                 antcomb->first_ratio = false;
1159                 } else if (antcomb->main_conf == ATH_ANT_DIV_COMB_LNA2) {
1160                         if (ath_is_alt_ant_ratio_better(alt_ratio,
1161                                                 ATH_ANT_DIV_COMB_LNA1_DELTA_MID,
1162                                                 ATH_ANT_DIV_COMB_LNA1_DELTA_LOW,
1163                                                 main_rssi_avg, alt_rssi_avg,
1164                                                 antcomb->total_pkt_count))
1165                                 antcomb->first_ratio = true;
1166                         else
1167                                 antcomb->first_ratio = false;
1168                 } else {
1169                         if ((((alt_ratio >= ATH_ANT_DIV_COMB_ALT_ANT_RATIO2) &&
1170                             (alt_rssi_avg > main_rssi_avg +
1171                             ATH_ANT_DIV_COMB_LNA1_DELTA_HI)) ||
1172                             (alt_rssi_avg > main_rssi_avg)) &&
1173                             (antcomb->total_pkt_count > 50))
1174                                 antcomb->first_ratio = true;
1175                         else
1176                                 antcomb->first_ratio = false;
1177                 }
1178                 break;
1179         case 2:
1180                 antcomb->alt_good = false;
1181                 antcomb->scan_not_start = false;
1182                 antcomb->scan = false;
1183                 antcomb->rssi_first = main_rssi_avg;
1184                 antcomb->rssi_third = alt_rssi_avg;
1185
1186                 if (antcomb->second_quick_scan_conf == ATH_ANT_DIV_COMB_LNA1)
1187                         antcomb->rssi_lna1 = alt_rssi_avg;
1188                 else if (antcomb->second_quick_scan_conf ==
1189                          ATH_ANT_DIV_COMB_LNA2)
1190                         antcomb->rssi_lna2 = alt_rssi_avg;
1191                 else if (antcomb->second_quick_scan_conf ==
1192                          ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2) {
1193                         if (antcomb->main_conf == ATH_ANT_DIV_COMB_LNA2)
1194                                 antcomb->rssi_lna2 = main_rssi_avg;
1195                         else if (antcomb->main_conf == ATH_ANT_DIV_COMB_LNA1)
1196                                 antcomb->rssi_lna1 = main_rssi_avg;
1197                 }
1198
1199                 if (antcomb->rssi_lna2 > antcomb->rssi_lna1 +
1200                     ATH_ANT_DIV_COMB_LNA1_LNA2_SWITCH_DELTA)
1201                         div_ant_conf->main_lna_conf = ATH_ANT_DIV_COMB_LNA2;
1202                 else
1203                         div_ant_conf->main_lna_conf = ATH_ANT_DIV_COMB_LNA1;
1204
1205                 if (antcomb->main_conf == ATH_ANT_DIV_COMB_LNA1) {
1206                         if (ath_is_alt_ant_ratio_better(alt_ratio,
1207                                                 ATH_ANT_DIV_COMB_LNA1_DELTA_HI,
1208                                                 ATH_ANT_DIV_COMB_LNA1_DELTA_LOW,
1209                                                 main_rssi_avg, alt_rssi_avg,
1210                                                 antcomb->total_pkt_count))
1211                                 antcomb->second_ratio = true;
1212                         else
1213                                 antcomb->second_ratio = false;
1214                 } else if (antcomb->main_conf == ATH_ANT_DIV_COMB_LNA2) {
1215                         if (ath_is_alt_ant_ratio_better(alt_ratio,
1216                                                 ATH_ANT_DIV_COMB_LNA1_DELTA_MID,
1217                                                 ATH_ANT_DIV_COMB_LNA1_DELTA_LOW,
1218                                                 main_rssi_avg, alt_rssi_avg,
1219                                                 antcomb->total_pkt_count))
1220                                 antcomb->second_ratio = true;
1221                         else
1222                                 antcomb->second_ratio = false;
1223                 } else {
1224                         if ((((alt_ratio >= ATH_ANT_DIV_COMB_ALT_ANT_RATIO2) &&
1225                             (alt_rssi_avg > main_rssi_avg +
1226                             ATH_ANT_DIV_COMB_LNA1_DELTA_HI)) ||
1227                             (alt_rssi_avg > main_rssi_avg)) &&
1228                             (antcomb->total_pkt_count > 50))
1229                                 antcomb->second_ratio = true;
1230                         else
1231                                 antcomb->second_ratio = false;
1232                 }
1233
1234                 /* set alt to the conf with maximun ratio */
1235                 if (antcomb->first_ratio && antcomb->second_ratio) {
1236                         if (antcomb->rssi_second > antcomb->rssi_third) {
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_quick_scan_conf ==
1255                                    ATH_ANT_DIV_COMB_LNA1) ||
1256                                    (antcomb->second_quick_scan_conf ==
1257                                    ATH_ANT_DIV_COMB_LNA2)) {
