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_buf *bf;
 209
 210         ath_rx_remove_buffer(sc, ATH9K_RX_QUEUE_LP);
 211         ath_rx_remove_buffer(sc, ATH9K_RX_QUEUE_HP);
 212
 213         list_for_each_entry(bf, &sc->rx.rxbuf, list) {
 214                 if (bf->bf_mpdu)
 215                         dev_kfree_skb_any(bf->bf_mpdu);
 216         }
 217
 218         INIT_LIST_HEAD(&sc->rx.rxbuf);
 219
 220         kfree(sc->rx.rx_bufptr);
 221         sc->rx.rx_bufptr = NULL;
 222 }
 223
 224 static void ath_rx_edma_init_queue(struct ath_rx_edma *rx_edma, int size)
 225 {
 226         skb_queue_head_init(&rx_edma->rx_fifo);
 227         skb_queue_head_init(&rx_edma->rx_buffers);
 228         rx_edma->rx_fifo_hwsize = size;
 229 }
 230
 231 static int ath_rx_edma_init(struct ath_softc *sc, int nbufs)
 232 {
 233         struct ath_common *common = ath9k_hw_common(sc->sc_ah);
 234         struct ath_hw *ah = sc->sc_ah;
 235         struct sk_buff *skb;
 236         struct ath_buf *bf;
 237         int error = 0, i;
 238         u32 size;
 239
 240         ath9k_hw_set_rx_bufsize(ah, common->rx_bufsize -
 241                                     ah->caps.rx_status_len);
 242
 243         ath_rx_edma_init_queue(&sc->rx.rx_edma[ATH9K_RX_QUEUE_LP],
 244                                ah->caps.rx_lp_qdepth);
 245         ath_rx_edma_init_queue(&sc->rx.rx_edma[ATH9K_RX_QUEUE_HP],
 246                                ah->caps.rx_hp_qdepth);
 247
 248         size = sizeof(struct ath_buf) * nbufs;
 249         bf = kzalloc(size, GFP_KERNEL);
 250         if (!bf)
 251                 return -ENOMEM;
 252
 253         INIT_LIST_HEAD(&sc->rx.rxbuf);
 254         sc->rx.rx_bufptr = bf;
 255
 256         for (i = 0; i < nbufs; i++, bf++) {
 257                 skb = ath_rxbuf_alloc(common, common->rx_bufsize, GFP_KERNEL);
 258                 if (!skb) {
 259                         error = -ENOMEM;
 260                         goto rx_init_fail;
 261                 }
 262
 263                 memset(skb->data, 0, common->rx_bufsize);
 264                 bf->bf_mpdu = skb;
 265
 266                 bf->bf_buf_addr = dma_map_single(sc->dev, skb->data,
 267                                                  common->rx_bufsize,
 268                                                  DMA_BIDIRECTIONAL);
 269                 if (unlikely(dma_mapping_error(sc->dev,
 270                                                 bf->bf_buf_addr))) {
 271                                 dev_kfree_skb_any(skb);
 272                                 bf->bf_mpdu = NULL;
 273                                 bf->bf_buf_addr = 0;
 274                                 ath_err(common,
 275                                         "dma_mapping_error() on RX init\n");
 276                                 error = -ENOMEM;
 277                                 goto rx_init_fail;
 278                 }
 279
 280                 list_add_tail(&bf->list, &sc->rx.rxbuf);
 281         }
 282
 283         return 0;
 284
 285 rx_init_fail:
 286         ath_rx_edma_cleanup(sc);
 287         return error;
 288 }
 289
 290 static void ath_edma_start_recv(struct ath_softc *sc)
 291 {
 292         spin_lock_bh(&sc->rx.rxbuflock);
 293
 294         ath9k_hw_rxena(sc->sc_ah);
 295
 296         ath_rx_addbuffer_edma(sc, ATH9K_RX_QUEUE_HP,
 297                               sc->rx.rx_edma[ATH9K_RX_QUEUE_HP].rx_fifo_hwsize);
 298
 299         ath_rx_addbuffer_edma(sc, ATH9K_RX_QUEUE_LP,
 300                               sc->rx.rx_edma[ATH9K_RX_QUEUE_LP].rx_fifo_hwsize);
 301
 302         ath_opmode_init(sc);
 303
 304         ath9k_hw_startpcureceive(sc->sc_ah, (sc->sc_flags & SC_OP_OFFCHANNEL));
 305
 306         spin_unlock_bh(&sc->rx.rxbuflock);
 307 }
 308
 309 static void ath_edma_stop_recv(struct ath_softc *sc)
 310 {
 311         ath_rx_remove_buffer(sc, ATH9K_RX_QUEUE_HP);
 312         ath_rx_remove_buffer(sc, ATH9K_RX_QUEUE_LP);
 313 }
 314
 315 int ath_rx_init(struct ath_softc *sc, int nbufs)
 316 {
 317         struct ath_common *common = ath9k_hw_common(sc->sc_ah);
 318         struct sk_buff *skb;
 319         struct ath_buf *bf;
 320         int error = 0;
 321
 322         spin_lock_init(&sc->sc_pcu_lock);
 323         sc->sc_flags &= ~SC_OP_RXFLUSH;
 324         spin_lock_init(&sc->rx.rxbuflock);
 325
 326         common->rx_bufsize = IEEE80211_MAX_MPDU_LEN / 2 +
 327                              sc->sc_ah->caps.rx_status_len;
 328
 329         if (sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_EDMA) {
 330                 return ath_rx_edma_init(sc, nbufs);
 331         } else {
 332                 ath_dbg(common, ATH_DBG_CONFIG, "cachelsz %u rxbufsize %u\n",
 333                         common->cachelsz, common->rx_bufsize);
 334
 335                 /* Initialize rx descriptors */
 336
 337                 error = ath_descdma_setup(sc, &sc->rx.rxdma, &sc->rx.rxbuf,
 338                                 "rx", nbufs, 1, 0);
 339                 if (error != 0) {
 340                         ath_err(common,
 341                                 "failed to allocate rx descriptors: %d\n",
 342                                 error);
 343                         goto err;
 344                 }
 345
 346                 list_for_each_entry(bf, &sc->rx.rxbuf, list) {
 347                         skb = ath_rxbuf_alloc(common, common->rx_bufsize,
 348                                               GFP_KERNEL);
 349                         if (skb == NULL) {
 350                                 error = -ENOMEM;
 351                                 goto err;
 352                         }
 353
 354                         bf->bf_mpdu = skb;
 355                         bf->bf_buf_addr = dma_map_single(sc->dev, skb->data,
 356                                         common->rx_bufsize,
 357                                         DMA_FROM_DEVICE);
 358                         if (unlikely(dma_mapping_error(sc->dev,
 359                                                         bf->bf_buf_addr))) {
 360                                 dev_kfree_skb_any(skb);
 361                                 bf->bf_mpdu = NULL;
 362                                 bf->bf_buf_addr = 0;
 363                                 ath_err(common,
 364                                         "dma_mapping_error() on RX init\n");
 365                                 error = -ENOMEM;
 366                                 goto err;
 367                         }
 368                 }
 369                 sc->rx.rxlink = NULL;
 370         }
 371
 372 err:
 373         if (error)
 374                 ath_rx_cleanup(sc);
 375
 376         return error;
 377 }
 378
 379 void ath_rx_cleanup(struct ath_softc *sc)
 380 {
 381         struct ath_hw *ah = sc->sc_ah;
 382         struct ath_common *common = ath9k_hw_common(ah);
 383         struct sk_buff *skb;
 384         struct ath_buf *bf;
 385
 386         if (sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_EDMA) {
 387                 ath_rx_edma_cleanup(sc);
 388                 return;
 389         } else {
 390                 list_for_each_entry(bf, &sc->rx.rxbuf, list) {
 391                         skb = bf->bf_mpdu;
 392                         if (skb) {
 393                                 dma_unmap_single(sc->dev, bf->bf_buf_addr,
 394                                                 common->rx_bufsize,
 395                                                 DMA_FROM_DEVICE);
 396                                 dev_kfree_skb(skb);
 397                                 bf->bf_buf_addr = 0;
 398                                 bf->bf_mpdu = NULL;
 399                         }
 400                 }
 401
 402                 if (sc->rx.rxdma.dd_desc_len != 0)
 403                         ath_descdma_cleanup(sc, &sc->rx.rxdma, &sc->rx.rxbuf);
 404         }
 405 }
 406
 407 /*
 408  * Calculate the receive filter according to the
 409  * operating mode and state:
 410  *
 411  * o always accept unicast, broadcast, and multicast traffic
 412  * o maintain current state of phy error reception (the hal
 413  *   may enable phy error frames for noise immunity work)
 414  * o probe request frames are accepted only when operating in
 415  *   hostap, adhoc, or monitor modes
 416  * o enable promiscuous mode according to the interface state
 417  * o accept beacons:
 418  *   - when operating in adhoc mode so the 802.11 layer creates
 419  *     node table entries for peers,
 420  *   - when operating in station mode for collecting rssi data when
 421  *     the station is otherwise quiet, or
 422  *   - when operating as a repeater so we see repeater-sta beacons
 423  *   - when scanning
 424  */
 425
 426 u32 ath_calcrxfilter(struct ath_softc *sc)
 427 {
 428 #define RX_FILTER_PRESERVE (ATH9K_RX_FILTER_PHYERR | ATH9K_RX_FILTER_PHYRADAR)
 429
 430         u32 rfilt;
 431
 432         rfilt = (ath9k_hw_getrxfilter(sc->sc_ah) & RX_FILTER_PRESERVE)
 433                 | ATH9K_RX_FILTER_UCAST | ATH9K_RX_FILTER_BCAST
 434                 | ATH9K_RX_FILTER_MCAST;
 435
 436         if (sc->rx.rxfilter & FIF_PROBE_REQ)
 437                 rfilt |= ATH9K_RX_FILTER_PROBEREQ;
 438
 439         /*
 440          * Set promiscuous mode when FIF_PROMISC_IN_BSS is enabled for station
 441          * mode interface or when in monitor mode. AP mode does not need this
 442          * since it receives all in-BSS frames anyway.
