drivers/net/wireless/iwlwifi/iwl-scan.c

   1 /******************************************************************************
   2  *
   3  * GPL LICENSE SUMMARY
   4  *
   5  * Copyright(c) 2008 - 2011 Intel Corporation. All rights reserved.
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of version 2 of the GNU General Public License as
   9  * published by the Free Software Foundation.
  10  *
  11  * This program is distributed in the hope that it will be useful, but
  12  * WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110,
  19  * USA
  20  *
  21  * The full GNU General Public License is included in this distribution
  22  * in the file called LICENSE.GPL.
  23  *
  24  * Contact Information:
  25  *  Intel Linux Wireless <ilw@linux.intel.com>
  26  * Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
  27  *****************************************************************************/
  28 #include <linux/slab.h>
  29 #include <linux/types.h>
  30 #include <linux/etherdevice.h>
  31 #include <net/mac80211.h>
  32
  33 #include "iwl-eeprom.h"
  34 #include "iwl-dev.h"
  35 #include "iwl-core.h"
  36 #include "iwl-sta.h"
  37 #include "iwl-io.h"
  38 #include "iwl-helpers.h"
  39 #include "iwl-agn.h"
  40 #include "iwl-trans.h"
  41
  42 /* For active scan, listen ACTIVE_DWELL_TIME (msec) on each channel after
  43  * sending probe req.  This should be set long enough to hear probe responses
  44  * from more than one AP.  */
  45 #define IWL_ACTIVE_DWELL_TIME_24    (30)       /* all times in msec */
  46 #define IWL_ACTIVE_DWELL_TIME_52    (20)
  47
  48 #define IWL_ACTIVE_DWELL_FACTOR_24GHZ (3)
  49 #define IWL_ACTIVE_DWELL_FACTOR_52GHZ (2)
  50
  51 /* For passive scan, listen PASSIVE_DWELL_TIME (msec) on each channel.
  52  * Must be set longer than active dwell time.
  53  * For the most reliable scan, set > AP beacon interval (typically 100msec). */
  54 #define IWL_PASSIVE_DWELL_TIME_24   (20)       /* all times in msec */
  55 #define IWL_PASSIVE_DWELL_TIME_52   (10)
  56 #define IWL_PASSIVE_DWELL_BASE      (100)
  57 #define IWL_CHANNEL_TUNE_TIME       5
  58
  59 static int iwl_send_scan_abort(struct iwl_priv *priv)
  60 {
  61         int ret;
  62         struct iwl_rx_packet *pkt;
  63         struct iwl_host_cmd cmd = {
  64                 .id = REPLY_SCAN_ABORT_CMD,
  65                 .flags = CMD_SYNC | CMD_WANT_SKB,
  66         };
  67
  68         /* Exit instantly with error when device is not ready
  69          * to receive scan abort command or it does not perform
  70          * hardware scan currently */
  71         if (!test_bit(STATUS_READY, &priv->status) ||
  72             !test_bit(STATUS_GEO_CONFIGURED, &priv->status) ||
  73             !test_bit(STATUS_SCAN_HW, &priv->status) ||
  74             test_bit(STATUS_FW_ERROR, &priv->status) ||
  75             test_bit(STATUS_EXIT_PENDING, &priv->status))
  76                 return -EIO;
  77
  78         ret = trans_send_cmd(&priv->trans, &cmd);
  79         if (ret)
  80                 return ret;
  81
  82         pkt = (struct iwl_rx_packet *)cmd.reply_page;
  83         if (pkt->u.status != CAN_ABORT_STATUS) {
  84                 /* The scan abort will return 1 for success or
  85                  * 2 for "failure".  A failure condition can be
  86                  * due to simply not being in an active scan which
  87                  * can occur if we send the scan abort before we
  88                  * the microcode has notified us that a scan is
  89                  * completed. */
  90                 IWL_DEBUG_SCAN(priv, "SCAN_ABORT ret %d.\n", pkt->u.status);
  91                 ret = -EIO;
  92         }
  93
  94         iwl_free_pages(priv, cmd.reply_page);
  95         return ret;
  96 }
  97
  98 static void iwl_complete_scan(struct iwl_priv *priv, bool aborted)
  99 {
 100         /* check if scan was requested from mac80211 */
 101         if (priv->scan_request) {
 102                 IWL_DEBUG_SCAN(priv, "Complete scan in mac80211\n");
 103                 ieee80211_scan_completed(priv->hw, aborted);
 104         }
 105
 106         priv->scan_type = IWL_SCAN_NORMAL;