1258                                 /* Set alt LNA1 or LNA2 */
1259                                 if (div_ant_conf->main_lna_conf ==
1260                                     ATH_ANT_DIV_COMB_LNA2)
1261                                         div_ant_conf->alt_lna_conf =
1262                                                 ATH_ANT_DIV_COMB_LNA1;
1263                                 else
1264                                         div_ant_conf->alt_lna_conf =
1265                                                 ATH_ANT_DIV_COMB_LNA2;
1266                         } else {
1267                                 /* Set alt to A+B or A-B */
1268                                 div_ant_conf->alt_lna_conf =
1269                                         antcomb->second_quick_scan_conf;
1270                         }
1271                 } else if (antcomb->first_ratio) {
1272                         /* first alt */
1273                         if ((antcomb->first_quick_scan_conf ==
1274                             ATH_ANT_DIV_COMB_LNA1) ||
1275                             (antcomb->first_quick_scan_conf ==
1276                             ATH_ANT_DIV_COMB_LNA2))
1277                                         /* Set alt LNA1 or LNA2 */
1278                                 if (div_ant_conf->main_lna_conf ==
1279                                     ATH_ANT_DIV_COMB_LNA2)
1280                                         div_ant_conf->alt_lna_conf =
1281                                                         ATH_ANT_DIV_COMB_LNA1;
1282                                 else
1283                                         div_ant_conf->alt_lna_conf =
1284                                                         ATH_ANT_DIV_COMB_LNA2;
1285                         else
1286                                 /* Set alt to A+B or A-B */
1287                                 div_ant_conf->alt_lna_conf =
1288                                                 antcomb->first_quick_scan_conf;
1289                 } else if (antcomb->second_ratio) {
1290                                 /* second alt */
1291                         if ((antcomb->second_quick_scan_conf ==
1292                             ATH_ANT_DIV_COMB_LNA1) ||
1293                             (antcomb->second_quick_scan_conf ==
1294                             ATH_ANT_DIV_COMB_LNA2))
1295                                 /* Set alt LNA1 or LNA2 */
1296                                 if (div_ant_conf->main_lna_conf ==
1297                                     ATH_ANT_DIV_COMB_LNA2)
1298                                         div_ant_conf->alt_lna_conf =
1299                                                 ATH_ANT_DIV_COMB_LNA1;
1300                                 else
1301                                         div_ant_conf->alt_lna_conf =
1302                                                 ATH_ANT_DIV_COMB_LNA2;
1303                         else
1304                                 /* Set alt to A+B or A-B */
1305                                 div_ant_conf->alt_lna_conf =
1306                                                 antcomb->second_quick_scan_conf;
1307                 } else {
1308                         /* main is largest */
1309                         if ((antcomb->main_conf == ATH_ANT_DIV_COMB_LNA1) ||
1310                             (antcomb->main_conf == ATH_ANT_DIV_COMB_LNA2))
1311                                 /* Set alt LNA1 or LNA2 */
1312                                 if (div_ant_conf->main_lna_conf ==
1313                                     ATH_ANT_DIV_COMB_LNA2)
1314                                         div_ant_conf->alt_lna_conf =
1315                                                         ATH_ANT_DIV_COMB_LNA1;
1316                                 else
1317                                         div_ant_conf->alt_lna_conf =
1318                                                         ATH_ANT_DIV_COMB_LNA2;
1319                         else
1320                                 /* Set alt to A+B or A-B */
1321                                 div_ant_conf->alt_lna_conf = antcomb->main_conf;
1322                 }
1323                 break;
1324         default:
1325                 break;
1326         }
1327 }
1328
1329 static void ath_ant_div_conf_fast_divbias(struct ath_hw_antcomb_conf *ant_conf,
1330                 struct ath_ant_comb *antcomb, int alt_ratio)
1331 {
1332         if (ant_conf->div_group == 0) {
1333                 /* Adjust the fast_div_bias based on main and alt lna conf */
1334                 switch ((ant_conf->main_lna_conf << 4) |
1335                                 ant_conf->alt_lna_conf) {
1336                 case 0x01: /* A-B LNA2 */
1337                         ant_conf->fast_div_bias = 0x3b;
1338                         break;
1339                 case 0x02: /* A-B LNA1 */
1340                         ant_conf->fast_div_bias = 0x3d;
1341                         break;
1342                 case 0x03: /* A-B A+B */
1343                         ant_conf->fast_div_bias = 0x1;
1344                         break;
1345                 case 0x10: /* LNA2 A-B */
