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 #if (defined CONFIG_CARL9170FW_LOOPBACK) || (defined CONFIG_CARL9170FW_DISCARD)
 296         wlan_tx_complete(super, true);
 297         unhide_super(desc);
 298 # ifdef CONFIG_CARL9170FW_LOOPBACK
 299         dma_put(&fw.pta.up_queue, desc);
 300         up_trigger();
 301 # elif CONFIG_CARL9170FW_DISCARD
 302         dma_reclaim(&fw.pta.down_queue, desc);
 303         down_trigger();
 304 # endif
 305 #else /* CONFIG_CARL9170FW_LOOPBACK */
 306
 307 # ifdef CONFIG_CARL9170FW_DEBUG
 308         BUG_ON(fw.phy.psm.state != CARL9170_PSM_WAKE);
 309 # endif /* CONFIG_CARL9170FW_DEBUG */
 310
 311         /* insert desc into the right queue */
 312         dma_put(&fw.wlan.tx_queue[super->s.queue], desc);
 313 #endif /* CONFIG_CARL9170FW_LOOPBACK */
 314 }
 315
 316 static void wlan_assign_seq(struct ieee80211_hdr *hdr, unsigned int vif)
 317 {
 318         hdr->seq_ctrl &= cpu_to_le16(~IEEE80211_SCTL_SEQ);
 319         hdr->seq_ctrl |= cpu_to_le16(fw.wlan.sequence[vif]);
 320
 321         if (!(hdr->seq_ctrl & cpu_to_le16(IEEE80211_SCTL_FRAG)))
 322                 fw.wlan.sequence[vif] += 0x10;
 323 }
 324
 325 /* prepares frame for the first transmission */
 326 static void _wlan_tx(struct dma_desc *desc)
 327 {
 328         struct carl9170_tx_superframe *super = get_super(desc);
 329
 330         if (unlikely(super->s.assign_seq))
 331                 wlan_assign_seq(&super->f.data.i3e, super->s.vif_id);
 332
 333         if (unlikely(super->s.ampdu_commit_density)) {
 334                 set(AR9170_MAC_REG_AMPDU_DENSITY,
 335                     MOD_VAL(AR9170_MAC_AMPDU_DENSITY,
 336                             get(AR9170_MAC_REG_AMPDU_DENSITY),
 337                             super->s.ampdu_density));
 338         }
 339
 340         if (unlikely(super->s.ampdu_commit_factor)) {
 341                 set(AR9170_MAC_REG_AMPDU_FACTOR,
 342                     MOD_VAL(AR9170_MAC_AMPDU_FACTOR,
 343                             get(AR9170_MAC_REG_AMPDU_FACTOR),
 344                             8 << super->s.ampdu_factor));
 345         }
 346
 347         __wlan_tx(desc);
 348 }
 349
 350 /* propagate transmission status back to the driver */
 351 static bool wlan_tx_status(struct dma_queue *queue,
 352                            struct dma_desc *desc)
 353 {
 354         struct carl9170_tx_superframe *super = get_super(desc);
 355         unsigned int qidx = super->s.queue;
 356         bool txfail = false, success;
 357
 358         success = true;
 359
 360         /* update hangcheck */
 361         fw.wlan.last_super_num[qidx] = 0;
 362
 363         if (!!(desc->ctrl & AR9170_CTRL_FAIL)) {
 364                 txfail = !!(desc->ctrl & AR9170_CTRL_TXFAIL);
 365
 366                 /* reset retry indicator flags */
 367                 desc->ctrl &= ~(AR9170_CTRL_TXFAIL | AR9170_CTRL_BAFAIL);
 368
 369                 if (wlan_tx_consume_retry(super)) {
 370                         /*
 371                          * retry for simple and aggregated 802.11 frames.
 372                          *
 373                          * Note: We must not mess up the original frame
 374                          * order.
 375                          */
 376
 377                         if (!super->f.hdr.mac.ampdu) {
 378                                 /*
 379                                  * 802.11 - 7.1.3.1.5.
 380                                  * set "Retry Field" for consecutive attempts
 381                                  *
 382                                  * Note: For AMPDU see:
 383                                  * 802.11n 9.9.1.6 "Retransmit Procedures"
 384                                  */
 385                                 super->f.data.i3e.frame_control |=
 386                                         cpu_to_le16(IEEE80211_FCTL_RETRY);
 387                         }
 388
 389                         if (txfail) {
 390                                 /* Normal TX Failure */
 391
 392                                 /* demise descriptor ownership back to the hardware */
 393                                 dma_rearm(desc);
 394
 395                                 /*
 396                                  * And this will get the queue going again.
 397                                  * To understand why: you have to get the HW
 398                                  * specs... But sadly I never saw them.