 443          */
 444         if (sc->sc_ah->is_monitoring)
 445                 rfilt |= ATH9K_RX_FILTER_PROM;
 446
 447         if (sc->rx.rxfilter & FIF_CONTROL)
 448                 rfilt |= ATH9K_RX_FILTER_CONTROL;
 449
 450         if ((sc->sc_ah->opmode == NL80211_IFTYPE_STATION) &&
 451             (sc->nvifs <= 1) &&
 452             !(sc->rx.rxfilter & FIF_BCN_PRBRESP_PROMISC))
 453                 rfilt |= ATH9K_RX_FILTER_MYBEACON;
 454         else
 455                 rfilt |= ATH9K_RX_FILTER_BEACON;
 456
 457         if ((sc->sc_ah->opmode == NL80211_IFTYPE_AP) ||
 458             (sc->rx.rxfilter & FIF_PSPOLL))
 459                 rfilt |= ATH9K_RX_FILTER_PSPOLL;
 460
 461         if (conf_is_ht(&sc->hw->conf))
 462                 rfilt |= ATH9K_RX_FILTER_COMP_BAR;
 463
 464         if (sc->nvifs > 1 || (sc->rx.rxfilter & FIF_OTHER_BSS)) {
 465                 /* The following may also be needed for other older chips */
 466                 if (sc->sc_ah->hw_version.macVersion == AR_SREV_VERSION_9160)
 467                         rfilt |= ATH9K_RX_FILTER_PROM;
 468                 rfilt |= ATH9K_RX_FILTER_MCAST_BCAST_ALL;
 469         }
 470
 471         return rfilt;
 472
 473 #undef RX_FILTER_PRESERVE
 474 }
 475
 476 int ath_startrecv(struct ath_softc *sc)
 477 {
 478         struct ath_hw *ah = sc->sc_ah;
 479         struct ath_buf *bf, *tbf;
 480
 481         if (ah->caps.hw_caps & ATH9K_HW_CAP_EDMA) {
 482                 ath_edma_start_recv(sc);
 483                 return 0;
 484         }
 485
 486         spin_lock_bh(&sc->rx.rxbuflock);
 487         if (list_empty(&sc->rx.rxbuf))
 488                 goto start_recv;
 489
 490         sc->rx.rxlink = NULL;
 491         list_for_each_entry_safe(bf, tbf, &sc->rx.rxbuf, list) {
 492                 ath_rx_buf_link(sc, bf);
 493         }
 494
 495         /* We could have deleted elements so the list may be empty now */
 496         if (list_empty(&sc->rx.rxbuf))
 497                 goto start_recv;
 498
 499         bf = list_first_entry(&sc->rx.rxbuf, struct ath_buf, list);
 500         ath9k_hw_putrxbuf(ah, bf->bf_daddr);
 501         ath9k_hw_rxena(ah);
 502
 503 start_recv:
 504         ath_opmode_init(sc);
 505         ath9k_hw_startpcureceive(ah, (sc->sc_flags & SC_OP_OFFCHANNEL));
 506
 507         spin_unlock_bh(&sc->rx.rxbuflock);
 508
 509         return 0;
 510 }
 511
 512 bool ath_stoprecv(struct ath_softc *sc)
 513 {
 514         struct ath_hw *ah = sc->sc_ah;
 515         bool stopped, reset = false;
 516
 517         spin_lock_bh(&sc->rx.rxbuflock);
 518         ath9k_hw_abortpcurecv(ah);
 519         ath9k_hw_setrxfilter(ah, 0);
 520         stopped = ath9k_hw_stopdmarecv(ah, &reset);
 521
 522         if (sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_EDMA)
 523                 ath_edma_stop_recv(sc);
 524         else
 525                 sc->rx.rxlink = NULL;
 526         spin_unlock_bh(&sc->rx.rxbuflock);
 527
 528         if (!(ah->ah_flags & AH_UNPLUGGED) &&
 529             unlikely(!stopped)) {
 530                 ath_err(ath9k_hw_common(sc->sc_ah),
 531                         "Could not stop RX, we could be "
 532                         "confusing the DMA engine when we start RX up\n");
 533                 ATH_DBG_WARN_ON_ONCE(!stopped);
 534         }
 535         return stopped && !reset;
 536 }
 537
 538 void ath_flushrecv(struct ath_softc *sc)
 539 {
 540         sc->sc_flags |= SC_OP_RXFLUSH;
 541         if (sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_EDMA)
 542                 ath_rx_tasklet(sc, 1, true);
 543         ath_rx_tasklet(sc, 1, false);
 544         sc->sc_flags &= ~SC_OP_RXFLUSH;
 545 }
 546
 547 static bool ath_beacon_dtim_pending_cab(struct sk_buff *skb)
 548 {
 549         /* Check whether the Beacon frame has DTIM indicating buffered bc/mc */
 550         struct ieee80211_mgmt *mgmt;
 551         u8 *pos, *end, id, elen;
 552         struct ieee80211_tim_ie *tim;
 553
 554         mgmt = (struct ieee80211_mgmt *)skb->data;
 555         pos = mgmt->u.beacon.variable;
 556         end = skb->data + skb->len;
 557
 558         while (pos + 2 < end) {
 559                 id = *pos++;
 560                 elen = *pos++;
 561                 if (pos + elen > end)
 562                         break;
 563
 564                 if (id == WLAN_EID_TIM) {
 565                         if (elen < sizeof(*tim))
 566                                 break;
 567                         tim = (struct ieee80211_tim_ie *) pos;
 568                         if (tim->dtim_count != 0)
 569                                 break;
 570                         return tim->bitmap_ctrl & 0x01;
 571                 }
 572
 573                 pos += elen;
 574         }
 575
 576         return false;
 577 }
 578
 579 static void ath_rx_ps_beacon(struct ath_softc *sc, struct sk_buff *skb)
 580 {
 581         struct ieee80211_mgmt *mgmt;
 582         struct ath_common *common = ath9k_hw_common(sc->sc_ah);
 583
 584         if (skb->len < 24 + 8 + 2 + 2)
 585                 return;
 586
 587         mgmt = (struct ieee80211_mgmt *)skb->data;
 588         if (memcmp(common->curbssid, mgmt->bssid, ETH_ALEN) != 0) {
 589                 /* TODO:  This doesn't work well if you have stations
 590                  * associated to two different APs because curbssid
 591                  * is just the last AP that any of the stations associated
 592                  * with.
 593                  */
 594                 return; /* not from our current AP */
 595         }
 596
 597         sc->ps_flags &= ~PS_WAIT_FOR_BEACON;
 598
 599         if (sc->ps_flags & PS_BEACON_SYNC) {
 600                 sc->ps_flags &= ~PS_BEACON_SYNC;
 601                 ath_dbg(common, ATH_DBG_PS,
 602                         "Reconfigure Beacon timers based on timestamp from the AP\n");
 603                 ath_set_beacon(sc);
 604                 sc->ps_flags &= ~PS_TSFOOR_SYNC;
 605         }
 606
 607         if (ath_beacon_dtim_pending_cab(skb)) {
 608                 /*
 609                  * Remain awake waiting for buffered broadcast/multicast
 610                  * frames. If the last broadcast/multicast frame is not
 611                  * received properly, the next beacon frame will work as
 612                  * a backup trigger for returning into NETWORK SLEEP state,
 613                  * so we are waiting for it as well.
 614                  */
 615                 ath_dbg(common, ATH_DBG_PS,
 616                         "Received DTIM beacon indicating buffered broadcast/multicast frame(s)\n");
 617                 sc->ps_flags |= PS_WAIT_FOR_CAB | PS_WAIT_FOR_BEACON;
 618                 return;
 619         }
 620
 621         if (sc->ps_flags & PS_WAIT_FOR_CAB) {
 622                 /*
 623                  * This can happen if a broadcast frame is dropped or the AP
 624                  * fails to send a frame indicating that all CAB frames have
 625                  * been delivered.
 626                  */
 627                 sc->ps_flags &= ~PS_WAIT_FOR_CAB;
 628                 ath_dbg(common, ATH_DBG_PS,
 629                         "PS wait for CAB frames timed out\n");
 630         }
 631 }
 632
 633 static void ath_rx_ps(struct ath_softc *sc, struct sk_buff *skb)
 634 {
 635         struct ieee80211_hdr *hdr;
 636         struct ath_common *common = ath9k_hw_common(sc->sc_ah);
 637
 638         hdr = (struct ieee80211_hdr *)skb->data;
 639
 640         /* Process Beacon and CAB receive in PS state */
 641         if (((sc->ps_flags & PS_WAIT_FOR_BEACON) || ath9k_check_auto_sleep(sc))
 642             && ieee80211_is_beacon(hdr->frame_control))
 643                 ath_rx_ps_beacon(sc, skb);
 644         else if ((sc->ps_flags & PS_WAIT_FOR_CAB) &&
 645                  (ieee80211_is_data(hdr->frame_control) ||
 646                   ieee80211_is_action(hdr->frame_control)) &&
 647                  is_multicast_ether_addr(hdr->addr1) &&
 648                  !ieee80211_has_moredata(hdr->frame_control)) {
 649                 /*
 650                  * No more broadcast/multicast frames to be received at this
 651                  * point.
