carlfw/src/wlan.c

   1 /*
   2  * carl9170 firmware - used by the ar9170 wireless device
   3  *
   4  * Interface to the WLAN part of the chip
   5  *
   6  * Copyright (c) 2000-2005 ZyDAS Technology Corporation
   7  * Copyright (c) 2007-2009 Atheros Communications, Inc.
   8  * Copyright    2009    Johannes Berg <johannes@sipsolutions.net>
   9  * Copyright 2009-2011  Christian Lamparter <chunkeey@googlemail.com>
  10  *
  11  * This program is free software; you can redistribute it and/or modify
  12  * it under the terms of the GNU General Public License as published by
  13  * the Free Software Foundation; either version 2 of the License, or
  14  * (at your option) any later version.
  15  *
  16  * This program is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19  * GNU General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU General Public License along
  22  * with this program; if not, write to the Free Software Foundation, Inc.,
  23  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  24  */
  25
  26 #include "carl9170.h"
  27 #include "shared/phy.h"
  28 #include "hostif.h"
  29 #include "timer.h"
  30 #include "wl.h"
  31 #include "printf.h"
  32 #include "rf.h"
  33 #include "linux/ieee80211.h"
  34 #include "wol.h"
  35
  36 static void wlan_txunstuck(unsigned int queue)
  37 {
  38         set_wlan_txq_dma_addr(queue, ((uint32_t) fw.wlan.tx_queue[queue].head) | 1);
  39 }
  40
  41 #ifdef CONFIG_CARL9170FW_DMA_QUEUE_BUMP
  42 static void wlan_txupdate(unsigned int queue)
  43 {
  44         set_wlan_txq_dma_addr(queue, ((uint32_t) fw.wlan.tx_queue[queue].head));
  45 }
  46
  47 static void wlan_dma_bump(unsigned int qidx)
  48 {
  49         unsigned int offset = qidx;
  50         uint32_t status, trigger;
  51
  52         status = get(AR9170_MAC_REG_DMA_STATUS) >> 12;
  53         trigger = get(AR9170_MAC_REG_DMA_TRIGGER) >> 12;
  54
  55         while (offset != 0) {
  56                 status >>= 4;
  57                 trigger >>= 4;
  58                 offset--;
  59         }
  60
  61         status &= 0xf;
  62         trigger &= 0xf;
  63
  64         if ((trigger == 0xa) && (status == 0x8)) {
  65                 DBG("UNSTUCK");
  66                 wlan_txunstuck(qidx);
  67         } else {
  68                 DBG("UPDATE");
  69                 wlan_txupdate(qidx);
  70         }
  71 }
  72 #endif /* CONFIG_CARL9170FW_DMA_QUEUE_BUMP */
  73
  74 #ifdef CONFIG_CARL9170FW_DEBUG
  75 static void wlan_dump_queue(unsigned int qidx)
  76 {
  77
  78         struct dma_desc *desc;
  79         struct carl9170_tx_superframe *super;
  80         int entries = 0;
  81
  82         __for_each_desc(desc, &fw.wlan.tx_queue[qidx]) {
  83                 super = get_super(desc);
  84                 DBG("%d: %p s:%x c:%x tl:%x ds:%x n:%p l:%p ", entries, desc,
  85                     desc->status, desc->ctrl, desc->totalLen,
  86                     desc->dataSize, desc->nextAddr, desc->lastAddr);
  87
  88                 DBG("c:%x tr:%d ri:%d l:%x m:%x p:%x fc:%x",
  89                     super->s.cookie, super->s.cnt, super->s.rix,
  90                     super->f.hdr.length, super->f.hdr.mac.set,
  91                     (unsigned int) le32_to_cpu(super->f.hdr.phy.set),
  92                     super->f.data.i3e.frame_control);
  93
  94                 entries++;
  95         }
  96
  97         desc = get_wlan_txq_addr(qidx);
  98
  99         DBG("Queue: %d: te:%d td:%d h:%p c:%p t:%p",
 100             qidx, entries, queue_len(&fw.wlan.tx_queue[qidx]),
 101             fw.wlan.tx_queue[qidx].head,
 102             desc, fw.wlan.tx_queue[qidx].terminator);
 103
 104         DBG("HW: t:%x s:%x ac:%x c:%x",
 105             (unsigned int) get(AR9170_MAC_REG_DMA_TRIGGER),
 106             (unsigned int) get(AR9170_MAC_REG_DMA_STATUS),
 107             (unsigned int) get(AR9170_MAC_REG_AMPDU_COUNT),
 108             (unsigned int) get(AR9170_MAC_REG_DMA_TXQX_ADDR_CURR));
 109 }
 110 #endif /* CONFIG_CARL9170FW_DEBUG */
 111
 112 static void wlan_send_buffered_tx_status(void)
 113 {
 114         unsigned int len;
 115
 116         while (fw.wlan.tx_status_pending) {
 117                 len = min((unsigned int)fw.wlan.tx_status_pending,
 118                           CARL9170_RSP_TX_STATUS_NUM);
 119                 len = min(len, CARL9170_TX_STATUS_NUM - fw.wlan.tx_status_head_idx);
 120
 121                 /*
 122                  * rather than memcpy each individual request into a large buffer,
 123                  * we _splice_ them all together.
 124                  *
 125                  * The only downside is however that we have to be careful around
 126                  * the edges of the tx_status_cache.
 127                  *
 128                  * Note:
 129                  * Each tx_status is about 2 bytes. However every command package
 130                  * must have a size which is a multiple of 4.
 131                  */
 132
 133                 send_cmd_to_host((len * sizeof(struct carl9170_tx_status) + 3) & ~3,
 134                                  CARL9170_RSP_TXCOMP, len, (void *)
 135                                  &fw.wlan.tx_status_cache[fw.wlan.tx_status_head_idx]);
 136
 137                 fw.wlan.tx_status_pending -= len;
 138                 fw.wlan.tx_status_head_idx += len;
 139                 fw.wlan.tx_status_head_idx %= CARL9170_TX_STATUS_NUM;
 140         }
 141 }
 142
 143 static struct carl9170_tx_status *wlan_get_tx_status_buffer(void)
 144 {
 145         struct carl9170_tx_status *tmp;
 146
 147         tmp = &fw.wlan.tx_status_cache[fw.wlan.tx_status_tail_idx++];
 148         fw.wlan.tx_status_tail_idx %= CARL9170_TX_STATUS_NUM;
 149
 150         if (fw.wlan.tx_status_pending == CARL9170_TX_STATUS_NUM)
 151                 wlan_send_buffered_tx_status();
 152
 153         fw.wlan.tx_status_pending++;
 154
 155         return tmp;
 156 }
 157
 158 /* generate _aggregated_ tx_status for the host */
 159 void wlan_tx_complete(struct carl9170_tx_superframe *super,
 160                       bool txs)
 161 {
 162         struct carl9170_tx_status *status;
 163
 164         status = wlan_get_tx_status_buffer();
 165
 166         /*
 167          * The *unique* cookie and AC_ID is used by the driver for
 168          * frame lookup.