1346                         ant_conf->fast_div_bias = 0x7;
1347                         break;
1348                 case 0x12: /* LNA2 LNA1 */
1349                         ant_conf->fast_div_bias = 0x2;
1350                         break;
1351                 case 0x13: /* LNA2 A+B */
1352                         ant_conf->fast_div_bias = 0x7;
1353                         break;
1354                 case 0x20: /* LNA1 A-B */
1355                         ant_conf->fast_div_bias = 0x6;
1356                         break;
1357                 case 0x21: /* LNA1 LNA2 */
1358                         ant_conf->fast_div_bias = 0x0;
1359                         break;
1360                 case 0x23: /* LNA1 A+B */
1361                         ant_conf->fast_div_bias = 0x6;
1362                         break;
1363                 case 0x30: /* A+B A-B */
1364                         ant_conf->fast_div_bias = 0x1;
1365                         break;
1366                 case 0x31: /* A+B LNA2 */
1367                         ant_conf->fast_div_bias = 0x3b;
1368                         break;
1369                 case 0x32: /* A+B LNA1 */
1370                         ant_conf->fast_div_bias = 0x3d;
1371                         break;
1372                 default:
1373                         break;
1374                 }
1375         } else if (ant_conf->div_group == 1) {
1376                 /* Adjust the fast_div_bias based on main and alt_lna_conf */
1377                 switch ((ant_conf->main_lna_conf << 4) |
1378                         ant_conf->alt_lna_conf) {
1379                 case 0x01: /* A-B LNA2 */
1380                         ant_conf->fast_div_bias = 0x1;
1381                         ant_conf->main_gaintb = 0;
1382                         ant_conf->alt_gaintb = 0;
1383                         break;
1384                 case 0x02: /* A-B LNA1 */
1385                         ant_conf->fast_div_bias = 0x1;
1386                         ant_conf->main_gaintb = 0;
1387                         ant_conf->alt_gaintb = 0;
1388                         break;
1389                 case 0x03: /* A-B A+B */
1390                         ant_conf->fast_div_bias = 0x1;
1391                         ant_conf->main_gaintb = 0;
1392                         ant_conf->alt_gaintb = 0;
1393                         break;
1394                 case 0x10: /* LNA2 A-B */
1395                         if (!(antcomb->scan) &&
1396                             (alt_ratio > ATH_ANT_DIV_COMB_ALT_ANT_RATIO))
1397                                 ant_conf->fast_div_bias = 0x3f;
1398                         else
1399                                 ant_conf->fast_div_bias = 0x1;
1400                         ant_conf->main_gaintb = 0;
1401                         ant_conf->alt_gaintb = 0;
1402                         break;
1403                 case 0x12: /* LNA2 LNA1 */
1404                         ant_conf->fast_div_bias = 0x1;
1405                         ant_conf->main_gaintb = 0;
1406                         ant_conf->alt_gaintb = 0;
1407                         break;
1408                 case 0x13: /* LNA2 A+B */
1409                         if (!(antcomb->scan) &&
1410                             (alt_ratio > ATH_ANT_DIV_COMB_ALT_ANT_RATIO))
1411                                 ant_conf->fast_div_bias = 0x3f;
1412                         else
1413                                 ant_conf->fast_div_bias = 0x1;
1414                         ant_conf->main_gaintb = 0;
1415                         ant_conf->alt_gaintb = 0;
1416                         break;
1417                 case 0x20: /* LNA1 A-B */
1418                         if (!(antcomb->scan) &&
1419                             (alt_ratio > ATH_ANT_DIV_COMB_ALT_ANT_RATIO))
1420                                 ant_conf->fast_div_bias = 0x3f;
1421                         else
1422                                 ant_conf->fast_div_bias = 0x1;
1423                         ant_conf->main_gaintb = 0;
1424                         ant_conf->alt_gaintb = 0;
1425                         break;
1426                 case 0x21: /* LNA1 LNA2 */
1427                         ant_conf->fast_div_bias = 0x1;
1428                         ant_conf->main_gaintb = 0;
1429                         ant_conf->alt_gaintb = 0;
1430                         break;
1431                 case 0x23: /* LNA1 A+B */
1432                         if (!(antcomb->scan) &&
1433                             (alt_ratio > ATH_ANT_DIV_COMB_ALT_ANT_RATIO))
1434                                 ant_conf->fast_div_bias = 0x3f;
1435                         else
1436                                 ant_conf->fast_div_bias = 0x1;
1437                         ant_conf->main_gaintb = 0;
1438                         ant_conf->alt_gaintb = 0;
1439                         break;
1440                 case 0x30: /* A+B A-B */
1441                         ant_conf->fast_div_bias = 0x1;
1442                         ant_conf->main_gaintb = 0;
1443                         ant_conf->alt_gaintb = 0;
1444                         break;