 107         priv->scan_vif = NULL;
 108         priv->scan_request = NULL;
 109 }
 110
 111 void iwl_force_scan_end(struct iwl_priv *priv)
 112 {
 113         lockdep_assert_held(&priv->mutex);
 114
 115         if (!test_bit(STATUS_SCANNING, &priv->status)) {
 116                 IWL_DEBUG_SCAN(priv, "Forcing scan end while not scanning\n");
 117                 return;
 118         }
 119
 120         IWL_DEBUG_SCAN(priv, "Forcing scan end\n");
 121         clear_bit(STATUS_SCANNING, &priv->status);
 122         clear_bit(STATUS_SCAN_HW, &priv->status);
 123         clear_bit(STATUS_SCAN_ABORTING, &priv->status);
 124         iwl_complete_scan(priv, true);
 125 }
 126
 127 static void iwl_do_scan_abort(struct iwl_priv *priv)
 128 {
 129         int ret;
 130
 131         lockdep_assert_held(&priv->mutex);
 132
 133         if (!test_bit(STATUS_SCANNING, &priv->status)) {
 134                 IWL_DEBUG_SCAN(priv, "Not performing scan to abort\n");
 135                 return;
 136         }
 137
 138         if (test_and_set_bit(STATUS_SCAN_ABORTING, &priv->status)) {
 139                 IWL_DEBUG_SCAN(priv, "Scan abort in progress\n");
 140                 return;
 141         }
 142
 143         ret = iwl_send_scan_abort(priv);
 144         if (ret) {
 145                 IWL_DEBUG_SCAN(priv, "Send scan abort failed %d\n", ret);
 146                 iwl_force_scan_end(priv);
 147         } else
 148                 IWL_DEBUG_SCAN(priv, "Successfully send scan abort\n");
 149 }
 150
 151 /**
 152  * iwl_scan_cancel - Cancel any currently executing HW scan
 153  */
 154 int iwl_scan_cancel(struct iwl_priv *priv)
 155 {
 156         IWL_DEBUG_SCAN(priv, "Queuing abort scan\n");
 157         queue_work(priv->workqueue, &priv->abort_scan);
 158         return 0;
 159 }
 160
 161 /**
 162  * iwl_scan_cancel_timeout - Cancel any currently executing HW scan
 163  * @ms: amount of time to wait (in milliseconds) for scan to abort
 164  *
 165  */
 166 int iwl_scan_cancel_timeout(struct iwl_priv *priv, unsigned long ms)
 167 {
 168         unsigned long timeout = jiffies + msecs_to_jiffies(ms);
 169
 170         lockdep_assert_held(&priv->mutex);
 171
 172         IWL_DEBUG_SCAN(priv, "Scan cancel timeout\n");
 173
 174         iwl_do_scan_abort(priv);
 175
 176         while (time_before_eq(jiffies, timeout)) {
 177                 if (!test_bit(STATUS_SCAN_HW, &priv->status))
 178                         break;
 179                 msleep(20);
 180         }
 181
 182         return test_bit(STATUS_SCAN_HW, &priv->status);
 183 }
 184
 185 /* Service response to REPLY_SCAN_CMD (0x80) */
 186 static void iwl_rx_reply_scan(struct iwl_priv *priv,
 187                               struct iwl_rx_mem_buffer *rxb)
 188 {
 189 #ifdef CONFIG_IWLWIFI_DEBUG
 190         struct iwl_rx_packet *pkt = rxb_addr(rxb);
 191         struct iwl_scanreq_notification *notif =
 192             (struct iwl_scanreq_notification *)pkt->u.raw;
 193
 194         IWL_DEBUG_SCAN(priv, "Scan request status = 0x%x\n", notif->status);
 195 #endif
 196 }
 197
 198 /* Service SCAN_START_NOTIFICATION (0x82) */
 199 static void iwl_rx_scan_start_notif(struct iwl_priv *priv,
 200                                     struct iwl_rx_mem_buffer *rxb)
 201 {
 202         struct iwl_rx_packet *pkt = rxb_addr(rxb);
 203         struct iwl_scanstart_notification *notif =
 204             (struct iwl_scanstart_notification *)pkt->u.raw;
 205         priv->scan_start_tsf = le32_to_cpu(notif->tsf_low);
 206         IWL_DEBUG_SCAN(priv, "Scan start: "
 207                        "%d [802.11%s] "
 208                        "(TSF: 0x%08X:%08X) - %d (beacon timer %u)\n",
 209                        notif->channel,
 210                        notif->band ? "bg" : "a",
 211                        le32_to_cpu(notif->tsf_high),
 212                        le32_to_cpu(notif->tsf_low),
 213                        notif->status, notif->beacon_timer);
 214 }
 215
 216 /* Service SCAN_RESULTS_NOTIFICATION (0x83) */
 217 static void iwl_rx_scan_results_notif(struct iwl_priv *priv,
 218                                       struct iwl_rx_mem_buffer *rxb)
 219 {
 220 #ifdef CONFIG_IWLWIFI_DEBUG