 169          */
 170         status->cookie = super->s.cookie;
 171         status->queue = super->s.queue;
 172         super->s.cookie = 0;
 173
 174         /*
 175          * This field holds the number of tries of the rate in
 176          * the rate index field (rix).
 177          */
 178         status->rix = super->s.rix;
 179         status->tries = super->s.cnt;
 180         status->success = (txs) ? 1 : 0;
 181 }
 182
 183 static bool wlan_tx_consume_retry(struct carl9170_tx_superframe *super)
 184 {
 185         /* check if this was the last possible retry with this rate */
 186         if (unlikely(super->s.cnt >= super->s.ri[super->s.rix].tries)) {
 187                 /* end of the road - indicate tx failure */
 188                 if (unlikely(super->s.rix == CARL9170_TX_MAX_RETRY_RATES))
 189                         return false;
 190
 191                 /* check if there are alternative rates available */
 192                 if (!super->s.rr[super->s.rix].set)
 193                         return false;
 194
 195                 /* try next retry rate */
 196                 super->f.hdr.phy.set = super->s.rr[super->s.rix].set;
 197
 198                 /* finally - mark the old rate as USED */
 199                 super->s.rix++;
 200
 201                 /* update MAC flags */
 202                 super->f.hdr.mac.erp_prot = super->s.ri[super->s.rix].erp_prot;
 203                 super->f.hdr.mac.ampdu = super->s.ri[super->s.rix].ampdu;
 204
 205                 /* reinitialize try counter */
 206                 super->s.cnt = 1;
 207         } else {
 208                 /* just increase retry counter */
 209                 super->s.cnt++;
 210         }
 211
 212         return true;
 213 }
 214
 215 static inline u16 get_tid(struct ieee80211_hdr *hdr)
 216 {
 217         return (ieee80211_get_qos_ctl(hdr))[0] & IEEE80211_QOS_CTL_TID_MASK;
 218 }
 219
 220 /* This function will only work on uint32_t-aligned pointers! */
 221 static bool same_hdr(const void *_d0, const void *_d1)
 222 {
 223         const uint32_t *d0 = _d0;
 224         const uint32_t *d1 = _d1;
 225
 226         /* BUG_ON((unsigned long)d0 & 3 || (unsigned long)d1 & 3)) */
 227         return !((d0[0] ^ d1[0]) |                      /* FC + DU */
 228                  (d0[1] ^ d1[1]) |                      /* addr1 */
 229                  (d0[2] ^ d1[2]) | (d0[3] ^ d1[3]) |    /* addr2 + addr3 */
 230                  (d0[4] ^ d1[4]));                      /* addr3 */
 231 }
 232
 233 static inline bool same_aggr(struct ieee80211_hdr *a, struct ieee80211_hdr *b)
 234 {
 235         return (get_tid(a) == get_tid(b)) || same_hdr(a, b);
 236 }
 237
 238 static void wlan_tx_ampdu_reset(unsigned int qidx)
 239 {
 240         fw.wlan.ampdu_prev[qidx] = NULL;
 241 }
 242
 243 static void wlan_tx_ampdu_end(unsigned int qidx)
 244 {
 245         struct carl9170_tx_superframe *ht_prev = fw.wlan.ampdu_prev[qidx];
 246
 247         if (ht_prev)
 248                 ht_prev->f.hdr.mac.ba_end = 1;
 249
 250         wlan_tx_ampdu_reset(qidx);
 251 }
 252
 253 static void wlan_tx_ampdu(struct carl9170_tx_superframe *super)
 254 {
 255         unsigned int qidx = super->s.queue;
 256         struct carl9170_tx_superframe *ht_prev = fw.wlan.ampdu_prev[qidx];
 257
 258         if (super->f.hdr.mac.ampdu) {
 259                 if (ht_prev &&
 260                     !same_aggr(&super->f.data.i3e, &ht_prev->f.data.i3e))
 261                         ht_prev->f.hdr.mac.ba_end = 1;
 262                 else
 263                         super->f.hdr.mac.ba_end = 0;
 264
 265                 fw.wlan.ampdu_prev[qidx] = super;
 266         } else {
 267                 wlan_tx_ampdu_end(qidx);
 268         }
 269 }
 270
 271 /* for all tries */
 272 static void __wlan_tx(struct dma_desc *desc)
 273 {
 274         struct carl9170_tx_superframe *super = get_super(desc);
 275
 276         if (unlikely(super->s.fill_in_tsf)) {
 277                 struct ieee80211_mgmt *mgmt = (void *) &super->f.data.i3e;
 278                 uint32_t *tsf = (uint32_t *) &mgmt->u.probe_resp.timestamp;
 279
 280                 /*
 281                  * Truth be told: this is a hack.
 282                  *
 283                  * The *real* TSF is definitely going to be higher/older.
 284                  * But this hardware emulation code is head and shoulders
 285                  * above anything a driver can possibly do.
 286                  *
 287                  * (even, if it's got an accurate atomic clock source).
