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, 2010 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
  35 static void wlan_txunstuck(unsigned int queue)
  36 {
  37         set_wlan_txq_dma_addr(queue, ((uint32_t) fw.wlan.tx_queue[queue].head) | 1);
  38         wlan_trigger(BIT(queue));
  39 }
  40
  41 static void wlan_txupdate(unsigned int queue)
  42 {
  43         set_wlan_txq_dma_addr(queue, ((uint32_t) fw.wlan.tx_queue[queue].head));
  44         wlan_trigger(BIT(queue));
  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
  73 #ifdef CONFIG_CARL9170FW_DEBUG
  74 static void wlan_dump_queue(unsigned int qidx)
  75 {
  76
  77         struct dma_desc *desc;
  78         struct carl9170_tx_superframe *super;
  79         int entries = 0;
  80
  81         __for_each_desc(desc, &fw.wlan.tx_queue[qidx]) {
  82                 super = get_super(desc);
  83                 DBG("%d: %p s:%x c:%x tl:%x ds:%x n:%p l:%p ", entries, desc,
  84                     desc->status, desc->ctrl, desc->totalLen,
  85                     desc->dataSize, desc->nextAddr, desc->lastAddr);
  86
  87                 DBG("c:%x tr:%d ri:%d l:%x m:%x p:%x fc:%x",
  88                     super->s.cookie, super->s.cnt, super->s.rix,
  89                     super->f.hdr.length, super->f.hdr.mac.set,
  90                     (unsigned int) le32_to_cpu(super->f.hdr.phy.set),
  91                     super->f.data.i3e.frame_control);
  92
  93                 entries++;
  94         }
  95
  96         desc = get_wlan_txq_addr(qidx);
  97
  98         DBG("Queue: %d: te:%d td:%d h:%p c:%p t:%p",
  99             qidx, entries, queue_len(&fw.wlan.tx_queue[qidx]),
 100             fw.wlan.tx_queue[qidx].head,
 101             desc, fw.wlan.tx_queue[qidx].terminator);
 102
 103         DBG("HW: t:%x s:%x ac:%x c:%x",
 104             (unsigned int) get(AR9170_MAC_REG_DMA_TRIGGER),
 105             (unsigned int) get(AR9170_MAC_REG_DMA_STATUS),
 106             (unsigned int) get(AR9170_MAC_REG_AMPDU_COUNT),
 107             (unsigned int) get(AR9170_MAC_REG_DMA_TXQX_ADDR_CURR));
 108 }
 109 #endif /* CONFIG_CARL9170FW_DEBUG */
 110
 111 static void wlan_send_buffered_tx_status(void)
 112 {
 113         unsigned int len;
 114
 115         while (fw.wlan.tx_status_pending) {
 116                 len = min((unsigned int)fw.wlan.tx_status_pending,
 117                           CARL9170_RSP_TX_STATUS_NUM);
 118                 len = min(len, CARL9170_TX_STATUS_NUM - fw.wlan.tx_status_head_idx);
 119
 120                 /*
 121                  * rather than memcpy each individual request into a large buffer,
 122                  * we _splice_ them all together.
 123                  *
 124                  * The only downside is however that we have to be careful around
 125                  * the edges of the tx_status_cache.
 126                  *
 127                  * Note:
 128                  * Each tx_status is about 2 bytes. However every command package
 129                  * must have a size which is a multiple of 4.
 130                  */
 131
 132                 send_cmd_to_host((len * sizeof(struct carl9170_tx_status) + 3) & ~3,
 133                                  CARL9170_RSP_TXCOMP, len, (void *)
 134                                  &fw.wlan.tx_status_cache[fw.wlan.tx_status_head_idx]);
 135
 136                 fw.wlan.tx_status_pending -= len;
 137                 fw.wlan.tx_status_head_idx += len;
 138                 fw.wlan.tx_status_head_idx %= CARL9170_TX_STATUS_NUM;
 139         }
 140 }
 141
 142 static struct carl9170_tx_status *wlan_get_tx_status_buffer(void)
 143 {
 144         struct carl9170_tx_status *tmp;
 145
 146         tmp = &fw.wlan.tx_status_cache[fw.wlan.tx_status_tail_idx++];
 147         fw.wlan.tx_status_tail_idx %= CARL9170_TX_STATUS_NUM;
 148
 149         if (fw.wlan.tx_status_pending == CARL9170_TX_STATUS_NUM)
 150                 wlan_send_buffered_tx_status();
 151
 152         fw.wlan.tx_status_pending++;
 153
 154         return tmp;
 155 }
 156
 157 /* generate _aggregated_ tx_status for the host */
 158 static void wlan_tx_complete(struct carl9170_tx_superframe *super,
 159                              bool txs)
 160 {
 161         struct carl9170_tx_status *status;
 162
 163         status = wlan_get_tx_status_buffer();
 164
 165         /*
 166          * The *unique* cookie and AC_ID is used by the driver for
 167          * frame lookup.
 168          */
 169         status->cookie = super->s.cookie;
 170         status->queue = super->s.queue;
 171
 172         /*
 173          * This field holds the number of tries of the rate in
 174          * the rate index field (rix).
