drivers/net/wireless/iwlwifi/dvm/scan.c

   1 /******************************************************************************
   2  *
   3  * GPL LICENSE SUMMARY
   4  *
   5  * Copyright(c) 2008 - 2012 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 "eeprom.h"
  34 #include "dev.h"
  35 #include "agn.h"
  36
  37 /* For active scan, listen ACTIVE_DWELL_TIME (msec) on each channel after
  38  * sending probe req.  This should be set long enough to hear probe responses
  39  * from more than one AP.  */
  40 #define IWL_ACTIVE_DWELL_TIME_24    (30)       /* all times in msec */
  41 #define IWL_ACTIVE_DWELL_TIME_52    (20)
  42
  43 #define IWL_ACTIVE_DWELL_FACTOR_24GHZ (3)
  44 #define IWL_ACTIVE_DWELL_FACTOR_52GHZ (2)
  45
  46 /* For passive scan, listen PASSIVE_DWELL_TIME (msec) on each channel.
  47  * Must be set longer than active dwell time.
  48  * For the most reliable scan, set > AP beacon interval (typically 100msec). */
  49 #define IWL_PASSIVE_DWELL_TIME_24   (20)       /* all times in msec */
  50 #define IWL_PASSIVE_DWELL_TIME_52   (10)
  51 #define IWL_PASSIVE_DWELL_BASE      (100)
  52 #define IWL_CHANNEL_TUNE_TIME       5
  53 #define MAX_SCAN_CHANNEL            50
  54
  55 static int iwl_send_scan_abort(struct iwl_priv *priv)
  56 {
  57         int ret;
  58         struct iwl_host_cmd cmd = {
  59                 .id = REPLY_SCAN_ABORT_CMD,
  60                 .flags = CMD_SYNC | CMD_WANT_SKB,
  61         };
  62         __le32 *status;
  63
  64         /* Exit instantly with error when device is not ready
  65          * to receive scan abort command or it does not perform
  66          * hardware scan currently */
  67         if (!test_bit(STATUS_READY, &priv->status) ||
  68             !test_bit(STATUS_GEO_CONFIGURED, &priv->status) ||
  69             !test_bit(STATUS_SCAN_HW, &priv->status) ||
  70             test_bit(STATUS_FW_ERROR, &priv->status))
  71                 return -EIO;
  72
  73         ret = iwl_dvm_send_cmd(priv, &cmd);
  74         if (ret)
  75                 return ret;
  76
  77         status = (void *)cmd.resp_pkt->data;
  78         if (*status != CAN_ABORT_STATUS) {
  79                 /* The scan abort will return 1 for success or
  80                  * 2 for "failure".  A failure condition can be
  81                  * due to simply not being in an active scan which
  82                  * can occur if we send the scan abort before we
  83                  * the microcode has notified us that a scan is
  84                  * completed. */
  85                 IWL_DEBUG_SCAN(priv, "SCAN_ABORT ret %d.\n",
  86                                le32_to_cpu(*status));
  87                 ret = -EIO;
  88         }
  89
  90         iwl_free_resp(&cmd);
  91         return ret;
  92 }
  93
  94 static void iwl_complete_scan(struct iwl_priv *priv, bool aborted)
  95 {
  96         /* check if scan was requested from mac80211 */
  97         if (priv->scan_request) {
  98                 IWL_DEBUG_SCAN(priv, "Complete scan in mac80211\n");
  99                 ieee80211_scan_completed(priv->hw, aborted);
 100         }
 101
 102         if (priv->scan_type == IWL_SCAN_ROC)
 103                 iwl_scan_roc_expired(priv);
 104
 105         priv->scan_type = IWL_SCAN_NORMAL;
 106         priv->scan_vif = NULL;
 107         priv->scan_request = NULL;
 108 }
 109
 110 static void iwl_process_scan_complete(struct iwl_priv *priv)
 111 {
 112         bool aborted;
 113
 114         lockdep_assert_held(&priv->mutex);
 115
 116         if (!test_and_clear_bit(STATUS_SCAN_COMPLETE, &priv->status))
 117                 return;
 118
 119         IWL_DEBUG_SCAN(priv, "Completed scan.\n");
 120
 121         cancel_delayed_work(&priv->scan_check);
 122
 123         aborted = test_and_clear_bit(STATUS_SCAN_ABORTING, &priv->status);
 124         if (aborted)
 125                 IWL_DEBUG_SCAN(priv, "Aborted scan completed.\n");
 126
 127         if (!test_and_clear_bit(STATUS_SCANNING, &priv->status)) {
 128                 IWL_DEBUG_SCAN(priv, "Scan already completed.\n");
 129                 goto out_settings;
 130         }
 131
 132         if (priv->scan_type == IWL_SCAN_ROC)