 288                  */
 289
 290                 read_tsf(tsf);
 291         }
 292
 293         wlan_tx_ampdu(super);
 294
 295 #ifdef CONFIG_CARL9170FW_DEBUG
 296         BUG_ON(fw.phy.psm.state != CARL9170_PSM_WAKE);
 297 #endif /* CONFIG_CARL9170FW_DEBUG */
 298
 299         /* insert desc into the right queue */
 300         dma_put(&fw.wlan.tx_queue[super->s.queue], desc);
 301 }
 302
 303 static void wlan_assign_seq(struct ieee80211_hdr *hdr, unsigned int vif)
 304 {
 305         hdr->seq_ctrl &= cpu_to_le16(~IEEE80211_SCTL_SEQ);
 306         hdr->seq_ctrl |= cpu_to_le16(fw.wlan.sequence[vif]);
 307
 308         if (ieee80211_is_first_frag(hdr->seq_ctrl))
 309                 fw.wlan.sequence[vif] += 0x10;
 310 }
 311
 312 /* prepares frame for the first transmission */
 313 static void _wlan_tx(struct dma_desc *desc)
 314 {
 315         struct carl9170_tx_superframe *super = get_super(desc);
 316
 317         if (unlikely(super->s.assign_seq))
 318                 wlan_assign_seq(&super->f.data.i3e, super->s.vif_id);
 319
 320         if (unlikely(super->s.ampdu_commit_density)) {
 321                 set(AR9170_MAC_REG_AMPDU_DENSITY,
 322                     MOD_VAL(AR9170_MAC_AMPDU_DENSITY,
 323                             get(AR9170_MAC_REG_AMPDU_DENSITY),
 324                             super->s.ampdu_density));
 325         }
 326
 327         if (unlikely(super->s.ampdu_commit_factor)) {
 328                 set(AR9170_MAC_REG_AMPDU_FACTOR,
 329                     MOD_VAL(AR9170_MAC_AMPDU_FACTOR,
 330                             get(AR9170_MAC_REG_AMPDU_FACTOR),
 331                             8 << super->s.ampdu_factor));
 332         }
 333 }
 334
 335 /* propagate transmission status back to the driver */
 336 static bool wlan_tx_status(struct dma_queue *queue,
 337                            struct dma_desc *desc)
 338 {
 339         struct carl9170_tx_superframe *super = get_super(desc);
 340         unsigned int qidx = super->s.queue;
 341         bool txfail = false, success;
 342
 343         success = true;
 344
 345         /* update hangcheck */
 346         fw.wlan.last_super_num[qidx] = 0;
 347
 348         if (!!(desc->ctrl & AR9170_CTRL_FAIL)) {
 349                 txfail = !!(desc->ctrl & AR9170_CTRL_TXFAIL);
 350
 351                 /* reset retry indicator flags */
 352                 desc->ctrl &= ~(AR9170_CTRL_TXFAIL | AR9170_CTRL_BAFAIL);
 353
 354                 /*
 355                  * Note: wlan_tx_consume_retry will override the old
 356                  * phy [CCK,OFDM, HT, BW20/40, MCS...] and mac vectors
 357                  * [AMPDU,RTS/CTS,...] therefore be careful when they
 358                  * are used.
 359                  */
 360                 if (wlan_tx_consume_retry(super)) {
 361                         /*
 362                          * retry for simple and aggregated 802.11 frames.
 363                          *
 364                          * Note: We must not mess up the original frame
 365                          * order.
 366                          */
 367
 368                         if (!super->f.hdr.mac.ampdu) {
 369                                 /*
 370                                  * 802.11 - 7.1.3.1.5.
 371                                  * set "Retry Field" for consecutive attempts
 372                                  *
 373                                  * Note: For AMPDU see:
 374                                  * 802.11n 9.9.1.6 "Retransmit Procedures"
 375                                  */
 376                                 super->f.data.i3e.frame_control |=
 377                                         cpu_to_le16(IEEE80211_FCTL_RETRY);
 378                         }
 379
 380                         if (txfail) {
 381                                 /* Normal TX Failure */
 382
 383                                 /* demise descriptor ownership back to the hardware */
 384                                 dma_rearm(desc);
 385
 386                                 /*
 387                                  * And this will get the queue going again.
 388                                  * To understand why: you have to get the HW
 389                                  * specs... But sadly I never saw them.
 390                                  */
 391                                 wlan_txunstuck(qidx);
 392
 393                                 /* abort cycle - this is necessary due to HW design */
 394                                 return false;
 395                         } else {
 396                                 /* (HT-) BlockACK failure */
 397
 398                                 /*
 399                                  * Unlink the failed attempt and put it into
 400                                  * the retry queue. The caller routine must
 401                                  * be aware of this so the frames don't get lost.
 402                                  */
 403
 404 #ifndef CONFIG_CARL9170FW_DEBUG
 405                                 dma_unlink_head(queue);
 406 #else /* CONFIG_CARL9170FW_DEBUG */
 407                                 BUG_ON(dma_unlink_head(queue) != desc);
 408 #endif /* CONFIG_CARL9170FW_DEBUG */
 409                                 dma_put(&fw.wlan.tx_retry, desc);
 410                                 return true;
 411                         }
 412                 } else {
 413                         /* out of frame attempts - discard frame */
 414                         success = false;
 415                 }
 416         }
 417
 418 #ifndef CONFIG_CARL9170FW_DEBUG
 419         dma_unlink_head(queue);
 420 #else /* CONFIG_CARL9170FW_DEBUG */
 421         BUG_ON(dma_unlink_head(queue) != desc);
 422 #endif /* CONFIG_CARL9170FW_DEBUG */
 423         if (txfail) {
 424                 /*
 425                  * Issue the queue bump,
 426                  * We need to do this in case this was the frame's last
 427                  * possible retry attempt and it unfortunately: it failed.