 175          */
 176         status->rix = super->s.rix;
 177         status->tries = super->s.cnt;
 178         status->success = (txs) ? 1 : 0;
 179 }
 180
 181 static bool wlan_tx_consume_retry(struct carl9170_tx_superframe *super)
 182 {
 183         /* check if this was the last possible retry with this rate */
 184         if (unlikely(super->s.cnt >= super->s.ri[super->s.rix].tries)) {
 185                 /* end of the road - indicate tx failure */
 186                 if (unlikely(super->s.rix == CARL9170_TX_MAX_RETRY_RATES))
 187                         return false;
 188
 189                 /* check if there are alternative rates available */
 190                 if (!super->s.rr[super->s.rix].set)
 191                         return false;
 192
 193                 /* try next retry rate */
 194                 super->f.hdr.phy.set = super->s.rr[super->s.rix].set;
 195
 196                 /* finally - mark the old rate as USED */
 197                 super->s.rix++;
 198
 199                 /* update MAC flags */
 200                 super->f.hdr.mac.erp_prot = super->s.ri[super->s.rix].erp_prot;
 201
 202                 /* reinitialize try counter */
 203                 super->s.cnt = 1;
 204         } else {
 205                 /* just increase retry counter */
 206                 super->s.cnt++;
 207         }
 208
 209         return true;
 210 }
 211
 212 /* for all tries */
 213 static void __wlan_tx(struct dma_desc *desc)
 214 {
 215         struct carl9170_tx_superframe *super = get_super(desc);
 216 #ifdef CONFIG_CARL9170FW_NORMAL_TX_RX
 217         unsigned int queue = super->s.queue;
 218 #endif /* CONFIG_CARL9170FW_LOOPBACK */
 219
 220         if (unlikely(super->s.fill_in_tsf)) {
 221                 struct ieee80211_mgmt *mgmt = (void *) &super->f.data.i3e;
 222                 uint32_t *tsf = (uint32_t *) &mgmt->u.probe_resp.timestamp;
 223
 224                 /*
 225                  * Truth be told: this is a hack.
 226                  *
 227                  * The *real* TSF is definitely going to be higher/older.
 228                  * But this hardware emulation code is head and shoulders
 229                  * above anything a driver can possibly do.
 230                  *
 231                  * (even, if it's got an accurate atomic clock source).
 232                  */
 233
 234                 read_tsf(tsf);
 235         }
 236
 237 #if (defined CONFIG_CARL9170FW_LOOPBACK) || (defined CONFIG_CARL9170FW_DISCARD)
 238         wlan_tx_complete(super, true);
 239         unhide_super(desc);
 240 # ifdef CONFIG_CARL9170FW_LOOPBACK
 241         dma_put(&fw.pta.up_queue, desc);
 242         up_trigger();
 243 # elif CONFIG_CARL9170FW_DISCARD
 244         dma_reclaim(&fw.pta.down_queue, desc);
 245         down_trigger();
 246 # endif
 247 #else /* CONFIG_CARL9170FW_LOOPBACK */
 248
 249 # if ((defined CONFIG_CARL9170FW_DEBUG) && (defined CONFIG_CARL9170FW_PSM))
 250         BUG_ON(fw.phy.psm.state != CARL9170_PSM_WAKE);
 251 # endif /* CONFIG_CARL9170FW_DEBUG && CONFIG_CARL9170FW_PSM */
 252
 253         /* insert desc into the right queue */
 254         dma_put(&fw.wlan.tx_queue[queue], desc);
 255         wlan_trigger(BIT(queue));
 256 #endif /* CONFIG_CARL9170FW_LOOPBACK */
 257 }
 258
 259 /* prepares frame for the first transmission */
 260 static void _wlan_tx(struct dma_desc *desc)
 261 {
 262         struct carl9170_tx_superframe *super = get_super(desc);
 263
 264         if (unlikely(super->s.ampdu_commit_density)) {
 265                 set(AR9170_MAC_REG_AMPDU_DENSITY,
 266                     MOD_VAL(AR9170_MAC_AMPDU_DENSITY,
 267                             get(AR9170_MAC_REG_AMPDU_DENSITY),
 268                             super->s.ampdu_density));
 269         }
 270
 271         if (unlikely(super->s.ampdu_commit_factor)) {
 272                 set(AR9170_MAC_REG_AMPDU_FACTOR,
 273                     MOD_VAL(AR9170_MAC_AMPDU_FACTOR,
 274                             get(AR9170_MAC_REG_AMPDU_FACTOR),
 275                             8 << super->s.ampdu_factor));
 276         }
 277
 278         __wlan_tx(desc);
 279 }
 280
 281 /* propagate transmission status back to the driver */
 282 static bool wlan_tx_status(struct dma_queue *queue,
 283                            struct dma_desc *desc)
 284 {
 285         struct ar9170_tx_frame *frame = DESC_PAYLOAD(desc);
 286         struct carl9170_tx_superframe *super = get_super(desc);
 287         struct ieee80211_hdr *hdr = &super->f.data.i3e;
 288         unsigned int qidx = super->s.queue;
 289         bool txfail, success;
 290
 291         success = true;
 292
 293         if (!!(desc->ctrl & AR9170_CTRL_FAIL)) {
 294                 txfail = !!(desc->ctrl & AR9170_CTRL_TXFAIL);
 295
 296                 /* reset retry indicator flags */
 297                 desc->ctrl &= ~(AR9170_CTRL_TXFAIL | AR9170_CTRL_BAFAIL);
 298
 299                 if (wlan_tx_consume_retry(super)) {
 300                         /*
 301                          * retry for simple and aggregated 802.11 frames.