 133                 iwl_scan_roc_expired(priv);
 134
 135         if (priv->scan_type != IWL_SCAN_NORMAL && !aborted) {
 136                 int err;
 137
 138                 /* Check if mac80211 requested scan during our internal scan */
 139                 if (priv->scan_request == NULL)
 140                         goto out_complete;
 141
 142                 /* If so request a new scan */
 143                 err = iwl_scan_initiate(priv, priv->scan_vif, IWL_SCAN_NORMAL,
 144                                         priv->scan_request->channels[0]->band);
 145                 if (err) {
 146                         IWL_DEBUG_SCAN(priv,
 147                                 "failed to initiate pending scan: %d\n", err);
 148                         aborted = true;
 149                         goto out_complete;
 150                 }
 151
 152                 return;
 153         }
 154
 155 out_complete:
 156         iwl_complete_scan(priv, aborted);
 157
 158 out_settings:
 159         /* Can we still talk to firmware ? */
 160         if (!iwl_is_ready_rf(priv))
 161                 return;
 162
 163         iwlagn_post_scan(priv);
 164 }
 165
 166 void iwl_force_scan_end(struct iwl_priv *priv)
 167 {
 168         lockdep_assert_held(&priv->mutex);
 169
 170         if (!test_bit(STATUS_SCANNING, &priv->status)) {
 171                 IWL_DEBUG_SCAN(priv, "Forcing scan end while not scanning\n");
 172                 return;
 173         }
 174
 175         IWL_DEBUG_SCAN(priv, "Forcing scan end\n");
 176         clear_bit(STATUS_SCANNING, &priv->status);
 177         clear_bit(STATUS_SCAN_HW, &priv->status);
 178         clear_bit(STATUS_SCAN_ABORTING, &priv->status);
 179         clear_bit(STATUS_SCAN_COMPLETE, &priv->status);
 180         iwl_complete_scan(priv, true);
 181 }
 182
 183 static void iwl_do_scan_abort(struct iwl_priv *priv)
 184 {
 185         int ret;
 186
 187         lockdep_assert_held(&priv->mutex);
 188
 189         if (!test_bit(STATUS_SCANNING, &priv->status)) {
 190                 IWL_DEBUG_SCAN(priv, "Not performing scan to abort\n");
 191                 return;
 192         }
 193
 194         if (test_and_set_bit(STATUS_SCAN_ABORTING, &priv->status)) {
 195                 IWL_DEBUG_SCAN(priv, "Scan abort in progress\n");
 196                 return;
 197         }
 198
 199         ret = iwl_send_scan_abort(priv);
 200         if (ret) {
 201                 IWL_DEBUG_SCAN(priv, "Send scan abort failed %d\n", ret);
 202                 iwl_force_scan_end(priv);
 203         } else
 204                 IWL_DEBUG_SCAN(priv, "Successfully send scan abort\n");
 205 }
 206
 207 /**
 208  * iwl_scan_cancel - Cancel any currently executing HW scan
 209  */
 210 int iwl_scan_cancel(struct iwl_priv *priv)
 211 {
 212         IWL_DEBUG_SCAN(priv, "Queuing abort scan\n");
 213         queue_work(priv->workqueue, &priv->abort_scan);
 214         return 0;
 215 }
 216
 217 /**
 218  * iwl_scan_cancel_timeout - Cancel any currently executing HW scan
 219  * @ms: amount of time to wait (in milliseconds) for scan to abort
 220  *
 221  */
 222 void iwl_scan_cancel_timeout(struct iwl_priv *priv, unsigned long ms)
 223 {
 224         unsigned long timeout = jiffies + msecs_to_jiffies(ms);
 225
 226         lockdep_assert_held(&priv->mutex);
 227
 228         IWL_DEBUG_SCAN(priv, "Scan cancel timeout\n");
 229
 230         iwl_do_scan_abort(priv);
 231
 232         while (time_before_eq(jiffies, timeout)) {
 233                 if (!test_bit(STATUS_SCAN_HW, &priv->status))
 234                         goto finished;
 235                 msleep(20);
 236         }
 237
 238         return;
 239
 240  finished:
 241         /*
 242          * Now STATUS_SCAN_HW is clear. This means that the
 243          * device finished, but the background work is going
 244          * to execute at best as soon as we release the mutex.
 245          * Since we need to be able to issue a new scan right
 246          * after this function returns, run the complete here.
 247          * The STATUS_SCAN_COMPLETE bit will then be cleared
 248          * and prevent the background work from "completing"
 249          * a possible new scan.