 399                                  */
 400                                 wlan_txunstuck(qidx);
 401
 402                                 /* abort cycle - this is necessary due to HW design */
 403                                 return false;
 404                         } else {
 405                                 /* (HT-) BlockACK failure */
 406
 407                                 /*
 408                                  * Unlink the failed attempt and put it into
 409                                  * the retry queue. The caller routine must
 410                                  * be aware of this so the frames don't get lost.
 411                                  */
 412
 413                                 dma_unlink_head(queue);
 414                                 dma_put(&fw.wlan.tx_retry, desc);
 415                                 return true;
 416                         }
 417                 } else {
 418                         /* out of frame attempts - discard frame */
 419                         success = false;
 420                 }
 421         }
 422
 423         dma_unlink_head(queue);
 424         if (txfail) {
 425                 /*
 426                  * Issue the queue bump,
 427                  * We need to do this in case this was the frame's last
 428                  * possible retry attempt and it unfortunately: it failed.
 429                  */
 430
 431                 wlan_txunstuck(qidx);
 432         }
 433
 434         unhide_super(desc);
 435
 436         if (unlikely(super == fw.wlan.fw_desc_data)) {
 437                 fw.wlan.fw_desc = desc;
 438                 fw.wlan.fw_desc_available = 1;
 439
 440                 if (fw.wlan.fw_desc_callback)
 441                         fw.wlan.fw_desc_callback(super, success);
 442
 443                 return true;
 444         }
 445
 446 #ifdef CONFIG_CARL9170FW_CAB_QUEUE
 447         if (unlikely(super->s.cab))
 448                 fw.wlan.cab_queue_len[super->s.vif_id]--;
 449 #endif /* CONFIG_CARL9170FW_CAB_QUEUE */
 450
 451         wlan_tx_complete(super, success);
 452
 453         /* recycle freed descriptors */
 454         dma_reclaim(&fw.pta.down_queue, desc);
 455         down_trigger();
 456         return true;
 457 }
 458
 459 static void handle_tx_completion(void)
 460 {
 461         struct dma_desc *desc;
 462         int i;
 463
 464         for (i = AR9170_TXQ_SPECIAL; i >= AR9170_TXQ0; i--) {
 465                 __while_desc_bits(desc, &fw.wlan.tx_queue[i], AR9170_OWN_BITS_SW) {
 466                         if (!wlan_tx_status(&fw.wlan.tx_queue[i], desc)) {
 467                                 /* termination requested. */
 468                                 break;
 469                         }
 470                 }
 471
 472
 473                 wlan_tx_ampdu_reset(i);
 474
 475                 for_each_desc(desc, &fw.wlan.tx_retry)
 476                         __wlan_tx(desc);
 477
 478                 wlan_tx_ampdu_end(i);
 479                 if (!queue_empty(&fw.wlan.tx_queue[i]))
 480                         wlan_trigger(BIT(i));
 481         }
 482 }
 483
 484 void __hot wlan_tx(struct dma_desc *desc)
 485 {
 486         struct carl9170_tx_superframe *super = DESC_PAYLOAD(desc);
 487
 488         /* initialize rate control struct */
 489         super->s.rix = 0;
 490         super->s.cnt = 1;
 491         hide_super(desc);
 492
 493 #ifdef CONFIG_CARL9170FW_CAB_QUEUE
 494         if (unlikely(super->s.cab)) {
 495                 fw.wlan.cab_queue_len[super->s.vif_id]++;
 496                 dma_put(&fw.wlan.cab_queue[super->s.vif_id], desc);
 497                 return;
 498         }
 499 #endif /* CONFIG_CARL9170FW_CAB_QUEUE */
 500
 501         _wlan_tx(desc);
 502         wlan_trigger(BIT(super->s.queue));
 503 }
 504
 505 void wlan_tx_fw(struct carl9170_tx_superdesc *super, fw_desc_callback_t cb)
 506 {
 507         if (!fw.wlan.fw_desc_available)
 508                 return;
 509
 510         fw.wlan.fw_desc_available = 0;
 511
 512         /* Format BlockAck */
 513         fw.wlan.fw_desc->ctrl = AR9170_CTRL_FS_BIT | AR9170_CTRL_LS_BIT;