 652                  */
 653                 sc->ps_flags &= ~(PS_WAIT_FOR_CAB | PS_WAIT_FOR_BEACON);
 654                 ath_dbg(common, ATH_DBG_PS,
 655                         "All PS CAB frames received, back to sleep\n");
 656         } else if ((sc->ps_flags & PS_WAIT_FOR_PSPOLL_DATA) &&
 657                    !is_multicast_ether_addr(hdr->addr1) &&
 658                    !ieee80211_has_morefrags(hdr->frame_control)) {
 659                 sc->ps_flags &= ~PS_WAIT_FOR_PSPOLL_DATA;
 660                 ath_dbg(common, ATH_DBG_PS,
 661                         "Going back to sleep after having received PS-Poll data (0x%lx)\n",
 662                         sc->ps_flags & (PS_WAIT_FOR_BEACON |
 663                                         PS_WAIT_FOR_CAB |
 664                                         PS_WAIT_FOR_PSPOLL_DATA |
 665                                         PS_WAIT_FOR_TX_ACK));
 666         }
 667 }
 668
 669 static bool ath_edma_get_buffers(struct ath_softc *sc,
 670                                  enum ath9k_rx_qtype qtype)
 671 {
 672         struct ath_rx_edma *rx_edma = &sc->rx.rx_edma[qtype];
 673         struct ath_hw *ah = sc->sc_ah;
 674         struct ath_common *common = ath9k_hw_common(ah);
 675         struct sk_buff *skb;
 676         struct ath_buf *bf;
 677         int ret;
 678
 679         skb = skb_peek(&rx_edma->rx_fifo);
 680         if (!skb)
 681                 return false;
 682
 683         bf = SKB_CB_ATHBUF(skb);
 684         BUG_ON(!bf);
 685
 686         dma_sync_single_for_cpu(sc->dev, bf->bf_buf_addr,
 687                                 common->rx_bufsize, DMA_FROM_DEVICE);
 688
 689         ret = ath9k_hw_process_rxdesc_edma(ah, NULL, skb->data);
 690         if (ret == -EINPROGRESS) {
 691                 /*let device gain the buffer again*/
 692                 dma_sync_single_for_device(sc->dev, bf->bf_buf_addr,
 693                                 common->rx_bufsize, DMA_FROM_DEVICE);
 694                 return false;
 695         }
 696
 697         __skb_unlink(skb, &rx_edma->rx_fifo);
 698         if (ret == -EINVAL) {
 699                 /* corrupt descriptor, skip this one and the following one */
 700                 list_add_tail(&bf->list, &sc->rx.rxbuf);
 701                 ath_rx_edma_buf_link(sc, qtype);
 702                 skb = skb_peek(&rx_edma->rx_fifo);
 703                 if (!skb)
 704                         return true;
 705
 706                 bf = SKB_CB_ATHBUF(skb);
 707                 BUG_ON(!bf);
 708
 709                 __skb_unlink(skb, &rx_edma->rx_fifo);
 710                 list_add_tail(&bf->list, &sc->rx.rxbuf);
 711                 ath_rx_edma_buf_link(sc, qtype);
 712                 return true;
 713         }
 714         skb_queue_tail(&rx_edma->rx_buffers, skb);
 715
 716         return true;
 717 }
 718
 719 static struct ath_buf *ath_edma_get_next_rx_buf(struct ath_softc *sc,
 720                                                 struct ath_rx_status *rs,
 721                                                 enum ath9k_rx_qtype qtype)
 722 {
 723         struct ath_rx_edma *rx_edma = &sc->rx.rx_edma[qtype];
 724         struct sk_buff *skb;
 725         struct ath_buf *bf;
 726
 727         while (ath_edma_get_buffers(sc, qtype));
 728         skb = __skb_dequeue(&rx_edma->rx_buffers);
 729         if (!skb)
 730                 return NULL;
 731
 732         bf = SKB_CB_ATHBUF(skb);
 733         ath9k_hw_process_rxdesc_edma(sc->sc_ah, rs, skb->data);
 734         return bf;
 735 }
 736
 737 static struct ath_buf *ath_get_next_rx_buf(struct ath_softc *sc,
 738                                            struct ath_rx_status *rs)
 739 {
 740         struct ath_hw *ah = sc->sc_ah;
 741         struct ath_common *common = ath9k_hw_common(ah);
 742         struct ath_desc *ds;
 743         struct ath_buf *bf;
 744         int ret;
 745
 746         if (list_empty(&sc->rx.rxbuf)) {
 747                 sc->rx.rxlink = NULL;
 748                 return NULL;
 749         }
 750
 751         bf = list_first_entry(&sc->rx.rxbuf, struct ath_buf, list);
 752         ds = bf->bf_desc;
 753
 754         /*
 755          * Must provide the virtual address of the current
 756          * descriptor, the physical address, and the virtual
 757          * address of the next descriptor in the h/w chain.
 758          * This allows the HAL to look ahead to see if the
 759          * hardware is done with a descriptor by checking the
 760          * done bit in the following descriptor and the address
 761          * of the current descriptor the DMA engine is working
 762          * on.  All this is necessary because of our use of
 763          * a self-linked list to avoid rx overruns.
 764          */
 765         ret = ath9k_hw_rxprocdesc(ah, ds, rs, 0);
 766         if (ret == -EINPROGRESS) {
 767                 struct ath_rx_status trs;
 768                 struct ath_buf *tbf;
 769                 struct ath_desc *tds;
 770
 771                 memset(&trs, 0, sizeof(trs));
 772                 if (list_is_last(&bf->list, &sc->rx.rxbuf)) {
 773                         sc->rx.rxlink = NULL;
 774                         return NULL;
 775                 }
 776
 777                 tbf = list_entry(bf->list.next, struct ath_buf, list);
 778
 779                 /*
 780                  * On some hardware the descriptor status words could
 781                  * get corrupted, including the done bit. Because of
 782                  * this, check if the next descriptor's done bit is
 783                  * set or not.
 784                  *
 785                  * If the next descriptor's done bit is set, the current
 786                  * descriptor has been corrupted. Force s/w to discard
 787                  * this descriptor and continue...
 788                  */
 789
 790                 tds = tbf->bf_desc;
 791                 ret = ath9k_hw_rxprocdesc(ah, tds, &trs, 0);
 792                 if (ret == -EINPROGRESS)
 793                         return NULL;
 794         }
 795
 796         if (!bf->bf_mpdu)
 797                 return bf;
 798
 799         /*
 800          * Synchronize the DMA transfer with CPU before
 801          * 1. accessing the frame
 802          * 2. requeueing the same buffer to h/w
 803          */
 804         dma_sync_single_for_cpu(sc->dev, bf->bf_buf_addr,
 805                         common->rx_bufsize,
 806                         DMA_FROM_DEVICE);
 807
 808         return bf;
 809 }
 810
 811 /* Assumes you've already done the endian to CPU conversion */
 812 static bool ath9k_rx_accept(struct ath_common *common,
 813                             struct ieee80211_hdr *hdr,
 814                             struct ieee80211_rx_status *rxs,
 815                             struct ath_rx_status *rx_stats,
 816                             bool *decrypt_error)
 817 {
 818 #define is_mc_or_valid_tkip_keyix ((is_mc ||                    \
 819                 (rx_stats->rs_keyix != ATH9K_RXKEYIX_INVALID && \
 820                 test_bit(rx_stats->rs_keyix, common->tkip_keymap))))
 821
 822         struct ath_hw *ah = common->ah;
 823         __le16 fc;
 824         u8 rx_status_len = ah->caps.rx_status_len;
 825
 826         fc = hdr->frame_control;
 827
 828         if (!rx_stats->rs_datalen)
 829                 return false;
 830         /*
 831          * rs_status follows rs_datalen so if rs_datalen is too large
 832          * we can take a hint that hardware corrupted it, so ignore
 833          * those frames.
 834          */
 835         if (rx_stats->rs_datalen > (common->rx_bufsize - rx_status_len))
 836                 return false;
 837
 838         /* Only use error bits from the last fragment */
 839         if (rx_stats->rs_more)
 840                 return true;
 841
 842         /*
 843          * The rx_stats->rs_status will not be set until the end of the
 844          * chained descriptors so it can be ignored if rs_more is set. The
 845          * rs_more will be false at the last element of the chained
 846          * descriptors.
 847          */
 848         if (rx_stats->rs_status != 0) {
 849                 if (rx_stats->rs_status & ATH9K_RXERR_CRC)
 850                         rxs->flag |= RX_FLAG_FAILED_FCS_CRC;
 851                 if (rx_stats->rs_status & ATH9K_RXERR_PHY)
 852                         return false;
 853
 854                 if (rx_stats->rs_status & ATH9K_RXERR_DECRYPT) {
 855                         *decrypt_error = true;
 856                 } else if (rx_stats->rs_status & ATH9K_RXERR_MIC) {
 857                         bool is_mc;
 858                         /*
 859                          * The MIC error bit is only valid if the frame
 860                          * is not a control frame or fragment, and it was
 861                          * decrypted using a valid TKIP key.
 862                          */
 863                         is_mc = !!is_multicast_ether_addr(hdr->addr1);
 864
 865                         if (!ieee80211_is_ctl(fc) &&
 866                             !ieee80211_has_morefrags(fc) &&
 867                             !(le16_to_cpu(hdr->seq_ctrl) & IEEE80211_SCTL_FRAG) &&
 868                             is_mc_or_valid_tkip_keyix)
 869                                 rxs->flag |= RX_FLAG_MMIC_ERROR;
 870                         else
 871                                 rx_stats->rs_status &= ~ATH9K_RXERR_MIC;
 872                 }
 873                 /*
 874                  * Reject error frames with the exception of
 875                  * decryption and MIC failures. For monitor mode,
 876                  * we also ignore the CRC error.