 250          */
 251         iwl_process_scan_complete(priv);
 252 }
 253
 254 /* Service response to REPLY_SCAN_CMD (0x80) */
 255 static int iwl_rx_reply_scan(struct iwl_priv *priv,
 256                               struct iwl_rx_cmd_buffer *rxb,
 257                               struct iwl_device_cmd *cmd)
 258 {
 259 #ifdef CONFIG_IWLWIFI_DEBUG
 260         struct iwl_rx_packet *pkt = rxb_addr(rxb);
 261         struct iwl_scanreq_notification *notif = (void *)pkt->data;
 262
 263         IWL_DEBUG_SCAN(priv, "Scan request status = 0x%x\n", notif->status);
 264 #endif
 265         return 0;
 266 }
 267
 268 /* Service SCAN_START_NOTIFICATION (0x82) */
 269 static int iwl_rx_scan_start_notif(struct iwl_priv *priv,
 270                                     struct iwl_rx_cmd_buffer *rxb,
 271                                     struct iwl_device_cmd *cmd)
 272 {
 273         struct iwl_rx_packet *pkt = rxb_addr(rxb);
 274         struct iwl_scanstart_notification *notif = (void *)pkt->data;
 275
 276         priv->scan_start_tsf = le32_to_cpu(notif->tsf_low);
 277         IWL_DEBUG_SCAN(priv, "Scan start: "
 278                        "%d [802.11%s] "
 279                        "(TSF: 0x%08X:%08X) - %d (beacon timer %u)\n",
 280                        notif->channel,
 281                        notif->band ? "bg" : "a",
 282                        le32_to_cpu(notif->tsf_high),
 283                        le32_to_cpu(notif->tsf_low),
 284                        notif->status, notif->beacon_timer);
 285
 286         if (priv->scan_type == IWL_SCAN_ROC &&
 287             !priv->hw_roc_start_notified) {
 288                 ieee80211_ready_on_channel(priv->hw);
 289                 priv->hw_roc_start_notified = true;
 290         }
 291
 292         return 0;
 293 }
 294
 295 /* Service SCAN_RESULTS_NOTIFICATION (0x83) */
 296 static int iwl_rx_scan_results_notif(struct iwl_priv *priv,
 297                                       struct iwl_rx_cmd_buffer *rxb,
 298                                       struct iwl_device_cmd *cmd)
 299 {
 300 #ifdef CONFIG_IWLWIFI_DEBUG
 301         struct iwl_rx_packet *pkt = rxb_addr(rxb);
 302         struct iwl_scanresults_notification *notif = (void *)pkt->data;
 303
 304         IWL_DEBUG_SCAN(priv, "Scan ch.res: "
 305                        "%d [802.11%s] "
 306                        "probe status: %u:%u "
 307                        "(TSF: 0x%08X:%08X) - %d "
 308                        "elapsed=%lu usec\n",
 309                        notif->channel,
 310                        notif->band ? "bg" : "a",
 311                        notif->probe_status, notif->num_probe_not_sent,
 312                        le32_to_cpu(notif->tsf_high),
 313                        le32_to_cpu(notif->tsf_low),
 314                        le32_to_cpu(notif->statistics[0]),
 315                        le32_to_cpu(notif->tsf_low) - priv->scan_start_tsf);
 316 #endif
 317         return 0;
 318 }
 319
 320 /* Service SCAN_COMPLETE_NOTIFICATION (0x84) */
 321 static int iwl_rx_scan_complete_notif(struct iwl_priv *priv,
 322                                        struct iwl_rx_cmd_buffer *rxb,
 323                                        struct iwl_device_cmd *cmd)
 324 {
 325         struct iwl_rx_packet *pkt = rxb_addr(rxb);
 326         struct iwl_scancomplete_notification *scan_notif = (void *)pkt->data;
 327
 328         IWL_DEBUG_SCAN(priv, "Scan complete: %d channels (TSF 0x%08X:%08X) - %d\n",
 329                        scan_notif->scanned_channels,
 330                        scan_notif->tsf_low,
 331                        scan_notif->tsf_high, scan_notif->status);
 332
 333         IWL_DEBUG_SCAN(priv, "Scan on %sGHz took %dms\n",
 334                        (priv->scan_band == IEEE80211_BAND_2GHZ) ? "2.4" : "5.2",
 335                        jiffies_to_msecs(jiffies - priv->scan_start));
 336
 337         /*
 338          * When aborting, we run the scan completed background work inline
 339          * and the background work must then do nothing. The SCAN_COMPLETE
 340          * bit helps implement that logic and thus needs to be set before
 341          * queueing the work. Also, since the scan abort waits for SCAN_HW
 342          * to clear, we need to set SCAN_COMPLETE before clearing SCAN_HW
 343          * to avoid a race there.