 514         fw.wlan.fw_desc->status = AR9170_OWN_BITS_SW;
 515
 516         fw.wlan.fw_desc->totalLen = fw.wlan.fw_desc->dataSize = super->len;
 517         fw.wlan.fw_desc_data = fw.wlan.fw_desc->dataAddr = super;
 518         fw.wlan.fw_desc->nextAddr = fw.wlan.fw_desc->lastAddr =
 519                 fw.wlan.fw_desc;
 520         fw.wlan.fw_desc_callback = cb;
 521         wlan_tx(fw.wlan.fw_desc);
 522 }
 523
 524 static void wlan_send_buffered_ba(void)
 525 {
 526         struct carl9170_tx_ba_superframe *baf = &dma_mem.reserved.ba.ba;
 527         struct ieee80211_ba *ba = (struct ieee80211_ba *) &baf->f.ba;
 528         struct carl9170_bar_ctx *ctx;
 529
 530         if (likely(fw.wlan.ba_head_idx == fw.wlan.ba_tail_idx))
 531                 return;
 532
 533         /* there's no point to continue when the ba_desc is not available. */
 534         if (!fw.wlan.fw_desc_available)
 535                 return;
 536
 537         ctx = &fw.wlan.ba_cache[fw.wlan.ba_head_idx];
 538         fw.wlan.ba_head_idx++;
 539         fw.wlan.ba_head_idx %= CONFIG_CARL9170FW_BACK_REQS_NUM;
 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         /* HW Duration / Backoff */
 550         baf->f.hdr.mac.backoff = 1;
 551         baf->f.hdr.mac.hw_duration = 1;
 552
 553         /* take the TX rate from the RX'd BAR */
 554         baf->f.hdr.phy.set = ctx->phy;
 555         baf->f.hdr.phy.tx_power = 29; /* 14.5 dBm */
 556
 557         /* format outgoing BA */
 558         ba->frame_control = cpu_to_le16(IEEE80211_FTYPE_CTL | IEEE80211_STYPE_NULLFUNC);
 559         ba->duration = cpu_to_le16(0);
 560         memcpy(ba->ta, ctx->ta, 6);
 561         memcpy(ba->ra, ctx->ra, 6);
 562
 563         /*
 564          * Unfortunately, we cannot look into the hardware's scoreboard.
 565          * Therefore we have to proceed as described in 802.11n 9.10.7.5
 566          * and send a null BlockAck.
 567          */
 568         memset(ba->bitmap, 0x0, sizeof(ba->bitmap));
 569
 570         /*
 571          * NB:
 572          * not entirely sure if this is 100% correct?!
 573          */
 574         ba->control = ctx->control | cpu_to_le16(1);
 575         ba->start_seq_num = ctx->start_seq_num;
 576         wlan_tx_fw(&baf->s, NULL);
 577 }
 578
 579 static struct carl9170_bar_ctx *wlan_get_bar_cache_buffer(void)
 580 {
 581         struct carl9170_bar_ctx *tmp;
 582
 583         tmp = &fw.wlan.ba_cache[fw.wlan.ba_tail_idx];
 584         fw.wlan.ba_tail_idx++;
 585         fw.wlan.ba_tail_idx %= CONFIG_CARL9170FW_BACK_REQS_NUM;
 586
 587         return tmp;
 588 }
 589
 590 static void handle_bar(struct dma_desc *desc, struct ieee80211_hdr *hdr,
 591                        unsigned int len, unsigned int mac_err)
 592 {
 593         struct ieee80211_bar *bar;
 594         struct carl9170_bar_ctx *ctx;
 595
 596         if (unlikely(mac_err)) {
 597                 /*
 598                  * This check does a number of things:
 599                  * 1. checks if the frame is in good nick
 600                  * 2. checks if the RA (MAC) matches
 601                  */
 602                 return ;
 603         }
 604
 605         if (unlikely(len < (sizeof(struct ieee80211_bar) + FCS_LEN))) {
 606                 /*
 607                  * Sneaky, corrupted BARs... but not with us!
 608                  */
 609
 610                 return ;
 611         }
 612
 613         bar = (void *) hdr;
 614
 615         if ((bar->control & cpu_to_le16(IEEE80211_BAR_CTRL_MULTI_TID)) ||
 616             !(bar->control & cpu_to_le16(IEEE80211_BAR_CTRL_CBMTID_COMPRESSED_BA))) {
 617                 /* not implemented yet */
 618
 619                 return ;
 620         }
 621
 622         ctx = wlan_get_bar_cache_buffer();
 623
 624         /* Brilliant! The BAR provides all necessary MACs! */
 625         memcpy(ctx->ra, bar->ta, 6);
 626         memcpy(ctx->ta, bar->ra, 6);
 627
 628         /*
 629          * NB:
 630          * not entirely sure if this is 100% correct to force the
 631          * imm ack bit or not...