 221         struct iwl_rx_packet *pkt = rxb_addr(rxb);
 222         struct iwl_scanresults_notification *notif =
 223             (struct iwl_scanresults_notification *)pkt->u.raw;
 224
 225         IWL_DEBUG_SCAN(priv, "Scan ch.res: "
 226                        "%d [802.11%s] "
 227                        "(TSF: 0x%08X:%08X) - %d "
 228                        "elapsed=%lu usec\n",
 229                        notif->channel,
 230                        notif->band ? "bg" : "a",
 231                        le32_to_cpu(notif->tsf_high),
 232                        le32_to_cpu(notif->tsf_low),
 233                        le32_to_cpu(notif->statistics[0]),
 234                        le32_to_cpu(notif->tsf_low) - priv->scan_start_tsf);
 235 #endif
 236 }
 237
 238 /* Service SCAN_COMPLETE_NOTIFICATION (0x84) */
 239 static void iwl_rx_scan_complete_notif(struct iwl_priv *priv,
 240                                        struct iwl_rx_mem_buffer *rxb)
 241 {
 242         struct iwl_rx_packet *pkt = rxb_addr(rxb);
 243         struct iwl_scancomplete_notification *scan_notif = (void *)pkt->u.raw;
 244
 245         IWL_DEBUG_SCAN(priv, "Scan complete: %d channels (TSF 0x%08X:%08X) - %d\n",
 246                        scan_notif->scanned_channels,
 247                        scan_notif->tsf_low,
 248                        scan_notif->tsf_high, scan_notif->status);
 249
 250         /* The HW is no longer scanning */
 251         clear_bit(STATUS_SCAN_HW, &priv->status);
 252
 253         IWL_DEBUG_SCAN(priv, "Scan on %sGHz took %dms\n",
 254                        (priv->scan_band == IEEE80211_BAND_2GHZ) ? "2.4" : "5.2",
 255                        jiffies_to_msecs(jiffies - priv->scan_start));
 256
 257         queue_work(priv->workqueue, &priv->scan_completed);
 258
 259         if (priv->iw_mode != NL80211_IFTYPE_ADHOC &&
 260             iwl_advanced_bt_coexist(priv) &&
 261             priv->bt_status != scan_notif->bt_status) {
 262                 if (scan_notif->bt_status) {
 263                         /* BT on */
 264                         if (!priv->bt_ch_announce)
 265                                 priv->bt_traffic_load =
 266                                         IWL_BT_COEX_TRAFFIC_LOAD_HIGH;
 267                         /*
 268                          * otherwise, no traffic load information provided
 269                          * no changes made
 270                          */
 271                 } else {
 272                         /* BT off */
 273                         priv->bt_traffic_load =
 274                                 IWL_BT_COEX_TRAFFIC_LOAD_NONE;
 275                 }
 276                 priv->bt_status = scan_notif->bt_status;
 277                 queue_work(priv->workqueue, &priv->bt_traffic_change_work);
 278         }
 279 }
 280
 281 void iwl_setup_rx_scan_handlers(struct iwl_priv *priv)
 282 {
 283         /* scan handlers */
 284         priv->rx_handlers[REPLY_SCAN_CMD] = iwl_rx_reply_scan;
 285         priv->rx_handlers[SCAN_START_NOTIFICATION] = iwl_rx_scan_start_notif;
 286         priv->rx_handlers[SCAN_RESULTS_NOTIFICATION] =
 287                                         iwl_rx_scan_results_notif;
 288         priv->rx_handlers[SCAN_COMPLETE_NOTIFICATION] =
 289                                         iwl_rx_scan_complete_notif;
 290 }
 291
 292 inline u16 iwl_get_active_dwell_time(struct iwl_priv *priv,
 293                                      enum ieee80211_band band,
 294                                      u8 n_probes)
 295 {
 296         if (band == IEEE80211_BAND_5GHZ)
 297                 return IWL_ACTIVE_DWELL_TIME_52 +
 298                         IWL_ACTIVE_DWELL_FACTOR_52GHZ * (n_probes + 1);
 299         else
 300                 return IWL_ACTIVE_DWELL_TIME_24 +
 301                         IWL_ACTIVE_DWELL_FACTOR_24GHZ * (n_probes + 1);
 302 }
 303
 304 u16 iwl_get_passive_dwell_time(struct iwl_priv *priv,
 305                                enum ieee80211_band band,
 306                                struct ieee80211_vif *vif)
 307 {
 308         struct iwl_rxon_context *ctx;
 309         u16 passive = (band == IEEE80211_BAND_2GHZ) ?