 877                  */
 878                 if (ah->is_monitoring) {
 879                         if (rx_stats->rs_status &
 880                             ~(ATH9K_RXERR_DECRYPT | ATH9K_RXERR_MIC |
 881                               ATH9K_RXERR_CRC))
 882                                 return false;
 883                 } else {
 884                         if (rx_stats->rs_status &
 885                             ~(ATH9K_RXERR_DECRYPT | ATH9K_RXERR_MIC)) {
 886                                 return false;
 887                         }
 888                 }
 889         }
 890         return true;
 891 }
 892
 893 static int ath9k_process_rate(struct ath_common *common,
 894                               struct ieee80211_hw *hw,
 895                               struct ath_rx_status *rx_stats,
 896                               struct ieee80211_rx_status *rxs)
 897 {
 898         struct ieee80211_supported_band *sband;
 899         enum ieee80211_band band;
 900         unsigned int i = 0;
 901
 902         band = hw->conf.channel->band;
 903         sband = hw->wiphy->bands[band];
 904
 905         if (rx_stats->rs_rate & 0x80) {
 906                 /* HT rate */
 907                 rxs->flag |= RX_FLAG_HT;
 908                 if (rx_stats->rs_flags & ATH9K_RX_2040)
 909                         rxs->flag |= RX_FLAG_40MHZ;
 910                 if (rx_stats->rs_flags & ATH9K_RX_GI)
 911                         rxs->flag |= RX_FLAG_SHORT_GI;
 912                 rxs->rate_idx = rx_stats->rs_rate & 0x7f;
 913                 return 0;
 914         }
 915
 916         for (i = 0; i < sband->n_bitrates; i++) {
 917                 if (sband->bitrates[i].hw_value == rx_stats->rs_rate) {
 918                         rxs->rate_idx = i;
 919                         return 0;
 920                 }
 921                 if (sband->bitrates[i].hw_value_short == rx_stats->rs_rate) {
 922                         rxs->flag |= RX_FLAG_SHORTPRE;
 923                         rxs->rate_idx = i;
 924                         return 0;
 925                 }
 926         }
 927
 928         /*
 929          * No valid hardware bitrate found -- we should not get here
 930          * because hardware has already validated this frame as OK.
 931          */
 932         ath_dbg(common, ATH_DBG_XMIT,
 933                 "unsupported hw bitrate detected 0x%02x using 1 Mbit\n",
 934                 rx_stats->rs_rate);
 935
 936         return -EINVAL;
 937 }
 938
 939 static void ath9k_process_rssi(struct ath_common *common,
 940                                struct ieee80211_hw *hw,
 941                                struct ieee80211_hdr *hdr,
 942                                struct ath_rx_status *rx_stats)
 943 {
 944         struct ath_softc *sc = hw->priv;
 945         struct ath_hw *ah = common->ah;
 946         int last_rssi;
 947         __le16 fc;
 948
 949         if ((ah->opmode != NL80211_IFTYPE_STATION) &&
 950             (ah->opmode != NL80211_IFTYPE_ADHOC))
 951                 return;
 952
 953         fc = hdr->frame_control;
 954         if (!ieee80211_is_beacon(fc) ||
 955             compare_ether_addr(hdr->addr3, common->curbssid)) {
 956                 /* TODO:  This doesn't work well if you have stations
 957                  * associated to two different APs because curbssid
 958                  * is just the last AP that any of the stations associated
 959                  * with.
 960                  */
 961                 return;
 962         }
 963
 964         if (rx_stats->rs_rssi != ATH9K_RSSI_BAD && !rx_stats->rs_moreaggr)
 965                 ATH_RSSI_LPF(sc->last_rssi, rx_stats->rs_rssi);
 966
 967         last_rssi = sc->last_rssi;
 968         if (likely(last_rssi != ATH_RSSI_DUMMY_MARKER))
 969                 rx_stats->rs_rssi = ATH_EP_RND(last_rssi,
 970                                               ATH_RSSI_EP_MULTIPLIER);
 971         if (rx_stats->rs_rssi < 0)
 972                 rx_stats->rs_rssi = 0;
 973
 974         /* Update Beacon RSSI, this is used by ANI. */
 975         ah->stats.avgbrssi = rx_stats->rs_rssi;
 976 }
 977
 978 /*
 979  * For Decrypt or Demic errors, we only mark packet status here and always push
 980  * up the frame up to let mac80211 handle the actual error case, be it no
 981  * decryption key or real decryption error. This let us keep statistics there.
 982  */
 983 static int ath9k_rx_skb_preprocess(struct ath_common *common,
 984                                    struct ieee80211_hw *hw,
 985                                    struct ieee80211_hdr *hdr,
 986                                    struct ath_rx_status *rx_stats,
 987                                    struct ieee80211_rx_status *rx_status,
 988                                    bool *decrypt_error)
 989 {
 990         memset(rx_status, 0, sizeof(struct ieee80211_rx_status));
 991
 992         /*
 993          * everything but the rate is checked here, the rate check is done
 994          * separately to avoid doing two lookups for a rate for each frame.
 995          */
 996         if (!ath9k_rx_accept(common, hdr, rx_status, rx_stats, decrypt_error))
 997                 return -EINVAL;
 998
 999         /* Only use status info from the last fragment */
1000         if (rx_stats->rs_more)
1001                 return 0;
1002
1003         ath9k_process_rssi(common, hw, hdr, rx_stats);
1004
1005         if (ath9k_process_rate(common, hw, rx_stats, rx_status))
1006                 return -EINVAL;
1007
1008         rx_status->band = hw->conf.channel->band;
1009         rx_status->freq = hw->conf.channel->center_freq;
1010         rx_status->signal = ATH_DEFAULT_NOISE_FLOOR + rx_stats->rs_rssi;
1011         rx_status->antenna = rx_stats->rs_antenna;
1012         rx_status->flag |= RX_FLAG_MACTIME_MPDU;
1013
1014         return 0;
1015 }
1016
1017 static void ath9k_rx_skb_postprocess(struct ath_common *common,
1018                                      struct sk_buff *skb,
1019                                      struct ath_rx_status *rx_stats,
1020                                      struct ieee80211_rx_status *rxs,
1021                                      bool decrypt_error)
1022 {
1023         struct ath_hw *ah = common->ah;
1024         struct ieee80211_hdr *hdr;
1025         int hdrlen, padpos, padsize;
1026         u8 keyix;
1027         __le16 fc;
1028
1029         /* see if any padding is done by the hw and remove it */
1030         hdr = (struct ieee80211_hdr *) skb->data;
1031         hdrlen = ieee80211_get_hdrlen_from_skb(skb);
1032         fc = hdr->frame_control;
1033         padpos = ath9k_cmn_padpos(hdr->frame_control);
1034
1035         /* The MAC header is padded to have 32-bit boundary if the
1036          * packet payload is non-zero. The general calculation for
1037          * padsize would take into account odd header lengths:
1038          * padsize = (4 - padpos % 4) % 4; However, since only
1039          * even-length headers are used, padding can only be 0 or 2
1040          * bytes and we can optimize this a bit. In addition, we must
1041          * not try to remove padding from short control frames that do
1042          * not have payload. */
1043         padsize = padpos & 3;
1044         if (padsize && skb->len>=padpos+padsize+FCS_LEN) {
1045                 memmove(skb->data + padsize, skb->data, padpos);
1046                 skb_pull(skb, padsize);
1047         }
1048
1049         keyix = rx_stats->rs_keyix;
1050
1051         if (!(keyix == ATH9K_RXKEYIX_INVALID) && !decrypt_error &&
1052             ieee80211_has_protected(fc)) {
1053                 rxs->flag |= RX_FLAG_DECRYPTED;
1054         } else if (ieee80211_has_protected(fc)
1055                    && !decrypt_error && skb->len >= hdrlen + 4) {
1056                 keyix = skb->data[hdrlen + 3] >> 6;
1057
1058                 if (test_bit(keyix, common->keymap))
1059                         rxs->flag |= RX_FLAG_DECRYPTED;
1060         }
1061         if (ah->sw_mgmt_crypto &&
1062             (rxs->flag & RX_FLAG_DECRYPTED) &&
1063             ieee80211_is_mgmt(fc))
1064                 /* Use software decrypt for management frames. */
1065                 rxs->flag &= ~RX_FLAG_DECRYPTED;
1066 }
1067
1068 static void ath_lnaconf_alt_good_scan(struct ath_ant_comb *antcomb,
1069                                       struct ath_hw_antcomb_conf ant_conf,
1070                                       int main_rssi_avg)
1071 {
1072         antcomb->quick_scan_cnt = 0;
1073
1074         if (ant_conf.main_lna_conf == ATH_ANT_DIV_COMB_LNA2)
1075                 antcomb->rssi_lna2 = main_rssi_avg;
1076         else if (ant_conf.main_lna_conf == ATH_ANT_DIV_COMB_LNA1)
1077                 antcomb->rssi_lna1 = main_rssi_avg;
1078
1079         switch ((ant_conf.main_lna_conf << 4) | ant_conf.alt_lna_conf) {
1080         case 0x10: /* LNA2 A-B */
1081                 antcomb->main_conf = ATH_ANT_DIV_COMB_LNA1_MINUS_LNA2;
1082                 antcomb->first_quick_scan_conf =
1083                         ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2;
1084                 antcomb->second_quick_scan_conf = ATH_ANT_DIV_COMB_LNA1;
1085                 break;
1086         case 0x20: /* LNA1 A-B */
1087                 antcomb->main_conf = ATH_ANT_DIV_COMB_LNA1_MINUS_LNA2;
1088                 antcomb->first_quick_scan_conf =
1089                         ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2;
1090                 antcomb->second_quick_scan_conf = ATH_ANT_DIV_COMB_LNA2;
1091                 break;
1092         case 0x21: /* LNA1 LNA2 */
1093                 antcomb->main_conf = ATH_ANT_DIV_COMB_LNA2;
1094                 antcomb->first_quick_scan_conf =
1095                         ATH_ANT_DIV_COMB_LNA1_MINUS_LNA2;
1096                 antcomb->second_quick_scan_conf =
1097                         ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2;
1098                 break;
1099         case 0x12: /* LNA2 LNA1 */
1100                 antcomb->main_conf = ATH_ANT_DIV_COMB_LNA1;
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 0x13: /* LNA2 A+B */
1107                 antcomb->main_conf = ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2;
1108                 antcomb->first_quick_scan_conf =
1109                         ATH_ANT_DIV_COMB_LNA1_MINUS_LNA2;
1110                 antcomb->second_quick_scan_conf = ATH_ANT_DIV_COMB_LNA1;
1111                 break;
1112         case 0x23: /* LNA1 A+B */
1113                 antcomb->main_conf = ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2;
1114                 antcomb->first_quick_scan_conf =
1115                         ATH_ANT_DIV_COMB_LNA1_MINUS_LNA2;
1116                 antcomb->second_quick_scan_conf = ATH_ANT_DIV_COMB_LNA2;
1117                 break;
1118         default:
1119                 break;
1120         }
1121 }
1122
1123 static void ath_select_ant_div_from_quick_scan(struct ath_ant_comb *antcomb,
1124                                 struct ath_hw_antcomb_conf *div_ant_conf,
1125                                 int main_rssi_avg, int alt_rssi_avg,
1126                                 int alt_ratio)
1127 {
1128         /* alt_good */
1129         switch (antcomb->quick_scan_cnt) {
1130         case 0:
1131                 /* set alt to main, and alt to first conf */
1132                 div_ant_conf->main_lna_conf = antcomb->main_conf;
1133                 div_ant_conf->alt_lna_conf = antcomb->first_quick_scan_conf;
1134                 break;
1135         case 1:
1136                 /* set alt to main, and alt to first conf */
1137                 div_ant_conf->main_lna_conf = antcomb->main_conf;
1138                 div_ant_conf->alt_lna_conf = antcomb->second_quick_scan_conf;
1139                 antcomb->rssi_first = main_rssi_avg;
1140                 antcomb->rssi_second = alt_rssi_avg;
1141
1142                 if (antcomb->main_conf == ATH_ANT_DIV_COMB_LNA1) {
1143                         /* main is LNA1 */
1144                         if (ath_is_alt_ant_ratio_better(alt_ratio,
1145                                                 ATH_ANT_DIV_COMB_LNA1_DELTA_HI,
1146                                                 ATH_ANT_DIV_COMB_LNA1_DELTA_LOW,
1147                                                 main_rssi_avg, alt_rssi_avg,
1148                                                 antcomb->total_pkt_count))
1149                                 antcomb->first_ratio = true;
1150                         else
1151                                 antcomb->first_ratio = false;
1152                 } else if (antcomb->main_conf == ATH_ANT_DIV_COMB_LNA2) {
1153                         if (ath_is_alt_ant_ratio_better(alt_ratio,
1154                                                 ATH_ANT_DIV_COMB_LNA1_DELTA_MID,
1155                                                 ATH_ANT_DIV_COMB_LNA1_DELTA_LOW,
1156                                                 main_rssi_avg, alt_rssi_avg,
1157                                                 antcomb->total_pkt_count))
1158                                 antcomb->first_ratio = true;
1159                         else
1160                                 antcomb->first_ratio = false;
1161                 } else {
1162                         if ((((alt_ratio >= ATH_ANT_DIV_COMB_ALT_ANT_RATIO2) &&
1163                             (alt_rssi_avg > main_rssi_avg +
1164                             ATH_ANT_DIV_COMB_LNA1_DELTA_HI)) ||
1165                             (alt_rssi_avg > main_rssi_avg)) &&
1166                             (antcomb->total_pkt_count > 50))
1167                                 antcomb->first_ratio = true;
1168                         else
1169                                 antcomb->first_ratio = false;
1170                 }
1171                 break;
1172         case 2:
1173                 antcomb->alt_good = false;
1174                 antcomb->scan_not_start = false;
1175                 antcomb->scan = false;
1176                 antcomb->rssi_first = main_rssi_avg;
1177                 antcomb->rssi_third = alt_rssi_avg;
1178
1179                 if (antcomb->second_quick_scan_conf == ATH_ANT_DIV_COMB_LNA1)
1180                         antcomb->rssi_lna1 = alt_rssi_avg;
1181                 else if (antcomb->second_quick_scan_conf ==
1182                          ATH_ANT_DIV_COMB_LNA2)
1183                         antcomb->rssi_lna2 = alt_rssi_avg;
1184                 else if (antcomb->second_quick_scan_conf ==
1185                          ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2) {
1186                         if (antcomb->main_conf == ATH_ANT_DIV_COMB_LNA2)
1187                                 antcomb->rssi_lna2 = main_rssi_avg;
1188                         else if (antcomb->main_conf == ATH_ANT_DIV_COMB_LNA1)
1189                                 antcomb->rssi_lna1 = main_rssi_avg;
1190                 }
1191
1192                 if (antcomb->rssi_lna2 > antcomb->rssi_lna1 +
1193                     ATH_ANT_DIV_COMB_LNA1_LNA2_SWITCH_DELTA)
1194                         div_ant_conf->main_lna_conf = ATH_ANT_DIV_COMB_LNA2;
1195                 else
1196                         div_ant_conf->main_lna_conf = ATH_ANT_DIV_COMB_LNA1;
1197
1198                 if (antcomb->main_conf == ATH_ANT_DIV_COMB_LNA1) {
1199                         if (ath_is_alt_ant_ratio_better(alt_ratio,
1200                                                 ATH_ANT_DIV_COMB_LNA1_DELTA_HI,
1201                                                 ATH_ANT_DIV_COMB_LNA1_DELTA_LOW,
1202                                                 main_rssi_avg, alt_rssi_avg,
1203                                                 antcomb->total_pkt_count))
1204                                 antcomb->second_ratio = true;
1205                         else
1206                                 antcomb->second_ratio = false;
1207                 } else if (antcomb->main_conf == ATH_ANT_DIV_COMB_LNA2) {
1208                         if (ath_is_alt_ant_ratio_better(alt_ratio,
1209                                                 ATH_ANT_DIV_COMB_LNA1_DELTA_MID,
1210                                                 ATH_ANT_DIV_COMB_LNA1_DELTA_LOW,
1211                                                 main_rssi_avg, alt_rssi_avg,
1212                                                 antcomb->total_pkt_count))
1213                                 antcomb->second_ratio = true;
1214                         else
1215                                 antcomb->second_ratio = false;
1216                 } else {
1217                         if ((((alt_ratio >= ATH_ANT_DIV_COMB_ALT_ANT_RATIO2) &&
1218                             (alt_rssi_avg > main_rssi_avg +
1219                             ATH_ANT_DIV_COMB_LNA1_DELTA_HI)) ||
1220                             (alt_rssi_avg > main_rssi_avg)) &&
1221                             (antcomb->total_pkt_count > 50))
1222                                 antcomb->second_ratio = true;
1223                         else
1224                                 antcomb->second_ratio = false;
1225                 }
1226
1227                 /* set alt to the conf with maximun ratio */
1228                 if (antcomb->first_ratio && antcomb->second_ratio) {
1229                         if (antcomb->rssi_second > antcomb->rssi_third) {
1230                                 /* first alt*/
1231                                 if ((antcomb->first_quick_scan_conf ==
1232                                     ATH_ANT_DIV_COMB_LNA1) ||
1233                                     (antcomb->first_quick_scan_conf ==
1234                                     ATH_ANT_DIV_COMB_LNA2))
1235                                         /* Set alt LNA1 or LNA2*/
1236                                         if (div_ant_conf->main_lna_conf ==
1237                                             ATH_ANT_DIV_COMB_LNA2)
1238                                                 div_ant_conf->alt_lna_conf =
1239                                                         ATH_ANT_DIV_COMB_LNA1;
1240                                         else
1241                                                 div_ant_conf->alt_lna_conf =
1242                                                         ATH_ANT_DIV_COMB_LNA2;
1243                                 else
1244                                         /* Set alt to A+B or A-B */
1245                                         div_ant_conf->alt_lna_conf =
1246                                                 antcomb->first_quick_scan_conf;
1247                         } else if ((antcomb->second_quick_scan_conf ==
1248                                    ATH_ANT_DIV_COMB_LNA1) ||
1249                                    (antcomb->second_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->second_quick_scan_conf;
1263                         }
1264                 } else if (antcomb->first_ratio) {
1265                         /* first alt */
1266                         if ((antcomb->first_quick_scan_conf ==
1267                             ATH_ANT_DIV_COMB_LNA1) ||
1268                             (antcomb->first_quick_scan_conf ==
1269                             ATH_ANT_DIV_COMB_LNA2))
1270                                         /* Set alt LNA1 or LNA2 */
1271                                 if (div_ant_conf->main_lna_conf ==
1272                                     ATH_ANT_DIV_COMB_LNA2)
1273                                         div_ant_conf->alt_lna_conf =
1274                                                         ATH_ANT_DIV_COMB_LNA1;
1275                                 else
1276                                         div_ant_conf->alt_lna_conf =
1277                                                         ATH_ANT_DIV_COMB_LNA2;
1278                         else
1279                                 /* Set alt to A+B or A-B */
1280                                 div_ant_conf->alt_lna_conf =
1281                                                 antcomb->first_quick_scan_conf;
1282                 } else if (antcomb->second_ratio) {
1283                                 /* second alt */
1284                         if ((antcomb->second_quick_scan_conf ==
1285                             ATH_ANT_DIV_COMB_LNA1) ||
1286                             (antcomb->second_quick_scan_conf ==
1287                             ATH_ANT_DIV_COMB_LNA2))
1288                                 /* Set alt LNA1 or LNA2 */
1289                                 if (div_ant_conf->main_lna_conf ==
1290                                     ATH_ANT_DIV_COMB_LNA2)
1291                                         div_ant_conf->alt_lna_conf =
1292                                                 ATH_ANT_DIV_COMB_LNA1;
1293                                 else
1294                                         div_ant_conf->alt_lna_conf =
1295                                                 ATH_ANT_DIV_COMB_LNA2;
1296                         else
1297                                 /* Set alt to A+B or A-B */
1298                                 div_ant_conf->alt_lna_conf =
1299                                                 antcomb->second_quick_scan_conf;
1300                 } else {
1301                         /* main is largest */
1302                         if ((antcomb->main_conf == ATH_ANT_DIV_COMB_LNA1) ||
1303                             (antcomb->main_conf == 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 = antcomb->main_conf;
1315                 }
1316                 break;
1317         default:
1318                 break;
1319         }
1320 }
1321
1322 static void ath_ant_div_conf_fast_divbias(struct ath_hw_antcomb_conf *ant_conf,
1323                 struct ath_ant_comb *antcomb, int alt_ratio)
1324 {
1325         if (ant_conf->div_group == 0) {
1326                 /* Adjust the fast_div_bias based on main and alt lna conf */
1327                 switch ((ant_conf->main_lna_conf << 4) |
1328                                 ant_conf->alt_lna_conf) {
1329                 case 0x01: /* A-B LNA2 */
1330                         ant_conf->fast_div_bias = 0x3b;
1331                         break;
1332                 case 0x02: /* A-B LNA1 */
1333                         ant_conf->fast_div_bias = 0x3d;
1334                         break;
1335                 case 0x03: /* A-B A+B */
1336                         ant_conf->fast_div_bias = 0x1;
1337                         break;
1338                 case 0x10: /* LNA2 A-B */
1339                         ant_conf->fast_div_bias = 0x7;
1340                         break;