 632          */
 633         ctx->control = bar->control | cpu_to_le16(1);
 634         ctx->start_seq_num = bar->start_seq_num;
 635         ctx->phy = ar9170_rx_to_phy(desc);
 636         if (unlikely(!ctx->phy)) {
 637                 /* provide a backup, in case ar9170_rx_to_phy fails */
 638                 ctx->phy = cpu_to_le32(0x2cc301);
 639         }
 640 }
 641
 642 static void wlan_check_rx_overrun(void)
 643 {
 644         uint32_t overruns, total;
 645
 646         fw.tally.rx_total += total = get(AR9170_MAC_REG_RX_TOTAL);
 647         fw.tally.rx_overrun += overruns = get(AR9170_MAC_REG_RX_OVERRUN);
 648         if (unlikely(overruns)) {
 649                 if (overruns == total) {
 650                         DBG("RX Overrun");
 651                         fw.wlan.mac_reset++;
 652                 }
 653
 654                 wlan_trigger(AR9170_DMA_TRIGGER_RXQ);
 655         }
 656 }
 657
 658 static unsigned int wlan_rx_filter(struct dma_desc *desc)
 659 {
 660         struct ieee80211_hdr *hdr;
 661         unsigned int data_len;
 662         unsigned int rx_filter;
 663         unsigned int mac_err;
 664
 665         data_len = ar9170_get_rx_mpdu_len(desc);
 666         mac_err = ar9170_get_rx_macstatus_error(desc);
 667
 668 #define AR9170_RX_ERROR_BAD (AR9170_RX_ERROR_FCS | AR9170_RX_ERROR_PLCP)
 669
 670         if (unlikely(data_len < (4 + 6 + FCS_LEN) ||
 671             desc->totalLen > CONFIG_CARL9170FW_RX_FRAME_LEN) ||
 672             mac_err & AR9170_RX_ERROR_BAD) {
 673                 /*
 674                  * This frame is too damaged to do anything
 675                  * useful with it.
 676                  */
 677
 678                 return CARL9170_RX_FILTER_BAD;
 679         }
 680
 681         rx_filter = 0;
 682         if (mac_err & AR9170_RX_ERROR_WRONG_RA)
 683                 rx_filter |= CARL9170_RX_FILTER_OTHER_RA;
 684
 685         if (mac_err & AR9170_RX_ERROR_DECRYPT)
 686                 rx_filter |= CARL9170_RX_FILTER_DECRY_FAIL;
 687
 688         hdr = ar9170_get_rx_i3e(desc);
 689         if (likely(ieee80211_is_data(hdr->frame_control))) {
 690                 rx_filter |= CARL9170_RX_FILTER_DATA;
 691         } else if (ieee80211_is_ctl(hdr->frame_control)) {
 692                 switch (le16_to_cpu(hdr->frame_control) & IEEE80211_FCTL_STYPE) {
 693                 case IEEE80211_STYPE_BACK_REQ:
 694                         handle_bar(desc, hdr, data_len, mac_err);
 695                         /* fallthrough */
 696                         rx_filter |= CARL9170_RX_FILTER_CTL_BACKR;
 697                         break;
 698                 case IEEE80211_STYPE_PSPOLL:
 699                         rx_filter |= CARL9170_RX_FILTER_CTL_PSPOLL;
 700                         break;
 701                 default:
 702                         rx_filter |= CARL9170_RX_FILTER_CTL_OTHER;
 703                         break;
 704                 }
 705         } else {
 706                 /* ieee80211_is_mgmt */
 707                 rx_filter |= CARL9170_RX_FILTER_MGMT;
 708         }
 709
 710         if (unlikely(fw.suspend_mode == CARL9170_HOST_SUSPENDED)) {
 711                 wol_rx(rx_filter, hdr, min(data_len,
 712                         (unsigned int)AR9170_BLOCK_SIZE));
 713         }
 714
 715 #undef AR9170_RX_ERROR_BAD
 716
 717         return rx_filter;
 718 }
 719
 720 static void handle_rx(void)
 721 {
 722         struct dma_desc *desc;
 723
 724         for_each_desc_not_bits(desc, &fw.wlan.rx_queue, AR9170_OWN_BITS_HW) {
 725                 if (!(wlan_rx_filter(desc) & fw.wlan.rx_filter)) {
 726                         dma_put(&fw.pta.up_queue, desc);
 727                         up_trigger();
 728                 } else {
 729                         dma_reclaim(&fw.wlan.rx_queue, desc);
 730                         wlan_trigger(AR9170_DMA_TRIGGER_RXQ);
 731                 }
 732         }
 733 }
 734
 735 #ifdef CONFIG_CARL9170FW_CAB_QUEUE
 736 void wlan_cab_flush_queue(const unsigned int vif)
 737 {
 738         struct dma_queue *cab_queue = &fw.wlan.cab_queue[vif];
 739         struct dma_desc *desc;
 740
 741         /* move queued frames into the main tx queues */
 742         for_each_desc(desc, cab_queue) {
 743                 struct carl9170_tx_superframe *super = get_super(desc);
 744                 if (!queue_empty(cab_queue)) {
 745                         /*
 746                          * Set MOREDATA flag for all,
 747                          * but the last queued frame.
 748                          * see: 802.11-2007 11.2.1.5 f)
 749                          *
 750                          * This is actually the reason to why
 751                          * we need to prevent the reentry.
