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 <linux/dma-mapping.h>
  18 #include "ath9k.h"
  19 #include "ar9003_mac.h"
  20
  21 #define SKB_CB_ATHBUF(__skb)    (*((struct ath_buf **)__skb->cb))
  22
  23 static inline bool ath_is_alt_ant_ratio_better(int alt_ratio, int maxdelta,
  24                                                int mindelta, int main_rssi_avg,
  25                                                int alt_rssi_avg, int pkt_count)
  26 {
  27         return (((alt_ratio >= ATH_ANT_DIV_COMB_ALT_ANT_RATIO2) &&
  28                 (alt_rssi_avg > main_rssi_avg + maxdelta)) ||
  29                 (alt_rssi_avg > main_rssi_avg + mindelta)) && (pkt_count > 50);
  30 }
  31
  32 static inline bool ath_ant_div_comb_alt_check(u8 div_group, int alt_ratio,
  33                                         int curr_main_set, int curr_alt_set,
  34                                         int alt_rssi_avg, int main_rssi_avg)
  35 {
  36         bool result = false;
  37         switch (div_group) {
  38         case 0:
  39                 if (alt_ratio > ATH_ANT_DIV_COMB_ALT_ANT_RATIO)
  40                         result = true;
  41                 break;
  42         case 1:
  43         case 2:
  44                 if ((((curr_main_set == ATH_ANT_DIV_COMB_LNA2) &&
  45                         (curr_alt_set == ATH_ANT_DIV_COMB_LNA1) &&
  46                                 (alt_rssi_avg >= (main_rssi_avg - 5))) ||
  47                         ((curr_main_set == ATH_ANT_DIV_COMB_LNA1) &&
  48                         (curr_alt_set == ATH_ANT_DIV_COMB_LNA2) &&
  49                                 (alt_rssi_avg >= (main_rssi_avg - 2)))) &&
  50                                                         (alt_rssi_avg >= 4))
  51                         result = true;
  52                 else
  53                         result = false;
  54                 break;
  55         }
  56
  57         return result;
  58 }
  59
  60 static inline bool ath9k_check_auto_sleep(struct ath_softc *sc)
  61 {
  62         return sc->ps_enabled &&
  63                (sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_AUTOSLEEP);
  64 }
  65
  66 /*
  67  * Setup and link descriptors.
  68  *
  69  * 11N: we can no longer afford to self link the last descriptor.
  70  * MAC acknowledges BA status as long as it copies frames to host
  71  * buffer (or rx fifo). This can incorrectly acknowledge packets
  72  * to a sender if last desc is self-linked.
  73  */
  74 static void ath_rx_buf_link(struct ath_softc *sc, struct ath_buf *bf)
  75 {
  76         struct ath_hw *ah = sc->sc_ah;
  77         struct ath_common *common = ath9k_hw_common(ah);
  78         struct ath_desc *ds;
  79         struct sk_buff *skb;
  80
  81         ATH_RXBUF_RESET(bf);
  82
  83         ds = bf->bf_desc;
  84         ds->ds_link = 0; /* link to null */
  85         ds->ds_data = bf->bf_buf_addr;
  86
  87         /* virtual addr of the beginning of the buffer. */
  88         skb = bf->bf_mpdu;
  89         BUG_ON(skb == NULL);
  90         ds->ds_vdata = skb->data;
  91
  92         /*
  93          * setup rx descriptors. The rx_bufsize here tells the hardware
  94          * how much data it can DMA to us and that we are prepared
  95          * to process
  96          */
  97         ath9k_hw_setuprxdesc(ah, ds,
  98                              common->rx_bufsize,
  99                              0);
 100
 101         if (sc->rx.rxlink == NULL)
 102                 ath9k_hw_putrxbuf(ah, bf->bf_daddr);
 103         else
 104                 *sc->rx.rxlink = bf->bf_daddr;
 105
 106         sc->rx.rxlink = &ds->ds_link;
 107 }
 108
 109 static void ath_setdefantenna(struct ath_softc *sc, u32 antenna)
 110 {
 111         /* XXX block beacon interrupts */
 112         ath9k_hw_setantenna(sc->sc_ah, antenna);
 113         sc->rx.defant = antenna;
 114         sc->rx.rxotherant = 0;
 115 }
 116
 117 static void ath_opmode_init(struct ath_softc *sc)
 118 {
 119         struct ath_hw *ah = sc->sc_ah;
 120         struct ath_common *common = ath9k_hw_common(ah);
 121
 122         u32 rfilt, mfilt[2];
 123
 124         /* configure rx filter */
 125         rfilt = ath_calcrxfilter(sc);
 126         ath9k_hw_setrxfilter(ah, rfilt);
 127
 128         /* configure bssid mask */
 129         ath_hw_setbssidmask(common);
 130
 131         /* configure operational mode */
 132         ath9k_hw_setopmode(ah);
 133
 134         /* calculate and install multicast filter */
 135         mfilt[0] = mfilt[1] = ~0;
 136         ath9k_hw_setmcastfilter(ah, mfilt[0], mfilt[1]);
 137 }
 138
 139 static bool ath_rx_edma_buf_link(struct ath_softc *sc,
 140                                  enum ath9k_rx_qtype qtype)
 141 {
 142         struct ath_hw *ah = sc->sc_ah;
 143         struct ath_rx_edma *rx_edma;
 144         struct sk_buff *skb;
 145         struct ath_buf *bf;
 146
 147         rx_edma = &sc->rx.rx_edma[qtype];
 148         if (skb_queue_len(&rx_edma->rx_fifo) >= rx_edma->rx_fifo_hwsize)
 149                 return false;
 150
 151         bf = list_first_entry(&sc->rx.rxbuf, struct ath_buf, list);
 152         list_del_init(&bf->list);
 153
 154         skb = bf->bf_mpdu;
 155
 156         ATH_RXBUF_RESET(bf);
 157         memset(skb->data, 0, ah->caps.rx_status_len);
 158         dma_sync_single_for_device(sc->dev, bf->bf_buf_addr,
 159                                 ah->caps.rx_status_len, DMA_TO_DEVICE);
 160
 161         SKB_CB_ATHBUF(skb) = bf;
 162         ath9k_hw_addrxbuf_edma(ah, bf->bf_buf_addr, qtype);
 163         skb_queue_tail(&rx_edma->rx_fifo, skb);
 164
 165         return true;
 166 }
 167
 168 static void ath_rx_addbuffer_edma(struct ath_softc *sc,
 169                                   enum ath9k_rx_qtype qtype, int size)
 170 {
 171         struct ath_common *common = ath9k_hw_common(sc->sc_ah);
 172         u32 nbuf = 0;
 173
 174         if (list_empty(&sc->rx.rxbuf)) {
 175                 ath_dbg(common, ATH_DBG_QUEUE, "No free rx buf available\n");
 176                 return;
 177         }
 178
 179         while (!list_empty(&sc->rx.rxbuf)) {
 180                 nbuf++;
 181
 182                 if (!ath_rx_edma_buf_link(sc, qtype))
 183                         break;
 184
 185                 if (nbuf >= size)
 186                         break;
 187         }
 188 }
 189
 190 static void ath_rx_remove_buffer(struct ath_softc *sc,
 191                                  enum ath9k_rx_qtype qtype)
 192 {
 193         struct ath_buf *bf;
 194         struct ath_rx_edma *rx_edma;
 195         struct sk_buff *skb;
 196
 197         rx_edma = &sc->rx.rx_edma[qtype];
 198
 199         while ((skb = skb_dequeue(&rx_edma->rx_fifo)) != NULL) {
 200                 bf = SKB_CB_ATHBUF(skb);
 201                 BUG_ON(!bf);
 202                 list_add_tail(&bf->list, &sc->rx.rxbuf);
 203         }
 204 }
 205
 206 static void ath_rx_edma_cleanup(struct ath_softc *sc)
 207 {
 208         struct ath_hw *ah = sc->sc_ah;
 209         struct ath_common *common = ath9k_hw_common(ah);
 210         struct ath_buf *bf;
 211
 212         ath_rx_remove_buffer(sc, ATH9K_RX_QUEUE_LP);
 213         ath_rx_remove_buffer(sc, ATH9K_RX_QUEUE_HP);
 214
 215         list_for_each_entry(bf, &sc->rx.rxbuf, list) {
 216                 if (bf->bf_mpdu) {
 217                         dma_unmap_single(sc->dev, bf->bf_buf_addr,
 218                                         common->rx_bufsize,
 219                                         DMA_BIDIRECTIONAL);
 220                         dev_kfree_skb_any(bf->bf_mpdu);
 221                         bf->bf_buf_addr = 0;
 222                         bf->bf_mpdu = NULL;
 223                 }
 224         }
 225
 226         INIT_LIST_HEAD(&sc->rx.rxbuf);
 227
 228         kfree(sc->rx.rx_bufptr);
 229         sc->rx.rx_bufptr = NULL;
 230 }
 231
 232 static void ath_rx_edma_init_queue(struct ath_rx_edma *rx_edma, int size)
 233 {
 234         skb_queue_head_init(&rx_edma->rx_fifo);
 235         skb_queue_head_init(&rx_edma->rx_buffers);
 236         rx_edma->rx_fifo_hwsize = size;
 237 }
 238
 239 static int ath_rx_edma_init(struct ath_softc *sc, int nbufs)
 240 {
 241         struct ath_common *common = ath9k_hw_common(sc->sc_ah);
 242         struct ath_hw *ah = sc->sc_ah;
 243         struct sk_buff *skb;
 244         struct ath_buf *bf;
 245         int error = 0, i;
 246         u32 size;
 247
 248         ath9k_hw_set_rx_bufsize(ah, common->rx_bufsize -
 249                                     ah->caps.rx_status_len);
 250
 251         ath_rx_edma_init_queue(&sc->rx.rx_edma[ATH9K_RX_QUEUE_LP],
 252                                ah->caps.rx_lp_qdepth);
 253         ath_rx_edma_init_queue(&sc->rx.rx_edma[ATH9K_RX_QUEUE_HP],
 254                                ah->caps.rx_hp_qdepth);
 255
 256         size = sizeof(struct ath_buf) * nbufs;
 257         bf = kzalloc(size, GFP_KERNEL);
 258         if (!bf)
 259                 return -ENOMEM;
 260
 261         INIT_LIST_HEAD(&sc->rx.rxbuf);
 262         sc->rx.rx_bufptr = bf;
 263
 264         for (i = 0; i < nbufs; i++, bf++) {
 265                 skb = ath_rxbuf_alloc(common, common->rx_bufsize, GFP_KERNEL);
 266                 if (!skb) {
 267                         error = -ENOMEM;
 268                         goto rx_init_fail;
 269                 }
 270
 271                 memset(skb->data, 0, common->rx_bufsize);
 272                 bf->bf_mpdu = skb;
 273
 274                 bf->bf_buf_addr = dma_map_single(sc->dev, skb->data,
 275                                                  common->rx_bufsize,
 276                                                  DMA_BIDIRECTIONAL);
 277                 if (unlikely(dma_mapping_error(sc->dev,
 278                                                 bf->bf_buf_addr))) {
 279                                 dev_kfree_skb_any(skb);
 280                                 bf->bf_mpdu = NULL;
 281                                 bf->bf_buf_addr = 0;
 282                                 ath_err(common,
 283                                         "dma_mapping_error() on RX init\n");
 284                                 error = -ENOMEM;
 285                                 goto rx_init_fail;
 286                 }
 287
 288                 list_add_tail(&bf->list, &sc->rx.rxbuf);
 289         }
 290
 291         return 0;
 292
 293 rx_init_fail:
 294         ath_rx_edma_cleanup(sc);
 295         return error;
 296 }
 297
 298 static void ath_edma_start_recv(struct ath_softc *sc)
 299 {
 300         spin_lock_bh(&sc->rx.rxbuflock);
 301
 302         ath9k_hw_rxena(sc->sc_ah);
 303
 304         ath_rx_addbuffer_edma(sc, ATH9K_RX_QUEUE_HP,
 305                               sc->rx.rx_edma[ATH9K_RX_QUEUE_HP].rx_fifo_hwsize);
 306
 307         ath_rx_addbuffer_edma(sc, ATH9K_RX_QUEUE_LP,
 308                               sc->rx.rx_edma[ATH9K_RX_QUEUE_LP].rx_fifo_hwsize);
 309
 310         ath_opmode_init(sc);
 311
 312         ath9k_hw_startpcureceive(sc->sc_ah, (sc->sc_flags & SC_OP_OFFCHANNEL));
 313
 314         spin_unlock_bh(&sc->rx.rxbuflock);
 315 }
 316