 310             IWL_PASSIVE_DWELL_BASE + IWL_PASSIVE_DWELL_TIME_24 :
 311             IWL_PASSIVE_DWELL_BASE + IWL_PASSIVE_DWELL_TIME_52;
 312
 313         if (iwl_is_any_associated(priv)) {
 314                 /*
 315                  * If we're associated, we clamp the maximum passive
 316                  * dwell time to be 98% of the smallest beacon interval
 317                  * (minus 2 * channel tune time)
 318                  */
 319                 for_each_context(priv, ctx) {
 320                         u16 value;
 321
 322                         if (!iwl_is_associated_ctx(ctx))
 323                                 continue;
 324                         value = ctx->vif ? ctx->vif->bss_conf.beacon_int : 0;
 325                         if ((value > IWL_PASSIVE_DWELL_BASE) || !value)
 326                                 value = IWL_PASSIVE_DWELL_BASE;
 327                         value = (value * 98) / 100 - IWL_CHANNEL_TUNE_TIME * 2;
 328                         passive = min(value, passive);
 329                 }
 330         }
 331
 332         return passive;
 333 }
 334
 335 void iwl_init_scan_params(struct iwl_priv *priv)
 336 {
 337         u8 ant_idx = fls(priv->hw_params.valid_tx_ant) - 1;
 338         if (!priv->scan_tx_ant[IEEE80211_BAND_5GHZ])
 339                 priv->scan_tx_ant[IEEE80211_BAND_5GHZ] = ant_idx;
 340         if (!priv->scan_tx_ant[IEEE80211_BAND_2GHZ])
 341                 priv->scan_tx_ant[IEEE80211_BAND_2GHZ] = ant_idx;
 342 }
 343
 344 int __must_check iwl_scan_initiate(struct iwl_priv *priv,
 345                                    struct ieee80211_vif *vif,
 346                                    enum iwl_scan_type scan_type,
 347                                    enum ieee80211_band band)
 348 {
 349         int ret;
 350
 351         lockdep_assert_held(&priv->mutex);
 352
 353         cancel_delayed_work(&priv->scan_check);
 354
 355         if (!iwl_is_ready_rf(priv)) {
 356                 IWL_WARN(priv, "Request scan called when driver not ready.\n");
 357                 return -EIO;
 358         }
 359
 360         if (test_bit(STATUS_SCAN_HW, &priv->status)) {
 361                 IWL_DEBUG_SCAN(priv,
 362                         "Multiple concurrent scan requests in parallel.\n");
 363                 return -EBUSY;
 364         }
 365
 366         if (test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
 367                 IWL_DEBUG_SCAN(priv, "Scan request while abort pending.\n");
 368                 return -EBUSY;
 369         }
 370
 371         IWL_DEBUG_SCAN(priv, "Starting %sscan...\n",
 372                         scan_type == IWL_SCAN_NORMAL ? "" :
 373                         scan_type == IWL_SCAN_OFFCH_TX ? "offchan TX " :
 374                         "internal short ");
 375
 376         set_bit(STATUS_SCANNING, &priv->status);
 377         priv->scan_type = scan_type;
 378         priv->scan_start = jiffies;
 379         priv->scan_band = band;
 380
 381         ret = iwlagn_request_scan(priv, vif);
 382         if (ret) {
 383                 clear_bit(STATUS_SCANNING, &priv->status);
 384                 priv->scan_type = IWL_SCAN_NORMAL;
 385                 return ret;
 386         }
 387
 388         queue_delayed_work(priv->workqueue, &priv->scan_check,
 389                            IWL_SCAN_CHECK_WATCHDOG);
 390
 391         return 0;
 392 }
 393
 394 int iwl_mac_hw_scan(struct ieee80211_hw *hw,
 395                     struct ieee80211_vif *vif,
 396                     struct cfg80211_scan_request *req)
 397 {
 398         struct iwl_priv *priv = hw->priv;
 399         int ret;
 400
 401         IWL_DEBUG_MAC80211(priv, "enter\n");
 402
 403         if (req->n_channels == 0)
 404                 return -EINVAL;
 405
 406         mutex_lock(&priv->mutex);
 407
 408         /*
 409          * If an internal scan is in progress, just set
 410          * up the scan_request as per above.