 752                          */
 753
 754                         super->f.data.i3e.frame_control |=
 755                                 cpu_to_le16(IEEE80211_FCTL_MOREDATA);
 756                 } else {
 757                         super->f.data.i3e.frame_control &=
 758                                 cpu_to_le16(~IEEE80211_FCTL_MOREDATA);
 759                 }
 760
 761                 /* ready to roll! */
 762                 _wlan_tx(desc);
 763                 wlan_trigger(BIT(super->s.queue));
 764         }
 765 }
 766
 767 static uint8_t *beacon_find_ie(uint8_t ie, void *addr,
 768                                const unsigned int len)
 769 {
 770         struct ieee80211_mgmt *mgmt = addr;
 771         uint8_t *pos, *end;
 772
 773         pos = mgmt->u.beacon.variable;
 774         end = (uint8_t *) ((unsigned long)mgmt + (len - FCS_LEN));
 775         while (pos < end) {
 776                 if (pos + 2 + pos[1] > end)
 777                         return NULL;
 778
 779                 if (pos[0] == ie)
 780                         return pos;
 781
 782                 pos += pos[1] + 2;
 783         }
 784
 785         return NULL;
 786 }
 787
 788 void wlan_modify_beacon(const unsigned int vif,
 789         const unsigned int addr, const unsigned int len)
 790 {
 791         uint8_t *_ie;
 792         struct ieee80211_tim_ie *ie;
 793
 794         _ie = beacon_find_ie(WLAN_EID_TIM, (void *)addr, len);
 795         if (likely(_ie)) {
 796                 ie = (struct ieee80211_tim_ie *) &_ie[2];
 797
 798                 if (!queue_empty(&fw.wlan.cab_queue[vif]) && (ie->dtim_count == 0)) {
 799                         /* schedule DTIM transfer */
 800                         fw.wlan.cab_flush_trigger[vif] = CARL9170_CAB_TRIGGER_ARMED;
 801                 } else if ((fw.wlan.cab_queue_len[vif] == 0) && (fw.wlan.cab_flush_trigger[vif])) {
 802                         /* undo all chances to the beacon structure */
 803                         ie->bitmap_ctrl &= ~0x1;
 804                         fw.wlan.cab_flush_trigger[vif] = CARL9170_CAB_TRIGGER_EMPTY;
 805                 }
 806
 807                 /* Triggered by CARL9170_CAB_TRIGGER_ARMED || CARL9170_CAB_TRIGGER_DEFER */
 808                 if (fw.wlan.cab_flush_trigger[vif]) {
 809                         /* Set the almighty Multicast Traffic Indication Bit. */
 810                         ie->bitmap_ctrl |= 0x1;
 811                 }
 812         }
 813
 814         /*
 815          * Ideally, the sequence number should be assigned by the TX arbiter
 816          * hardware. But AFAIK that's not possible, so we have to go for the
 817          * next best thing and write it into the beacon fifo during the open
 818          * beacon update window.
 819          */
 820
 821         wlan_assign_seq((struct ieee80211_hdr *)addr, vif);
 822 }
 823
 824 static void wlan_send_buffered_cab(void)
 825 {
 826         unsigned int i;
 827
 828         for (i = 0; i < CARL9170_INTF_NUM; i++) {
 829                 if (unlikely(fw.wlan.cab_flush_trigger[i] == CARL9170_CAB_TRIGGER_ARMED)) {
 830                         /*
 831                          * This is hardcoded into carl9170usb driver.
 832                          *
 833                          * The driver must set the PRETBTT event to beacon_interval -
 834                          * CARL9170_PRETBTT_KUS (usually 6) Kus.
 835                          *
 836                          * But still, we can only do so much about 802.11-2007 9.3.2.1 &
 837                          * 11.2.1.6. Let's hope the current solution is adequate enough.
 838                          */
 839
 840                         if (is_after_msecs(fw.wlan.cab_flush_time, (CARL9170_TBTT_DELTA))) {
 841                                 wlan_cab_flush_queue(i);
 842
 843                                 /*
 844                                  * This prevents the code from sending new BC/MC frames
 845                                  * which were queued after the previous buffered traffic
 846                                  * has been sent out... They will have to wait until the
 847                                  * next DTIM beacon comes along.