 317 static void ath_edma_stop_recv(struct ath_softc *sc)
 318 {
 319         ath_rx_remove_buffer(sc, ATH9K_RX_QUEUE_HP);
 320         ath_rx_remove_buffer(sc, ATH9K_RX_QUEUE_LP);
 321 }
 322
 323 int ath_rx_init(struct ath_softc *sc, int nbufs)
 324 {
 325         struct ath_common *common = ath9k_hw_common(sc->sc_ah);
 326         struct sk_buff *skb;
 327         struct ath_buf *bf;
 328         int error = 0;
 329
 330         spin_lock_init(&sc->sc_pcu_lock);
 331         sc->sc_flags &= ~SC_OP_RXFLUSH;
 332         spin_lock_init(&sc->rx.rxbuflock);
 333
 334         common->rx_bufsize = IEEE80211_MAX_MPDU_LEN / 2 +
 335                              sc->sc_ah->caps.rx_status_len;
 336
 337         if (sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_EDMA) {
 338                 return ath_rx_edma_init(sc, nbufs);
 339         } else {
 340                 ath_dbg(common, ATH_DBG_CONFIG, "cachelsz %u rxbufsize %u\n",
 341                         common->cachelsz, common->rx_bufsize);
 342
 343                 /* Initialize rx descriptors */
 344
 345                 error = ath_descdma_setup(sc, &sc->rx.rxdma, &sc->rx.rxbuf,
 346                                 "rx", nbufs, 1, 0);
 347                 if (error != 0) {
 348                         ath_err(common,
 349                                 "failed to allocate rx descriptors: %d\n",
 350                                 error);
 351                         goto err;
 352                 }
 353
 354                 list_for_each_entry(bf, &sc->rx.rxbuf, list) {
 355                         skb = ath_rxbuf_alloc(common, common->rx_bufsize,
 356                                               GFP_KERNEL);
 357                         if (skb == NULL) {
 358                                 error = -ENOMEM;
 359                                 goto err;
 360                         }
 361
 362                         bf->bf_mpdu = skb;
 363                         bf->bf_buf_addr = dma_map_single(sc->dev, skb->data,
 364                                         common->rx_bufsize,
 365                                         DMA_FROM_DEVICE);
 366                         if (unlikely(dma_mapping_error(sc->dev,
 367                                                         bf->bf_buf_addr))) {
 368                                 dev_kfree_skb_any(skb);
 369                                 bf->bf_mpdu = NULL;
 370                                 bf->bf_buf_addr = 0;
 371                                 ath_err(common,
 372                                         "dma_mapping_error() on RX init\n");
 373                                 error = -ENOMEM;
 374                                 goto err;
 375                         }
 376                 }
 377                 sc->rx.rxlink = NULL;
 378         }
 379
 380 err:
 381         if (error)
 382                 ath_rx_cleanup(sc);
 383
 384         return error;
 385 }
 386
 387 void ath_rx_cleanup(struct ath_softc *sc)
 388 {
 389         struct ath_hw *ah = sc->sc_ah;
 390         struct ath_common *common = ath9k_hw_common(ah);
 391         struct sk_buff *skb;
 392         struct ath_buf *bf;
 393
 394         if (sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_EDMA) {
 395                 ath_rx_edma_cleanup(sc);
 396                 return;
 397         } else {
 398                 list_for_each_entry(bf, &sc->rx.rxbuf, list) {
 399                         skb = bf->bf_mpdu;
 400                         if (skb) {
 401                                 dma_unmap_single(sc->dev, bf->bf_buf_addr,
 402                                                 common->rx_bufsize,
 403                                                 DMA_FROM_DEVICE);
 404                                 dev_kfree_skb(skb);
 405                                 bf->bf_buf_addr = 0;
 406                                 bf->bf_mpdu = NULL;
 407                         }
 408                 }
 409
 410                 if (sc->rx.rxdma.dd_desc_len != 0)
 411                         ath_descdma_cleanup(sc, &sc->rx.rxdma, &sc->rx.rxbuf);
 412         }
 413 }
 414
 415 /*
 416  * Calculate the receive filter according to the
 417  * operating mode and state:
 418  *
 419  * o always accept unicast, broadcast, and multicast traffic
 420  * o maintain current state of phy error reception (the hal
 421  *   may enable phy error frames for noise immunity work)
 422  * o probe request frames are accepted only when operating in
 423  *   hostap, adhoc, or monitor modes
 424  * o enable promiscuous mode according to the interface state
 425  * o accept beacons:
 426  *   - when operating in adhoc mode so the 802.11 layer creates
 427  *     node table entries for peers,
 428  *   - when operating in station mode for collecting rssi data when
 429  *     the station is otherwise quiet, or
 430  *   - when operating as a repeater so we see repeater-sta beacons
 431  *   - when scanning
 432  */
 433
 434 u32 ath_calcrxfilter(struct ath_softc *sc)
 435 {
 436 #define RX_FILTER_PRESERVE (ATH9K_RX_FILTER_PHYERR | ATH9K_RX_FILTER_PHYRADAR)
 437
 438         u32 rfilt;
 439
 440         rfilt = (ath9k_hw_getrxfilter(sc->sc_ah) & RX_FILTER_PRESERVE)
 441                 | ATH9K_RX_FILTER_UCAST | ATH9K_RX_FILTER_BCAST
 442                 | ATH9K_RX_FILTER_MCAST;
 443
 444         if (sc->rx.rxfilter & FIF_PROBE_REQ)
 445                 rfilt |= ATH9K_RX_FILTER_PROBEREQ;
 446
 447         /*
 448          * Set promiscuous mode when FIF_PROMISC_IN_BSS is enabled for station
 449          * mode interface or when in monitor mode. AP mode does not need this
 450          * since it receives all in-BSS frames anyway.
 451          */
 452         if (sc->sc_ah->is_monitoring)
 453                 rfilt |= ATH9K_RX_FILTER_PROM;
 454
 455         if (sc->rx.rxfilter & FIF_CONTROL)
 456                 rfilt |= ATH9K_RX_FILTER_CONTROL;
 457
 458         if ((sc->sc_ah->opmode == NL80211_IFTYPE_STATION) &&
 459             (sc->nvifs <= 1) &&
 460             !(sc->rx.rxfilter & FIF_BCN_PRBRESP_PROMISC))
 461                 rfilt |= ATH9K_RX_FILTER_MYBEACON;
 462         else
 463                 rfilt |= ATH9K_RX_FILTER_BEACON;
 464
 465         if ((sc->sc_ah->opmode == NL80211_IFTYPE_AP) ||
 466             (sc->rx.rxfilter & FIF_PSPOLL))
 467                 rfilt |= ATH9K_RX_FILTER_PSPOLL;
 468
 469         if (conf_is_ht(&sc->hw->conf))
 470                 rfilt |= ATH9K_RX_FILTER_COMP_BAR;
 471
 472         if (sc->nvifs > 1 || (sc->rx.rxfilter & FIF_OTHER_BSS)) {
 473                 /* The following may also be needed for other older chips */
 474                 if (sc->sc_ah->hw_version.macVersion == AR_SREV_VERSION_9160)
 475                         rfilt |= ATH9K_RX_FILTER_PROM;
 476                 rfilt |= ATH9K_RX_FILTER_MCAST_BCAST_ALL;
 477         }
 478
 479         return rfilt;
 480
 481 #undef RX_FILTER_PRESERVE
 482 }
 483
 484 int ath_startrecv(struct ath_softc *sc)
 485 {
 486         struct ath_hw *ah = sc->sc_ah;
 487         struct ath_buf *bf, *tbf;
 488
 489         if (ah->caps.hw_caps & ATH9K_HW_CAP_EDMA) {
 490                 ath_edma_start_recv(sc);
 491                 return 0;
 492         }
 493
 494         spin_lock_bh(&sc->rx.rxbuflock);
 495         if (list_empty(&sc->rx.rxbuf))
 496                 goto start_recv;
 497
 498         sc->rx.rxlink = NULL;
 499         list_for_each_entry_safe(bf, tbf, &sc->rx.rxbuf, list) {
 500                 ath_rx_buf_link(sc, bf);
 501         }
 502
 503         /* We could have deleted elements so the list may be empty now */
 504         if (list_empty(&sc->rx.rxbuf))
 505                 goto start_recv;
 506
 507         bf = list_first_entry(&sc->rx.rxbuf, struct ath_buf, list);
 508         ath9k_hw_putrxbuf(ah, bf->bf_daddr);
 509         ath9k_hw_rxena(ah);
 510
 511 start_recv:
 512         ath_opmode_init(sc);
 513         ath9k_hw_startpcureceive(ah, (sc->sc_flags & SC_OP_OFFCHANNEL));
 514
 515         spin_unlock_bh(&sc->rx.rxbuflock);
 516
 517         return 0;
 518 }
 519
 520 bool ath_stoprecv(struct ath_softc *sc)
 521 {
 522         struct ath_hw *ah = sc->sc_ah;
 523         bool stopped, reset = false;
 524
 525         spin_lock_bh(&sc->rx.rxbuflock);
 526         ath9k_hw_abortpcurecv(ah);
 527         ath9k_hw_setrxfilter(ah, 0);
 528         stopped = ath9k_hw_stopdmarecv(ah, &reset);
 529
 530         if (sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_EDMA)
 531                 ath_edma_stop_recv(sc);
 532         else
 533                 sc->rx.rxlink = NULL;
 534         spin_unlock_bh(&sc->rx.rxbuflock);
 535
 536         if (!(ah->ah_flags & AH_UNPLUGGED) &&
 537             unlikely(!stopped)) {
 538                 ath_err(ath9k_hw_common(sc->sc_ah),
 539                         "Could not stop RX, we could be "
 540                         "confusing the DMA engine when we start RX up\n");
 541                 ATH_DBG_WARN_ON_ONCE(!stopped);
 542         }
 543         return stopped && !reset;
 544 }
 545
 546 void ath_flushrecv(struct ath_softc *sc)
 547 {
 548         sc->sc_flags |= SC_OP_RXFLUSH;
 549         if (sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_EDMA)
 550                 ath_rx_tasklet(sc, 1, true);
 551         ath_rx_tasklet(sc, 1, false);
 552         sc->sc_flags &= ~SC_OP_RXFLUSH;
 553 }
 554
 555 static bool ath_beacon_dtim_pending_cab(struct sk_buff *skb)
 556 {
 557         /* Check whether the Beacon frame has DTIM indicating buffered bc/mc */
 558         struct ieee80211_mgmt *mgmt;
 559         u8 *pos, *end, id, elen;
 560         struct ieee80211_tim_ie *tim;
 561
 562         mgmt = (struct ieee80211_mgmt *)skb->data;
 563         pos = mgmt->u.beacon.variable;
 564         end = skb->data + skb->len;
 565
 566         while (pos + 2 < end) {
 567                 id = *pos++;
 568                 elen = *pos++;
 569                 if (pos + elen > end)
 570                         break;
 571
 572                 if (id == WLAN_EID_TIM) {
 573                         if (elen < sizeof(*tim))
 574                                 break;
 575                         tim = (struct ieee80211_tim_ie *) pos;
 576                         if (tim->dtim_count != 0)
 577                                 break;
 578                         return tim->bitmap_ctrl & 0x01;
 579                 }
 580
 581                 pos += elen;
 582         }
 583
 584         return false;
 585 }
 586
 587 static void ath_rx_ps_beacon(struct ath_softc *sc, struct sk_buff *skb)
 588 {
 589         struct ieee80211_mgmt *mgmt;
 590         struct ath_common *common = ath9k_hw_common(sc->sc_ah);
 591
 592         if (skb->len < 24 + 8 + 2 + 2)
 593                 return;
 594
 595         mgmt = (struct ieee80211_mgmt *)skb->data;
 596         if (memcmp(common->curbssid, mgmt->bssid, ETH_ALEN) != 0) {
 597                 /* TODO:  This doesn't work well if you have stations
 598                  * associated to two different APs because curbssid
 599                  * is just the last AP that any of the stations associated
 600                  * with.