 428                  */
 429
 430                 wlan_txunstuck(qidx);
 431         }
 432
 433         unhide_super(desc);
 434
 435         if (unlikely(super == fw.wlan.fw_desc_data)) {
 436                 fw.wlan.fw_desc = desc;
 437                 fw.wlan.fw_desc_available = 1;
 438
 439                 if (fw.wlan.fw_desc_callback)
 440                         fw.wlan.fw_desc_callback(super, success);
 441
 442                 return true;
 443         }
 444
 445 #ifdef CONFIG_CARL9170FW_CAB_QUEUE
 446         if (unlikely(super->s.cab))
 447                 fw.wlan.cab_queue_len[super->s.vif_id]--;
 448 #endif /* CONFIG_CARL9170FW_CAB_QUEUE */
 449
 450         wlan_tx_complete(super, success);
 451
 452         /* recycle freed descriptors */
 453         dma_reclaim(&fw.pta.down_queue, desc);
 454         down_trigger();
 455         return true;
 456 }
 457
 458 static void handle_tx_completion(void)
 459 {
 460         struct dma_desc *desc;
 461         int i;
 462
 463         for (i = AR9170_TXQ_SPECIAL; i >= AR9170_TXQ0; i--) {
 464                 __while_desc_bits(desc, &fw.wlan.tx_queue[i], AR9170_OWN_BITS_SW) {
 465                         if (!wlan_tx_status(&fw.wlan.tx_queue[i], desc)) {
 466                                 /* termination requested. */
 467                                 break;
 468                         }
 469                 }
 470
 471                 wlan_tx_ampdu_reset(i);
 472
 473                 for_each_desc(desc, &fw.wlan.tx_retry)
 474                         __wlan_tx(desc);
 475
 476                 wlan_tx_ampdu_end(i);
 477                 if (!queue_empty(&fw.wlan.tx_queue[i]))
 478                         wlan_trigger(BIT(i));
 479         }
 480 }
 481
 482 void __hot wlan_tx(struct dma_desc *desc)
 483 {
 484         struct carl9170_tx_superframe *super = DESC_PAYLOAD(desc);
 485
 486         /* initialize rate control struct */
 487         super->s.rix = 0;
 488         super->s.cnt = 1;
 489         hide_super(desc);
 490
 491 #ifdef CONFIG_CARL9170FW_CAB_QUEUE
 492         if (unlikely(super->s.cab)) {
 493                 fw.wlan.cab_queue_len[super->s.vif_id]++;
 494                 dma_put(&fw.wlan.cab_queue[super->s.vif_id], desc);
 495                 return;
 496         }
 497 #endif /* CONFIG_CARL9170FW_CAB_QUEUE */
 498
 499         _wlan_tx(desc);
 500         __wlan_tx(desc);
 501         wlan_trigger(BIT(super->s.queue));
 502 }
 503
 504 void wlan_tx_fw(struct carl9170_tx_superdesc *super, fw_desc_callback_t cb)
 505 {
 506         if (!fw.wlan.fw_desc_available)
 507                 return;
 508
 509         fw.wlan.fw_desc_available = 0;
 510
 511         /* Format BlockAck */
 512         fw.wlan.fw_desc->ctrl = AR9170_CTRL_FS_BIT | AR9170_CTRL_LS_BIT;
 513         fw.wlan.fw_desc->status = AR9170_OWN_BITS_SW;
 514
 515         fw.wlan.fw_desc->totalLen = fw.wlan.fw_desc->dataSize = super->len;
 516         fw.wlan.fw_desc_data = fw.wlan.fw_desc->dataAddr = super;
 517         fw.wlan.fw_desc->nextAddr = fw.wlan.fw_desc->lastAddr =
 518                 fw.wlan.fw_desc;
 519         fw.wlan.fw_desc_callback = cb;
 520         wlan_tx(fw.wlan.fw_desc);
 521 }
 522
 523 static void wlan_send_buffered_ba(void)
 524 {
 525         struct carl9170_tx_ba_superframe *baf = &dma_mem.reserved.ba.ba;
 526         struct ieee80211_ba *ba = (struct ieee80211_ba *) &baf->f.ba;
 527         struct carl9170_bar_ctx *ctx;
 528
 529         if (likely(!fw.wlan.queued_ba))
 530                 return;
 531
 532         /* there's no point to continue when the ba_desc is not available. */
 533         if (!fw.wlan.fw_desc_available)
 534                 return;
 535
 536         ctx = &fw.wlan.ba_cache[fw.wlan.ba_head_idx];
 537         fw.wlan.ba_head_idx++;
 538         fw.wlan.ba_head_idx %= CONFIG_CARL9170FW_BACK_REQS_NUM;
 539         fw.wlan.queued_ba--;
 540
 541         baf->s.len = sizeof(struct carl9170_tx_superdesc) +
 542                      sizeof(struct ar9170_tx_hwdesc) +
 543                      sizeof(struct ieee80211_ba);
 544         baf->s.ri[0].tries = 1;
 545         baf->s.cookie = 0;
 546         baf->s.queue = AR9170_TXQ_VO;
 547         baf->f.hdr.length = sizeof(struct ieee80211_ba) + FCS_LEN;
 548
 549         baf->f.hdr.mac.no_ack = 1;
 550
 551         baf->f.hdr.phy.modulation = 1; /* OFDM */
 552         baf->f.hdr.phy.tx_power = 34; /* 17 dBm */
 553         baf->f.hdr.phy.chains = 1;
 554         baf->f.hdr.phy.mcs = AR9170_TXRX_PHY_RATE_OFDM_6M;
 555
 556         /* format outgoing BA */
 557         ba->frame_control = cpu_to_le16(IEEE80211_FTYPE_CTL | IEEE80211_STYPE_BACK);
 558         ba->duration = cpu_to_le16(0);
 559         memcpy(ba->ta, ctx->ta, 6);
 560         memcpy(ba->ra, ctx->ra, 6);
 561
 562         /*
 563          * Unfortunately, we cannot look into the hardware's scoreboard.
 564          * Therefore we have to proceed as described in 802.11n 9.10.7.5
 565          * and send a null BlockAck.
 566          */
 567         memset(ba->bitmap, 0x0, sizeof(ba->bitmap));
 568
 569         ba->control = ctx->control;
 570         ba->start_seq_num = ctx->start_seq_num;
 571         wlan_tx_fw(&baf->s, NULL);
 572 }
 573
 574 static struct carl9170_bar_ctx *wlan_get_bar_cache_buffer(void)
 575 {
 576         struct carl9170_bar_ctx *tmp;
 577
 578         tmp = &fw.wlan.ba_cache[fw.wlan.ba_tail_idx];
 579         fw.wlan.ba_tail_idx++;
 580         fw.wlan.ba_tail_idx %= CONFIG_CARL9170FW_BACK_REQS_NUM;
 581         if (fw.wlan.queued_ba < CONFIG_CARL9170FW_BACK_REQS_NUM)
 582                 fw.wlan.queued_ba++;
 583
 584         return tmp;
 585 }
 586
 587 static void handle_bar(struct dma_desc *desc __unused, struct ieee80211_hdr *hdr,
 588                        unsigned int len, unsigned int mac_err)
 589 {
 590         struct ieee80211_bar *bar;
 591         struct carl9170_bar_ctx *ctx;
 592
 593         if (unlikely(mac_err)) {
 594                 /*
 595                  * This check does a number of things:
 596                  * 1. checks if the frame is in good nick
 597                  * 2. checks if the RA (MAC) matches
 598                  */
 599                 return ;
 600         }
 601
 602         if (unlikely(len < (sizeof(struct ieee80211_bar) + FCS_LEN))) {
 603                 /*
 604                  * Sneaky, corrupted BARs... but not with us!