 848                                  */
 849                                 fw.wlan.cab_flush_trigger[i] = CARL9170_CAB_TRIGGER_DEFER;
 850                         }
 851                 }
 852
 853         }
 854 }
 855 #endif /* CONFIG_CARL9170FW_CAB_QUEUE */
 856
 857 static void handle_beacon_config(void)
 858 {
 859         uint32_t bcn_count;
 860
 861         bcn_count = get(AR9170_MAC_REG_BCN_COUNT);
 862         send_cmd_to_host(4, CARL9170_RSP_BEACON_CONFIG, 0x00,
 863                          (uint8_t *) &bcn_count);
 864 }
 865
 866 static void handle_pretbtt(void)
 867 {
 868 #ifdef CONFIG_CARL9170FW_CAB_QUEUE
 869         fw.wlan.cab_flush_time = get_clock_counter();
 870 #endif /* CONFIG_CARL9170FW_CAB_QUEUE */
 871
 872 #ifdef CONFIG_CARL9170FW_RADIO_FUNCTIONS
 873         rf_psm();
 874
 875         send_cmd_to_host(4, CARL9170_RSP_PRETBTT, 0x00,
 876                          (uint8_t *) &fw.phy.psm.state);
 877 #endif /* CONFIG_CARL9170FW_RADIO_FUNCTIONS */
 878 }
 879
 880 static void handle_atim(void)
 881 {
 882         send_cmd_to_host(0, CARL9170_RSP_ATIM, 0x00, NULL);
 883 }
 884
 885 #ifdef CONFIG_CARL9170FW_DEBUG
 886 static void handle_qos(void)
 887 {
 888         /*
 889          * What is the QoS Bit used for?
 890          * Is it only an indicator for TXOP & Burst, or
 891          * should we do something here?
 892          */
 893 }
 894
 895 static void handle_radar(void)
 896 {
 897         send_cmd_to_host(0, CARL9170_RSP_RADAR, 0x00, NULL);
 898 }
 899 #endif /* CONFIG_CARL9170FW_DEBUG */
 900
 901 static void wlan_janitor(void)
 902 {
 903 #ifdef CONFIG_CARL9170FW_CAB_QUEUE
 904         wlan_send_buffered_cab();
 905 #endif /* CONFIG_CARL9170FW_CAB_QUEUE */
 906
 907         wlan_send_buffered_tx_status();
 908
 909         wlan_send_buffered_ba();
 910
 911         wol_janitor();
 912 }
 913
 914 void handle_wlan(void)
 915 {
 916         uint32_t intr;
 917
 918         intr = get(AR9170_MAC_REG_INT_CTRL);
 919         /* ACK Interrupt */
 920         set(AR9170_MAC_REG_INT_CTRL, intr);
 921
 922 #define HANDLER(intr, flag, func)                       \
 923         do {                                            \
 924                 if ((intr & flag) != 0) {               \
 925                         func();                         \
 926                 }                                       \
 927         } while (0)
 928
 929         intr |= fw.wlan.soft_int;
 930         fw.wlan.soft_int = 0;
 931
 932         HANDLER(intr, AR9170_MAC_INT_PRETBTT, handle_pretbtt);
 933
 934         HANDLER(intr, AR9170_MAC_INT_ATIM, handle_atim);
 935
 936         HANDLER(intr, AR9170_MAC_INT_RXC, handle_rx);
 937
 938         HANDLER(intr, (AR9170_MAC_INT_TXC | AR9170_MAC_INT_RETRY_FAIL),
 939                 handle_tx_completion);
 940
 941 #ifdef CONFIG_CARL9170FW_DEBUG
 942         HANDLER(intr, AR9170_MAC_INT_QOS, handle_qos);
 943
 944         HANDLER(intr, AR9170_MAC_INT_RADAR, handle_radar);
 945 #endif /* CONFIG_CARL9170FW_DEBUG */
 946
 947         HANDLER(intr, AR9170_MAC_INT_CFG_BCN, handle_beacon_config);
 948
 949         if (unlikely(intr))
 950                 DBG("Unhandled Interrupt %x\n", (unsigned int) intr);
 951
 952         wlan_janitor();
 953
 954 #undef HANDLER
 955 }
 956
 957 enum {
 958         CARL9170FW_TX_MAC_BUMP = 4,
 959         CARL9170FW_TX_MAC_DEBUG = 6,
 960         CARL9170FW_TX_MAC_RESET = 7,
 961 };
 962
 963 static void wlan_check_hang(void)
 964 {
 965         struct dma_desc *desc;
 966         int i;
 967
 968         for (i = AR9170_TXQ_SPECIAL; i >= AR9170_TXQ0; i--) {
 969                 if (queue_empty(&fw.wlan.tx_queue[i])) {
 970                         /* Nothing to do here... move along */
 971                         continue;
 972                 }
 973
 974                 /* fetch the current DMA queue position */
 975                 desc = (struct dma_desc *)get_wlan_txq_addr(i);
 976
 977                 /* Stuck frame detection */
 978                 if (unlikely(DESC_PAYLOAD(desc) == fw.wlan.last_super[i])) {
 979                         fw.wlan.last_super_num[i]++;
 980
 981                         if (unlikely(fw.wlan.last_super_num[i] >= CARL9170FW_TX_MAC_RESET)) {
 982                                 /*
 983                                  * schedule MAC reset (aka OFF/ON => dead)
 984                                  *
 985                                  * This will almost certainly kill
 986                                  * the device for good, but it's the
 987                                  * recommended thing to do...