 601                  */
 602                 return; /* not from our current AP */
 603         }
 604
 605         sc->ps_flags &= ~PS_WAIT_FOR_BEACON;
 606
 607         if (sc->ps_flags & PS_BEACON_SYNC) {
 608                 sc->ps_flags &= ~PS_BEACON_SYNC;
 609                 ath_dbg(common, ATH_DBG_PS,
 610                         "Reconfigure Beacon timers based on timestamp from the AP\n");
 611                 ath_set_beacon(sc);
 612                 sc->ps_flags &= ~PS_TSFOOR_SYNC;
 613         }
 614
 615         if (ath_beacon_dtim_pending_cab(skb)) {
 616                 /*
 617                  * Remain awake waiting for buffered broadcast/multicast
 618                  * frames. If the last broadcast/multicast frame is not
 619                  * received properly, the next beacon frame will work as
 620                  * a backup trigger for returning into NETWORK SLEEP state,
 621                  * so we are waiting for it as well.
 622                  */
 623                 ath_dbg(common, ATH_DBG_PS,
 624                         "Received DTIM beacon indicating buffered broadcast/multicast frame(s)\n");
 625                 sc->ps_flags |= PS_WAIT_FOR_CAB | PS_WAIT_FOR_BEACON;
 626                 return;
 627         }
 628
 629         if (sc->ps_flags & PS_WAIT_FOR_CAB) {
 630                 /*
 631                  * This can happen if a broadcast frame is dropped or the AP
 632                  * fails to send a frame indicating that all CAB frames have
 633                  * been delivered.
 634                  */
 635                 sc->ps_flags &= ~PS_WAIT_FOR_CAB;
 636                 ath_dbg(common, ATH_DBG_PS,
 637                         "PS wait for CAB frames timed out\n");
 638         }
 639 }
 640
 641 static void ath_rx_ps(struct ath_softc *sc, struct sk_buff *skb)
 642 {
 643         struct ieee80211_hdr *hdr;
 644         struct ath_common *common = ath9k_hw_common(sc->sc_ah);
 645
 646         hdr = (struct ieee80211_hdr *)skb->data;
 647
 648         /* Process Beacon and CAB receive in PS state */
 649         if (((sc->ps_flags & PS_WAIT_FOR_BEACON) || ath9k_check_auto_sleep(sc))
 650             && ieee80211_is_beacon(hdr->frame_control))
 651                 ath_rx_ps_beacon(sc, skb);
 652         else if ((sc->ps_flags & PS_WAIT_FOR_CAB) &&
 653                  (ieee80211_is_data(hdr->frame_control) ||
 654                   ieee80211_is_action(hdr->frame_control)) &&
 655                  is_multicast_ether_addr(hdr->addr1) &&
 656                  !ieee80211_has_moredata(hdr->frame_control)) {
 657                 /*
 658                  * No more broadcast/multicast frames to be received at this
 659                  * point.
 660                  */
 661                 sc->ps_flags &= ~(PS_WAIT_FOR_CAB | PS_WAIT_FOR_BEACON);
 662                 ath_dbg(common, ATH_DBG_PS,
 663                         "All PS CAB frames received, back to sleep\n");
 664         } else if ((sc->ps_flags & PS_WAIT_FOR_PSPOLL_DATA) &&
 665                    !is_multicast_ether_addr(hdr->addr1) &&
 666                    !ieee80211_has_morefrags(hdr->frame_control)) {
 667                 sc->ps_flags &= ~PS_WAIT_FOR_PSPOLL_DATA;
 668                 ath_dbg(common, ATH_DBG_PS,
 669                         "Going back to sleep after having received PS-Poll data (0x%lx)\n",
 670                         sc->ps_flags & (PS_WAIT_FOR_BEACON |
 671                                         PS_WAIT_FOR_CAB |
 672                                         PS_WAIT_FOR_PSPOLL_DATA |
 673                                         PS_WAIT_FOR_TX_ACK));
 674         }
 675 }
 676
 677 static bool ath_edma_get_buffers(struct ath_softc *sc,
 678                                  enum ath9k_rx_qtype qtype)
 679 {
 680         struct ath_rx_edma *rx_edma = &sc->rx.rx_edma[qtype];
 681         struct ath_hw *ah = sc->sc_ah;
 682         struct ath_common *common = ath9k_hw_common(ah);
 683         struct sk_buff *skb;
 684         struct ath_buf *bf;
 685         int ret;
 686
 687         skb = skb_peek(&rx_edma->rx_fifo);
 688         if (!skb)
 689                 return false;
 690
 691         bf = SKB_CB_ATHBUF(skb);
 692         BUG_ON(!bf);
 693
 694         dma_sync_single_for_cpu(sc->dev, bf->bf_buf_addr,
 695                                 common->rx_bufsize, DMA_FROM_DEVICE);
 696
 697         ret = ath9k_hw_process_rxdesc_edma(ah, NULL, skb->data);
 698         if (ret == -EINPROGRESS) {
 699                 /*let device gain the buffer again*/
 700                 dma_sync_single_for_device(sc->dev, bf->bf_buf_addr,
 701                                 common->rx_bufsize, DMA_FROM_DEVICE);
 702                 return false;
 703         }
 704
 705         __skb_unlink(skb, &rx_edma->rx_fifo);
 706         if (ret == -EINVAL) {
 707                 /* corrupt descriptor, skip this one and the following one */
 708                 list_add_tail(&bf->list, &sc->rx.rxbuf);
 709                 ath_rx_edma_buf_link(sc, qtype);
 710                 skb = skb_peek(&rx_edma->rx_fifo);
 711                 if (!skb)
 712                         return true;
 713
 714                 bf = SKB_CB_ATHBUF(skb);
 715                 BUG_ON(!bf);
 716
 717                 __skb_unlink(skb, &rx_edma->rx_fifo);
 718                 list_add_tail(&bf->list, &sc->rx.rxbuf);
 719                 ath_rx_edma_buf_link(sc, qtype);
 720                 return true;
 721         }
 722         skb_queue_tail(&rx_edma->rx_buffers, skb);
 723
 724         return true;
 725 }
 726
 727 static struct ath_buf *ath_edma_get_next_rx_buf(struct ath_softc *sc,
 728                                                 struct ath_rx_status *rs,
 729                                                 enum ath9k_rx_qtype qtype)
 730 {
 731         struct ath_rx_edma *rx_edma = &sc->rx.rx_edma[qtype];
 732         struct sk_buff *skb;
 733         struct ath_buf *bf;
 734
 735         while (ath_edma_get_buffers(sc, qtype));
 736         skb = __skb_dequeue(&rx_edma->rx_buffers);
 737         if (!skb)
 738                 return NULL;
 739
 740         bf = SKB_CB_ATHBUF(skb);
 741         ath9k_hw_process_rxdesc_edma(sc->sc_ah, rs, skb->data);
 742         return bf;
 743 }
 744
 745 static struct ath_buf *ath_get_next_rx_buf(struct ath_softc *sc,
 746                                            struct ath_rx_status *rs)
 747 {
 748         struct ath_hw *ah = sc->sc_ah;
 749         struct ath_common *common = ath9k_hw_common(ah);
 750         struct ath_desc *ds;
 751         struct ath_buf *bf;
 752         int ret;
 753
 754         if (list_empty(&sc->rx.rxbuf)) {
 755                 sc->rx.rxlink = NULL;
 756                 return NULL;
 757         }
 758
 759         bf = list_first_entry(&sc->rx.rxbuf, struct ath_buf, list);
 760         ds = bf->bf_desc;
 761
 762         /*
 763          * Must provide the virtual address of the current
 764          * descriptor, the physical address, and the virtual
 765          * address of the next descriptor in the h/w chain.
 766          * This allows the HAL to look ahead to see if the
 767          * hardware is done with a descriptor by checking the
 768          * done bit in the following descriptor and the address
 769          * of the current descriptor the DMA engine is working
 770          * on.  All this is necessary because of our use of
 771          * a self-linked list to avoid rx overruns.
 772          */
 773         ret = ath9k_hw_rxprocdesc(ah, ds, rs, 0);
 774         if (ret == -EINPROGRESS) {
 775                 struct ath_rx_status trs;
 776                 struct ath_buf *tbf;
 777                 struct ath_desc *tds;
 778
 779                 memset(&trs, 0, sizeof(trs));
 780                 if (list_is_last(&bf->list, &sc->rx.rxbuf)) {
 781                         sc->rx.rxlink = NULL;
 782                         return NULL;
 783                 }
 784
 785                 tbf = list_entry(bf->list.next, struct ath_buf, list);
 786
 787                 /*
 788                  * On some hardware the descriptor status words could
 789                  * get corrupted, including the done bit. Because of
 790                  * this, check if the next descriptor's done bit is
 791                  * set or not.