 605                  */
 606
 607                 return ;
 608         }
 609
 610         bar = (void *) hdr;
 611
 612         if ((bar->control & cpu_to_le16(IEEE80211_BAR_CTRL_MULTI_TID)) ||
 613             !(bar->control & cpu_to_le16(IEEE80211_BAR_CTRL_CBMTID_COMPRESSED_BA))) {
 614                 /* not implemented yet */
 615
 616                 return ;
 617         }
 618
 619         ctx = wlan_get_bar_cache_buffer();
 620
 621         /* Brilliant! The BAR provides all necessary MACs! */
 622         memcpy(ctx->ra, bar->ta, 6);
 623         memcpy(ctx->ta, bar->ra, 6);
 624         ctx->control = bar->control;
 625         ctx->start_seq_num = bar->start_seq_num;
 626 }
 627
 628 static void wlan_check_rx_overrun(void)
 629 {
 630         uint32_t overruns, total;
 631
 632         fw.tally.rx_total += total = get(AR9170_MAC_REG_RX_TOTAL);
 633         fw.tally.rx_overrun += overruns = get(AR9170_MAC_REG_RX_OVERRUN);
 634         if (unlikely(overruns)) {
 635                 if (overruns == total) {
 636                         DBG("RX Overrun");
 637                         fw.wlan.mac_reset++;
 638                 }
 639
 640                 wlan_trigger(AR9170_DMA_TRIGGER_RXQ);
 641         }
 642 }
 643
 644 static unsigned int wlan_rx_filter(struct dma_desc *desc)
 645 {
 646         struct ieee80211_hdr *hdr;
 647         unsigned int data_len;
 648         unsigned int rx_filter;
 649         unsigned int mac_err;
 650
 651         data_len = ar9170_get_rx_mpdu_len(desc);
 652         mac_err = ar9170_get_rx_macstatus_error(desc);
 653
 654 #define AR9170_RX_ERROR_BAD (AR9170_RX_ERROR_FCS | AR9170_RX_ERROR_PLCP)
 655
 656         if (unlikely(data_len < (4 + 6 + FCS_LEN) ||
 657             desc->totalLen > CONFIG_CARL9170FW_RX_FRAME_LEN) ||
 658             mac_err & AR9170_RX_ERROR_BAD) {
 659                 /*
 660                  * This frame is too damaged to do anything
 661                  * useful with it.
 662                  */
 663
 664                 return CARL9170_RX_FILTER_BAD;
 665         }
 666
 667         rx_filter = 0;
 668         if (mac_err & AR9170_RX_ERROR_WRONG_RA)
 669                 rx_filter |= CARL9170_RX_FILTER_OTHER_RA;
 670
 671         if (mac_err & AR9170_RX_ERROR_DECRYPT)
 672                 rx_filter |= CARL9170_RX_FILTER_DECRY_FAIL;
 673
 674         hdr = ar9170_get_rx_i3e(desc);
 675         if (likely(ieee80211_is_data(hdr->frame_control))) {
 676                 rx_filter |= CARL9170_RX_FILTER_DATA;
 677         } else if (ieee80211_is_ctl(hdr->frame_control)) {
 678                 switch (le16_to_cpu(hdr->frame_control) & IEEE80211_FCTL_STYPE) {
 679                 case IEEE80211_STYPE_BACK_REQ:
 680                         handle_bar(desc, hdr, data_len, mac_err);
 681                         /* fallthrough */
 682                         rx_filter |= CARL9170_RX_FILTER_CTL_BACKR;
 683                         break;
 684                 case IEEE80211_STYPE_PSPOLL:
 685                         rx_filter |= CARL9170_RX_FILTER_CTL_PSPOLL;
 686                         break;
 687                 default:
 688                         rx_filter |= CARL9170_RX_FILTER_CTL_OTHER;
 689                         break;
 690                 }
 691         } else {
 692                 /* ieee80211_is_mgmt */
 693                 rx_filter |= CARL9170_RX_FILTER_MGMT;
 694         }
 695
 696         if (unlikely(fw.suspend_mode == CARL9170_HOST_SUSPENDED)) {
 697                 wol_rx(rx_filter, hdr, min(data_len,
 698                         (unsigned int)AR9170_BLOCK_SIZE));
 699         }
 700
 701 #undef AR9170_RX_ERROR_BAD
 702
 703         return rx_filter;
 704 }
 705
 706 static void handle_rx(void)
 707 {
 708         struct dma_desc *desc;
 709
 710         for_each_desc_not_bits(desc, &fw.wlan.rx_queue, AR9170_OWN_BITS_HW) {
 711                 if (!(wlan_rx_filter(desc) & fw.wlan.rx_filter)) {
 712                         dma_put(&fw.pta.up_queue, desc);
 713                         up_trigger();
 714                 } else {
 715                         dma_reclaim(&fw.wlan.rx_queue, desc);
 716                         wlan_trigger(AR9170_DMA_TRIGGER_RXQ);
 717                 }
 718         }
 719 }
 720
 721 #ifdef CONFIG_CARL9170FW_CAB_QUEUE
 722 void wlan_cab_flush_queue(const unsigned int vif)
 723 {
 724         struct dma_queue *cab_queue = &fw.wlan.cab_queue[vif];
 725         struct dma_desc *desc;
 726
 727         /* move queued frames into the main tx queues */
 728         for_each_desc(desc, cab_queue) {
 729                 struct carl9170_tx_superframe *super = get_super(desc);
 730                 if (!queue_empty(cab_queue)) {
 731                         /*
 732                          * Set MOREDATA flag for all,
 733                          * but the last queued frame.
 734                          * see: 802.11-2007 11.2.1.5 f)
 735                          *
 736                          * This is actually the reason to why
 737                          * we need to prevent the reentry.