 411          */
 412         if (priv->scan_type != IWL_SCAN_NORMAL) {
 413                 IWL_DEBUG_SCAN(priv,
 414                                "SCAN request during internal scan - defer\n");
 415                 priv->scan_request = req;
 416                 priv->scan_vif = vif;
 417                 ret = 0;
 418         } else {
 419                 priv->scan_request = req;
 420                 priv->scan_vif = vif;
 421                 /*
 422                  * mac80211 will only ask for one band at a time
 423                  * so using channels[0] here is ok
 424                  */
 425                 ret = iwl_scan_initiate(priv, vif, IWL_SCAN_NORMAL,
 426                                         req->channels[0]->band);
 427                 if (ret) {
 428                         priv->scan_request = NULL;
 429                         priv->scan_vif = NULL;
 430                 }
 431         }
 432
 433         IWL_DEBUG_MAC80211(priv, "leave\n");
 434
 435         mutex_unlock(&priv->mutex);
 436
 437         return ret;
 438 }
 439
 440 /*
 441  * internal short scan, this function should only been called while associated.
 442  * It will reset and tune the radio to prevent possible RF related problem
 443  */
 444 void iwl_internal_short_hw_scan(struct iwl_priv *priv)
 445 {
 446         queue_work(priv->workqueue, &priv->start_internal_scan);
 447 }
 448
 449 static void iwl_bg_start_internal_scan(struct work_struct *work)
 450 {
 451         struct iwl_priv *priv =
 452                 container_of(work, struct iwl_priv, start_internal_scan);
 453
 454         IWL_DEBUG_SCAN(priv, "Start internal scan\n");
 455
 456         mutex_lock(&priv->mutex);
 457
 458         if (priv->scan_type == IWL_SCAN_RADIO_RESET) {
 459                 IWL_DEBUG_SCAN(priv, "Internal scan already in progress\n");
 460                 goto unlock;
 461         }
 462
 463         if (test_bit(STATUS_SCANNING, &priv->status)) {
 464                 IWL_DEBUG_SCAN(priv, "Scan already in progress.\n");
 465                 goto unlock;
 466         }
 467
 468         if (iwl_scan_initiate(priv, NULL, IWL_SCAN_RADIO_RESET, priv->band))
 469                 IWL_DEBUG_SCAN(priv, "failed to start internal short scan\n");
 470  unlock:
 471         mutex_unlock(&priv->mutex);
 472 }
 473
 474 static void iwl_bg_scan_check(struct work_struct *data)
 475 {
 476         struct iwl_priv *priv =
 477             container_of(data, struct iwl_priv, scan_check.work);
 478
 479         IWL_DEBUG_SCAN(priv, "Scan check work\n");
 480
 481         /* Since we are here firmware does not finish scan and
 482          * most likely is in bad shape, so we don't bother to
 483          * send abort command, just force scan complete to mac80211 */
 484         mutex_lock(&priv->mutex);
 485         iwl_force_scan_end(priv);
 486         mutex_unlock(&priv->mutex);
 487 }
 488
 489 /**
 490  * iwl_fill_probe_req - fill in all required fields and IE for probe request
 491  */
 492
 493 u16 iwl_fill_probe_req(struct iwl_priv *priv, struct ieee80211_mgmt *frame,
 494                        const u8 *ta, const u8 *ies, int ie_len, int left)
 495 {
 496         int len = 0;
 497         u8 *pos = NULL;
 498
 499         /* Make sure there is enough space for the probe request,
 500          * two mandatory IEs and the data */
 501         left -= 24;
 502         if (left < 0)
 503                 return 0;
 504
 505         frame->frame_control = cpu_to_le16(IEEE80211_STYPE_PROBE_REQ);
 506         memcpy(frame->da, iwl_bcast_addr, ETH_ALEN);
 507         memcpy(frame->sa, ta, ETH_ALEN);
 508         memcpy(frame->bssid, iwl_bcast_addr, ETH_ALEN);
 509         frame->seq_ctrl = 0;
 510
 511         len += 24;
 512
 513         /* ...next IE... */
 514         pos = &frame->u.probe_req.variable[0];
 515
 516         /* fill in our indirect SSID IE */
 517         left -= 2;
 518         if (left < 0)