 302                          *
 303                          * Note: We must not mess up the original frame
 304                          * order.
 305                          */
 306
 307                         if (!frame->hdr.mac.ampdu) {
 308                                 /*
 309                                  * 802.11 - 7.1.3.1.5.
 310                                  * set "Retry Field" for consecutive attempts
 311                                  *
 312                                  * Note: For AMPDU see:
 313                                  * 802.11n 9.9.1.6 "Retransmit Procedures"
 314                                  */
 315
 316                                 hdr->frame_control |= cpu_to_le16(IEEE80211_FCTL_RETRY);
 317                         }
 318
 319                         if (txfail) {
 320                                 /* Normal TX Failure */
 321
 322                                 /* demise descriptor ownership back to the hardware */
 323                                 dma_rearm(desc);
 324
 325                                 /*
 326                                  * And this will get the queue going again.
 327                                  * To understand why: you have to get the HW
 328                                  * specs... But sadly I never saw them.
 329                                  */
 330                                 wlan_txunstuck(qidx);
 331
 332                                 /* abort cycle - this is necessary due to HW design */
 333                                 return false;
 334                         } else {
 335                                 /* (HT-) BlockACK failure */
 336
 337                                 /*
 338                                  * Unlink the failed attempt and put it into
 339                                  * the retry queue. The caller routine must
 340                                  * be aware of this so the frames don't get lost.
 341                                  */
 342
 343                                 dma_unlink_head(queue);
 344 #ifdef CONFIG_CARL9170FW_DELAYED_TX
 345                                 dma_put(&fw.wlan.tx_retry, desc);
 346 #else
 347                                 __wlan_tx(desc);
 348 #endif /* CONFIG_CARL9170FW_DELAYED_TX */
 349                                 return true;
 350                         }
 351                 } else {
 352                         /* out of frame attempts - discard frame */
 353                         success = false;
 354                 }
 355         }
 356
 357         dma_unlink_head(queue);
 358         if (txfail) {
 359                 /*
 360                  * Issue the queue bump,
 361                  * We need to do this in case this was the frame's last
 362                  * possible retry attempt and it unfortunately: it failed.
 363                  */
 364
 365                 wlan_txunstuck(qidx);
 366         }
 367
 368         unhide_super(desc);
 369
 370         /* update hangcheck */
 371         fw.wlan.last_tx_desc_num[qidx] = 0;
 372
 373 #ifdef CONFIG_CARL9170FW_HANDLE_BACK_REQ
 374         if (unlikely(super == (void *) &dma_mem.reserved.ba)) {
 375                 fw.wlan.ba_desc = desc;
 376                 fw.wlan.ba_desc_available = 1;
 377                 return true;
 378         }
 379 #endif /* CONFIG_CARL9170FW_HANDLE_BACK_REQ */
 380
 381         wlan_tx_complete(super, success);
 382
 383 #ifdef CONFIG_CARL9170FW_CAB_QUEUE
 384         if (unlikely(super->s.cab))
 385                 fw.wlan.cab_queue_len--;
 386 #endif /* CONFIG_CARL9170FW_CAB_QUEUE */
 387
 388         /* recycle freed descriptors */
 389         dma_reclaim(&fw.pta.down_queue, desc);
 390         down_trigger();
 391         return true;
 392 }
 393
 394 static void handle_tx_completion(void)
 395 {
 396         struct dma_desc *desc;
 397         unsigned int i;
 398
 399         for (i = 0; i < __AR9170_NUM_TX_QUEUES; i++) {
 400                 __while_desc_bits(desc, &fw.wlan.tx_queue[i], AR9170_OWN_BITS_SW) {
 401                         if (!wlan_tx_status(&fw.wlan.tx_queue[i], desc)) {
 402                                 /* termination requested. */
 403                                 break;
 404                         }
 405                 }
 406
 407 #ifdef CONFIG_CARL9170FW_DELAYED_TX
 408                 for_each_desc(desc, &fw.wlan.tx_retry)
 409                         __wlan_tx(desc);
 410
 411                 for_each_desc(desc, &fw.wlan.tx_delay[i])
 412                         _wlan_tx(desc);
 413 #endif /* CONFIG_CARL9170FW_DELAYED_TX */
 414         }
 415 }
 416
 417 void __hot wlan_tx(struct dma_desc *desc)
 418 {
 419         struct carl9170_tx_superframe *super = DESC_PAYLOAD(desc);