 738                          */
 739
 740                         super->f.data.i3e.frame_control |=
 741                                 cpu_to_le16(IEEE80211_FCTL_MOREDATA);
 742                 } else {
 743                         super->f.data.i3e.frame_control &=
 744                                 cpu_to_le16(~IEEE80211_FCTL_MOREDATA);
 745                 }
 746
 747                 /* ready to roll! */
 748                 _wlan_tx(desc);
 749                 __wlan_tx(desc);
 750                 wlan_trigger(BIT(super->s.queue));
 751         }
 752 }
 753
 754 static uint8_t *beacon_find_ie(uint8_t ie, void *addr,
 755                                const unsigned int len)
 756 {
 757         struct ieee80211_mgmt *mgmt = addr;
 758         uint8_t *pos, *end;
 759
 760         pos = mgmt->u.beacon.variable;
 761         end = (uint8_t *) ((unsigned long)mgmt + (len - FCS_LEN));
 762         while (pos < end) {
 763                 if (pos + 2 + pos[1] > end)
 764                         return NULL;
 765
 766                 if (pos[0] == ie)
 767                         return pos;
 768
 769                 pos += pos[1] + 2;
 770         }
 771
 772         return NULL;
 773 }
 774
 775 void wlan_modify_beacon(const unsigned int vif,
 776         const unsigned int addr, const unsigned int len)
 777 {
 778         uint8_t *_ie;
 779         struct ieee80211_tim_ie *ie;
 780
 781         _ie = beacon_find_ie(WLAN_EID_TIM, (void *)addr, len);
 782         if (likely(_ie)) {
 783                 ie = (struct ieee80211_tim_ie *) &_ie[2];
 784
 785                 if (!queue_empty(&fw.wlan.cab_queue[vif]) && (ie->dtim_count == 0)) {
 786                         /* schedule DTIM transfer */
 787                         fw.wlan.cab_flush_trigger[vif] = CARL9170_CAB_TRIGGER_ARMED;
 788                 } else if ((fw.wlan.cab_queue_len[vif] == 0) && (fw.wlan.cab_flush_trigger[vif])) {
 789                         /* undo all chances to the beacon structure */
 790                         ie->bitmap_ctrl &= ~0x1;
 791                         fw.wlan.cab_flush_trigger[vif] = CARL9170_CAB_TRIGGER_EMPTY;
 792                 }
 793
 794                 /* Triggered by CARL9170_CAB_TRIGGER_ARMED || CARL9170_CAB_TRIGGER_DEFER */
 795                 if (fw.wlan.cab_flush_trigger[vif]) {
 796                         /* Set the almighty Multicast Traffic Indication Bit. */
 797                         ie->bitmap_ctrl |= 0x1;
 798                 }
 799         }
 800
 801         /*
 802          * Ideally, the sequence number should be assigned by the TX arbiter
 803          * hardware. But AFAIK that's not possible, so we have to go for the
 804          * next best thing and write it into the beacon fifo during the open
 805          * beacon update window.
 806          */
 807
 808         wlan_assign_seq((struct ieee80211_hdr *)addr, vif);
 809 }
 810
 811 static void wlan_send_buffered_cab(void)
 812 {
 813         unsigned int i;
 814
 815         for (i = 0; i < CARL9170_INTF_NUM; i++) {
 816                 if (unlikely(fw.wlan.cab_flush_trigger[i] == CARL9170_CAB_TRIGGER_ARMED)) {
 817                         /*
 818                          * This is hardcoded into carl9170usb driver.
 819                          *
 820                          * The driver must set the PRETBTT event to beacon_interval -
 821                          * CARL9170_PRETBTT_KUS (usually 6) Kus.
 822                          *
 823                          * But still, we can only do so much about 802.11-2007 9.3.2.1 &
 824                          * 11.2.1.6. Let's hope the current solution is adequate enough.
 825                          */
 826
 827                         if (is_after_msecs(fw.wlan.cab_flush_time, (CARL9170_TBTT_DELTA))) {
 828                                 wlan_cab_flush_queue(i);
 829
 830                                 /*
 831                                  * This prevents the code from sending new BC/MC frames
 832                                  * which were queued after the previous buffered traffic
 833                                  * has been sent out... They will have to wait until the
 834                                  * next DTIM beacon comes along.
 835                                  */
 836                                 fw.wlan.cab_flush_trigger[i] = CARL9170_CAB_TRIGGER_DEFER;
 837                         }
 838                 }
 839
 840         }
 841 }
 842 #endif /* CONFIG_CARL9170FW_CAB_QUEUE */
 843
 844 static void handle_beacon_config(void)
 845 {
 846         uint32_t bcn_count;
 847
 848         bcn_count = get(AR9170_MAC_REG_BCN_COUNT);
 849         send_cmd_to_host(4, CARL9170_RSP_BEACON_CONFIG, 0x00,
 850                          (uint8_t *) &bcn_count);
 851 }
 852
 853 static void handle_pretbtt(void)
 854 {
 855 #ifdef CONFIG_CARL9170FW_CAB_QUEUE
 856         fw.wlan.cab_flush_time = get_clock_counter();
 857 #endif /* CONFIG_CARL9170FW_CAB_QUEUE */
 858
 859 #ifdef CONFIG_CARL9170FW_RADIO_FUNCTIONS
 860         rf_psm();
 861
 862         send_cmd_to_host(4, CARL9170_RSP_PRETBTT, 0x00,
 863                          (uint8_t *) &fw.phy.psm.state);
 864 #endif /* CONFIG_CARL9170FW_RADIO_FUNCTIONS */
 865 }
 866
 867 static void handle_atim(void)
 868 {
 869         send_cmd_to_host(0, CARL9170_RSP_ATIM, 0x00, NULL);
 870 }
 871
 872 #ifdef CONFIG_CARL9170FW_DEBUG
 873 static void handle_qos(void)
 874 {
 875         /*
 876          * What is the QoS Bit used for?
 877          * Is it only an indicator for TXOP & Burst, or
 878          * should we do something here?