 344          */
 345         set_bit(STATUS_SCAN_COMPLETE, &priv->status);
 346         clear_bit(STATUS_SCAN_HW, &priv->status);
 347         queue_work(priv->workqueue, &priv->scan_completed);
 348
 349         if (priv->iw_mode != NL80211_IFTYPE_ADHOC &&
 350             iwl_advanced_bt_coexist(priv) &&
 351             priv->bt_status != scan_notif->bt_status) {
 352                 if (scan_notif->bt_status) {
 353                         /* BT on */
 354                         if (!priv->bt_ch_announce)
 355                                 priv->bt_traffic_load =
 356                                         IWL_BT_COEX_TRAFFIC_LOAD_HIGH;
 357                         /*
 358                          * otherwise, no traffic load information provided
 359                          * no changes made
 360                          */
 361                 } else {
 362                         /* BT off */
 363                         priv->bt_traffic_load =
 364                                 IWL_BT_COEX_TRAFFIC_LOAD_NONE;
 365                 }
 366                 priv->bt_status = scan_notif->bt_status;
 367                 queue_work(priv->workqueue,
 368                            &priv->bt_traffic_change_work);
 369         }
 370         return 0;
 371 }
 372
 373 void iwl_setup_rx_scan_handlers(struct iwl_priv *priv)
 374 {
 375         /* scan handlers */
 376         priv->rx_handlers[REPLY_SCAN_CMD] = iwl_rx_reply_scan;
 377         priv->rx_handlers[SCAN_START_NOTIFICATION] = iwl_rx_scan_start_notif;
 378         priv->rx_handlers[SCAN_RESULTS_NOTIFICATION] =
 379                                         iwl_rx_scan_results_notif;
 380         priv->rx_handlers[SCAN_COMPLETE_NOTIFICATION] =
 381                                         iwl_rx_scan_complete_notif;
 382 }
 383
 384 static u16 iwl_get_active_dwell_time(struct iwl_priv *priv,
 385                                      enum ieee80211_band band, u8 n_probes)
 386 {
 387         if (band == IEEE80211_BAND_5GHZ)
 388                 return IWL_ACTIVE_DWELL_TIME_52 +
 389                         IWL_ACTIVE_DWELL_FACTOR_52GHZ * (n_probes + 1);
 390         else
 391                 return IWL_ACTIVE_DWELL_TIME_24 +
 392                         IWL_ACTIVE_DWELL_FACTOR_24GHZ * (n_probes + 1);
 393 }
 394
 395 static u16 iwl_limit_dwell(struct iwl_priv *priv, u16 dwell_time)
 396 {
 397         struct iwl_rxon_context *ctx;
 398
 399         /*
 400          * If we're associated, we clamp the dwell time 98%
 401          * of the smallest beacon interval (minus 2 * channel
 402          * tune time)
 403          */
 404         for_each_context(priv, ctx) {
 405                 u16 value;
 406
 407                 switch (ctx->staging.dev_type) {
 408                 case RXON_DEV_TYPE_P2P:
 409                         /* no timing constraints */
 410                         continue;
 411                 case RXON_DEV_TYPE_ESS:
 412                 default:
 413                         /* timing constraints if associated */
 414                         if (!iwl_is_associated_ctx(ctx))
 415                                 continue;
 416                         break;
 417                 case RXON_DEV_TYPE_CP:
 418                 case RXON_DEV_TYPE_2STA:
 419                         /*
 420                          * These seem to always have timers for TBTT
 421                          * active in uCode even when not associated yet.
 422                          */
 423                         break;
 424                 }
 425
 426                 value = ctx->beacon_int;
 427                 if (!value)
 428                         value = IWL_PASSIVE_DWELL_BASE;
 429                 value = (value * 98) / 100 - IWL_CHANNEL_TUNE_TIME * 2;
 430                 dwell_time = min(value, dwell_time);
 431         }
 432
 433         return dwell_time;
 434 }
 435
 436 static u16 iwl_get_passive_dwell_time(struct iwl_priv *priv,
 437                                       enum ieee80211_band band)
 438 {
 439         u16 passive = (band == IEEE80211_BAND_2GHZ) ?