 792                  *
 793                  * If the next descriptor's done bit is set, the current
 794                  * descriptor has been corrupted. Force s/w to discard
 795                  * this descriptor and continue...
 796                  */
 797
 798                 tds = tbf->bf_desc;
 799                 ret = ath9k_hw_rxprocdesc(ah, tds, &trs, 0);
 800                 if (ret == -EINPROGRESS)
 801                         return NULL;
 802         }
 803
 804         if (!bf->bf_mpdu)
 805                 return bf;
 806
 807         /*
 808          * Synchronize the DMA transfer with CPU before
 809          * 1. accessing the frame
 810          * 2. requeueing the same buffer to h/w
 811          */
 812         dma_sync_single_for_cpu(sc->dev, bf->bf_buf_addr,
 813                         common->rx_bufsize,
 814                         DMA_FROM_DEVICE);
 815
 816         return bf;
 817 }
 818
 819 /* Assumes you've already done the endian to CPU conversion */
 820 static bool ath9k_rx_accept(struct ath_common *common,
 821                             struct ieee80211_hdr *hdr,
 822                             struct ieee80211_rx_status *rxs,
 823                             struct ath_rx_status *rx_stats,
 824                             bool *decrypt_error)
 825 {
 826         bool is_mc, is_valid_tkip, strip_mic, mic_error;
 827         struct ath_hw *ah = common->ah;
 828         __le16 fc;
 829         u8 rx_status_len = ah->caps.rx_status_len;
 830
 831         fc = hdr->frame_control;
 832
 833         is_mc = !!is_multicast_ether_addr(hdr->addr1);
 834         is_valid_tkip = rx_stats->rs_keyix != ATH9K_RXKEYIX_INVALID &&
 835                 test_bit(rx_stats->rs_keyix, common->tkip_keymap);
 836         strip_mic = is_valid_tkip && !(rx_stats->rs_status &
 837                 (ATH9K_RXERR_DECRYPT | ATH9K_RXERR_CRC | ATH9K_RXERR_MIC));
 838
 839         if (!rx_stats->rs_datalen)
 840                 return false;
 841         /*
 842          * rs_status follows rs_datalen so if rs_datalen is too large
 843          * we can take a hint that hardware corrupted it, so ignore
 844          * those frames.
 845          */
 846         if (rx_stats->rs_datalen > (common->rx_bufsize - rx_status_len))
 847                 return false;
 848
 849         /* Only use error bits from the last fragment */
 850         if (rx_stats->rs_more)
 851                 return true;
 852
 853         mic_error = is_valid_tkip && !ieee80211_is_ctl(fc) &&
 854                 !ieee80211_has_morefrags(fc) &&
 855                 !(le16_to_cpu(hdr->seq_ctrl) & IEEE80211_SCTL_FRAG) &&
 856                 (rx_stats->rs_status & ATH9K_RXERR_MIC);
 857
 858         /*
 859          * The rx_stats->rs_status will not be set until the end of the
 860          * chained descriptors so it can be ignored if rs_more is set. The
 861          * rs_more will be false at the last element of the chained
 862          * descriptors.
 863          */
 864         if (rx_stats->rs_status != 0) {
 865                 if (rx_stats->rs_status & ATH9K_RXERR_CRC) {
 866                         rxs->flag |= RX_FLAG_FAILED_FCS_CRC;
 867                         mic_error = false;
 868                 }
 869                 if (rx_stats->rs_status & ATH9K_RXERR_PHY)
 870                         return false;
 871
 872                 if (rx_stats->rs_status & ATH9K_RXERR_DECRYPT) {
 873                         *decrypt_error = true;
 874                         mic_error = false;
 875                 }
 876
 877                 /*
 878                  * Reject error frames with the exception of
 879                  * decryption and MIC failures. For monitor mode,
 880                  * we also ignore the CRC error.
 881                  */
 882                 if (ah->is_monitoring) {
 883                         if (rx_stats->rs_status &
 884                             ~(ATH9K_RXERR_DECRYPT | ATH9K_RXERR_MIC |
 885                               ATH9K_RXERR_CRC))
 886                                 return false;
 887                 } else {
 888                         if (rx_stats->rs_status &
 889                             ~(ATH9K_RXERR_DECRYPT | ATH9K_RXERR_MIC)) {
 890                                 return false;
 891                         }
 892                 }
 893         }
 894
 895         /*
 896          * For unicast frames the MIC error bit can have false positives,
 897          * so all MIC error reports need to be validated in software.
 898          * False negatives are not common, so skip software verification
 899          * if the hardware considers the MIC valid.
 900          */
 901         if (strip_mic)
 902                 rxs->flag |= RX_FLAG_MMIC_STRIPPED;
 903         else if (is_mc && mic_error)
 904                 rxs->flag |= RX_FLAG_MMIC_ERROR;
 905
 906         return true;
 907 }
 908
 909 static int ath9k_process_rate(struct ath_common *common,
 910                               struct ieee80211_hw *hw,
 911                               struct ath_rx_status *rx_stats,
 912                               struct ieee80211_rx_status *rxs)
 913 {
 914         struct ieee80211_supported_band *sband;
 915         enum ieee80211_band band;
 916         unsigned int i = 0;
 917
 918         band = hw->conf.channel->band;
 919         sband = hw->wiphy->bands[band];
 920
 921         if (rx_stats->rs_rate & 0x80) {
 922                 /* HT rate */
 923                 rxs->flag |= RX_FLAG_HT;
 924                 if (rx_stats->rs_flags & ATH9K_RX_2040)
 925                         rxs->flag |= RX_FLAG_40MHZ;
 926                 if (rx_stats->rs_flags & ATH9K_RX_GI)
 927                         rxs->flag |= RX_FLAG_SHORT_GI;
 928                 rxs->rate_idx = rx_stats->rs_rate & 0x7f;
 929                 return 0;
 930         }
 931
 932         for (i = 0; i < sband->n_bitrates; i++) {
 933                 if (sband->bitrates[i].hw_value == rx_stats->rs_rate) {
 934                         rxs->rate_idx = i;
 935                         return 0;
 936                 }
 937                 if (sband->bitrates[i].hw_value_short == rx_stats->rs_rate) {
 938                         rxs->flag |= RX_FLAG_SHORTPRE;
 939                         rxs->rate_idx = i;
 940                         return 0;
 941                 }
 942         }
 943
 944         /*
 945          * No valid hardware bitrate found -- we should not get here
 946          * because hardware has already validated this frame as OK.
 947          */
 948         ath_dbg(common, ATH_DBG_XMIT,
 949                 "unsupported hw bitrate detected 0x%02x using 1 Mbit\n",
 950                 rx_stats->rs_rate);
 951
 952         return -EINVAL;
 953 }
 954
 955 static void ath9k_process_rssi(struct ath_common *common,
 956                                struct ieee80211_hw *hw,
 957                                struct ieee80211_hdr *hdr,
 958                                struct ath_rx_status *rx_stats)
 959 {
 960         struct ath_softc *sc = hw->priv;
 961         struct ath_hw *ah = common->ah;
 962         int last_rssi;
 963         __le16 fc;
 964
 965         if ((ah->opmode != NL80211_IFTYPE_STATION) &&
 966             (ah->opmode != NL80211_IFTYPE_ADHOC))
 967                 return;
 968
 969         fc = hdr->frame_control;
 970         if (!ieee80211_is_beacon(fc) ||
 971             compare_ether_addr(hdr->addr3, common->curbssid)) {
 972                 /* TODO:  This doesn't work well if you have stations
 973                  * associated to two different APs because curbssid
 974                  * is just the last AP that any of the stations associated
 975                  * with.
 976                  */
 977                 return;
 978         }
 979
 980         if (rx_stats->rs_rssi != ATH9K_RSSI_BAD && !rx_stats->rs_moreaggr)
 981                 ATH_RSSI_LPF(sc->last_rssi, rx_stats->rs_rssi);
 982
 983         last_rssi = sc->last_rssi;
 984         if (likely(last_rssi != ATH_RSSI_DUMMY_MARKER))
 985                 rx_stats->rs_rssi = ATH_EP_RND(last_rssi,
 986                                               ATH_RSSI_EP_MULTIPLIER);
 987         if (rx_stats->rs_rssi < 0)
 988                 rx_stats->rs_rssi = 0;
 989
 990         /* Update Beacon RSSI, this is used by ANI. */
 991         ah->stats.avgbrssi = rx_stats->rs_rssi;
 992 }
 993
 994 /*
 995  * For Decrypt or Demic errors, we only mark packet status here and always push
 996  * up the frame up to let mac80211 handle the actual error case, be it no
 997  * decryption key or real decryption error. This let us keep statistics there.
 998  */
 999 static int ath9k_rx_skb_preprocess(struct ath_common *common,
1000                                    struct ieee80211_hw *hw,
1001                                    struct ieee80211_hdr *hdr,
1002                                    struct ath_rx_status *rx_stats,
1003                                    struct ieee80211_rx_status *rx_status,
1004                                    bool *decrypt_error)
1005 {
1006         memset(rx_status, 0, sizeof(struct ieee80211_rx_status));
1007
1008         /*
1009          * everything but the rate is checked here, the rate check is done
1010          * separately to avoid doing two lookups for a rate for each frame.