 879          */
 880 }
 881
 882 static void handle_radar(void)
 883 {
 884         send_cmd_to_host(0, CARL9170_RSP_RADAR, 0x00, NULL);
 885 }
 886 #endif /* CONFIG_CARL9170FW_DEBUG */
 887
 888 static void wlan_janitor(void)
 889 {
 890 #ifdef CONFIG_CARL9170FW_CAB_QUEUE
 891         wlan_send_buffered_cab();
 892 #endif /* CONFIG_CARL9170FW_CAB_QUEUE */
 893
 894         wlan_send_buffered_tx_status();
 895
 896         wlan_send_buffered_ba();
 897
 898         wol_janitor();
 899 }
 900
 901 void handle_wlan(void)
 902 {
 903         uint32_t intr;
 904
 905         intr = get(AR9170_MAC_REG_INT_CTRL);
 906         /* ACK Interrupt */
 907         set(AR9170_MAC_REG_INT_CTRL, intr);
 908
 909 #define HANDLER(intr, flag, func)                       \
 910         do {                                            \
 911                 if ((intr & flag) != 0) {               \
 912                         func();                         \
 913                 }                                       \
 914         } while (0)
 915
 916         intr |= fw.wlan.soft_int;
 917         fw.wlan.soft_int = 0;
 918
 919         HANDLER(intr, AR9170_MAC_INT_PRETBTT, handle_pretbtt);
 920
 921         HANDLER(intr, AR9170_MAC_INT_ATIM, handle_atim);
 922
 923         HANDLER(intr, AR9170_MAC_INT_RXC, handle_rx);
 924
 925         HANDLER(intr, (AR9170_MAC_INT_TXC | AR9170_MAC_INT_RETRY_FAIL),
 926                 handle_tx_completion);
 927
 928 #ifdef CONFIG_CARL9170FW_DEBUG
 929         HANDLER(intr, AR9170_MAC_INT_QOS, handle_qos);
 930
 931         HANDLER(intr, AR9170_MAC_INT_RADAR, handle_radar);
 932 #endif /* CONFIG_CARL9170FW_DEBUG */
 933
 934         HANDLER(intr, AR9170_MAC_INT_CFG_BCN, handle_beacon_config);
 935
 936         if (unlikely(intr))
 937                 DBG("Unhandled Interrupt %x\n", (unsigned int) intr);
 938
 939         wlan_janitor();
 940
 941 #undef HANDLER
 942 }
 943
 944 enum {
 945         CARL9170FW_TX_MAC_BUMP = 4,
 946         CARL9170FW_TX_MAC_DEBUG = 6,
 947         CARL9170FW_TX_MAC_RESET = 7,
 948 };
 949
 950 static void wlan_check_hang(void)
 951 {
 952         struct dma_desc *desc;
 953         int i;
 954
 955         for (i = AR9170_TXQ_SPECIAL; i >= AR9170_TXQ0; i--) {
 956                 if (queue_empty(&fw.wlan.tx_queue[i])) {
 957                         /* Nothing to do here... move along */
 958                         continue;
 959                 }
 960
 961                 /* fetch the current DMA queue position */
 962                 desc = (struct dma_desc *)get_wlan_txq_addr(i);
 963
 964                 /* Stuck frame detection */
 965                 if (unlikely(DESC_PAYLOAD(desc) == fw.wlan.last_super[i])) {
 966                         fw.wlan.last_super_num[i]++;
 967
 968                         if (unlikely(fw.wlan.last_super_num[i] >= CARL9170FW_TX_MAC_RESET)) {
 969                                 /*
 970                                  * schedule MAC reset (aka OFF/ON => dead)
 971                                  *
 972                                  * This will almost certainly kill
 973                                  * the device for good, but it's the
 974                                  * recommended thing to do...
 975                                  */
 976
 977                                 fw.wlan.mac_reset++;
 978                         }
 979
 980 #ifdef CONFIG_CARL9170FW_DEBUG
 981                         if (unlikely(fw.wlan.last_super_num[i] >= CARL9170FW_TX_MAC_DEBUG)) {
 982                                 /*
 983                                  * Sigh, the queue is almost certainly
 984                                  * dead. Dump the queue content to the
 985                                  * user, maybe we find out why it got
 986                                  * so stuck.
 987                                  */
 988
 989                                 wlan_dump_queue(i);
 990                         }
 991 #endif /* CONFIG_CARL9170FW_DEBUG */
 992
 993 #ifdef CONFIG_CARL9170FW_DMA_QUEUE_BUMP
 994                         if (unlikely(fw.wlan.last_super_num[i] >= CARL9170FW_TX_MAC_BUMP)) {
 995                                 /*
 996                                  * Hrrm, bump the queue a bit.
 997                                  * maybe this will get it going again.
 998                                  */
 999
1000                                 wlan_dma_bump(i);
1001                                 wlan_trigger(BIT(i));
1002                         }
1003 #endif /* CONFIG_CARL9170FW_DMA_QUEUE_BUMP */
1004                 } else {
1005                         /* Nothing stuck */
1006                         fw.wlan.last_super[i] = DESC_PAYLOAD(desc);
1007                         fw.wlan.last_super_num[i] = 0;
1008                 }
1009         }
1010 }
1011
1012 #ifdef CONFIG_CARL9170FW_FW_MAC_RESET
1013 /*
1014  * NB: Resetting the MAC is a two-edged sword.
1015  * On most occasions, it does what it is supposed to do.
1016  * But there is a chance that this will make it
1017  * even worse and the radio dies silently.