1445                 case 0x31: /* A+B LNA2 */
1446                         ant_conf->fast_div_bias = 0x1;
1447                         ant_conf->main_gaintb = 0;
1448                         ant_conf->alt_gaintb = 0;
1449                         break;
1450                 case 0x32: /* A+B LNA1 */
1451                         ant_conf->fast_div_bias = 0x1;
1452                         ant_conf->main_gaintb = 0;
1453                         ant_conf->alt_gaintb = 0;
1454                         break;
1455                 default:
1456                         break;
1457                 }
1458         } else if (ant_conf->div_group == 2) {
1459                 /* Adjust the fast_div_bias based on main and alt_lna_conf */
1460                 switch ((ant_conf->main_lna_conf << 4) |
1461                                 ant_conf->alt_lna_conf) {
1462                 case 0x01: /* A-B LNA2 */
1463                         ant_conf->fast_div_bias = 0x1;
1464                         ant_conf->main_gaintb = 0;
1465                         ant_conf->alt_gaintb = 0;
1466                         break;
1467                 case 0x02: /* A-B LNA1 */
1468                         ant_conf->fast_div_bias = 0x1;
1469                         ant_conf->main_gaintb = 0;
1470                         ant_conf->alt_gaintb = 0;
1471                         break;
1472                 case 0x03: /* A-B A+B */
1473                         ant_conf->fast_div_bias = 0x1;
1474                         ant_conf->main_gaintb = 0;
1475                         ant_conf->alt_gaintb = 0;
1476                         break;
1477                 case 0x10: /* LNA2 A-B */
1478                         if (!(antcomb->scan) &&
1479                                 (alt_ratio > ATH_ANT_DIV_COMB_ALT_ANT_RATIO))
1480                                 ant_conf->fast_div_bias = 0x1;
1481                         else
1482                                 ant_conf->fast_div_bias = 0x2;
1483                         ant_conf->main_gaintb = 0;
1484                         ant_conf->alt_gaintb = 0;
1485                         break;
1486                 case 0x12: /* LNA2 LNA1 */
1487                         ant_conf->fast_div_bias = 0x1;
1488                         ant_conf->main_gaintb = 0;
1489                         ant_conf->alt_gaintb = 0;
1490                         break;
1491                 case 0x13: /* LNA2 A+B */
1492                         if (!(antcomb->scan) &&
1493                                 (alt_ratio > ATH_ANT_DIV_COMB_ALT_ANT_RATIO))
1494                                 ant_conf->fast_div_bias = 0x1;
1495                         else
1496                                 ant_conf->fast_div_bias = 0x2;
1497                         ant_conf->main_gaintb = 0;
1498                         ant_conf->alt_gaintb = 0;
1499                         break;
1500                 case 0x20: /* LNA1 A-B */
1501                         if (!(antcomb->scan) &&
1502                                 (alt_ratio > ATH_ANT_DIV_COMB_ALT_ANT_RATIO))
1503                                 ant_conf->fast_div_bias = 0x1;
1504                         else
1505                                 ant_conf->fast_div_bias = 0x2;
1506                         ant_conf->main_gaintb = 0;
1507                         ant_conf->alt_gaintb = 0;
1508                         break;
1509                 case 0x21: /* LNA1 LNA2 */
1510                         ant_conf->fast_div_bias = 0x1;
1511                         ant_conf->main_gaintb = 0;
1512                         ant_conf->alt_gaintb = 0;
1513                         break;
1514                 case 0x23: /* LNA1 A+B */
1515                         if (!(antcomb->scan) &&
1516                                 (alt_ratio > ATH_ANT_DIV_COMB_ALT_ANT_RATIO))
1517                                 ant_conf->fast_div_bias = 0x1;
1518                         else
1519                                 ant_conf->fast_div_bias = 0x2;
1520                         ant_conf->main_gaintb = 0;
1521                         ant_conf->alt_gaintb = 0;
1522                         break;
1523                 case 0x30: /* A+B A-B */
1524                         ant_conf->fast_div_bias = 0x1;
1525                         ant_conf->main_gaintb = 0;
1526                         ant_conf->alt_gaintb = 0;
1527                         break;
1528                 case 0x31: /* A+B LNA2 */
1529                         ant_conf->fast_div_bias = 0x1;
1530                         ant_conf->main_gaintb = 0;
1531                         ant_conf->alt_gaintb = 0;
1532                         break;
1533                 case 0x32: /* A+B LNA1 */
1534                         ant_conf->fast_div_bias = 0x1;
1535                         ant_conf->main_gaintb = 0;
1536                         ant_conf->alt_gaintb = 0;
1537                         break;
1538                 default:
1539                         break;
1540                 }
1541         }
1542 }
1543
1544 /* Antenna diversity and combining */
1545 static void ath_ant_comb_scan(struct ath_softc *sc, struct ath_rx_status *rs)
1546 {