1011          */
1012         if (!ath9k_rx_accept(common, hdr, rx_status, rx_stats, decrypt_error))
1013                 return -EINVAL;
1014
1015         /* Only use status info from the last fragment */
1016         if (rx_stats->rs_more)
1017                 return 0;
1018
1019         ath9k_process_rssi(common, hw, hdr, rx_stats);
1020
1021         if (ath9k_process_rate(common, hw, rx_stats, rx_status))
1022                 return -EINVAL;
1023
1024         rx_status->band = hw->conf.channel->band;
1025         rx_status->freq = hw->conf.channel->center_freq;
1026         rx_status->signal = ATH_DEFAULT_NOISE_FLOOR + rx_stats->rs_rssi;
1027         rx_status->antenna = rx_stats->rs_antenna;
1028         rx_status->flag |= RX_FLAG_MACTIME_MPDU;
1029
1030         return 0;
1031 }
1032
1033 static void ath9k_rx_skb_postprocess(struct ath_common *common,
1034                                      struct sk_buff *skb,
1035                                      struct ath_rx_status *rx_stats,
1036                                      struct ieee80211_rx_status *rxs,
1037                                      bool decrypt_error)
1038 {
1039         struct ath_hw *ah = common->ah;
1040         struct ieee80211_hdr *hdr;
1041         int hdrlen, padpos, padsize;
1042         u8 keyix;
1043         __le16 fc;
1044
1045         /* see if any padding is done by the hw and remove it */
1046         hdr = (struct ieee80211_hdr *) skb->data;
1047         hdrlen = ieee80211_get_hdrlen_from_skb(skb);
1048         fc = hdr->frame_control;
1049         padpos = ath9k_cmn_padpos(hdr->frame_control);
1050
1051         /* The MAC header is padded to have 32-bit boundary if the
1052          * packet payload is non-zero. The general calculation for
1053          * padsize would take into account odd header lengths:
1054          * padsize = (4 - padpos % 4) % 4; However, since only
1055          * even-length headers are used, padding can only be 0 or 2
1056          * bytes and we can optimize this a bit. In addition, we must
1057          * not try to remove padding from short control frames that do
1058          * not have payload. */
1059         padsize = padpos & 3;
1060         if (padsize && skb->len>=padpos+padsize+FCS_LEN) {
1061                 memmove(skb->data + padsize, skb->data, padpos);
1062                 skb_pull(skb, padsize);
1063         }
1064
1065         keyix = rx_stats->rs_keyix;
1066
1067         if (!(keyix == ATH9K_RXKEYIX_INVALID) && !decrypt_error &&
1068             ieee80211_has_protected(fc)) {
1069                 rxs->flag |= RX_FLAG_DECRYPTED;
1070         } else if (ieee80211_has_protected(fc)
1071                    && !decrypt_error && skb->len >= hdrlen + 4) {
1072                 keyix = skb->data[hdrlen + 3] >> 6;
1073
1074                 if (test_bit(keyix, common->keymap))
1075                         rxs->flag |= RX_FLAG_DECRYPTED;
1076         }
1077         if (ah->sw_mgmt_crypto &&
1078             (rxs->flag & RX_FLAG_DECRYPTED) &&
1079             ieee80211_is_mgmt(fc))
1080                 /* Use software decrypt for management frames. */
1081                 rxs->flag &= ~RX_FLAG_DECRYPTED;
1082 }
1083
1084 static void ath_lnaconf_alt_good_scan(struct ath_ant_comb *antcomb,
1085                                       struct ath_hw_antcomb_conf ant_conf,
1086                                       int main_rssi_avg)
1087 {
1088         antcomb->quick_scan_cnt = 0;
1089
1090         if (ant_conf.main_lna_conf == ATH_ANT_DIV_COMB_LNA2)
1091                 antcomb->rssi_lna2 = main_rssi_avg;
1092         else if (ant_conf.main_lna_conf == ATH_ANT_DIV_COMB_LNA1)
1093                 antcomb->rssi_lna1 = main_rssi_avg;
1094
1095         switch ((ant_conf.main_lna_conf << 4) | ant_conf.alt_lna_conf) {
1096         case 0x10: /* LNA2 A-B */
1097                 antcomb->main_conf = ATH_ANT_DIV_COMB_LNA1_MINUS_LNA2;
1098                 antcomb->first_quick_scan_conf =
1099                         ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2;
1100                 antcomb->second_quick_scan_conf = ATH_ANT_DIV_COMB_LNA1;
1101                 break;
1102         case 0x20: /* LNA1 A-B */
1103                 antcomb->main_conf = ATH_ANT_DIV_COMB_LNA1_MINUS_LNA2;
1104                 antcomb->first_quick_scan_conf =
1105                         ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2;
1106                 antcomb->second_quick_scan_conf = ATH_ANT_DIV_COMB_LNA2;
1107                 break;
1108         case 0x21: /* LNA1 LNA2 */
1109                 antcomb->main_conf = ATH_ANT_DIV_COMB_LNA2;
1110                 antcomb->first_quick_scan_conf =
1111                         ATH_ANT_DIV_COMB_LNA1_MINUS_LNA2;
1112                 antcomb->second_quick_scan_conf =
1113                         ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2;
1114                 break;
1115         case 0x12: /* LNA2 LNA1 */
1116                 antcomb->main_conf = ATH_ANT_DIV_COMB_LNA1;
1117                 antcomb->first_quick_scan_conf =
1118                         ATH_ANT_DIV_COMB_LNA1_MINUS_LNA2;
1119                 antcomb->second_quick_scan_conf =
1120                         ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2;
1121                 break;
1122         case 0x13: /* LNA2 A+B */
1123                 antcomb->main_conf = ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2;
1124                 antcomb->first_quick_scan_conf =
1125                         ATH_ANT_DIV_COMB_LNA1_MINUS_LNA2;
1126                 antcomb->second_quick_scan_conf = ATH_ANT_DIV_COMB_LNA1;
1127                 break;
1128         case 0x23: /* LNA1 A+B */
1129                 antcomb->main_conf = ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2;
1130                 antcomb->first_quick_scan_conf =
1131                         ATH_ANT_DIV_COMB_LNA1_MINUS_LNA2;
1132                 antcomb->second_quick_scan_conf = ATH_ANT_DIV_COMB_LNA2;
1133                 break;
1134         default:
1135                 break;
1136         }
1137 }
1138
1139 static void ath_select_ant_div_from_quick_scan(struct ath_ant_comb *antcomb,
1140                                 struct ath_hw_antcomb_conf *div_ant_conf,
1141                                 int main_rssi_avg, int alt_rssi_avg,
1142                                 int alt_ratio)
1143 {
1144         /* alt_good */
1145         switch (antcomb->quick_scan_cnt) {
1146         case 0:
1147                 /* set alt to main, and alt to first conf */
1148                 div_ant_conf->main_lna_conf = antcomb->main_conf;
1149                 div_ant_conf->alt_lna_conf = antcomb->first_quick_scan_conf;
1150                 break;
1151         case 1:
1152                 /* set alt to main, and alt to first conf */
1153                 div_ant_conf->main_lna_conf = antcomb->main_conf;
1154                 div_ant_conf->alt_lna_conf = antcomb->second_quick_scan_conf;
1155                 antcomb->rssi_first = main_rssi_avg;
1156                 antcomb->rssi_second = alt_rssi_avg;
1157
1158                 if (antcomb->main_conf == ATH_ANT_DIV_COMB_LNA1) {
1159                         /* main is LNA1 */
1160                         if (ath_is_alt_ant_ratio_better(alt_ratio,
1161                                                 ATH_ANT_DIV_COMB_LNA1_DELTA_HI,
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 if (antcomb->main_conf == ATH_ANT_DIV_COMB_LNA2) {
1169                         if (ath_is_alt_ant_ratio_better(alt_ratio,
1170                                                 ATH_ANT_DIV_COMB_LNA1_DELTA_MID,
1171                                                 ATH_ANT_DIV_COMB_LNA1_DELTA_LOW,
1172                                                 main_rssi_avg, alt_rssi_avg,
1173                                                 antcomb->total_pkt_count))
1174                                 antcomb->first_ratio = true;
1175                         else
1176                                 antcomb->first_ratio = false;
1177                 } else {
1178                         if ((((alt_ratio >= ATH_ANT_DIV_COMB_ALT_ANT_RATIO2) &&
1179                             (alt_rssi_avg > main_rssi_avg +
1180                             ATH_ANT_DIV_COMB_LNA1_DELTA_HI)) ||
1181                             (alt_rssi_avg > main_rssi_avg)) &&
1182                             (antcomb->total_pkt_count > 50))
1183                                 antcomb->first_ratio = true;
1184                         else
1185                                 antcomb->first_ratio = false;
1186                 }
1187                 break;
1188         case 2:
1189                 antcomb->alt_good = false;
1190                 antcomb->scan_not_start = false;
1191                 antcomb->scan = false;
1192                 antcomb->rssi_first = main_rssi_avg;
1193                 antcomb->rssi_third = alt_rssi_avg;
1194
1195                 if (antcomb->second_quick_scan_conf == ATH_ANT_DIV_COMB_LNA1)
1196                         antcomb->rssi_lna1 = alt_rssi_avg;
1197                 else if (antcomb->second_quick_scan_conf ==
1198                          ATH_ANT_DIV_COMB_LNA2)
1199                         antcomb->rssi_lna2 = alt_rssi_avg;
1200                 else if (antcomb->second_quick_scan_conf ==
1201                          ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2) {
1202                         if (antcomb->main_conf == ATH_ANT_DIV_COMB_LNA2)
1203                                 antcomb->rssi_lna2 = main_rssi_avg;
1204                         else if (antcomb->main_conf == ATH_ANT_DIV_COMB_LNA1)
1205                                 antcomb->rssi_lna1 = main_rssi_avg;
1206                 }
1207
1208                 if (antcomb->rssi_lna2 > antcomb->rssi_lna1 +
1209                     ATH_ANT_DIV_COMB_LNA1_LNA2_SWITCH_DELTA)
1210                         div_ant_conf->main_lna_conf = ATH_ANT_DIV_COMB_LNA2;
1211                 else
1212                         div_ant_conf->main_lna_conf = ATH_ANT_DIV_COMB_LNA1;
1213
1214                 if (antcomb->main_conf == ATH_ANT_DIV_COMB_LNA1) {
1215                         if (ath_is_alt_ant_ratio_better(alt_ratio,
1216                                                 ATH_ANT_DIV_COMB_LNA1_DELTA_HI,
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 if (antcomb->main_conf == ATH_ANT_DIV_COMB_LNA2) {
1224                         if (ath_is_alt_ant_ratio_better(alt_ratio,
1225                                                 ATH_ANT_DIV_COMB_LNA1_DELTA_MID,
1226                                                 ATH_ANT_DIV_COMB_LNA1_DELTA_LOW,
1227                                                 main_rssi_avg, alt_rssi_avg,
1228                                                 antcomb->total_pkt_count))
1229                                 antcomb->second_ratio = true;
1230                         else
1231                                 antcomb->second_ratio = false;
1232                 } else {
1233                         if ((((alt_ratio >= ATH_ANT_DIV_COMB_ALT_ANT_RATIO2) &&
1234                             (alt_rssi_avg > main_rssi_avg +
1235                             ATH_ANT_DIV_COMB_LNA1_DELTA_HI)) ||
1236                             (alt_rssi_avg > main_rssi_avg)) &&
1237                             (antcomb->total_pkt_count > 50))
1238                                 antcomb->second_ratio = true;
1239                         else
1240                                 antcomb->second_ratio = false;
1241                 }
1242
1243                 /* set alt to the conf with maximun ratio */
1244                 if (antcomb->first_ratio && antcomb->second_ratio) {
1245                         if (antcomb->rssi_second > antcomb->rssi_third) {
1246                                 /* first alt*/
1247                                 if ((antcomb->first_quick_scan_conf ==
1248                                     ATH_ANT_DIV_COMB_LNA1) ||
1249                                     (antcomb->first_quick_scan_conf ==
1250                                     ATH_ANT_DIV_COMB_LNA2))
1251                                         /* Set alt LNA1 or LNA2*/
1252                                         if (div_ant_conf->main_lna_conf ==
1253                                             ATH_ANT_DIV_COMB_LNA2)
1254                                                 div_ant_conf->alt_lna_conf =
1255                                                         ATH_ANT_DIV_COMB_LNA1;
1256                                         else
1257                                                 div_ant_conf->alt_lna_conf =
1258                                                         ATH_ANT_DIV_COMB_LNA2;
1259                                 else
1260                                         /* Set alt to A+B or A-B */
1261                                         div_ant_conf->alt_lna_conf =
1262                                                 antcomb->first_quick_scan_conf;
1263                         } else if ((antcomb->second_quick_scan_conf ==
1264                                    ATH_ANT_DIV_COMB_LNA1) ||
1265                                    (antcomb->second_quick_scan_conf ==
1266                                    ATH_ANT_DIV_COMB_LNA2)) {
1267                                 /* Set alt LNA1 or LNA2 */
1268                                 if (div_ant_conf->main_lna_conf ==
1269                                     ATH_ANT_DIV_COMB_LNA2)
1270                                         div_ant_conf->alt_lna_conf =
1271                                                 ATH_ANT_DIV_COMB_LNA1;