1018  */
1019 static void wlan_mac_reset(void)
1020 {
1021         uint32_t val;
1022         uint32_t agg_wait_counter;
1023         uint32_t agg_density;
1024         uint32_t bcn_start_addr;
1025         uint32_t rctl, rcth;
1026         uint32_t cam_mode;
1027         uint32_t ack_power;
1028         uint32_t rts_cts_tpc;
1029         uint32_t rts_cts_rate;
1030         int i;
1031
1032 #ifdef CONFIG_CARL9170FW_RADIO_FUNCTIONS
1033         uint32_t rx_BB;
1034 #endif /* CONFIG_CARL9170FW_RADIO_FUNCTIONS */
1035
1036 #ifdef CONFIG_CARL9170FW_NOISY_MAC_RESET
1037         INFO("MAC RESET");
1038 #endif /* CONFIG_CARL9170FW_NOISY_MAC_RESET */
1039
1040         /* Save aggregation parameters */
1041         agg_wait_counter = get(AR9170_MAC_REG_AMPDU_FACTOR);
1042         agg_density = get(AR9170_MAC_REG_AMPDU_DENSITY);
1043
1044         bcn_start_addr = get(AR9170_MAC_REG_BCN_ADDR);
1045
1046         cam_mode = get(AR9170_MAC_REG_CAM_MODE);
1047         rctl = get(AR9170_MAC_REG_CAM_ROLL_CALL_TBL_L);
1048         rcth = get(AR9170_MAC_REG_CAM_ROLL_CALL_TBL_H);
1049
1050         ack_power = get(AR9170_MAC_REG_ACK_TPC);
1051         rts_cts_tpc = get(AR9170_MAC_REG_RTS_CTS_TPC);
1052         rts_cts_rate = get(AR9170_MAC_REG_RTS_CTS_RATE);
1053
1054 #ifdef CONFIG_CARL9170FW_RADIO_FUNCTIONS
1055         /* 0x1c8960 write only */
1056         rx_BB = get(AR9170_PHY_REG_SWITCH_CHAIN_0);
1057 #endif /* CONFIG_CARL9170FW_RADIO_FUNCTIONS */
1058
1059         /* TX/RX must be stopped by now */
1060         val = get(AR9170_MAC_REG_POWER_STATE_CTRL);
1061
1062         val |= AR9170_MAC_POWER_STATE_CTRL_RESET;
1063
1064         /*
1065          * Manipulate CCA threshold to stop transmission
1066          *
1067          * set(AR9170_PHY_REG_CCA_THRESHOLD, 0x300);
1068          */
1069
1070         /*
1071          * check Rx state in 0(idle) 9(disable)
1072          *
1073          * chState = (get(AR9170_MAC_REG_MISC_684) >> 16) & 0xf;
1074          * while( (chState != 0) && (chState != 9)) {
1075          *      chState = (get(AR9170_MAC_REG_MISC_684) >> 16) & 0xf;
1076          * }
1077          */
1078
1079         set(AR9170_MAC_REG_POWER_STATE_CTRL, val);
1080
1081         delay(2);
1082
1083         /* Restore aggregation parameters */
1084         set(AR9170_MAC_REG_AMPDU_FACTOR, agg_wait_counter);
1085         set(AR9170_MAC_REG_AMPDU_DENSITY, agg_density);
1086
1087         set(AR9170_MAC_REG_BCN_ADDR, bcn_start_addr);
1088         set(AR9170_MAC_REG_CAM_MODE, cam_mode);
1089         set(AR9170_MAC_REG_CAM_ROLL_CALL_TBL_L, rctl);
1090         set(AR9170_MAC_REG_CAM_ROLL_CALL_TBL_H, rcth);
1091
1092         set(AR9170_MAC_REG_RTS_CTS_TPC, rts_cts_tpc);
1093         set(AR9170_MAC_REG_ACK_TPC, ack_power);
1094         set(AR9170_MAC_REG_RTS_CTS_RATE, rts_cts_rate);
1095
1096 #ifdef CONFIG_CARL9170FW_RADIO_FUNCTIONS
1097         set(AR9170_PHY_REG_SWITCH_CHAIN_2, rx_BB);
1098 #endif /* CONFIG_CARL9170FW_RADIO_FUNCTIONS */
1099
1100         /*
1101          * Manipulate CCA threshold to resume transmission
1102          *
1103          * set(AR9170_PHY_REG_CCA_THRESHOLD, 0x0);
1104          */
1105
1106         val = AR9170_DMA_TRIGGER_RXQ;
1107         /* Reinitialize all WLAN TX DMA queues. */
1108         for (i = AR9170_TXQ_SPECIAL; i >= AR9170_TXQ0; i--) {
1109                 struct dma_desc *iter;
1110
1111                 __for_each_desc_bits(iter, &fw.wlan.tx_queue[i], AR9170_OWN_BITS_SW);
1112
1113                 /* kill the stuck frame */
1114                 if (!is_terminator(&fw.wlan.tx_queue[i], iter) &&
1115                     fw.wlan.last_super_num[i] >= CARL9170FW_TX_MAC_RESET &&
1116                     fw.wlan.last_super[i] == DESC_PAYLOAD(iter)) {
1117                         struct carl9170_tx_superframe *super = get_super(iter);
1118
1119                         iter->status = AR9170_OWN_BITS_SW;
1120                         /*
1121                          * Mark the frame as failed.
1122                          * The BAFAIL flag allows the frame to sail through
1123                          * wlan_tx_status without much "unstuck" trouble.
1124                          */
1125                         iter->ctrl &= ~(AR9170_CTRL_FAIL);
1126                         iter->ctrl |= AR9170_CTRL_BAFAIL;
1127
1128                         super->s.cnt = CARL9170_TX_MAX_RATE_TRIES;
1129                         super->s.rix = CARL9170_TX_MAX_RETRY_RATES;
1130
1131                         fw.wlan.last_super_num[i] = 0;
1132                         fw.wlan.last_super[i] = NULL;
1133                         iter = iter->lastAddr->nextAddr;
1134                 }
1135
1136                 set_wlan_txq_dma_addr(i, (uint32_t) iter);
1137                 if (!is_terminator(&fw.wlan.tx_queue[i], iter))
1138                         val |= BIT(i);
1139
1140                 DBG("Q:%d l:%d h:%p t:%p cu:%p it:%p ct:%x st:%x\n", i, queue_len(&fw.wlan.tx_queue[i]),
1141                      fw.wlan.tx_queue[i].head, fw.wlan.tx_queue[i].terminator,
1142                      get_wlan_txq_addr(i), iter, iter->ctrl, iter->status);
1143         }
1144
1145         fw.wlan.soft_int |= AR9170_MAC_INT_RXC | AR9170_MAC_INT_TXC |
1146                             AR9170_MAC_INT_RETRY_FAIL;
1147
1148         set(AR9170_MAC_REG_DMA_RXQ_ADDR, (uint32_t) fw.wlan.rx_queue.head);
1149         wlan_trigger(val);
1150 }
1151 #else
1152 static void wlan_mac_reset(void)
1153 {
1154         /* The driver takes care of reinitializing the device */
1155         BUG("MAC RESET");
1156 }
1157 #endif /* CONFIG_CARL9170FW_FW_MAC_RESET */
1158
1159 void __cold wlan_timer(void)
1160 {
1161         unsigned int cached_mac_reset;
1162
1163         cached_mac_reset = fw.wlan.mac_reset;
1164
1165         /* TX Queue Hang check */
1166         wlan_check_hang();
1167
1168         /* RX Overrun check */
1169         wlan_check_rx_overrun();
1170
1171         if (unlikely(fw.wlan.mac_reset >= CARL9170_MAC_RESET_RESET)) {
1172                 wlan_mac_reset();
1173                 fw.wlan.mac_reset = CARL9170_MAC_RESET_OFF;
1174         } else {
1175                 if (fw.wlan.mac_reset && cached_mac_reset == fw.wlan.mac_reset)
1176                         fw.wlan.mac_reset--;
1177         }
1178 }