1547         struct ath_hw_antcomb_conf div_ant_conf;
1548         struct ath_ant_comb *antcomb = &sc->ant_comb;
1549         int alt_ratio = 0, alt_rssi_avg = 0, main_rssi_avg = 0, curr_alt_set;
1550         int curr_main_set;
1551         int main_rssi = rs->rs_rssi_ctl0;
1552         int alt_rssi = rs->rs_rssi_ctl1;
1553         int rx_ant_conf,  main_ant_conf;
1554         bool short_scan = false;
1555
1556         rx_ant_conf = (rs->rs_rssi_ctl2 >> ATH_ANT_RX_CURRENT_SHIFT) &
1557                        ATH_ANT_RX_MASK;
1558         main_ant_conf = (rs->rs_rssi_ctl2 >> ATH_ANT_RX_MAIN_SHIFT) &
1559                          ATH_ANT_RX_MASK;
1560
1561         /* Record packet only when both main_rssi and  alt_rssi is positive */
1562         if (main_rssi > 0 && alt_rssi > 0) {
1563                 antcomb->total_pkt_count++;
1564                 antcomb->main_total_rssi += main_rssi;
1565                 antcomb->alt_total_rssi  += alt_rssi;
1566                 if (main_ant_conf == rx_ant_conf)
1567                         antcomb->main_recv_cnt++;
1568                 else
1569                         antcomb->alt_recv_cnt++;
1570         }
1571
1572         /* Short scan check */
1573         if (antcomb->scan && antcomb->alt_good) {
1574                 if (time_after(jiffies, antcomb->scan_start_time +
1575                     msecs_to_jiffies(ATH_ANT_DIV_COMB_SHORT_SCAN_INTR)))
1576                         short_scan = true;
1577                 else
1578                         if (antcomb->total_pkt_count ==
1579                             ATH_ANT_DIV_COMB_SHORT_SCAN_PKTCOUNT) {
1580                                 alt_ratio = ((antcomb->alt_recv_cnt * 100) /
1581                                             antcomb->total_pkt_count);
1582                                 if (alt_ratio < ATH_ANT_DIV_COMB_ALT_ANT_RATIO)
1583                                         short_scan = true;
1584                         }
1585         }
1586
1587         if (((antcomb->total_pkt_count < ATH_ANT_DIV_COMB_MAX_PKTCOUNT) ||
1588             rs->rs_moreaggr) && !short_scan)
1589                 return;
1590
1591         if (antcomb->total_pkt_count) {
1592                 alt_ratio = ((antcomb->alt_recv_cnt * 100) /
1593                              antcomb->total_pkt_count);
1594                 main_rssi_avg = (antcomb->main_total_rssi /
1595                                  antcomb->total_pkt_count);
1596                 alt_rssi_avg = (antcomb->alt_total_rssi /
1597                                  antcomb->total_pkt_count);
1598         }
1599
1600
1601         ath9k_hw_antdiv_comb_conf_get(sc->sc_ah, &div_ant_conf);
1602         curr_alt_set = div_ant_conf.alt_lna_conf;
1603         curr_main_set = div_ant_conf.main_lna_conf;
1604
1605         antcomb->count++;
1606
1607         if (antcomb->count == ATH_ANT_DIV_COMB_MAX_COUNT) {
1608                 if (alt_ratio > ATH_ANT_DIV_COMB_ALT_ANT_RATIO) {
1609                         ath_lnaconf_alt_good_scan(antcomb, div_ant_conf,
1610                                                   main_rssi_avg);
1611                         antcomb->alt_good = true;
1612                 } else {
1613                         antcomb->alt_good = false;
1614                 }
1615
1616                 antcomb->count = 0;
1617                 antcomb->scan = true;
1618                 antcomb->scan_not_start = true;
1619         }
1620
1621         if (!antcomb->scan) {
1622                 if (ath_ant_div_comb_alt_check(div_ant_conf.div_group,
1623                                         alt_ratio, curr_main_set, curr_alt_set,
1624                                         alt_rssi_avg, main_rssi_avg)) {
1625                         if (curr_alt_set == ATH_ANT_DIV_COMB_LNA2) {
1626                                 /* Switch main and alt LNA */
1627                                 div_ant_conf.main_lna_conf =
1628                                                 ATH_ANT_DIV_COMB_LNA2;
1629                                 div_ant_conf.alt_lna_conf  =
1630                                                 ATH_ANT_DIV_COMB_LNA1;
1631                         } else if (curr_alt_set == ATH_ANT_DIV_COMB_LNA1) {
1632                                 div_ant_conf.main_lna_conf =
1633                                                 ATH_ANT_DIV_COMB_LNA1;
1634                                 div_ant_conf.alt_lna_conf  =
1635                                                 ATH_ANT_DIV_COMB_LNA2;
1636                         }
1637
1638                         goto div_comb_done;
1639                 } else if ((curr_alt_set != ATH_ANT_DIV_COMB_LNA1) &&
1640                            (curr_alt_set != ATH_ANT_DIV_COMB_LNA2)) {
1641                         /* Set alt to another LNA */
1642                         if (curr_main_set == ATH_ANT_DIV_COMB_LNA2)
1643                                 div_ant_conf.alt_lna_conf =
1644                                                 ATH_ANT_DIV_COMB_LNA1;
1645                         else if (curr_main_set == ATH_ANT_DIV_COMB_LNA1)
1646                                 div_ant_conf.alt_lna_conf =