1272                                 else
1273                                         div_ant_conf->alt_lna_conf =
1274                                                 ATH_ANT_DIV_COMB_LNA2;
1275                         } else {
1276                                 /* Set alt to A+B or A-B */
1277                                 div_ant_conf->alt_lna_conf =
1278                                         antcomb->second_quick_scan_conf;
1279                         }
1280                 } else if (antcomb->first_ratio) {
1281                         /* first alt */
1282                         if ((antcomb->first_quick_scan_conf ==
1283                             ATH_ANT_DIV_COMB_LNA1) ||
1284                             (antcomb->first_quick_scan_conf ==
1285                             ATH_ANT_DIV_COMB_LNA2))
1286                                         /* Set alt LNA1 or LNA2 */
1287                                 if (div_ant_conf->main_lna_conf ==
1288                                     ATH_ANT_DIV_COMB_LNA2)
1289                                         div_ant_conf->alt_lna_conf =
1290                                                         ATH_ANT_DIV_COMB_LNA1;
1291                                 else
1292                                         div_ant_conf->alt_lna_conf =
1293                                                         ATH_ANT_DIV_COMB_LNA2;
1294                         else
1295                                 /* Set alt to A+B or A-B */
1296                                 div_ant_conf->alt_lna_conf =
1297                                                 antcomb->first_quick_scan_conf;
1298                 } else if (antcomb->second_ratio) {
1299                                 /* second alt */
1300                         if ((antcomb->second_quick_scan_conf ==
1301                             ATH_ANT_DIV_COMB_LNA1) ||
1302                             (antcomb->second_quick_scan_conf ==
1303                             ATH_ANT_DIV_COMB_LNA2))
1304                                 /* Set alt LNA1 or LNA2 */
1305                                 if (div_ant_conf->main_lna_conf ==
1306                                     ATH_ANT_DIV_COMB_LNA2)
1307                                         div_ant_conf->alt_lna_conf =
1308                                                 ATH_ANT_DIV_COMB_LNA1;
1309                                 else
1310                                         div_ant_conf->alt_lna_conf =
1311                                                 ATH_ANT_DIV_COMB_LNA2;
1312                         else
1313                                 /* Set alt to A+B or A-B */
1314                                 div_ant_conf->alt_lna_conf =
1315                                                 antcomb->second_quick_scan_conf;
1316                 } else {
1317                         /* main is largest */
1318                         if ((antcomb->main_conf == ATH_ANT_DIV_COMB_LNA1) ||
1319                             (antcomb->main_conf == ATH_ANT_DIV_COMB_LNA2))
1320                                 /* Set alt LNA1 or LNA2 */
1321                                 if (div_ant_conf->main_lna_conf ==
1322                                     ATH_ANT_DIV_COMB_LNA2)
1323                                         div_ant_conf->alt_lna_conf =
1324                                                         ATH_ANT_DIV_COMB_LNA1;
1325                                 else
1326                                         div_ant_conf->alt_lna_conf =
1327                                                         ATH_ANT_DIV_COMB_LNA2;
1328                         else
1329                                 /* Set alt to A+B or A-B */
1330                                 div_ant_conf->alt_lna_conf = antcomb->main_conf;
1331                 }
1332                 break;
1333         default:
1334                 break;
1335         }
1336 }
1337
1338 static void ath_ant_div_conf_fast_divbias(struct ath_hw_antcomb_conf *ant_conf,
1339                 struct ath_ant_comb *antcomb, int alt_ratio)
1340 {
1341         if (ant_conf->div_group == 0) {
1342                 /* Adjust the fast_div_bias based on main and alt lna conf */
1343                 switch ((ant_conf->main_lna_conf << 4) |
1344                                 ant_conf->alt_lna_conf) {
1345                 case 0x01: /* A-B LNA2 */
1346                         ant_conf->fast_div_bias = 0x3b;
1347                         break;
1348                 case 0x02: /* A-B LNA1 */
1349                         ant_conf->fast_div_bias = 0x3d;
1350                         break;
1351                 case 0x03: /* A-B A+B */
1352                         ant_conf->fast_div_bias = 0x1;
1353                         break;
1354                 case 0x10: /* LNA2 A-B */
1355                         ant_conf->fast_div_bias = 0x7;
1356                         break;
1357                 case 0x12: /* LNA2 LNA1 */
1358                         ant_conf->fast_div_bias = 0x2;
1359                         break;
1360                 case 0x13: /* LNA2 A+B */
1361                         ant_conf->fast_div_bias = 0x7;
1362                         break;
1363                 case 0x20: /* LNA1 A-B */
1364                         ant_conf->fast_div_bias = 0x6;
1365                         break;
1366                 case 0x21: /* LNA1 LNA2 */
1367                         ant_conf->fast_div_bias = 0x0;
1368                         break;
1369                 case 0x23: /* LNA1 A+B */
1370                         ant_conf->fast_div_bias = 0x6;
1371                         break;
1372                 case 0x30: /* A+B A-B */
1373                         ant_conf->fast_div_bias = 0x1;
1374                         break;
1375                 case 0x31: /* A+B LNA2 */
1376                         ant_conf->fast_div_bias = 0x3b;
1377                         break;
1378                 case 0x32: /* A+B LNA1 */
1379                         ant_conf->fast_div_bias = 0x3d;
1380                         break;
1381                 default:
1382                         break;
1383                 }
1384         } else if (ant_conf->div_group == 1) {
1385                 /* Adjust the fast_div_bias based on main and alt_lna_conf */
1386                 switch ((ant_conf->main_lna_conf << 4) |
1387                         ant_conf->alt_lna_conf) {
1388                 case 0x01: /* A-B LNA2 */
1389                         ant_conf->fast_div_bias = 0x1;
1390                         ant_conf->main_gaintb = 0;
1391                         ant_conf->alt_gaintb = 0;
1392                         break;
1393                 case 0x02: /* A-B LNA1 */
1394                         ant_conf->fast_div_bias = 0x1;
1395                         ant_conf->main_gaintb = 0;
1396                         ant_conf->alt_gaintb = 0;
1397                         break;
1398                 case 0x03: /* A-B A+B */
1399                         ant_conf->fast_div_bias = 0x1;
1400                         ant_conf->main_gaintb = 0;
1401                         ant_conf->alt_gaintb = 0;
1402                         break;
1403                 case 0x10: /* LNA2 A-B */
1404                         if (!(antcomb->scan) &&
1405                             (alt_ratio > ATH_ANT_DIV_COMB_ALT_ANT_RATIO))
1406                                 ant_conf->fast_div_bias = 0x3f;
1407                         else
1408                                 ant_conf->fast_div_bias = 0x1;
1409                         ant_conf->main_gaintb = 0;
1410                         ant_conf->alt_gaintb = 0;
1411                         break;
1412                 case 0x12: /* LNA2 LNA1 */
1413                         ant_conf->fast_div_bias = 0x1;
1414                         ant_conf->main_gaintb = 0;
1415                         ant_conf->alt_gaintb = 0;
1416                         break;
1417                 case 0x13: /* LNA2 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 0x20: /* LNA1 A-B */
1427                         if (!(antcomb->scan) &&
1428                             (alt_ratio > ATH_ANT_DIV_COMB_ALT_ANT_RATIO))
1429                                 ant_conf->fast_div_bias = 0x3f;
1430                         else
1431                                 ant_conf->fast_div_bias = 0x1;
1432                         ant_conf->main_gaintb = 0;
1433                         ant_conf->alt_gaintb = 0;
1434                         break;
1435                 case 0x21: /* LNA1 LNA2 */
1436                         ant_conf->fast_div_bias = 0x1;
1437                         ant_conf->main_gaintb = 0;
1438                         ant_conf->alt_gaintb = 0;
1439                         break;
1440                 case 0x23: /* LNA1 A+B */
1441                         if (!(antcomb->scan) &&
1442                             (alt_ratio > ATH_ANT_DIV_COMB_ALT_ANT_RATIO))
1443                                 ant_conf->fast_div_bias = 0x3f;
1444                         else
1445                                 ant_conf->fast_div_bias = 0x1;
1446                         ant_conf->main_gaintb = 0;
1447                         ant_conf->alt_gaintb = 0;
1448                         break;
1449                 case 0x30: /* A+B A-B */
1450                         ant_conf->fast_div_bias = 0x1;
1451                         ant_conf->main_gaintb = 0;
1452                         ant_conf->alt_gaintb = 0;
1453                         break;
1454                 case 0x31: /* A+B LNA2 */
1455                         ant_conf->fast_div_bias = 0x1;
1456                         ant_conf->main_gaintb = 0;
1457                         ant_conf->alt_gaintb = 0;
1458                         break;
1459                 case 0x32: /* A+B LNA1 */
1460                         ant_conf->fast_div_bias = 0x1;
1461                         ant_conf->main_gaintb = 0;
1462                         ant_conf->alt_gaintb = 0;
1463                         break;
1464                 default:
1465                         break;
1466                 }
1467         } else if (ant_conf->div_group == 2) {
1468                 /* Adjust the fast_div_bias based on main and alt_lna_conf */
1469                 switch ((ant_conf->main_lna_conf << 4) |
1470                                 ant_conf->alt_lna_conf) {
1471                 case 0x01: /* A-B LNA2 */
1472                         ant_conf->fast_div_bias = 0x1;
1473                         ant_conf->main_gaintb = 0;
1474                         ant_conf->alt_gaintb = 0;
1475                         break;
1476                 case 0x02: /* A-B LNA1 */
1477                         ant_conf->fast_div_bias = 0x1;
1478                         ant_conf->main_gaintb = 0;
1479                         ant_conf->alt_gaintb = 0;
1480                         break;
1481                 case 0x03: /* A-B A+B */
1482                         ant_conf->fast_div_bias = 0x1;
1483                         ant_conf->main_gaintb = 0;
1484                         ant_conf->alt_gaintb = 0;
1485                         break;
1486                 case 0x10: /* LNA2 A-B */
1487                         if (!(antcomb->scan) &&
1488                                 (alt_ratio > ATH_ANT_DIV_COMB_ALT_ANT_RATIO))
1489                                 ant_conf->fast_div_bias = 0x1;
1490                         else
1491                                 ant_conf->fast_div_bias = 0x2;
1492                         ant_conf->main_gaintb = 0;
1493                         ant_conf->alt_gaintb = 0;
1494                         break;
1495                 case 0x12: /* LNA2 LNA1 */
1496                         ant_conf->fast_div_bias = 0x1;
1497                         ant_conf->main_gaintb = 0;
1498                         ant_conf->alt_gaintb = 0;
1499                         break;
1500                 case 0x13: /* LNA2 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 0x20: /* LNA1 A-B */
1510                         if (!(antcomb->scan) &&
1511                                 (alt_ratio > ATH_ANT_DIV_COMB_ALT_ANT_RATIO))
1512                                 ant_conf->fast_div_bias = 0x1;
1513                         else
1514                                 ant_conf->fast_div_bias = 0x2;
1515                         ant_conf->main_gaintb = 0;
1516                         ant_conf->alt_gaintb = 0;
1517                         break;
1518                 case 0x21: /* LNA1 LNA2 */
1519                         ant_conf->fast_div_bias = 0x1;
1520                         ant_conf->main_gaintb = 0;
1521                         ant_conf->alt_gaintb = 0;
1522                         break;
1523                 case 0x23: /* LNA1 A+B */
1524                         if (!(antcomb->scan) &&
1525                                 (alt_ratio > ATH_ANT_DIV_COMB_ALT_ANT_RATIO))
1526                                 ant_conf->fast_div_bias = 0x1;
1527                         else
1528                                 ant_conf->fast_div_bias = 0x2;
1529                         ant_conf->main_gaintb = 0;
1530                         ant_conf->alt_gaintb = 0;
1531                         break;
1532                 case 0x30: /* A+B A-B */
1533                         ant_conf->fast_div_bias = 0x1;
1534                         ant_conf->main_gaintb = 0;
1535                         ant_conf->alt_gaintb = 0;
1536                         break;
1537                 case 0x31: /* A+B LNA2 */
1538                         ant_conf->fast_div_bias = 0x1;
1539                         ant_conf->main_gaintb = 0;
1540                         ant_conf->alt_gaintb = 0;
1541                         break;