 420
 421         /* initialize rate control struct */
 422         super->s.rix = 0;
 423         super->s.cnt = 1;
 424         hide_super(desc);
 425
 426 #ifdef CONFIG_CARL9170FW_DELAYED_TX
 427         if (!queue_empty(&fw.wlan.tx_queue[super->s.queue])) {
 428                 dma_put(&fw.wlan.tx_delay[super->s.queue], desc);
 429                 return;
 430         }
 431 #endif /* CONFIG_CARL9170FW_DELAYED_TX */
 432
 433 #ifdef CONFIG_CARL9170FW_CAB_QUEUE
 434         if (unlikely(super->s.cab)) {
 435                 fw.wlan.cab_queue_len++;
 436                 dma_put(&fw.wlan.cab_queue, desc);
 437                 return;
 438         }
 439 #endif /* CONFIG_CARL9170FW_CAB_QUEUE */
 440
 441         _wlan_tx(desc);
 442 }
 443
 444 #ifdef CONFIG_CARL9170FW_HANDLE_BACK_REQ
 445 static void wlan_send_buffered_ba(void)
 446 {
 447         struct carl9170_tx_ba_superframe *baf = &dma_mem.reserved.ba.ba;
 448         struct ieee80211_ba *ba = (struct ieee80211_ba *) &baf->f.ba;
 449         struct carl9170_bar_ctx *ctx;
 450
 451         if (likely(fw.wlan.ba_head_idx == fw.wlan.ba_tail_idx))
 452                 return;
 453
 454         /* there's no point to continue when the ba_desc is not available. */
 455         if (!fw.wlan.ba_desc_available)
 456                 return;
 457
 458         ctx = &fw.wlan.ba_cache[fw.wlan.ba_head_idx % CONFIG_CARL9170FW_BACK_REQS_NUM];
 459         fw.wlan.ba_head_idx++;
 460
 461         /* Format BlockAck */
 462         fw.wlan.ba_desc->status = 0;
 463         fw.wlan.ba_desc->ctrl = AR9170_CTRL_FS_BIT | AR9170_CTRL_LS_BIT;
 464         fw.wlan.ba_desc_available = 0;
 465         fw.wlan.ba_desc->nextAddr = fw.wlan.ba_desc->lastAddr =
 466                 fw.wlan.ba_desc;
 467
 468         baf->s.len = fw.wlan.ba_desc->totalLen = fw.wlan.ba_desc->dataSize =
 469                 sizeof(struct carl9170_tx_superdesc) +
 470                 sizeof(struct ar9170_tx_hwdesc) +
 471                 sizeof(struct ieee80211_ba);
 472
 473         baf->s.ri[0].tries = 3;
 474         baf->s.queue = 0;
 475         baf->f.hdr.length = sizeof(struct ieee80211_ba) + FCS_LEN;
 476
 477         /* HW Duration / Backoff */
 478         baf->f.hdr.mac.backoff = 1;
 479         baf->f.hdr.mac.hw_duration = 1;
 480
 481         /* take the TX rate from the RX'd BAR */
 482         baf->f.hdr.phy.set = ctx->phy;
 483         baf->f.hdr.phy.tx_power = 29; /* 14.5 dBm */
 484
 485         /* format outgoing BA */
 486         ba->frame_control = cpu_to_le16(IEEE80211_FTYPE_CTL | IEEE80211_STYPE_BACK);
 487         ba->duration = cpu_to_le16(0);
 488         memcpy(ba->ta, ctx->ta, 6);
 489         memcpy(ba->ra, ctx->ra, 6);
 490
 491         /*
 492          * Unfortunately, we cannot look into the hardware's scoreboard.
 493          * Therefore we have to proceed as described in 802.11n 9.10.7.5
 494          * and send a null BlockAck.
 495          */
 496         memset(ba->bitmap, 0x0, sizeof(ba->bitmap));
 497
 498         /*
 499          * NB:
 500          * not entirely sure if this is 100% correct?!
 501          */
 502         ba->control = ctx->control | cpu_to_le16(1);
 503         ba->start_seq_num = ctx->start_seq_num;
 504
 505         wlan_tx(fw.wlan.ba_desc);
 506 }
 507
 508 static struct carl9170_bar_ctx *wlan_get_bar_cache_buffer(void)
 509 {
 510         struct carl9170_bar_ctx *tmp;
 511
 512         /* expire oldest entry, if we ran out of ba_ctx' */
 513         if (fw.wlan.ba_head_idx + CONFIG_CARL9170FW_BACK_REQS_NUM < fw.wlan.ba_tail_idx)
 514                 fw.wlan.ba_head_idx++;
 515
 516         tmp = &fw.wlan.ba_cache[fw.wlan.ba_tail_idx % CONFIG_CARL9170FW_BACK_REQS_NUM];
 517         fw.wlan.ba_tail_idx++;
 518
 519         return tmp;
 520 }
 521
 522 static void handle_bar(struct dma_desc *desc)
 523 {
 524         struct ieee80211_hdr *hdr;
 525         struct ieee80211_bar *bar;
 526         struct carl9170_bar_ctx *ctx;
 527
 528         hdr = ar9170_get_rx_i3e(desc);
 529
 530         /* check if this is a BAR for us */
 531         if (likely(!ieee80211_is_back_req(hdr->frame_control)))
 532                 return ;
 533
 534         if (unlikely(ar9170_get_rx_macstatus_error(desc))) {
 535                 /*
 536                  * This check does a number of things:
 537                  * 1. checks if the frame is in good nick
 538                  * 2. checks if the RA (MAC) matches
 539                  */
 540                 return ;
 541         }
 542
 543         if (unlikely(ar9170_get_rx_mpdu_len(desc) <
 544             sizeof(struct ieee80211_bar))) {
 545                 /*
 546                  * Sneaky, corrupted BARs... but not with us!