1341                 case 0x12: /* LNA2 LNA1 */
1342                         ant_conf->fast_div_bias = 0x2;
1343                         break;
1344                 case 0x13: /* LNA2 A+B */
1345                         ant_conf->fast_div_bias = 0x7;
1346                         break;
1347                 case 0x20: /* LNA1 A-B */
1348                         ant_conf->fast_div_bias = 0x6;
1349                         break;
1350                 case 0x21: /* LNA1 LNA2 */
1351                         ant_conf->fast_div_bias = 0x0;
1352                         break;
1353                 case 0x23: /* LNA1 A+B */
1354                         ant_conf->fast_div_bias = 0x6;
1355                         break;
1356                 case 0x30: /* A+B A-B */
1357                         ant_conf->fast_div_bias = 0x1;
1358                         break;
1359                 case 0x31: /* A+B LNA2 */
1360                         ant_conf->fast_div_bias = 0x3b;
1361                         break;
1362                 case 0x32: /* A+B LNA1 */
1363                         ant_conf->fast_div_bias = 0x3d;
1364                         break;
1365                 default:
1366                         break;
1367                 }
1368         } else if (ant_conf->div_group == 1) {
1369                 /* Adjust the fast_div_bias based on main and alt_lna_conf */
1370                 switch ((ant_conf->main_lna_conf << 4) |
1371                         ant_conf->alt_lna_conf) {
1372                 case 0x01: /* A-B LNA2 */
1373                         ant_conf->fast_div_bias = 0x1;
1374                         ant_conf->main_gaintb = 0;
1375                         ant_conf->alt_gaintb = 0;
1376                         break;
1377                 case 0x02: /* A-B LNA1 */
1378                         ant_conf->fast_div_bias = 0x1;
1379                         ant_conf->main_gaintb = 0;
1380                         ant_conf->alt_gaintb = 0;
1381                         break;
1382                 case 0x03: /* A-B A+B */
1383                         ant_conf->fast_div_bias = 0x1;
1384                         ant_conf->main_gaintb = 0;
1385                         ant_conf->alt_gaintb = 0;
1386                         break;
1387                 case 0x10: /* LNA2 A-B */
1388                         if (!(antcomb->scan) &&
1389                             (alt_ratio > ATH_ANT_DIV_COMB_ALT_ANT_RATIO))
1390                                 ant_conf->fast_div_bias = 0x3f;
1391                         else
1392                                 ant_conf->fast_div_bias = 0x1;
1393                         ant_conf->main_gaintb = 0;
1394                         ant_conf->alt_gaintb = 0;
1395                         break;
1396                 case 0x12: /* LNA2 LNA1 */
1397                         ant_conf->fast_div_bias = 0x1;
1398                         ant_conf->main_gaintb = 0;
1399                         ant_conf->alt_gaintb = 0;
1400                         break;
1401                 case 0x13: /* LNA2 A+B */
1402                         if (!(antcomb->scan) &&
1403                             (alt_ratio > ATH_ANT_DIV_COMB_ALT_ANT_RATIO))
1404                                 ant_conf->fast_div_bias = 0x3f;
1405                         else
1406                                 ant_conf->fast_div_bias = 0x1;
1407                         ant_conf->main_gaintb = 0;
1408                         ant_conf->alt_gaintb = 0;
1409                         break;
1410                 case 0x20: /* LNA1 A-B */
1411                         if (!(antcomb->scan) &&
1412                             (alt_ratio > ATH_ANT_DIV_COMB_ALT_ANT_RATIO))
1413                                 ant_conf->fast_div_bias = 0x3f;
1414                         else
1415                                 ant_conf->fast_div_bias = 0x1;
1416                         ant_conf->main_gaintb = 0;
1417                         ant_conf->alt_gaintb = 0;
1418                         break;
1419                 case 0x21: /* LNA1 LNA2 */
1420                         ant_conf->fast_div_bias = 0x1;
1421                         ant_conf->main_gaintb = 0;
1422                         ant_conf->alt_gaintb = 0;
1423                         break;
1424                 case 0x23: /* LNA1 A+B */
1425                         if (!(antcomb->scan) &&
1426                             (alt_ratio > ATH_ANT_DIV_COMB_ALT_ANT_RATIO))
1427                                 ant_conf->fast_div_bias = 0x3f;
1428                         else
1429                                 ant_conf->fast_div_bias = 0x1;
1430                         ant_conf->main_gaintb = 0;
1431                         ant_conf->alt_gaintb = 0;
1432                         break;
1433                 case 0x30: /* A+B A-B */
1434                         ant_conf->fast_div_bias = 0x1;
1435                         ant_conf->main_gaintb = 0;
1436                         ant_conf->alt_gaintb = 0;
1437                         break;
1438                 case 0x31: /* A+B LNA2 */
1439                         ant_conf->fast_div_bias = 0x1;
1440                         ant_conf->main_gaintb = 0;
1441                         ant_conf->alt_gaintb = 0;
1442                         break;
1443                 case 0x32: /* A+B LNA1 */
1444                         ant_conf->fast_div_bias = 0x1;
1445                         ant_conf->main_gaintb = 0;
1446                         ant_conf->alt_gaintb = 0;
1447                         break;
1448                 default:
1449                         break;
1450                 }
1451         } else if (ant_conf->div_group == 2) {
1452                 /* Adjust the fast_div_bias based on main and alt_lna_conf */
1453                 switch ((ant_conf->main_lna_conf << 4) |
1454                                 ant_conf->alt_lna_conf) {
1455                 case 0x01: /* A-B LNA2 */
1456                         ant_conf->fast_div_bias = 0x1;
1457                         ant_conf->main_gaintb = 0;
1458                         ant_conf->alt_gaintb = 0;
1459                         break;
1460                 case 0x02: /* A-B LNA1 */
1461                         ant_conf->fast_div_bias = 0x1;
1462                         ant_conf->main_gaintb = 0;
1463                         ant_conf->alt_gaintb = 0;
1464                         break;
1465                 case 0x03: /* A-B A+B */
1466                         ant_conf->fast_div_bias = 0x1;
1467                         ant_conf->main_gaintb = 0;
1468                         ant_conf->alt_gaintb = 0;
1469                         break;
1470                 case 0x10: /* LNA2 A-B */
1471                         if (!(antcomb->scan) &&
1472                                 (alt_ratio > ATH_ANT_DIV_COMB_ALT_ANT_RATIO))
1473                                 ant_conf->fast_div_bias = 0x1;
1474                         else
1475                                 ant_conf->fast_div_bias = 0x2;
1476                         ant_conf->main_gaintb = 0;
1477                         ant_conf->alt_gaintb = 0;
1478                         break;
1479                 case 0x12: /* LNA2 LNA1 */
1480                         ant_conf->fast_div_bias = 0x1;
1481                         ant_conf->main_gaintb = 0;
1482                         ant_conf->alt_gaintb = 0;
1483                         break;
1484                 case 0x13: /* LNA2 A+B */
1485                         if (!(antcomb->scan) &&
1486                                 (alt_ratio > ATH_ANT_DIV_COMB_ALT_ANT_RATIO))
1487                                 ant_conf->fast_div_bias = 0x1;
1488                         else
1489                                 ant_conf->fast_div_bias = 0x2;
1490                         ant_conf->main_gaintb = 0;
1491                         ant_conf->alt_gaintb = 0;
1492                         break;
1493                 case 0x20: /* LNA1 A-B */
1494                         if (!(antcomb->scan) &&
1495                                 (alt_ratio > ATH_ANT_DIV_COMB_ALT_ANT_RATIO))
1496                                 ant_conf->fast_div_bias = 0x1;
1497                         else
1498                                 ant_conf->fast_div_bias = 0x2;
1499                         ant_conf->main_gaintb = 0;
1500                         ant_conf->alt_gaintb = 0;
1501                         break;
1502                 case 0x21: /* LNA1 LNA2 */
1503                         ant_conf->fast_div_bias = 0x1;
1504                         ant_conf->main_gaintb = 0;
1505                         ant_conf->alt_gaintb = 0;
1506                         break;
1507                 case 0x23: /* LNA1 A+B */
1508                         if (!(antcomb->scan) &&
1509                                 (alt_ratio > ATH_ANT_DIV_COMB_ALT_ANT_RATIO))
1510                                 ant_conf->fast_div_bias = 0x1;
1511                         else
1512                                 ant_conf->fast_div_bias = 0x2;
1513                         ant_conf->main_gaintb = 0;
1514                         ant_conf->alt_gaintb = 0;
1515                         break;
1516                 case 0x30: /* A+B A-B */
1517                         ant_conf->fast_div_bias = 0x1;
1518                         ant_conf->main_gaintb = 0;
1519                         ant_conf->alt_gaintb = 0;
1520                         break;
1521                 case 0x31: /* A+B LNA2 */
1522                         ant_conf->fast_div_bias = 0x1;
1523                         ant_conf->main_gaintb = 0;
1524                         ant_conf->alt_gaintb = 0;
1525                         break;
1526                 case 0x32: /* A+B LNA1 */
1527                         ant_conf->fast_div_bias = 0x1;
1528                         ant_conf->main_gaintb = 0;
1529                         ant_conf->alt_gaintb = 0;
1530                         break;
1531                 default:
1532                         break;
1533                 }
1534         }
1535 }
1536
1537 /* Antenna diversity and combining */
1538 static void ath_ant_comb_scan(struct ath_softc *sc, struct ath_rx_status *rs)
1539 {
1540         struct ath_hw_antcomb_conf div_ant_conf;
1541         struct ath_ant_comb *antcomb = &sc->ant_comb;
1542         int alt_ratio = 0, alt_rssi_avg = 0, main_rssi_avg = 0, curr_alt_set;
1543         int curr_main_set;
1544         int main_rssi = rs->rs_rssi_ctl0;
1545         int alt_rssi = rs->rs_rssi_ctl1;
1546         int rx_ant_conf,  main_ant_conf;
1547         bool short_scan = false;
1548
1549         rx_ant_conf = (rs->rs_rssi_ctl2 >> ATH_ANT_RX_CURRENT_SHIFT) &
1550                        ATH_ANT_RX_MASK;
1551         main_ant_conf = (rs->rs_rssi_ctl2 >> ATH_ANT_RX_MAIN_SHIFT) &
1552                          ATH_ANT_RX_MASK;
1553
1554         /* Record packet only when both main_rssi and  alt_rssi is positive */
1555         if (main_rssi > 0 && alt_rssi > 0) {
1556                 antcomb->total_pkt_count++;
1557                 antcomb->main_total_rssi += main_rssi;
1558                 antcomb->alt_total_rssi  += alt_rssi;
1559                 if (main_ant_conf == rx_ant_conf)
1560                         antcomb->main_recv_cnt++;
1561                 else
1562                         antcomb->alt_recv_cnt++;
1563         }
1564
1565         /* Short scan check */