1542                 case 0x32: /* A+B LNA1 */
1543                         ant_conf->fast_div_bias = 0x1;
1544                         ant_conf->main_gaintb = 0;
1545                         ant_conf->alt_gaintb = 0;
1546                         break;
1547                 default:
1548                         break;
1549                 }
1550         }
1551 }
1552
1553 /* Antenna diversity and combining */
1554 static void ath_ant_comb_scan(struct ath_softc *sc, struct ath_rx_status *rs)
1555 {
1556         struct ath_hw_antcomb_conf div_ant_conf;
1557         struct ath_ant_comb *antcomb = &sc->ant_comb;
1558         int alt_ratio = 0, alt_rssi_avg = 0, main_rssi_avg = 0, curr_alt_set;
1559         int curr_main_set;
1560         int main_rssi = rs->rs_rssi_ctl0;
1561         int alt_rssi = rs->rs_rssi_ctl1;
1562         int rx_ant_conf,  main_ant_conf;
1563         bool short_scan = false;
1564
1565         rx_ant_conf = (rs->rs_rssi_ctl2 >> ATH_ANT_RX_CURRENT_SHIFT) &
1566                        ATH_ANT_RX_MASK;
1567         main_ant_conf = (rs->rs_rssi_ctl2 >> ATH_ANT_RX_MAIN_SHIFT) &
1568                          ATH_ANT_RX_MASK;
1569
1570         /* Record packet only when both main_rssi and  alt_rssi is positive */
1571         if (main_rssi > 0 && alt_rssi > 0) {
1572                 antcomb->total_pkt_count++;
1573                 antcomb->main_total_rssi += main_rssi;
1574                 antcomb->alt_total_rssi  += alt_rssi;
1575                 if (main_ant_conf == rx_ant_conf)
1576                         antcomb->main_recv_cnt++;
1577                 else
1578                         antcomb->alt_recv_cnt++;
1579         }
1580
1581         /* Short scan check */
1582         if (antcomb->scan && antcomb->alt_good) {
1583                 if (time_after(jiffies, antcomb->scan_start_time +
1584                     msecs_to_jiffies(ATH_ANT_DIV_COMB_SHORT_SCAN_INTR)))
1585                         short_scan = true;
1586                 else
1587                         if (antcomb->total_pkt_count ==
1588                             ATH_ANT_DIV_COMB_SHORT_SCAN_PKTCOUNT) {
1589                                 alt_ratio = ((antcomb->alt_recv_cnt * 100) /
1590                                             antcomb->total_pkt_count);
1591                                 if (alt_ratio < ATH_ANT_DIV_COMB_ALT_ANT_RATIO)
1592                                         short_scan = true;
1593                         }
1594         }
1595
1596         if (((antcomb->total_pkt_count < ATH_ANT_DIV_COMB_MAX_PKTCOUNT) ||
1597             rs->rs_moreaggr) && !short_scan)
1598                 return;
1599
1600         if (antcomb->total_pkt_count) {
1601                 alt_ratio = ((antcomb->alt_recv_cnt * 100) /
1602                              antcomb->total_pkt_count);
1603                 main_rssi_avg = (antcomb->main_total_rssi /
1604                                  antcomb->total_pkt_count);
1605                 alt_rssi_avg = (antcomb->alt_total_rssi /
1606                                  antcomb->total_pkt_count);
1607         }
1608
1609
1610         ath9k_hw_antdiv_comb_conf_get(sc->sc_ah, &div_ant_conf);
1611         curr_alt_set = div_ant_conf.alt_lna_conf;
1612         curr_main_set = div_ant_conf.main_lna_conf;
1613
1614         antcomb->count++;
1615
1616         if (antcomb->count == ATH_ANT_DIV_COMB_MAX_COUNT) {
1617                 if (alt_ratio > ATH_ANT_DIV_COMB_ALT_ANT_RATIO) {
1618                         ath_lnaconf_alt_good_scan(antcomb, div_ant_conf,
1619                                                   main_rssi_avg);
1620                         antcomb->alt_good = true;
1621                 } else {
1622                         antcomb->alt_good = false;
1623                 }
1624
1625                 antcomb->count = 0;
1626                 antcomb->scan = true;
1627                 antcomb->scan_not_start = true;
1628         }
1629
1630         if (!antcomb->scan) {
1631                 if (ath_ant_div_comb_alt_check(div_ant_conf.div_group,
1632                                         alt_ratio, curr_main_set, curr_alt_set,
1633                                         alt_rssi_avg, main_rssi_avg)) {
1634                         if (curr_alt_set == ATH_ANT_DIV_COMB_LNA2) {
1635                                 /* Switch main and alt LNA */
1636                                 div_ant_conf.main_lna_conf =
1637                                                 ATH_ANT_DIV_COMB_LNA2;
1638                                 div_ant_conf.alt_lna_conf  =
1639                                                 ATH_ANT_DIV_COMB_LNA1;
1640                         } else if (curr_alt_set == ATH_ANT_DIV_COMB_LNA1) {
1641                                 div_ant_conf.main_lna_conf =
1642                                                 ATH_ANT_DIV_COMB_LNA1;
1643                                 div_ant_conf.alt_lna_conf  =
1644                                                 ATH_ANT_DIV_COMB_LNA2;
1645                         }
1646
1647                         goto div_comb_done;
1648                 } else if ((curr_alt_set != ATH_ANT_DIV_COMB_LNA1) &&
1649                            (curr_alt_set != ATH_ANT_DIV_COMB_LNA2)) {
1650                         /* Set alt to another LNA */
1651                         if (curr_main_set == ATH_ANT_DIV_COMB_LNA2)
1652                                 div_ant_conf.alt_lna_conf =
1653                                                 ATH_ANT_DIV_COMB_LNA1;
1654                         else if (curr_main_set == ATH_ANT_DIV_COMB_LNA1)
1655                                 div_ant_conf.alt_lna_conf =
1656                                                 ATH_ANT_DIV_COMB_LNA2;
1657
1658                         goto div_comb_done;
1659                 }
1660
1661                 if ((alt_rssi_avg < (main_rssi_avg +
1662                                                 div_ant_conf.lna1_lna2_delta)))
1663                         goto div_comb_done;
1664         }
1665
1666         if (!antcomb->scan_not_start) {
1667                 switch (curr_alt_set) {
1668                 case ATH_ANT_DIV_COMB_LNA2:
1669                         antcomb->rssi_lna2 = alt_rssi_avg;
1670                         antcomb->rssi_lna1 = main_rssi_avg;
1671                         antcomb->scan = true;
1672                         /* set to A+B */
1673                         div_ant_conf.main_lna_conf =
1674                                 ATH_ANT_DIV_COMB_LNA1;
1675                         div_ant_conf.alt_lna_conf  =
1676                                 ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2;
1677                         break;
1678                 case ATH_ANT_DIV_COMB_LNA1:
1679                         antcomb->rssi_lna1 = alt_rssi_avg;
1680                         antcomb->rssi_lna2 = main_rssi_avg;
1681                         antcomb->scan = true;
1682                         /* set to A+B */
1683                         div_ant_conf.main_lna_conf = ATH_ANT_DIV_COMB_LNA2;
1684                         div_ant_conf.alt_lna_conf  =
1685                                 ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2;
1686                         break;
1687                 case ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2:
1688                         antcomb->rssi_add = alt_rssi_avg;
1689                         antcomb->scan = true;
1690                         /* set to A-B */
1691                         div_ant_conf.alt_lna_conf =
1692                                 ATH_ANT_DIV_COMB_LNA1_MINUS_LNA2;
1693                         break;
1694                 case ATH_ANT_DIV_COMB_LNA1_MINUS_LNA2:
1695                         antcomb->rssi_sub = alt_rssi_avg;
1696                         antcomb->scan = false;
1697                         if (antcomb->rssi_lna2 >
1698                             (antcomb->rssi_lna1 +
1699                             ATH_ANT_DIV_COMB_LNA1_LNA2_SWITCH_DELTA)) {
1700                                 /* use LNA2 as main LNA */
1701                                 if ((antcomb->rssi_add > antcomb->rssi_lna1) &&
1702                                     (antcomb->rssi_add > antcomb->rssi_sub)) {
1703                                         /* set to A+B */
1704                                         div_ant_conf.main_lna_conf =
1705                                                 ATH_ANT_DIV_COMB_LNA2;
1706                                         div_ant_conf.alt_lna_conf  =
1707                                                 ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2;
1708                                 } else if (antcomb->rssi_sub >
1709                                            antcomb->rssi_lna1) {
1710                                         /* set to A-B */
1711                                         div_ant_conf.main_lna_conf =
1712                                                 ATH_ANT_DIV_COMB_LNA2;
1713                                         div_ant_conf.alt_lna_conf =
1714                                                 ATH_ANT_DIV_COMB_LNA1_MINUS_LNA2;
1715                                 } else {
1716                                         /* set to LNA1 */
1717                                         div_ant_conf.main_lna_conf =
1718                                                 ATH_ANT_DIV_COMB_LNA2;
1719                                         div_ant_conf.alt_lna_conf =
1720                                                 ATH_ANT_DIV_COMB_LNA1;
1721                                 }
1722                         } else {
1723                                 /* use LNA1 as main LNA */
1724                                 if ((antcomb->rssi_add > antcomb->rssi_lna2) &&
1725                                     (antcomb->rssi_add > antcomb->rssi_sub)) {
1726                                         /* set to A+B */
1727                                         div_ant_conf.main_lna_conf =
1728                                                 ATH_ANT_DIV_COMB_LNA1;
1729                                         div_ant_conf.alt_lna_conf  =
1730                                                 ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2;
1731                                 } else if (antcomb->rssi_sub >
1732                                            antcomb->rssi_lna1) {
1733                                         /* set to A-B */
1734                                         div_ant_conf.main_lna_conf =
1735                                                 ATH_ANT_DIV_COMB_LNA1;
1736                                         div_ant_conf.alt_lna_conf =
1737                                                 ATH_ANT_DIV_COMB_LNA1_MINUS_LNA2;
1738                                 } else {
1739                                         /* set to LNA2 */
1740                                         div_ant_conf.main_lna_conf =
1741                                                 ATH_ANT_DIV_COMB_LNA1;
1742                                         div_ant_conf.alt_lna_conf =
1743                                                 ATH_ANT_DIV_COMB_LNA2;
1744                                 }
1745                         }
1746                         break;
1747                 default:
1748                         break;
1749                 }
1750         } else {
1751                 if (!antcomb->alt_good) {
1752                         antcomb->scan_not_start = false;
1753                         /* Set alt to another LNA */
1754                         if (curr_main_set == ATH_ANT_DIV_COMB_LNA2) {
1755                                 div_ant_conf.main_lna_conf =
1756                                                 ATH_ANT_DIV_COMB_LNA2;
1757                                 div_ant_conf.alt_lna_conf =
1758                                                 ATH_ANT_DIV_COMB_LNA1;
1759                         } else if (curr_main_set == ATH_ANT_DIV_COMB_LNA1) {
1760                                 div_ant_conf.main_lna_conf =
1761                                                 ATH_ANT_DIV_COMB_LNA1;
1762                                 div_ant_conf.alt_lna_conf =
1763                                                 ATH_ANT_DIV_COMB_LNA2;
1764                         }
1765                         goto div_comb_done;
1766                 }
1767         }
1768
1769         ath_select_ant_div_from_quick_scan(antcomb, &div_ant_conf,
1770                                            main_rssi_avg, alt_rssi_avg,
1771                                            alt_ratio);
1772
1773         antcomb->quick_scan_cnt++;
1774
1775 div_comb_done:
1776         ath_ant_div_conf_fast_divbias(&div_ant_conf, antcomb, alt_ratio);
1777         ath9k_hw_antdiv_comb_conf_set(sc->sc_ah, &div_ant_conf);
1778
1779         antcomb->scan_start_time = jiffies;
1780         antcomb->total_pkt_count = 0;
1781         antcomb->main_total_rssi = 0;
1782         antcomb->alt_total_rssi = 0;
1783         antcomb->main_recv_cnt = 0;
1784         antcomb->alt_recv_cnt = 0;
1785 }
1786
1787 int ath_rx_tasklet(struct ath_softc *sc, int flush, bool hp)
1788 {
1789         struct ath_buf *bf;
1790         struct sk_buff *skb = NULL, *requeue_skb, *hdr_skb;
1791         struct ieee80211_rx_status *rxs;
1792         struct ath_hw *ah = sc->sc_ah;
1793         struct ath_common *common = ath9k_hw_common(ah);
1794         /*
1795          * The hw can technically differ from common->hw when using ath9k
1796          * virtual wiphy so to account for that we iterate over the active
1797          * wiphys and find the appropriate wiphy and therefore hw.