 547                  */
 548
 549                 return ;
 550         }
 551
 552         bar = (void *) hdr;
 553
 554         if ((bar->control & cpu_to_le16(IEEE80211_BAR_CTRL_MULTI_TID)) ||
 555             !(bar->control & cpu_to_le16(IEEE80211_BAR_CTRL_CBMTID_COMPRESSED_BA))) {
 556                 /* not implemented yet */
 557
 558                 return ;
 559         }
 560
 561         ctx = wlan_get_bar_cache_buffer();
 562
 563         /* Brilliant! The BAR provides all necessary MACs! */
 564         memcpy(ctx->ra, bar->ta, 6);
 565         memcpy(ctx->ta, bar->ra, 6);
 566
 567         /*
 568          * NB:
 569          * not entirely sure if this is 100% correct to force the
 570          * imm ack bit or not...
 571          */
 572         ctx->control = bar->control | cpu_to_le16(1);
 573         ctx->start_seq_num = bar->start_seq_num;
 574         ctx->phy = ar9170_rx_to_phy(desc);
 575         if (unlikely(!ctx->phy)) {
 576                 /* provide a backup, in case ar9170_rx_to_phy fails */
 577                 ctx->phy = cpu_to_le32(0x2cc301);
 578         }
 579 }
 580 #endif /* CONFIG_CARL9170FW_HANDLE_BACK_REQ */
 581
 582 static void wlan_check_rx_overrun(void)
 583 {
 584         uint32_t overruns, total;
 585
 586         fw.wlan.rx_total += total = get(AR9170_MAC_REG_RX_TOTAL);
 587         fw.wlan.rx_overruns += overruns = get(AR9170_MAC_REG_RX_OVERRUN);
 588         if (unlikely(overruns)) {
 589                 if (overruns == total) {
 590                         DBG("RX Overrun");
 591                         fw.wlan.mac_reset++;
 592                 }
 593         }
 594 }
 595
 596 static void handle_rx(void)
 597 {
 598         struct dma_desc *desc;
 599
 600         wlan_check_rx_overrun();
 601
 602         for_each_desc_not_bits(desc, &fw.wlan.rx_queue, AR9170_OWN_BITS_HW) {
 603                 if (unlikely(desc->totalLen < 26 ||
 604                     desc->totalLen > CONFIG_CARL9170FW_RX_FRAME_LEN)) {
 605                         /*
 606                          * This frame is too damaged to do anything
 607                          * useful with it.
 608                          */
 609                         dma_reclaim(&fw.wlan.rx_queue, desc);
 610                         _wlan_trigger(AR9170_DMA_TRIGGER_RXQ);
 611                 } else {
 612 #ifdef CONFIG_CARL9170FW_HANDLE_BACK_REQ
 613                         handle_bar(desc);
 614 #endif /* CONFIG_CARL9170FW_HANDLE_BACK_REQ */
 615
 616                         dma_put(&fw.pta.up_queue, desc);
 617                         up_trigger();
 618                 }
 619         }
 620 }
 621
 622 #ifdef CONFIG_CARL9170FW_CAB_QUEUE
 623 static uint8_t *beacon_find_ie(uint8_t ie)
 624 {
 625         struct ieee80211_mgmt *mgmt = getp(AR9170_MAC_REG_BCN_ADDR);
 626         uint8_t *pos, *end;
 627         unsigned int len;
 628
 629         len = get(AR9170_MAC_REG_BCN_LENGTH);
 630
 631         if (len < FCS_LEN + sizeof(mgmt))
 632                 return NULL;
 633
 634         pos = mgmt->u.beacon.variable;
 635         end = (uint8_t *) ((unsigned long)mgmt + (len - FCS_LEN));
 636         while (pos < end) {
 637                 if (pos + 2 + pos[1] > end)
 638                         return NULL;
 639
 640                 if (pos[0] == ie)
 641                         return pos;
 642
 643                 pos += pos[1] + 2;
 644         }
 645
 646         return NULL;
 647 }
 648
 649 static void wlan_cab_flush_queue(void)
 650 {
 651         struct dma_desc *desc;
 652         uint8_t *_ie;
 653         struct ieee80211_tim_ie *ie;
 654
 655         /*
 656          * This prevents the code from sending new BC/MC frames
 657          * which were queued after the previous buffered traffic
 658          * has been sent out... They will have to wait until the
 659          * next DTIM beacon comes along.
 660          */
 661         if (unlikely(fw.wlan.cab_flush_trigger == CARL9170_CAB_TRIGGER_DEFER))
 662                 return ;
 663
 664         _ie = beacon_find_ie(WLAN_EID_TIM);
 665         if (unlikely(!_ie))
 666                 return ;
 667
 668         ie = (struct ieee80211_tim_ie *) &_ie[2];
 669
 670         /* Ideally, check here for == AR9170_CAB_TRIGGER_ARMED */
 671         if (fw.wlan.cab_flush_trigger) {
 672                 /* move queued frames into the main tx queues */
 673                 for_each_desc(desc, &fw.wlan.cab_queue) {
 674                         struct carl9170_tx_superframe *super = get_super(desc);
 675
 676                         if (!queue_empty(&fw.wlan.cab_queue)) {
 677                                 /*
 678                                  * Set MOREDATA flag for all,
 679                                  * but the last queued frame.