 440             IWL_PASSIVE_DWELL_BASE + IWL_PASSIVE_DWELL_TIME_24 :
 441             IWL_PASSIVE_DWELL_BASE + IWL_PASSIVE_DWELL_TIME_52;
 442
 443         return iwl_limit_dwell(priv, passive);
 444 }
 445
 446 /* Return valid, unused, channel for a passive scan to reset the RF */
 447 static u8 iwl_get_single_channel_number(struct iwl_priv *priv,
 448                                         enum ieee80211_band band)
 449 {
 450         struct ieee80211_supported_band *sband = priv->hw->wiphy->bands[band];
 451         struct iwl_rxon_context *ctx;
 452         int i;
 453
 454         for (i = 0; i < sband->n_channels; i++) {
 455                 bool busy = false;
 456
 457                 for_each_context(priv, ctx) {
 458                         busy = sband->channels[i].hw_value ==
 459                                 le16_to_cpu(ctx->staging.channel);
 460                         if (busy)
 461                                 break;
 462                 }
 463
 464                 if (busy)
 465                         continue;
 466
 467                 if (!(sband->channels[i].flags & IEEE80211_CHAN_DISABLED))
 468                         return sband->channels[i].hw_value;
 469         }
 470
 471         return 0;
 472 }
 473
 474 static int iwl_get_single_channel_for_scan(struct iwl_priv *priv,
 475                                            struct ieee80211_vif *vif,
 476                                            enum ieee80211_band band,
 477                                            struct iwl_scan_channel *scan_ch)
 478 {
 479         const struct ieee80211_supported_band *sband;
 480         u16 passive_dwell = 0;
 481         u16 active_dwell = 0;
 482         int added = 0;
 483         u16 channel = 0;
 484
 485         sband = iwl_get_hw_mode(priv, band);
 486         if (!sband) {
 487                 IWL_ERR(priv, "invalid band\n");
 488                 return added;
 489         }
 490
 491         active_dwell = iwl_get_active_dwell_time(priv, band, 0);
 492         passive_dwell = iwl_get_passive_dwell_time(priv, band);
 493
 494         if (passive_dwell <= active_dwell)
 495                 passive_dwell = active_dwell + 1;
 496
 497         channel = iwl_get_single_channel_number(priv, band);
 498         if (channel) {
 499                 scan_ch->channel = cpu_to_le16(channel);
 500                 scan_ch->type = SCAN_CHANNEL_TYPE_PASSIVE;
 501                 scan_ch->active_dwell = cpu_to_le16(active_dwell);
 502                 scan_ch->passive_dwell = cpu_to_le16(passive_dwell);
 503                 /* Set txpower levels to defaults */
 504                 scan_ch->dsp_atten = 110;
 505                 if (band == IEEE80211_BAND_5GHZ)
 506                         scan_ch->tx_gain = ((1 << 5) | (3 << 3)) | 3;
 507                 else
 508                         scan_ch->tx_gain = ((1 << 5) | (5 << 3));
 509                 added++;
 510         } else
 511                 IWL_ERR(priv, "no valid channel found\n");
 512         return added;
 513 }
 514
 515 static int iwl_get_channels_for_scan(struct iwl_priv *priv,
 516                                      struct ieee80211_vif *vif,
 517                                      enum ieee80211_band band,
 518                                      u8 is_active, u8 n_probes,
 519                                      struct iwl_scan_channel *scan_ch)
 520 {
 521         struct ieee80211_channel *chan;
 522         const struct ieee80211_supported_band *sband;
 523         u16 passive_dwell = 0;
 524         u16 active_dwell = 0;
 525         int added, i;
 526         u16 channel;
 527
 528         sband = iwl_get_hw_mode(priv, band);
 529         if (!sband)
 530                 return 0;
 531
 532         active_dwell = iwl_get_active_dwell_time(priv, band, n_probes);
 533         passive_dwell = iwl_get_passive_dwell_time(priv, band);
 534
 535         if (passive_dwell <= active_dwell)
 536                 passive_dwell = active_dwell + 1;
 537
 538         for (i = 0, added = 0; i < priv->scan_request->n_channels; i++) {
 539                 chan = priv->scan_request->channels[i];
 540
 541                 if (chan->band != band)
 542                         continue;
 543
 544                 channel = chan->hw_value;
 545                 scan_ch->channel = cpu_to_le16(channel);
 546
 547                 if (!is_active || (chan->flags & IEEE80211_CHAN_PASSIVE_SCAN))
 548                         scan_ch->type = SCAN_CHANNEL_TYPE_PASSIVE;
 549                 else
 550                         scan_ch->type = SCAN_CHANNEL_TYPE_ACTIVE;
 551
 552                 if (n_probes)
 553                         scan_ch->type |= IWL_SCAN_PROBE_MASK(n_probes);
 554
 555                 scan_ch->active_dwell = cpu_to_le16(active_dwell);
 556                 scan_ch->passive_dwell = cpu_to_le16(passive_dwell);
 557
 558                 /* Set txpower levels to defaults */
 559                 scan_ch->dsp_atten = 110;
 560
 561                 /* NOTE: if we were doing 6Mb OFDM for scans we'd use
 562                  * power level:
 563                  * scan_ch->tx_gain = ((1 << 5) | (2 << 3)) | 3;
 564                  */
 565                 if (band == IEEE80211_BAND_5GHZ)
 566                         scan_ch->tx_gain = ((1 << 5) | (3 << 3)) | 3;
 567                 else
 568                         scan_ch->tx_gain = ((1 << 5) | (5 << 3));
 569
 570                 IWL_DEBUG_SCAN(priv, "Scanning ch=%d prob=0x%X [%s %d]\n",
 571                                channel, le32_to_cpu(scan_ch->type),
 572                                (scan_ch->type & SCAN_CHANNEL_TYPE_ACTIVE) ?
 573                                 "ACTIVE" : "PASSIVE",
 574                                (scan_ch->type & SCAN_CHANNEL_TYPE_ACTIVE) ?