 519                 return 0;
 520         *pos++ = WLAN_EID_SSID;
 521         *pos++ = 0;
 522
 523         len += 2;
 524
 525         if (WARN_ON(left < ie_len))
 526                 return len;
 527
 528         if (ies && ie_len) {
 529                 memcpy(pos, ies, ie_len);
 530                 len += ie_len;
 531         }
 532
 533         return (u16)len;
 534 }
 535
 536 static void iwl_bg_abort_scan(struct work_struct *work)
 537 {
 538         struct iwl_priv *priv = container_of(work, struct iwl_priv, abort_scan);
 539
 540         IWL_DEBUG_SCAN(priv, "Abort scan work\n");
 541
 542         /* We keep scan_check work queued in case when firmware will not
 543          * report back scan completed notification */
 544         mutex_lock(&priv->mutex);
 545         iwl_scan_cancel_timeout(priv, 200);
 546         mutex_unlock(&priv->mutex);
 547 }
 548
 549 static void iwl_bg_scan_completed(struct work_struct *work)
 550 {
 551         struct iwl_priv *priv =
 552             container_of(work, struct iwl_priv, scan_completed);
 553         bool aborted;
 554
 555         IWL_DEBUG_SCAN(priv, "Completed scan.\n");
 556
 557         cancel_delayed_work(&priv->scan_check);
 558
 559         mutex_lock(&priv->mutex);
 560
 561         aborted = test_and_clear_bit(STATUS_SCAN_ABORTING, &priv->status);
 562         if (aborted)
 563                 IWL_DEBUG_SCAN(priv, "Aborted scan completed.\n");
 564
 565         if (!test_and_clear_bit(STATUS_SCANNING, &priv->status)) {
 566                 IWL_DEBUG_SCAN(priv, "Scan already completed.\n");
 567                 goto out_settings;
 568         }
 569
 570         if (priv->scan_type == IWL_SCAN_OFFCH_TX && priv->offchan_tx_skb) {
 571                 ieee80211_tx_status_irqsafe(priv->hw,
 572                                             priv->offchan_tx_skb);
 573                 priv->offchan_tx_skb = NULL;
 574         }
 575
 576         if (priv->scan_type != IWL_SCAN_NORMAL && !aborted) {
 577                 int err;
 578
 579                 /* Check if mac80211 requested scan during our internal scan */
 580                 if (priv->scan_request == NULL)
 581                         goto out_complete;
 582
 583                 /* If so request a new scan */
 584                 err = iwl_scan_initiate(priv, priv->scan_vif, IWL_SCAN_NORMAL,
 585                                         priv->scan_request->channels[0]->band);
 586                 if (err) {
 587                         IWL_DEBUG_SCAN(priv,
 588                                 "failed to initiate pending scan: %d\n", err);
 589                         aborted = true;
 590                         goto out_complete;
 591                 }
 592
 593                 goto out;
 594         }
 595
 596 out_complete:
 597         iwl_complete_scan(priv, aborted);
 598
 599 out_settings:
 600         /* Can we still talk to firmware ? */
 601         if (!iwl_is_ready_rf(priv))
 602                 goto out;
 603
 604         iwlagn_post_scan(priv);
 605
 606 out:
 607         mutex_unlock(&priv->mutex);
 608 }
 609
 610 void iwl_setup_scan_deferred_work(struct iwl_priv *priv)
 611 {
 612         INIT_WORK(&priv->scan_completed, iwl_bg_scan_completed);
 613         INIT_WORK(&priv->abort_scan, iwl_bg_abort_scan);
 614         INIT_WORK(&priv->start_internal_scan, iwl_bg_start_internal_scan);
 615         INIT_DELAYED_WORK(&priv->scan_check, iwl_bg_scan_check);
 616 }
 617
 618 void iwl_cancel_scan_deferred_work(struct iwl_priv *priv)
 619 {
 620         cancel_work_sync(&priv->start_internal_scan);
 621         cancel_work_sync(&priv->abort_scan);
 622         cancel_work_sync(&priv->scan_completed);
 623
 624         if (cancel_delayed_work_sync(&priv->scan_check)) {
 625                 mutex_lock(&priv->mutex);
 626                 iwl_force_scan_end(priv);
 627                 mutex_unlock(&priv->mutex);
 628         }
 629 }