1647                                                 ATH_ANT_DIV_COMB_LNA2;
1648
1649                         goto div_comb_done;
1650                 }
1651
1652                 if ((alt_rssi_avg < (main_rssi_avg +
1653                                                 div_ant_conf.lna1_lna2_delta)))
1654                         goto div_comb_done;
1655         }
1656
1657         if (!antcomb->scan_not_start) {
1658                 switch (curr_alt_set) {
1659                 case ATH_ANT_DIV_COMB_LNA2:
1660                         antcomb->rssi_lna2 = alt_rssi_avg;
1661                         antcomb->rssi_lna1 = main_rssi_avg;
1662                         antcomb->scan = true;
1663                         /* set to A+B */
1664                         div_ant_conf.main_lna_conf =
1665                                 ATH_ANT_DIV_COMB_LNA1;
1666                         div_ant_conf.alt_lna_conf  =
1667                                 ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2;
1668                         break;
1669                 case ATH_ANT_DIV_COMB_LNA1:
1670                         antcomb->rssi_lna1 = alt_rssi_avg;
1671                         antcomb->rssi_lna2 = main_rssi_avg;
1672                         antcomb->scan = true;
1673                         /* set to A+B */
1674                         div_ant_conf.main_lna_conf = ATH_ANT_DIV_COMB_LNA2;
1675                         div_ant_conf.alt_lna_conf  =
1676                                 ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2;
1677                         break;
1678                 case ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2:
1679                         antcomb->rssi_add = alt_rssi_avg;
1680                         antcomb->scan = true;
1681                         /* set to A-B */
1682                         div_ant_conf.alt_lna_conf =
1683                                 ATH_ANT_DIV_COMB_LNA1_MINUS_LNA2;
1684                         break;
1685                 case ATH_ANT_DIV_COMB_LNA1_MINUS_LNA2:
1686                         antcomb->rssi_sub = alt_rssi_avg;
1687                         antcomb->scan = false;
1688                         if (antcomb->rssi_lna2 >
1689                             (antcomb->rssi_lna1 +
1690                             ATH_ANT_DIV_COMB_LNA1_LNA2_SWITCH_DELTA)) {
1691                                 /* use LNA2 as main LNA */
1692                                 if ((antcomb->rssi_add > antcomb->rssi_lna1) &&
1693                                     (antcomb->rssi_add > antcomb->rssi_sub)) {
1694                                         /* set to A+B */
1695                                         div_ant_conf.main_lna_conf =
1696                                                 ATH_ANT_DIV_COMB_LNA2;
1697                                         div_ant_conf.alt_lna_conf  =
1698                                                 ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2;
1699                                 } else if (antcomb->rssi_sub >
1700                                            antcomb->rssi_lna1) {
1701                                         /* set to A-B */
1702                                         div_ant_conf.main_lna_conf =
1703                                                 ATH_ANT_DIV_COMB_LNA2;
1704                                         div_ant_conf.alt_lna_conf =
1705                                                 ATH_ANT_DIV_COMB_LNA1_MINUS_LNA2;
1706                                 } else {
1707                                         /* set to LNA1 */
1708                                         div_ant_conf.main_lna_conf =
1709                                                 ATH_ANT_DIV_COMB_LNA2;
1710                                         div_ant_conf.alt_lna_conf =
1711                                                 ATH_ANT_DIV_COMB_LNA1;
1712                                 }
1713                         } else {
1714                                 /* use LNA1 as main LNA */
1715                                 if ((antcomb->rssi_add > antcomb->rssi_lna2) &&
1716                                     (antcomb->rssi_add > antcomb->rssi_sub)) {
1717                                         /* set to A+B */
1718                                         div_ant_conf.main_lna_conf =
1719                                                 ATH_ANT_DIV_COMB_LNA1;
1720                                         div_ant_conf.alt_lna_conf  =
1721                                                 ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2;
1722                                 } else if (antcomb->rssi_sub >
1723                                            antcomb->rssi_lna1) {
1724                                         /* set to A-B */
1725                                         div_ant_conf.main_lna_conf =
1726                                                 ATH_ANT_DIV_COMB_LNA1;
1727                                         div_ant_conf.alt_lna_conf =
1728                                                 ATH_ANT_DIV_COMB_LNA1_MINUS_LNA2;