 575                                active_dwell : passive_dwell);
 576
 577                 scan_ch++;
 578                 added++;
 579         }
 580
 581         IWL_DEBUG_SCAN(priv, "total channels to scan %d\n", added);
 582         return added;
 583 }
 584
 585 /**
 586  * iwl_fill_probe_req - fill in all required fields and IE for probe request
 587  */
 588
 589 static u16 iwl_fill_probe_req(struct ieee80211_mgmt *frame, const u8 *ta,
 590                               const u8 *ies, int ie_len, const u8 *ssid,
 591                               u8 ssid_len, int left)
 592 {
 593         int len = 0;
 594         u8 *pos = NULL;
 595
 596         /* Make sure there is enough space for the probe request,
 597          * two mandatory IEs and the data */
 598         left -= 24;
 599         if (left < 0)
 600                 return 0;
 601
 602         frame->frame_control = cpu_to_le16(IEEE80211_STYPE_PROBE_REQ);
 603         memcpy(frame->da, iwl_bcast_addr, ETH_ALEN);
 604         memcpy(frame->sa, ta, ETH_ALEN);
 605         memcpy(frame->bssid, iwl_bcast_addr, ETH_ALEN);
 606         frame->seq_ctrl = 0;
 607
 608         len += 24;
 609
 610         /* ...next IE... */
 611         pos = &frame->u.probe_req.variable[0];
 612
 613         /* fill in our SSID IE */
 614         left -= ssid_len + 2;
 615         if (left < 0)
 616                 return 0;
 617         *pos++ = WLAN_EID_SSID;
 618         *pos++ = ssid_len;
 619         if (ssid && ssid_len) {
 620                 memcpy(pos, ssid, ssid_len);
 621                 pos += ssid_len;
 622         }
 623
 624         len += ssid_len + 2;
 625
 626         if (WARN_ON(left < ie_len))
 627                 return len;
 628
 629         if (ies && ie_len) {
 630                 memcpy(pos, ies, ie_len);
 631                 len += ie_len;
 632         }
 633
 634         return (u16)len;
 635 }
 636
 637 static int iwlagn_request_scan(struct iwl_priv *priv, struct ieee80211_vif *vif)
 638 {
 639         struct iwl_host_cmd cmd = {
 640                 .id = REPLY_SCAN_CMD,
 641                 .len = { sizeof(struct iwl_scan_cmd), },
 642                 .flags = CMD_SYNC,
 643         };
 644         struct iwl_scan_cmd *scan;
 645         struct iwl_rxon_context *ctx = &priv->contexts[IWL_RXON_CTX_BSS];
 646         u32 rate_flags = 0;
 647         u16 cmd_len = 0;
 648         u16 rx_chain = 0;
 649         enum ieee80211_band band;
 650         u8 n_probes = 0;
 651         u8 rx_ant = priv->hw_params.valid_rx_ant;
 652         u8 rate;
 653         bool is_active = false;
 654         int  chan_mod;
 655         u8 active_chains;
 656         u8 scan_tx_antennas = priv->hw_params.valid_tx_ant;
 657         int ret;
 658         int scan_cmd_size = sizeof(struct iwl_scan_cmd) +
 659                             MAX_SCAN_CHANNEL * sizeof(struct iwl_scan_channel) +
 660                             priv->fw->ucode_capa.max_probe_length;
 661         const u8 *ssid = NULL;
 662         u8 ssid_len = 0;
 663
 664         if (WARN_ON_ONCE(priv->scan_request &&
 665                          priv->scan_request->n_channels > MAX_SCAN_CHANNEL))
 666                 return -EINVAL;
 667
 668         lockdep_assert_held(&priv->mutex);
 669
 670         if (vif)
 671                 ctx = iwl_rxon_ctx_from_vif(vif);
 672
 673         if (!priv->scan_cmd) {
 674                 priv->scan_cmd = kmalloc(scan_cmd_size, GFP_KERNEL);
 675                 if (!priv->scan_cmd) {
 676                         IWL_DEBUG_SCAN(priv,
 677                                        "fail to allocate memory for scan\n");
 678                         return -ENOMEM;
 679                 }
 680         }
 681         scan = priv->scan_cmd;
 682         memset(scan, 0, scan_cmd_size);
 683
 684         scan->quiet_plcp_th = IWL_PLCP_QUIET_THRESH;
 685         scan->quiet_time = IWL_ACTIVE_QUIET_TIME;
 686
 687         if (priv->scan_type != IWL_SCAN_ROC &&
 688             iwl_is_any_associated(priv)) {
 689                 u16 interval = 0;
 690                 u32 extra;
 691                 u32 suspend_time = 100;
 692                 u32 scan_suspend_time = 100;
 693
 694                 IWL_DEBUG_INFO(priv, "Scanning while associated...\n");
 695                 switch (priv->scan_type) {
 696                 case IWL_SCAN_ROC:
 697                         WARN_ON(1);
 698                         break;
 699                 case IWL_SCAN_RADIO_RESET:
 700                         interval = 0;
 701                         break;
 702                 case IWL_SCAN_NORMAL:
 703                         interval = vif->bss_conf.beacon_int;
 704                         break;