 680                                  * see: 802.11-2007 11.2.1.5 f)
 681                                  *
 682                                  * This is actually the reason to why
 683                                  * we need to prevent the reentry.
 684                                  */
 685
 686                                 super->f.data.i3e.frame_control |=
 687                                         cpu_to_le16(IEEE80211_FCTL_MOREDATA);
 688                         } else {
 689                                 super->f.data.i3e.frame_control &=
 690                                         cpu_to_le16(~IEEE80211_FCTL_MOREDATA);
 691                         }
 692
 693                         /* ready to roll! */
 694                         _wlan_tx(desc);
 695                 }
 696         }
 697
 698         /* Transfer finished - waiting for tx status */
 699         fw.wlan.cab_flush_trigger = CARL9170_CAB_TRIGGER_DEFER;
 700 }
 701
 702 static void wlan_cab_modify_dtim_beacon(void)
 703 {
 704         uint8_t *_ie;
 705         struct ieee80211_tim_ie *ie;
 706
 707         _ie = beacon_find_ie(WLAN_EID_TIM);
 708         if (likely(_ie)) {
 709                 ie = (struct ieee80211_tim_ie *) &_ie[2];
 710
 711                 if (!queue_empty(&fw.wlan.cab_queue) && (ie->dtim_count == 0)) {
 712                         /* schedule DTIM transfer */
 713                         fw.wlan.cab_flush_trigger = CARL9170_CAB_TRIGGER_ARMED;
 714                 } else if ((fw.wlan.cab_queue_len == 0) && (fw.wlan.cab_flush_trigger)) {
 715                         /* undo all chances to the beacon structure */
 716                         ie->bitmap_ctrl &= ~0x1;
 717                         fw.wlan.cab_flush_trigger = CARL9170_CAB_TRIGGER_EMPTY;
 718                 }
 719
 720                 if (fw.wlan.cab_flush_trigger) {
 721                         /* Set the almighty Multicast Traffic Indication Bit. */
 722                         ie->bitmap_ctrl |= 0x1;
 723                 }
 724         }
 725 }
 726 #endif /* CONFIG_CARL9170FW_CAB_QUEUE */
 727
 728 static void handle_beacon_config(void)
 729 {
 730         uint32_t bcn_count;
 731
 732 #ifdef CONFIG_CARL9170FW_CAB_QUEUE
 733         /*
 734          * The application has now updated the relevant beacon data.
 735          * Now it should be the perfect time to apply the DTIM
 736          * multicast information.
 737          */
 738
 739         wlan_cab_modify_dtim_beacon();
 740 #endif /* CONFIG_CARL9170FW_CAB_QUEUE */
 741
 742         bcn_count = get(AR9170_MAC_REG_BCN_COUNT);
 743         send_cmd_to_host(4, CARL9170_RSP_BEACON_CONFIG, 0x00,
 744                          (uint8_t *) &bcn_count);
 745 }
 746
 747 static void handle_pretbtt(void)
 748 {
 749 #ifdef CONFIG_CARL9170FW_CAB_QUEUE
 750         fw.wlan.cab_flush_time = get_clock_counter();
 751 #endif /* CONFIG_CARL9170FW_CAB_QUEUE */
 752
 753 #ifdef CONFIG_CARL9170FW_PSM
 754         rf_psm();
 755
 756         send_cmd_to_host(4, CARL9170_RSP_PRETBTT, 0x00,
 757                          (uint8_t *) &fw.phy.psm.state);
 758 #else
 759         send_cmd_to_host(0, CARL9170_RSP_PRETBTT, 0x00, NULL);
 760 #endif /* CONFIG_CARL9170FW_PSM */
 761
 762 }
 763
 764 static void handle_atim(void)
 765 {
 766         send_cmd_to_host(0, CARL9170_RSP_ATIM, 0x00, NULL);
 767 }
 768
 769 #ifdef CONFIG_CARL9170FW_DEBUG
 770 static void handle_qos(void)
 771 {
 772         /*
 773          * What is the QoS Bit used for?
 774          * Is it only an indicator for TXOP & Burst, or
 775          * should we do something here?
 776          */
 777 }
 778
 779 static void handle_radar(void)
 780 {
 781         send_cmd_to_host(0, CARL9170_RSP_RADAR, 0x00, NULL);
 782 }
 783 #endif /* CONFIG_CARL9170FW_DEBUG */
 784
 785 static void wlan_janitor(void)
 786 {
 787 #ifdef CONFIG_CARL9170FW_CAB_QUEUE
 788         if (unlikely(fw.wlan.cab_flush_trigger)) {
 789                 /*
 790                  * This is hardcoded into carl9170usb driver.
 791                  *
 792                  * The driver must set the PRETBTT event to beacon_interval -
 793                  * CARL9170_PRETBTT_KUS (usually 6) Kus.
 794                  *
 795                  * But still, we can only do so much about 802.11-2007 9.3.2.1 &
 796                  * 11.2.1.6. Let's hope the current solution is adequate enough.