1729                                 } else {
1730                                         /* set to LNA2 */
1731                                         div_ant_conf.main_lna_conf =
1732                                                 ATH_ANT_DIV_COMB_LNA1;
1733                                         div_ant_conf.alt_lna_conf =
1734                                                 ATH_ANT_DIV_COMB_LNA2;
1735                                 }
1736                         }
1737                         break;
1738                 default:
1739                         break;
1740                 }
1741         } else {
1742                 if (!antcomb->alt_good) {
1743                         antcomb->scan_not_start = false;
1744                         /* Set alt to another LNA */
1745                         if (curr_main_set == ATH_ANT_DIV_COMB_LNA2) {
1746                                 div_ant_conf.main_lna_conf =
1747                                                 ATH_ANT_DIV_COMB_LNA2;
1748                                 div_ant_conf.alt_lna_conf =
1749                                                 ATH_ANT_DIV_COMB_LNA1;
1750                         } else if (curr_main_set == ATH_ANT_DIV_COMB_LNA1) {
1751                                 div_ant_conf.main_lna_conf =
1752                                                 ATH_ANT_DIV_COMB_LNA1;
1753                                 div_ant_conf.alt_lna_conf =
1754                                                 ATH_ANT_DIV_COMB_LNA2;
1755                         }
1756                         goto div_comb_done;
1757                 }
1758         }
1759
1760         ath_select_ant_div_from_quick_scan(antcomb, &div_ant_conf,
1761                                            main_rssi_avg, alt_rssi_avg,
1762                                            alt_ratio);
1763
1764         antcomb->quick_scan_cnt++;
1765
1766 div_comb_done:
1767         ath_ant_div_conf_fast_divbias(&div_ant_conf, antcomb, alt_ratio);
1768         ath9k_hw_antdiv_comb_conf_set(sc->sc_ah, &div_ant_conf);
1769
1770         antcomb->scan_start_time = jiffies;
1771         antcomb->total_pkt_count = 0;
1772         antcomb->main_total_rssi = 0;
1773         antcomb->alt_total_rssi = 0;
1774         antcomb->main_recv_cnt = 0;
1775         antcomb->alt_recv_cnt = 0;
1776 }
1777
1778 int ath_rx_tasklet(struct ath_softc *sc, int flush, bool hp)
1779 {
1780         struct ath_buf *bf;
1781         struct sk_buff *skb = NULL, *requeue_skb, *hdr_skb;
1782         struct ieee80211_rx_status *rxs;
1783         struct ath_hw *ah = sc->sc_ah;
1784         struct ath_common *common = ath9k_hw_common(ah);
1785         /*
1786          * The hw can technically differ from common->hw when using ath9k
1787          * virtual wiphy so to account for that we iterate over the active
1788          * wiphys and find the appropriate wiphy and therefore hw.
1789          */
1790         struct ieee80211_hw *hw = sc->hw;
1791         struct ieee80211_hdr *hdr;
1792         int retval;
1793         bool decrypt_error = false;
1794         struct ath_rx_status rs;
1795         enum ath9k_rx_qtype qtype;
1796         bool edma = !!(ah->caps.hw_caps & ATH9K_HW_CAP_EDMA);
1797         int dma_type;
1798         u8 rx_status_len = ah->caps.rx_status_len;
1799         u64 tsf = 0;
1800         u32 tsf_lower = 0;
1801         unsigned long flags;
1802
1803         if (edma)
1804                 dma_type = DMA_BIDIRECTIONAL;
1805         else
1806                 dma_type = DMA_FROM_DEVICE;
1807
1808         qtype = hp ? ATH9K_RX_QUEUE_HP : ATH9K_RX_QUEUE_LP;
1809         spin_lock_bh(&sc->rx.rxbuflock);
1810
1811         tsf = ath9k_hw_gettsf64(ah);
1812         tsf_lower = tsf & 0xffffffff;
1813
1814         do {
1815                 /* If handling rx interrupt and flush is in progress => exit */
1816                 if ((sc->sc_flags & SC_OP_RXFLUSH) && (flush == 0))
1817                         break;
1818
1819                 memset(&rs, 0, sizeof(rs));
1820                 if (edma)
1821                         bf = ath_edma_get_next_rx_buf(sc, &rs, qtype);
1822                 else
1823                         bf = ath_get_next_rx_buf(sc, &rs);
1824
1825                 if (!bf)
1826                         break;
1827
1828                 skb = bf->bf_mpdu;
1829                 if (!skb)
1830                         continue;
1831
1832                 /*
1833                  * Take frame header from the first fragment and RX status from
1834                  * the last one.
1835                  */
1836                 if (sc->rx.frag)
1837                         hdr_skb = sc->rx.frag;
1838                 else
1839                         hdr_skb = skb;
1840
1841                 hdr = (struct ieee80211_hdr *) (hdr_skb->data + rx_status_len);
1842                 rxs = IEEE80211_SKB_RXCB(hdr_skb);
1843
1844                 ath_debug_stat_rx(sc, &rs);
1845
1846                 /*
1847                  * If we're asked to flush receive queue, directly
1848                  * chain it back at the queue without processing it.