 705                 }
 706
 707                 scan->suspend_time = 0;
 708                 scan->max_out_time = cpu_to_le32(200 * 1024);
 709                 if (!interval)
 710                         interval = suspend_time;
 711
 712                 extra = (suspend_time / interval) << 22;
 713                 scan_suspend_time = (extra |
 714                     ((suspend_time % interval) * 1024));
 715                 scan->suspend_time = cpu_to_le32(scan_suspend_time);
 716                 IWL_DEBUG_SCAN(priv, "suspend_time 0x%X beacon interval %d\n",
 717                                scan_suspend_time, interval);
 718         } else if (priv->scan_type == IWL_SCAN_ROC) {
 719                 scan->suspend_time = 0;
 720                 scan->max_out_time = 0;
 721                 scan->quiet_time = 0;
 722                 scan->quiet_plcp_th = 0;
 723         }
 724
 725         switch (priv->scan_type) {
 726         case IWL_SCAN_RADIO_RESET:
 727                 IWL_DEBUG_SCAN(priv, "Start internal passive scan.\n");
 728                 break;
 729         case IWL_SCAN_NORMAL:
 730                 if (priv->scan_request->n_ssids) {
 731                         int i, p = 0;
 732                         IWL_DEBUG_SCAN(priv, "Kicking off active scan\n");
 733                         /*
 734                          * The highest priority SSID is inserted to the
 735                          * probe request template.
 736                          */
 737                         ssid_len = priv->scan_request->ssids[0].ssid_len;
 738                         ssid = priv->scan_request->ssids[0].ssid;
 739
 740                         /*
 741                          * Invert the order of ssids, the firmware will invert
 742                          * it back.
 743                          */
 744                         for (i = priv->scan_request->n_ssids - 1; i >= 1; i--) {
 745                                 scan->direct_scan[p].id = WLAN_EID_SSID;
 746                                 scan->direct_scan[p].len =
 747                                         priv->scan_request->ssids[i].ssid_len;
 748                                 memcpy(scan->direct_scan[p].ssid,
 749                                        priv->scan_request->ssids[i].ssid,
 750                                        priv->scan_request->ssids[i].ssid_len);
 751                                 n_probes++;
 752                                 p++;
 753                         }
 754                         is_active = true;
 755                 } else
 756                         IWL_DEBUG_SCAN(priv, "Start passive scan.\n");
 757                 break;
 758         case IWL_SCAN_ROC:
 759                 IWL_DEBUG_SCAN(priv, "Start ROC scan.\n");
 760                 break;
 761         }
 762
 763         scan->tx_cmd.tx_flags = TX_CMD_FLG_SEQ_CTL_MSK;
 764         scan->tx_cmd.sta_id = ctx->bcast_sta_id;
 765         scan->tx_cmd.stop_time.life_time = TX_CMD_LIFE_TIME_INFINITE;
 766
 767         switch (priv->scan_band) {
 768         case IEEE80211_BAND_2GHZ:
 769                 scan->flags = RXON_FLG_BAND_24G_MSK | RXON_FLG_AUTO_DETECT_MSK;
 770                 chan_mod = le32_to_cpu(
 771                         priv->contexts[IWL_RXON_CTX_BSS].active.flags &
 772                                                 RXON_FLG_CHANNEL_MODE_MSK)
 773                                        >> RXON_FLG_CHANNEL_MODE_POS;
 774                 if ((priv->scan_request && priv->scan_request->no_cck) ||
 775                     chan_mod == CHANNEL_MODE_PURE_40) {
 776                         rate = IWL_RATE_6M_PLCP;
 777                 } else {
 778                         rate = IWL_RATE_1M_PLCP;
 779                         rate_flags = RATE_MCS_CCK_MSK;
 780                 }
 781                 /*
 782                  * Internal scans are passive, so we can indiscriminately set
 783                  * the BT ignore flag on 2.4 GHz since it applies to TX only.
 784                  */
 785                 if (priv->cfg->bt_params &&
 786                     priv->cfg->bt_params->advanced_bt_coexist)
 787                         scan->tx_cmd.tx_flags |= TX_CMD_FLG_IGNORE_BT;
 788                 break;
 789         case IEEE80211_BAND_5GHZ:
 790                 rate = IWL_RATE_6M_PLCP;
 791                 break;
 792         default:
 793                 IWL_WARN(priv, "Invalid scan band\n");
 794                 return -EIO;
 795         }
 796
 797         /*
 798          * If active scanning is requested but a certain channel is
 799          * marked passive, we can do active scanning if we detect
 800          * transmissions.