 797                  */
 798
 799                 if (is_after_msecs(fw.wlan.cab_flush_time,
 800                     (CARL9170_TBTT_DELTA))) {
 801                         wlan_cab_flush_queue();
 802                 }
 803         }
 804 #endif /* CONFIG_CARL9170FW_CAB_QUEUE */
 805
 806 #ifdef CONFIG_CARL9170FW_DELAYED_TX
 807         if (fw.wlan.tx_trigger) {
 808                 _wlan_trigger(fw.wlan.tx_trigger);
 809                 fw.wlan.tx_trigger = 0;
 810         }
 811 #endif /* CONFIG_CARL9170FW_DELAYED_TX */
 812
 813         wlan_send_buffered_tx_status();
 814
 815 #ifdef CONFIG_CARL9170FW_HANDLE_BACK_REQ
 816         wlan_send_buffered_ba();
 817 #endif /* CONFIG_CARL9170FW_HANDLE_BACK_REQ */
 818 }
 819
 820 void handle_wlan(void)
 821 {
 822         uint32_t intr;
 823
 824         intr = get(AR9170_MAC_REG_INT_CTRL);
 825         /* ACK Interrupt */
 826         set(AR9170_MAC_REG_INT_CTRL, intr);
 827
 828 #define HANDLER(intr, flag, func)                       \
 829         do {                                            \
 830                 if ((intr & flag) != 0) {               \
 831                         func();                         \
 832                 }                                       \
 833         } while (0)
 834
 835         HANDLER(intr, AR9170_MAC_INT_PRETBTT, handle_pretbtt);
 836
 837         HANDLER(intr, AR9170_MAC_INT_ATIM, handle_atim);
 838
 839         HANDLER(intr, AR9170_MAC_INT_RXC, handle_rx);
 840
 841         HANDLER(intr, (AR9170_MAC_INT_TXC | AR9170_MAC_INT_RETRY_FAIL),
 842                 handle_tx_completion);
 843
 844 #ifdef CONFIG_CARL9170FW_DEBUG
 845         HANDLER(intr, AR9170_MAC_INT_QOS, handle_qos);
 846
 847         HANDLER(intr, AR9170_MAC_INT_RADAR, handle_radar);
 848 #endif /* CONFIG_CARL9170FW_DEBUG */
 849
 850         HANDLER(intr, AR9170_MAC_INT_CFG_BCN, handle_beacon_config);
 851
 852         if (unlikely(intr))
 853                 DBG("Unhandled Interrupt %x\n", (unsigned int) intr);
 854
 855         wlan_janitor();
 856
 857 #undef HANDLER
 858 }
 859
 860 static void wlan_check_hang(void)
 861 {
 862         struct dma_desc *desc;
 863         unsigned int i;
 864
 865         for (i = 0; i < __AR9170_NUM_TX_QUEUES; i++) {
 866                 if (queue_empty(&fw.wlan.tx_queue[i])) {
 867                         /* Nothing to do here... move along */
 868                         continue;
 869                 }
 870
 871                 /* fetch the current DMA queue position */
 872                 desc = get_wlan_txq_addr(i);
 873
 874                 /* Stuck frame detection */
 875                 if (unlikely(desc == fw.wlan.last_tx_desc[i])) {
 876                         fw.wlan.last_tx_desc_num[i]++;
 877
 878                         if (unlikely(fw.wlan.last_tx_desc_num[i] > 6)) {
 879                                 /*
 880                                  * schedule MAC reset (aka OFF/ON => dead)
 881                                  *
 882                                  * This will almost certainly kill
 883                                  * the device for good, but it's the
 884                                  * recommended thing to do...
 885                                  */
 886
 887                                 fw.wlan.mac_reset++;
 888                         }
 889
 890 #ifdef CONFIG_CARL9170FW_DEBUG
 891                         if (unlikely(fw.wlan.last_tx_desc_num[i] > 5)) {
 892                                 /*
 893                                  * Sigh, the queue is almost certainly
 894                                  * dead. Dump the queue content to the
 895                                  * user, maybe we find out why it got
 896                                  * so stuck.
 897                                  */
 898
 899                                 wlan_dump_queue(i);
 900                         }
 901 #endif /* CONFIG_CARL9170FW_DEBUG */
 902
 903                         if (unlikely(fw.wlan.last_tx_desc_num[i] > 3)) {
 904                                 /*
 905                                  * Hrrm, bump the queue a bit.
 906                                  * maybe this will get it going again.
 907                                  */
 908
 909                                 wlan_dma_bump(i);
 910                         }
 911                 } else {
 912                         /* Nothing stuck */
 913                         fw.wlan.last_tx_desc[i] = desc;
 914                         fw.wlan.last_tx_desc_num[i] = 0;
 915                 }
 916         }
 917 }
 918
 919 /*
 920  * NB: Resetting the MAC is a two-edged sword.
 921  * On most occasions, it does what it is supposed to do.
 922  * But there is a chance that this will make it
 923  * even worse and the radio dies silently.