 988                                  */
 989
 990                                 fw.wlan.mac_reset++;
 991                         }
 992
 993 #ifdef CONFIG_CARL9170FW_DEBUG
 994                         if (unlikely(fw.wlan.last_super_num[i] >= CARL9170FW_TX_MAC_DEBUG)) {
 995                                 /*
 996                                  * Sigh, the queue is almost certainly
 997                                  * dead. Dump the queue content to the
 998                                  * user, maybe we find out why it got
 999                                  * so stuck.
1000                                  */
1001
1002                                 wlan_dump_queue(i);
1003                         }
1004 #endif /* CONFIG_CARL9170FW_DEBUG */
1005
1006 #ifdef CONFIG_CARL9170FW_DMA_QUEUE_BUMP
1007                         if (unlikely(fw.wlan.last_super_num[i] >= CARL9170FW_TX_MAC_BUMP)) {
1008                                 /*
1009                                  * Hrrm, bump the queue a bit.
1010                                  * maybe this will get it going again.
1011                                  */
1012
1013                                 wlan_dma_bump(i);
1014                                 wlan_trigger(BIT(i));
1015                         }
1016 #endif /* CONFIG_CARL9170FW_DMA_QUEUE_BUMP */
1017                 } else {
1018                         /* Nothing stuck */
1019                         fw.wlan.last_super[i] = DESC_PAYLOAD(desc);
1020                         fw.wlan.last_super_num[i] = 0;
1021                 }
1022         }
1023 }
1024
1025 #ifdef CONFIG_CARL9170FW_FW_MAC_RESET
1026 /*
1027  * NB: Resetting the MAC is a two-edged sword.
1028  * On most occasions, it does what it is supposed to do.
1029  * But there is a chance that this will make it
1030  * even worse and the radio dies silently.
1031  */
1032 static void wlan_mac_reset(void)
1033 {
1034         uint32_t val;
1035         uint32_t agg_wait_counter;
1036         uint32_t agg_density;
1037         uint32_t bcn_start_addr;
1038         uint32_t rctl, rcth;
1039         uint32_t cam_mode;
1040         uint32_t ack_power;
1041         uint32_t rts_cts_tpc;
1042         uint32_t rts_cts_rate;
1043         int i;
1044
1045 #ifdef CONFIG_CARL9170FW_RADIO_FUNCTIONS
1046         uint32_t rx_BB;
1047 #endif /* CONFIG_CARL9170FW_RADIO_FUNCTIONS */
1048
1049 #ifdef CONFIG_CARL9170FW_NOISY_MAC_RESET
1050         INFO("MAC RESET");
1051 #endif /* CONFIG_CARL9170FW_NOISY_MAC_RESET */
1052
1053         /* Save aggregation parameters */
1054         agg_wait_counter = get(AR9170_MAC_REG_AMPDU_FACTOR);
1055         agg_density = get(AR9170_MAC_REG_AMPDU_DENSITY);
1056
1057         bcn_start_addr = get(AR9170_MAC_REG_BCN_ADDR);
1058
1059         cam_mode = get(AR9170_MAC_REG_CAM_MODE);
1060         rctl = get(AR9170_MAC_REG_CAM_ROLL_CALL_TBL_L);
1061         rcth = get(AR9170_MAC_REG_CAM_ROLL_CALL_TBL_H);
1062
1063         ack_power = get(AR9170_MAC_REG_ACK_TPC);
1064         rts_cts_tpc = get(AR9170_MAC_REG_RTS_CTS_TPC);
1065         rts_cts_rate = get(AR9170_MAC_REG_RTS_CTS_RATE);
1066
1067 #ifdef CONFIG_CARL9170FW_RADIO_FUNCTIONS
1068         /* 0x1c8960 write only */
1069         rx_BB = get(AR9170_PHY_REG_SWITCH_CHAIN_0);
1070 #endif /* CONFIG_CARL9170FW_RADIO_FUNCTIONS */
1071
1072         /* TX/RX must be stopped by now */
1073         val = get(AR9170_MAC_REG_POWER_STATE_CTRL);
1074
1075         val |= AR9170_MAC_POWER_STATE_CTRL_RESET;
1076
1077         /*
1078          * Manipulate CCA threshold to stop transmission
1079          *
1080          * set(AR9170_PHY_REG_CCA_THRESHOLD, 0x300);
1081          */
1082
1083         /*
1084          * check Rx state in 0(idle) 9(disable)
1085          *
1086          * chState = (get(AR9170_MAC_REG_MISC_684) >> 16) & 0xf;
1087          * while( (chState != 0) && (chState != 9)) {
1088          *      chState = (get(AR9170_MAC_REG_MISC_684) >> 16) & 0xf;
1089          * }
1090          */
1091
1092         set(AR9170_MAC_REG_POWER_STATE_CTRL, val);