1798          */
1799         struct ieee80211_hw *hw = sc->hw;
1800         struct ieee80211_hdr *hdr;
1801         int retval;
1802         bool decrypt_error = false;
1803         struct ath_rx_status rs;
1804         enum ath9k_rx_qtype qtype;
1805         bool edma = !!(ah->caps.hw_caps & ATH9K_HW_CAP_EDMA);
1806         int dma_type;
1807         u8 rx_status_len = ah->caps.rx_status_len;
1808         u64 tsf = 0;
1809         u32 tsf_lower = 0;
1810         unsigned long flags;
1811
1812         if (edma)
1813                 dma_type = DMA_BIDIRECTIONAL;
1814         else
1815                 dma_type = DMA_FROM_DEVICE;
1816
1817         qtype = hp ? ATH9K_RX_QUEUE_HP : ATH9K_RX_QUEUE_LP;
1818         spin_lock_bh(&sc->rx.rxbuflock);
1819
1820         tsf = ath9k_hw_gettsf64(ah);
1821         tsf_lower = tsf & 0xffffffff;
1822
1823         do {
1824                 /* If handling rx interrupt and flush is in progress => exit */
1825                 if ((sc->sc_flags & SC_OP_RXFLUSH) && (flush == 0))
1826                         break;
1827
1828                 memset(&rs, 0, sizeof(rs));
1829                 if (edma)
1830                         bf = ath_edma_get_next_rx_buf(sc, &rs, qtype);
1831                 else
1832                         bf = ath_get_next_rx_buf(sc, &rs);
1833
1834                 if (!bf)
1835                         break;
1836
1837                 skb = bf->bf_mpdu;
1838                 if (!skb)
1839                         continue;
1840
1841                 /*
1842                  * Take frame header from the first fragment and RX status from
1843                  * the last one.
1844                  */
1845                 if (sc->rx.frag)
1846                         hdr_skb = sc->rx.frag;
1847                 else
1848                         hdr_skb = skb;
1849
1850                 hdr = (struct ieee80211_hdr *) (hdr_skb->data + rx_status_len);
1851                 rxs = IEEE80211_SKB_RXCB(hdr_skb);
1852
1853                 ath_debug_stat_rx(sc, &rs);
1854
1855                 /*
1856                  * If we're asked to flush receive queue, directly
1857                  * chain it back at the queue without processing it.
1858                  */
1859                 if (flush)
1860                         goto requeue_drop_frag;
1861
1862                 retval = ath9k_rx_skb_preprocess(common, hw, hdr, &rs,
1863                                                  rxs, &decrypt_error);
1864                 if (retval)
1865                         goto requeue_drop_frag;
1866
1867                 rxs->mactime = (tsf & ~0xffffffffULL) | rs.rs_tstamp;
1868                 if (rs.rs_tstamp > tsf_lower &&
1869                     unlikely(rs.rs_tstamp - tsf_lower > 0x10000000))
1870                         rxs->mactime -= 0x100000000ULL;
1871
1872                 if (rs.rs_tstamp < tsf_lower &&
1873                     unlikely(tsf_lower - rs.rs_tstamp > 0x10000000))
1874                         rxs->mactime += 0x100000000ULL;
1875
1876                 /* Ensure we always have an skb to requeue once we are done
1877                  * processing the current buffer's skb */
1878                 requeue_skb = ath_rxbuf_alloc(common, common->rx_bufsize, GFP_ATOMIC);
1879
1880                 /* If there is no memory we ignore the current RX'd frame,
1881                  * tell hardware it can give us a new frame using the old
1882                  * skb and put it at the tail of the sc->rx.rxbuf list for
1883                  * processing. */
1884                 if (!requeue_skb)
1885                         goto requeue_drop_frag;
1886
1887                 /* Unmap the frame */
1888                 dma_unmap_single(sc->dev, bf->bf_buf_addr,
1889                                  common->rx_bufsize,
1890                                  dma_type);
1891
1892                 skb_put(skb, rs.rs_datalen + ah->caps.rx_status_len);
1893                 if (ah->caps.rx_status_len)
1894                         skb_pull(skb, ah->caps.rx_status_len);
1895
1896                 if (!rs.rs_more)
1897                         ath9k_rx_skb_postprocess(common, hdr_skb, &rs,
1898                                                  rxs, decrypt_error);
1899
1900                 /* We will now give hardware our shiny new allocated skb */
1901                 bf->bf_mpdu = requeue_skb;
1902                 bf->bf_buf_addr = dma_map_single(sc->dev, requeue_skb->data,
1903                                                  common->rx_bufsize,
1904                                                  dma_type);
1905                 if (unlikely(dma_mapping_error(sc->dev,
1906                           bf->bf_buf_addr))) {
1907                         dev_kfree_skb_any(requeue_skb);
1908                         bf->bf_mpdu = NULL;
1909                         bf->bf_buf_addr = 0;
1910                         ath_err(common, "dma_mapping_error() on RX\n");
1911                         ieee80211_rx(hw, skb);
1912                         break;
1913                 }
1914
1915                 if (rs.rs_more) {
1916                         /*
1917                          * rs_more indicates chained descriptors which can be
1918                          * used to link buffers together for a sort of
1919                          * scatter-gather operation.
1920                          */
1921                         if (sc->rx.frag) {
1922                                 /* too many fragments - cannot handle frame */
1923                                 dev_kfree_skb_any(sc->rx.frag);
1924                                 dev_kfree_skb_any(skb);
1925                                 skb = NULL;
1926                         }
1927                         sc->rx.frag = skb;
1928                         goto requeue;
1929                 }
1930
1931                 if (sc->rx.frag) {
1932                         int space = skb->len - skb_tailroom(hdr_skb);
1933
1934                         sc->rx.frag = NULL;
1935
1936                         if (pskb_expand_head(hdr_skb, 0, space, GFP_ATOMIC) < 0) {
1937                                 dev_kfree_skb(skb);
1938                                 goto requeue_drop_frag;
1939                         }
1940
1941                         skb_copy_from_linear_data(skb, skb_put(hdr_skb, skb->len),
1942                                                   skb->len);
1943                         dev_kfree_skb_any(skb);
1944                         skb = hdr_skb;
1945                 }
1946
1947                 /*
1948                  * change the default rx antenna if rx diversity chooses the
1949                  * other antenna 3 times in a row.
1950                  */
1951                 if (sc->rx.defant != rs.rs_antenna) {
1952                         if (++sc->rx.rxotherant >= 3)
1953                                 ath_setdefantenna(sc, rs.rs_antenna);
1954                 } else {
1955                         sc->rx.rxotherant = 0;
1956                 }
1957
1958                 if (rxs->flag & RX_FLAG_MMIC_STRIPPED)
1959                         skb_trim(skb, skb->len - 8);
1960
1961                 spin_lock_irqsave(&sc->sc_pm_lock, flags);
1962
1963                 if ((sc->ps_flags & (PS_WAIT_FOR_BEACON |
1964                                               PS_WAIT_FOR_CAB |
1965                                               PS_WAIT_FOR_PSPOLL_DATA)) ||
1966                                                 ath9k_check_auto_sleep(sc))
1967                         ath_rx_ps(sc, skb);
1968                 spin_unlock_irqrestore(&sc->sc_pm_lock, flags);
1969
1970                 if (ah->caps.hw_caps & ATH9K_HW_CAP_ANT_DIV_COMB)
1971                         ath_ant_comb_scan(sc, &rs);
1972
1973                 ieee80211_rx(hw, skb);
1974
1975 requeue_drop_frag:
1976                 if (sc->rx.frag) {
1977                         dev_kfree_skb_any(sc->rx.frag);
1978                         sc->rx.frag = NULL;
1979                 }
1980 requeue:
1981                 if (edma) {
1982                         list_add_tail(&bf->list, &sc->rx.rxbuf);
1983                         ath_rx_edma_buf_link(sc, qtype);
1984                 } else {
1985                         list_move_tail(&bf->list, &sc->rx.rxbuf);
1986                         ath_rx_buf_link(sc, bf);
1987                         ath9k_hw_rxena(ah);
1988                 }
1989         } while (1);
1990
1991         spin_unlock_bh(&sc->rx.rxbuflock);
1992
1993         return 0;
1994 }