 924  */
 925 static void wlan_mac_reset(void)
 926 {
 927         uint32_t val;
 928         uint32_t agg_wait_counter;
 929         uint32_t agg_density;
 930         uint32_t bcn_start_addr;
 931         uint32_t rctl, rcth;
 932         uint32_t cam_mode;
 933         uint32_t ack_power;
 934         uint32_t rts_cts_tpc;
 935         unsigned int i;
 936
 937 #ifdef CONFIG_CARL9170FW_RADIO_FUNCTIONS
 938         uint32_t rx_BB;
 939 #endif /* CONFIG_CARL9170FW_RADIO_FUNCTIONS */
 940
 941         ERR("MAC RESET");
 942
 943         /* Save aggregation parameters */
 944         agg_wait_counter = get(AR9170_MAC_REG_AMPDU_FACTOR);
 945         agg_density = get(AR9170_MAC_REG_AMPDU_DENSITY);
 946
 947         bcn_start_addr = get(AR9170_MAC_REG_BCN_ADDR);
 948
 949         cam_mode = get(AR9170_MAC_REG_CAM_MODE);
 950         rctl = get(AR9170_MAC_REG_CAM_ROLL_CALL_TBL_L);
 951         rcth = get(AR9170_MAC_REG_CAM_ROLL_CALL_TBL_H);
 952
 953         ack_power = get(AR9170_MAC_REG_ACK_TPC);
 954         rts_cts_tpc = get(AR9170_MAC_REG_RTS_CTS_TPC);
 955
 956 #ifdef CONFIG_CARL9170FW_RADIO_FUNCTIONS
 957         /* 0x1c8960 write only */
 958         rx_BB = get(AR9170_PHY_REG_SWITCH_CHAIN_0);
 959 #endif /* CONFIG_CARL9170FW_RADIO_FUNCTIONS */
 960
 961         /* TX/RX must be stopped by now */
 962         val = get(AR9170_MAC_REG_POWER_STATE_CTRL);
 963
 964         val |= AR9170_MAC_POWER_STATE_CTRL_RESET;
 965
 966         /*
 967          * Manipulate CCA threshold to stop transmission
 968          *
 969          * set(AR9170_PHY_REG_CCA_THRESHOLD, 0x300);
 970          */
 971
 972         /*
 973          * check Rx state in 0(idle) 9(disable)
 974          *
 975          * chState = (get(AR9170_MAC_REG_MISC_684) >> 16) & 0xf;
 976          * while( (chState != 0) && (chState != 9)) {
 977          *      chState = (get(AR9170_MAC_REG_MISC_684) >> 16) & 0xf;
 978          * }
 979          */
 980
 981         set(AR9170_MAC_REG_POWER_STATE_CTRL, val);
 982
 983         delay(2);
 984
 985         /* Restore aggregation parameters */
 986         set(AR9170_MAC_REG_AMPDU_FACTOR, agg_wait_counter);
 987         set(AR9170_MAC_REG_AMPDU_DENSITY, agg_density);
 988
 989         set(AR9170_MAC_REG_BCN_ADDR, bcn_start_addr);
 990         set(AR9170_MAC_REG_CAM_MODE, cam_mode);
 991         set(AR9170_MAC_REG_CAM_ROLL_CALL_TBL_L, rctl);
 992         set(AR9170_MAC_REG_CAM_ROLL_CALL_TBL_H, rcth);
 993
 994         set(AR9170_MAC_REG_RTS_CTS_TPC, rts_cts_tpc);
 995         set(AR9170_MAC_REG_ACK_TPC, ack_power);
 996
 997 #ifdef CONFIG_CARL9170FW_RADIO_FUNCTIONS
 998         set(AR9170_PHY_REG_SWITCH_CHAIN_2, rx_BB);
 999 #endif /* CONFIG_CARL9170FW_RADIO_FUNCTIONS */
1000
1001         /*
1002          * Manipulate CCA threshold to resume transmission
1003          *
1004          * set(AR9170_PHY_REG_CCA_THRESHOLD, 0x0);
1005          */
1006
1007         for (i = 0; i < __AR9170_NUM_TX_QUEUES; i++) {
1008                 DBG("Q:%d l:%d h:%p t:%p\n", i, queue_len(&fw.wlan.tx_queue[i]),
1009                      fw.wlan.tx_queue[i].head, fw.wlan.tx_queue[i].terminator);
1010
1011                 set_wlan_txq_dma_addr(i, (uint32_t) fw.wlan.tx_queue[i].head);
1012
1013                 if (!queue_empty(&fw.wlan.tx_queue[i]))
1014                         wlan_trigger(BIT(i));
1015         }
1016
1017         handle_rx();
1018         set(AR9170_MAC_REG_DMA_RXQ_ADDR, (uint32_t) fw.wlan.rx_queue.head);
1019         wlan_trigger(AR9170_DMA_TRIGGER_RXQ);
1020 }
1021
1022 void __cold wlan_timer(void)
1023 {
1024         unsigned int cached_mac_reset;
1025
1026         cached_mac_reset = fw.wlan.mac_reset;
1027
1028         /* TX Queue Hang check */
1029         wlan_check_hang();
1030
1031         /* RX Overrun check */
1032         wlan_check_rx_overrun();
1033
1034         if (unlikely(fw.wlan.mac_reset >= CARL9170_MAC_RESET_RESET)) {
1035                 wlan_mac_reset();
1036                 fw.wlan.mac_reset = CARL9170_MAC_RESET_OFF;
1037         } else {
1038                 if (fw.wlan.mac_reset && cached_mac_reset == fw.wlan.mac_reset)
1039                         fw.wlan.mac_reset--;
1040         }
1041 }