1849                  */
1850                 if (flush)
1851                         goto requeue_drop_frag;
1852
1853                 retval = ath9k_rx_skb_preprocess(common, hw, hdr, &rs,
1854                                                  rxs, &decrypt_error);
1855                 if (retval)
1856                         goto requeue_drop_frag;
1857
1858                 rxs->mactime = (tsf & ~0xffffffffULL) | rs.rs_tstamp;
1859                 if (rs.rs_tstamp > tsf_lower &&
1860                     unlikely(rs.rs_tstamp - tsf_lower > 0x10000000))
1861                         rxs->mactime -= 0x100000000ULL;
1862
1863                 if (rs.rs_tstamp < tsf_lower &&
1864                     unlikely(tsf_lower - rs.rs_tstamp > 0x10000000))
1865                         rxs->mactime += 0x100000000ULL;
1866
1867                 /* Ensure we always have an skb to requeue once we are done
1868                  * processing the current buffer's skb */
1869                 requeue_skb = ath_rxbuf_alloc(common, common->rx_bufsize, GFP_ATOMIC);
1870
1871                 /* If there is no memory we ignore the current RX'd frame,
1872                  * tell hardware it can give us a new frame using the old
1873                  * skb and put it at the tail of the sc->rx.rxbuf list for
1874                  * processing. */
1875                 if (!requeue_skb)
1876                         goto requeue_drop_frag;
1877
1878                 /* Unmap the frame */
1879                 dma_unmap_single(sc->dev, bf->bf_buf_addr,
1880                                  common->rx_bufsize,
1881                                  dma_type);
1882
1883                 skb_put(skb, rs.rs_datalen + ah->caps.rx_status_len);
1884                 if (ah->caps.rx_status_len)
1885                         skb_pull(skb, ah->caps.rx_status_len);
1886
1887                 if (!rs.rs_more)
1888                         ath9k_rx_skb_postprocess(common, hdr_skb, &rs,
1889                                                  rxs, decrypt_error);
1890
1891                 /* We will now give hardware our shiny new allocated skb */
1892                 bf->bf_mpdu = requeue_skb;
1893                 bf->bf_buf_addr = dma_map_single(sc->dev, requeue_skb->data,
1894                                                  common->rx_bufsize,
1895                                                  dma_type);
1896                 if (unlikely(dma_mapping_error(sc->dev,
1897                           bf->bf_buf_addr))) {
1898                         dev_kfree_skb_any(requeue_skb);
1899                         bf->bf_mpdu = NULL;
1900                         bf->bf_buf_addr = 0;
1901                         ath_err(common, "dma_mapping_error() on RX\n");
1902                         ieee80211_rx(hw, skb);
1903                         break;
1904                 }
1905
1906                 if (rs.rs_more) {
1907                         /*
1908                          * rs_more indicates chained descriptors which can be
1909                          * used to link buffers together for a sort of
1910                          * scatter-gather operation.
1911                          */
1912                         if (sc->rx.frag) {
1913                                 /* too many fragments - cannot handle frame */
1914                                 dev_kfree_skb_any(sc->rx.frag);
1915                                 dev_kfree_skb_any(skb);
1916                                 skb = NULL;
1917                         }
1918                         sc->rx.frag = skb;
1919                         goto requeue;
1920                 }
1921
1922                 if (sc->rx.frag) {
1923                         int space = skb->len - skb_tailroom(hdr_skb);
1924
1925                         sc->rx.frag = NULL;
1926
1927                         if (pskb_expand_head(hdr_skb, 0, space, GFP_ATOMIC) < 0) {
1928                                 dev_kfree_skb(skb);
1929                                 goto requeue_drop_frag;
1930                         }
1931
1932                         skb_copy_from_linear_data(skb, skb_put(hdr_skb, skb->len),
1933                                                   skb->len);
1934                         dev_kfree_skb_any(skb);
1935                         skb = hdr_skb;
1936                 }
1937
1938                 /*
1939                  * change the default rx antenna if rx diversity chooses the
1940                  * other antenna 3 times in a row.
1941                  */
1942                 if (sc->rx.defant != rs.rs_antenna) {
1943                         if (++sc->rx.rxotherant >= 3)
1944                                 ath_setdefantenna(sc, rs.rs_antenna);
1945                 } else {
1946                         sc->rx.rxotherant = 0;
1947                 }
1948
1949                 if (rxs->flag & RX_FLAG_MMIC_STRIPPED)
1950                         skb_trim(skb, skb->len - 8);
1951
1952                 spin_lock_irqsave(&sc->sc_pm_lock, flags);
1953
1954                 if ((sc->ps_flags & (PS_WAIT_FOR_BEACON |
1955                                               PS_WAIT_FOR_CAB |
1956                                               PS_WAIT_FOR_PSPOLL_DATA)) ||
1957                                                 ath9k_check_auto_sleep(sc))
1958                         ath_rx_ps(sc, skb);
1959                 spin_unlock_irqrestore(&sc->sc_pm_lock, flags);
1960
1961                 if (ah->caps.hw_caps & ATH9K_HW_CAP_ANT_DIV_COMB)
1962                         ath_ant_comb_scan(sc, &rs);
1963
1964                 ieee80211_rx(hw, skb);
1965
1966 requeue_drop_frag:
1967                 if (sc->rx.frag) {
1968                         dev_kfree_skb_any(sc->rx.frag);
1969                         sc->rx.frag = NULL;
1970                 }
1971 requeue:
1972                 if (edma) {
1973                         list_add_tail(&bf->list, &sc->rx.rxbuf);
1974                         ath_rx_edma_buf_link(sc, qtype);
1975                 } else {
1976                         list_move_tail(&bf->list, &sc->rx.rxbuf);
1977                         ath_rx_buf_link(sc, bf);
1978                         ath9k_hw_rxena(ah);
1979                 }
1980         } while (1);
1981
1982         spin_unlock_bh(&sc->rx.rxbuflock);
1983
1984         return 0;
1985 }