1093
1094         delay(2);
1095
1096         /* Restore aggregation parameters */
1097         set(AR9170_MAC_REG_AMPDU_FACTOR, agg_wait_counter);
1098         set(AR9170_MAC_REG_AMPDU_DENSITY, agg_density);
1099
1100         set(AR9170_MAC_REG_BCN_ADDR, bcn_start_addr);
1101         set(AR9170_MAC_REG_CAM_MODE, cam_mode);
1102         set(AR9170_MAC_REG_CAM_ROLL_CALL_TBL_L, rctl);
1103         set(AR9170_MAC_REG_CAM_ROLL_CALL_TBL_H, rcth);
1104
1105         set(AR9170_MAC_REG_RTS_CTS_TPC, rts_cts_tpc);
1106         set(AR9170_MAC_REG_ACK_TPC, ack_power);
1107         set(AR9170_MAC_REG_RTS_CTS_RATE, rts_cts_rate);
1108
1109 #ifdef CONFIG_CARL9170FW_RADIO_FUNCTIONS
1110         set(AR9170_PHY_REG_SWITCH_CHAIN_2, rx_BB);
1111 #endif /* CONFIG_CARL9170FW_RADIO_FUNCTIONS */
1112
1113         /*
1114          * Manipulate CCA threshold to resume transmission
1115          *
1116          * set(AR9170_PHY_REG_CCA_THRESHOLD, 0x0);
1117          */
1118
1119         val = AR9170_DMA_TRIGGER_RXQ;
1120         /* Reinitialize all WLAN TX DMA queues. */
1121         for (i = AR9170_TXQ_SPECIAL; i >= AR9170_TXQ0; i--) {
1122                 struct dma_desc *iter;
1123
1124                 __for_each_desc_bits(iter, &fw.wlan.tx_queue[i], AR9170_OWN_BITS_SW);
1125
1126                 /* kill the stuck frame */
1127                 if (!is_terminator(&fw.wlan.tx_queue[i], iter) &&
1128                     fw.wlan.last_super_num[i] >= CARL9170FW_TX_MAC_RESET &&
1129                     fw.wlan.last_super[i] == DESC_PAYLOAD(iter)) {
1130                         struct carl9170_tx_superframe *super = get_super(iter);
1131
1132                         iter->status = AR9170_OWN_BITS_SW;
1133                         /*
1134                          * Mark the frame as failed.
1135                          * The BAFAIL flag allows the frame to sail through
1136                          * wlan_tx_status without much "unstuck" trouble.
1137                          */
1138                         iter->ctrl &= ~(AR9170_CTRL_FAIL);
1139                         iter->ctrl |= AR9170_CTRL_BAFAIL;
1140
1141                         super->s.cnt = CARL9170_TX_MAX_RATE_TRIES;
1142                         super->s.rix = CARL9170_TX_MAX_RETRY_RATES;
1143
1144                         fw.wlan.last_super_num[i] = 0;
1145                         fw.wlan.last_super[i] = NULL;
1146                         iter = iter->lastAddr->nextAddr;
1147                 }
1148
1149                 set_wlan_txq_dma_addr(i, (uint32_t) iter);
1150                 if (!is_terminator(&fw.wlan.tx_queue[i], iter))
1151                         val |= BIT(i);
1152
1153                 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]),
1154                      fw.wlan.tx_queue[i].head, fw.wlan.tx_queue[i].terminator,
1155                      get_wlan_txq_addr(i), iter, iter->ctrl, iter->status);
1156         }
1157
1158         fw.wlan.soft_int |= AR9170_MAC_INT_RXC | AR9170_MAC_INT_TXC |
1159                             AR9170_MAC_INT_RETRY_FAIL;
1160
1161         set(AR9170_MAC_REG_DMA_RXQ_ADDR, (uint32_t) fw.wlan.rx_queue.head);
1162         wlan_trigger(val);
1163 }
1164 #else
1165 static void wlan_mac_reset(void)
1166 {
1167         /* The driver takes care of reinitializing the device */
1168         BUG("MAC RESET");
1169 }
1170 #endif /* CONFIG_CARL9170FW_FW_MAC_RESET */
1171
1172 void __cold wlan_timer(void)
1173 {
1174         unsigned int cached_mac_reset;
1175
1176         cached_mac_reset = fw.wlan.mac_reset;
1177
1178         /* TX Queue Hang check */
1179         wlan_check_hang();
1180
1181         /* RX Overrun check */
1182         wlan_check_rx_overrun();
1183
1184         if (unlikely(fw.wlan.mac_reset >= CARL9170_MAC_RESET_RESET)) {
1185                 wlan_mac_reset();
1186                 fw.wlan.mac_reset = CARL9170_MAC_RESET_OFF;
1187         } else {
1188                 if (fw.wlan.mac_reset && cached_mac_reset == fw.wlan.mac_reset)
1189                         fw.wlan.mac_reset--;
1190         }
1191 }