1566         if (antcomb->scan && antcomb->alt_good) {
1567                 if (time_after(jiffies, antcomb->scan_start_time +
1568                     msecs_to_jiffies(ATH_ANT_DIV_COMB_SHORT_SCAN_INTR)))
1569                         short_scan = true;
1570                 else
1571                         if (antcomb->total_pkt_count ==
1572                             ATH_ANT_DIV_COMB_SHORT_SCAN_PKTCOUNT) {
1573                                 alt_ratio = ((antcomb->alt_recv_cnt * 100) /
1574                                             antcomb->total_pkt_count);
1575                                 if (alt_ratio < ATH_ANT_DIV_COMB_ALT_ANT_RATIO)
1576                                         short_scan = true;
1577                         }
1578         }
1579
1580         if (((antcomb->total_pkt_count < ATH_ANT_DIV_COMB_MAX_PKTCOUNT) ||
1581             rs->rs_moreaggr) && !short_scan)
1582                 return;
1583
1584         if (antcomb->total_pkt_count) {
1585                 alt_ratio = ((antcomb->alt_recv_cnt * 100) /
1586                              antcomb->total_pkt_count);
1587                 main_rssi_avg = (antcomb->main_total_rssi /
1588                                  antcomb->total_pkt_count);
1589                 alt_rssi_avg = (antcomb->alt_total_rssi /
1590                                  antcomb->total_pkt_count);
1591         }
1592
1593
1594         ath9k_hw_antdiv_comb_conf_get(sc->sc_ah, &div_ant_conf);
1595         curr_alt_set = div_ant_conf.alt_lna_conf;
1596         curr_main_set = div_ant_conf.main_lna_conf;
1597
1598         antcomb->count++;
1599
1600         if (antcomb->count == ATH_ANT_DIV_COMB_MAX_COUNT) {
1601                 if (alt_ratio > ATH_ANT_DIV_COMB_ALT_ANT_RATIO) {
1602                         ath_lnaconf_alt_good_scan(antcomb, div_ant_conf,
1603                                                   main_rssi_avg);
1604                         antcomb->alt_good = true;
1605                 } else {
1606                         antcomb->alt_good = false;
1607                 }
1608
1609                 antcomb->count = 0;
1610                 antcomb->scan = true;
1611                 antcomb->scan_not_start = true;
1612         }
1613
1614         if (!antcomb->scan) {
1615                 if (ath_ant_div_comb_alt_check(div_ant_conf.div_group,
1616                                         alt_ratio, curr_main_set, curr_alt_set,
1617                                         alt_rssi_avg, main_rssi_avg)) {
1618                         if (curr_alt_set == ATH_ANT_DIV_COMB_LNA2) {
1619                                 /* Switch main and alt LNA */
1620                                 div_ant_conf.main_lna_conf =
1621                                                 ATH_ANT_DIV_COMB_LNA2;
1622                                 div_ant_conf.alt_lna_conf  =
1623                                                 ATH_ANT_DIV_COMB_LNA1;
1624                         } else if (curr_alt_set == ATH_ANT_DIV_COMB_LNA1) {
1625                                 div_ant_conf.main_lna_conf =
1626                                                 ATH_ANT_DIV_COMB_LNA1;
1627                                 div_ant_conf.alt_lna_conf  =
1628                                                 ATH_ANT_DIV_COMB_LNA2;
1629                         }
1630
1631                         goto div_comb_done;
1632                 } else if ((curr_alt_set != ATH_ANT_DIV_COMB_LNA1) &&
1633                            (curr_alt_set != ATH_ANT_DIV_COMB_LNA2)) {
1634                         /* Set alt to another LNA */
1635                         if (curr_main_set == ATH_ANT_DIV_COMB_LNA2)
1636                                 div_ant_conf.alt_lna_conf =
1637                                                 ATH_ANT_DIV_COMB_LNA1;
1638                         else if (curr_main_set == ATH_ANT_DIV_COMB_LNA1)
1639                                 div_ant_conf.alt_lna_conf =
1640                                                 ATH_ANT_DIV_COMB_LNA2;
1641
1642                         goto div_comb_done;
1643                 }
1644
1645                 if ((alt_rssi_avg < (main_rssi_avg +
1646                                                 div_ant_conf.lna1_lna2_delta)))
1647                         goto div_comb_done;
1648         }
1649
1650         if (!antcomb->scan_not_start) {
1651                 switch (curr_alt_set) {
1652                 case ATH_ANT_DIV_COMB_LNA2:
1653                         antcomb->rssi_lna2 = alt_rssi_avg;
1654                         antcomb->rssi_lna1 = main_rssi_avg;
1655                         antcomb->scan = true;
1656                         /* set to A+B */
1657                         div_ant_conf.main_lna_conf =
1658                                 ATH_ANT_DIV_COMB_LNA1;
1659                         div_ant_conf.alt_lna_conf  =
1660                                 ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2;
1661                         break;
1662                 case ATH_ANT_DIV_COMB_LNA1:
1663                         antcomb->rssi_lna1 = alt_rssi_avg;
1664                         antcomb->rssi_lna2 = main_rssi_avg;
1665                         antcomb->scan = true;
1666                         /* set to A+B */
1667                         div_ant_conf.main_lna_conf = ATH_ANT_DIV_COMB_LNA2;
1668                         div_ant_conf.alt_lna_conf  =
1669                                 ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2;
1670                         break;
1671                 case ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2:
1672                         antcomb->rssi_add = alt_rssi_avg;
1673                         antcomb->scan = true;
1674                         /* set to A-B */
1675                         div_ant_conf.alt_lna_conf =
1676                                 ATH_ANT_DIV_COMB_LNA1_MINUS_LNA2;
1677                         break;
1678                 case ATH_ANT_DIV_COMB_LNA1_MINUS_LNA2:
1679                         antcomb->rssi_sub = alt_rssi_avg;
1680                         antcomb->scan = false;
1681                         if (antcomb->rssi_lna2 >
1682                             (antcomb->rssi_lna1 +
1683                             ATH_ANT_DIV_COMB_LNA1_LNA2_SWITCH_DELTA)) {
1684                                 /* use LNA2 as main LNA */
1685                                 if ((antcomb->rssi_add > antcomb->rssi_lna1) &&
1686                                     (antcomb->rssi_add > antcomb->rssi_sub)) {
1687                                         /* set to A+B */
1688                                         div_ant_conf.main_lna_conf =
1689                                                 ATH_ANT_DIV_COMB_LNA2;
1690                                         div_ant_conf.alt_lna_conf  =
1691                                                 ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2;
1692                                 } else if (antcomb->rssi_sub >
1693                                            antcomb->rssi_lna1) {
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_MINUS_LNA2;
1699                                 } else {
1700                                         /* set to LNA1 */
1701                                         div_ant_conf.main_lna_conf =
1702                                                 ATH_ANT_DIV_COMB_LNA2;
1703                                         div_ant_conf.alt_lna_conf =
1704                                                 ATH_ANT_DIV_COMB_LNA1;
1705                                 }
1706                         } else {
1707                                 /* use LNA1 as main LNA */
1708                                 if ((antcomb->rssi_add > antcomb->rssi_lna2) &&
1709                                     (antcomb->rssi_add > antcomb->rssi_sub)) {
1710                                         /* set to A+B */
1711                                         div_ant_conf.main_lna_conf =
1712                                                 ATH_ANT_DIV_COMB_LNA1;
1713                                         div_ant_conf.alt_lna_conf  =
1714                                                 ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2;
1715                                 } else if (antcomb->rssi_sub >
1716                                            antcomb->rssi_lna1) {
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_MINUS_LNA2;
1722                                 } else {
1723                                         /* set to LNA2 */
1724                                         div_ant_conf.main_lna_conf =
1725                                                 ATH_ANT_DIV_COMB_LNA1;
1726                                         div_ant_conf.alt_lna_conf =
1727                                                 ATH_ANT_DIV_COMB_LNA2;
1728                                 }
1729                         }
1730                         break;
1731                 default:
1732                         break;
1733                 }
1734         } else {
1735                 if (!antcomb->alt_good) {
1736                         antcomb->scan_not_start = false;
1737                         /* Set alt to another LNA */
1738                         if (curr_main_set == ATH_ANT_DIV_COMB_LNA2) {
1739                                 div_ant_conf.main_lna_conf =
1740                                                 ATH_ANT_DIV_COMB_LNA2;
1741                                 div_ant_conf.alt_lna_conf =
1742                                                 ATH_ANT_DIV_COMB_LNA1;
1743                         } else if (curr_main_set == ATH_ANT_DIV_COMB_LNA1) {
1744                                 div_ant_conf.main_lna_conf =
1745                                                 ATH_ANT_DIV_COMB_LNA1;
1746                                 div_ant_conf.alt_lna_conf =
1747                                                 ATH_ANT_DIV_COMB_LNA2;
1748                         }
1749                         goto div_comb_done;
1750                 }
1751         }
1752
1753         ath_select_ant_div_from_quick_scan(antcomb, &div_ant_conf,
1754                                            main_rssi_avg, alt_rssi_avg,
1755                                            alt_ratio);
1756
1757         antcomb->quick_scan_cnt++;
1758
1759 div_comb_done:
1760         ath_ant_div_conf_fast_divbias(&div_ant_conf, antcomb, alt_ratio);
1761         ath9k_hw_antdiv_comb_conf_set(sc->sc_ah, &div_ant_conf);
1762
1763         antcomb->scan_start_time = jiffies;
1764         antcomb->total_pkt_count = 0;
1765         antcomb->main_total_rssi = 0;
1766         antcomb->alt_total_rssi = 0;
1767         antcomb->main_recv_cnt = 0;
1768         antcomb->alt_recv_cnt = 0;
1769 }
1770
1771 int ath_rx_tasklet(struct ath_softc *sc, int flush, bool hp)
1772 {
1773         struct ath_buf *bf;
1774         struct sk_buff *skb = NULL, *requeue_skb, *hdr_skb;
1775         struct ieee80211_rx_status *rxs;
1776         struct ath_hw *ah = sc->sc_ah;
1777         struct ath_common *common = ath9k_hw_common(ah);
1778         /*
1779          * The hw can technically differ from common->hw when using ath9k
1780          * virtual wiphy so to account for that we iterate over the active
1781          * wiphys and find the appropriate wiphy and therefore hw.
1782          */
1783         struct ieee80211_hw *hw = sc->hw;
1784         struct ieee80211_hdr *hdr;
1785         int retval;
1786         bool decrypt_error = false;
1787         struct ath_rx_status rs;
1788         enum ath9k_rx_qtype qtype;
1789         bool edma = !!(ah->caps.hw_caps & ATH9K_HW_CAP_EDMA);
1790         int dma_type;
1791         u8 rx_status_len = ah->caps.rx_status_len;
1792         u64 tsf = 0;
1793         u32 tsf_lower = 0;
1794         unsigned long flags;
1795
1796         if (edma)
1797                 dma_type = DMA_BIDIRECTIONAL;
1798         else
1799                 dma_type = DMA_FROM_DEVICE;
1800
1801         qtype = hp ? ATH9K_RX_QUEUE_HP : ATH9K_RX_QUEUE_LP;
1802         spin_lock_bh(&sc->rx.rxbuflock);
1803
1804         tsf = ath9k_hw_gettsf64(ah);
1805         tsf_lower = tsf & 0xffffffff;
1806
1807         do {
1808                 /* If handling rx interrupt and flush is in progress => exit */
1809                 if ((sc->sc_flags & SC_OP_RXFLUSH) && (flush == 0))
1810                         break;
1811
1812                 memset(&rs, 0, sizeof(rs));
1813                 if (edma)
1814                         bf = ath_edma_get_next_rx_buf(sc, &rs, qtype);
1815                 else
1816                         bf = ath_get_next_rx_buf(sc, &rs);
1817
1818                 if (!bf)
1819                         break;
1820
1821                 skb = bf->bf_mpdu;
1822                 if (!skb)
1823                         continue;
1824
1825                 /*
1826                  * Take frame header from the first fragment and RX status from
1827                  * the last one.
1828                  */
1829                 if (sc->rx.frag)
1830                         hdr_skb = sc->rx.frag;
1831                 else
1832                         hdr_skb = skb;
1833
1834                 hdr = (struct ieee80211_hdr *) (hdr_skb->data + rx_status_len);
1835                 rxs = IEEE80211_SKB_RXCB(hdr_skb);
1836
1837                 ath_debug_stat_rx(sc, &rs);
1838
1839                 /*
1840                  * If we're asked to flush receive queue, directly
1841                  * chain it back at the queue without processing it.
1842                  */
1843                 if (flush)
1844                         goto requeue_drop_frag;
1845
1846                 retval = ath9k_rx_skb_preprocess(common, hw, hdr, &rs,
1847                                                  rxs, &decrypt_error);
1848                 if (retval)
1849                         goto requeue_drop_frag;
1850
1851                 rxs->mactime = (tsf & ~0xffffffffULL) | rs.rs_tstamp;
1852                 if (rs.rs_tstamp > tsf_lower &&
1853                     unlikely(rs.rs_tstamp - tsf_lower > 0x10000000))
1854                         rxs->mactime -= 0x100000000ULL;
1855
1856                 if (rs.rs_tstamp < tsf_lower &&
1857                     unlikely(tsf_lower - rs.rs_tstamp > 0x10000000))
1858                         rxs->mactime += 0x100000000ULL;
1859
1860                 /* Ensure we always have an skb to requeue once we are done
1861                  * processing the current buffer's skb */
1862                 requeue_skb = ath_rxbuf_alloc(common, common->rx_bufsize, GFP_ATOMIC);
1863
1864                 /* If there is no memory we ignore the current RX'd frame,
1865                  * tell hardware it can give us a new frame using the old
1866                  * skb and put it at the tail of the sc->rx.rxbuf list for
1867                  * processing. */
1868                 if (!requeue_skb)
1869                         goto requeue_drop_frag;
1870
1871                 /* Unmap the frame */
1872                 dma_unmap_single(sc->dev, bf->bf_buf_addr,
1873                                  common->rx_bufsize,
1874                                  dma_type);
1875
1876                 skb_put(skb, rs.rs_datalen + ah->caps.rx_status_len);
1877                 if (ah->caps.rx_status_len)
1878                         skb_pull(skb, ah->caps.rx_status_len);
1879
1880                 if (!rs.rs_more)
1881                         ath9k_rx_skb_postprocess(common, hdr_skb, &rs,
1882                                                  rxs, decrypt_error);
1883
1884                 /* We will now give hardware our shiny new allocated skb */
1885                 bf->bf_mpdu = requeue_skb;
1886                 bf->bf_buf_addr = dma_map_single(sc->dev, requeue_skb->data,
1887                                                  common->rx_bufsize,
1888                                                  dma_type);
1889                 if (unlikely(dma_mapping_error(sc->dev,
1890                           bf->bf_buf_addr))) {
1891                         dev_kfree_skb_any(requeue_skb);
1892                         bf->bf_mpdu = NULL;
1893                         bf->bf_buf_addr = 0;
1894                         ath_err(common, "dma_mapping_error() on RX\n");
1895                         ieee80211_rx(hw, skb);
1896                         break;
1897                 }
1898
1899                 if (rs.rs_more) {
1900                         /*
1901                          * rs_more indicates chained descriptors which can be
1902                          * used to link buffers together for a sort of
1903                          * scatter-gather operation.
1904                          */
1905                         if (sc->rx.frag) {
1906                                 /* too many fragments - cannot handle frame */
1907                                 dev_kfree_skb_any(sc->rx.frag);
1908                                 dev_kfree_skb_any(skb);
1909                                 skb = NULL;
1910                         }
1911                         sc->rx.frag = skb;
1912                         goto requeue;
1913                 }
1914
1915                 if (sc->rx.frag) {
1916                         int space = skb->len - skb_tailroom(hdr_skb);
1917
1918                         sc->rx.frag = NULL;
1919
1920                         if (pskb_expand_head(hdr_skb, 0, space, GFP_ATOMIC) < 0) {
1921                                 dev_kfree_skb(skb);
1922                                 goto requeue_drop_frag;
1923                         }
1924
1925                         skb_copy_from_linear_data(skb, skb_put(hdr_skb, skb->len),
1926                                                   skb->len);
1927                         dev_kfree_skb_any(skb);
1928                         skb = hdr_skb;
1929                 }
1930
1931                 /*
1932                  * change the default rx antenna if rx diversity chooses the
1933                  * other antenna 3 times in a row.
1934                  */
1935                 if (sc->rx.defant != rs.rs_antenna) {
1936                         if (++sc->rx.rxotherant >= 3)
1937                                 ath_setdefantenna(sc, rs.rs_antenna);
1938                 } else {
1939                         sc->rx.rxotherant = 0;
1940                 }
1941
1942                 spin_lock_irqsave(&sc->sc_pm_lock, flags);
1943
1944                 if ((sc->ps_flags & (PS_WAIT_FOR_BEACON |
1945                                               PS_WAIT_FOR_CAB |
1946                                               PS_WAIT_FOR_PSPOLL_DATA)) ||
1947                                                 ath9k_check_auto_sleep(sc))
1948                         ath_rx_ps(sc, skb);
1949                 spin_unlock_irqrestore(&sc->sc_pm_lock, flags);
1950
1951                 if (ah->caps.hw_caps & ATH9K_HW_CAP_ANT_DIV_COMB)
1952                         ath_ant_comb_scan(sc, &rs);
1953
1954                 ieee80211_rx(hw, skb);
1955
1956 requeue_drop_frag:
1957                 if (sc->rx.frag) {
1958                         dev_kfree_skb_any(sc->rx.frag);
1959                         sc->rx.frag = NULL;
1960                 }
1961 requeue:
1962                 if (edma) {
1963                         list_add_tail(&bf->list, &sc->rx.rxbuf);
1964                         ath_rx_edma_buf_link(sc, qtype);
1965                 } else {
1966                         list_move_tail(&bf->list, &sc->rx.rxbuf);
1967                         ath_rx_buf_link(sc, bf);
1968                         ath9k_hw_rxena(ah);
1969                 }
1970         } while (1);
1971
1972         spin_unlock_bh(&sc->rx.rxbuflock);
1973
1974         return 0;
1975 }