 801          *
 802          * There is an issue with some firmware versions that triggers
 803          * a sysassert on a "good CRC threshold" of zero (== disabled),
 804          * on a radar channel even though this means that we should NOT
 805          * send probes.
 806          *
 807          * The "good CRC threshold" is the number of frames that we
 808          * need to receive during our dwell time on a channel before
 809          * sending out probes -- setting this to a huge value will
 810          * mean we never reach it, but at the same time work around
 811          * the aforementioned issue. Thus use IWL_GOOD_CRC_TH_NEVER
 812          * here instead of IWL_GOOD_CRC_TH_DISABLED.
 813          *
 814          * This was fixed in later versions along with some other
 815          * scan changes, and the threshold behaves as a flag in those
 816          * versions.
 817          */
 818         if (priv->new_scan_threshold_behaviour)
 819                 scan->good_CRC_th = is_active ? IWL_GOOD_CRC_TH_DEFAULT :
 820                                                 IWL_GOOD_CRC_TH_DISABLED;
 821         else
 822                 scan->good_CRC_th = is_active ? IWL_GOOD_CRC_TH_DEFAULT :
 823                                                 IWL_GOOD_CRC_TH_NEVER;
 824
 825         band = priv->scan_band;
 826
 827         if (band == IEEE80211_BAND_2GHZ &&
 828             priv->cfg->bt_params &&
 829             priv->cfg->bt_params->advanced_bt_coexist) {
 830                 /* transmit 2.4 GHz probes only on first antenna */
 831                 scan_tx_antennas = first_antenna(scan_tx_antennas);
 832         }
 833
 834         priv->scan_tx_ant[band] = iwl_toggle_tx_ant(priv,
 835                                                     priv->scan_tx_ant[band],
 836                                                     scan_tx_antennas);
 837         rate_flags |= iwl_ant_idx_to_flags(priv->scan_tx_ant[band]);
 838         scan->tx_cmd.rate_n_flags = iwl_hw_set_rate_n_flags(rate, rate_flags);
 839
 840         /*
 841          * In power save mode while associated use one chain,
 842          * otherwise use all chains
 843          */
 844         if (test_bit(STATUS_POWER_PMI, &priv->status) &&
 845             !(priv->hw->conf.flags & IEEE80211_CONF_IDLE)) {
 846                 /* rx_ant has been set to all valid chains previously */
 847                 active_chains = rx_ant &
 848                                 ((u8)(priv->chain_noise_data.active_chains));
 849                 if (!active_chains)
 850                         active_chains = rx_ant;
 851
 852                 IWL_DEBUG_SCAN(priv, "chain_noise_data.active_chains: %u\n",
 853                                 priv->chain_noise_data.active_chains);
 854
 855                 rx_ant = first_antenna(active_chains);
 856         }
 857         if (priv->cfg->bt_params &&
 858             priv->cfg->bt_params->advanced_bt_coexist &&
 859             priv->bt_full_concurrent) {
 860                 /* operated as 1x1 in full concurrency mode */
 861                 rx_ant = first_antenna(rx_ant);
 862         }
 863
 864         /* MIMO is not used here, but value is required */
 865         rx_chain |=
 866                 priv->hw_params.valid_rx_ant << RXON_RX_CHAIN_VALID_POS;
 867         rx_chain |= rx_ant << RXON_RX_CHAIN_FORCE_MIMO_SEL_POS;
 868         rx_chain |= rx_ant << RXON_RX_CHAIN_FORCE_SEL_POS;
 869         rx_chain |= 0x1 << RXON_RX_CHAIN_DRIVER_FORCE_POS;
 870         scan->rx_chain = cpu_to_le16(rx_chain);
 871         switch (priv->scan_type) {
 872         case IWL_SCAN_NORMAL:
 873                 cmd_len = iwl_fill_probe_req(
 874                                         (struct ieee80211_mgmt *)scan->data,
 875                                         vif->addr,
 876                                         priv->scan_request->ie,
 877                                         priv->scan_request->ie_len,
 878                                         ssid, ssid_len,
 879                                         scan_cmd_size - sizeof(*scan));
 880                 break;
 881         case IWL_SCAN_RADIO_RESET:
 882         case IWL_SCAN_ROC:
 883                 /* use bcast addr, will not be transmitted but must be valid */
 884                 cmd_len = iwl_fill_probe_req(
 885                                         (struct ieee80211_mgmt *)scan->data,
 886                                         iwl_bcast_addr, NULL, 0,
 887                                         NULL, 0,
 888                                         scan_cmd_size - sizeof(*scan));
 889                 break;
 890         default:
 891                 BUG();
 892         }
 893         scan->tx_cmd.len = cpu_to_le16(cmd_len);
 894
 895         scan->filter_flags |= (RXON_FILTER_ACCEPT_GRP_MSK |
 896                                RXON_FILTER_BCON_AWARE_MSK);
 897
 898         switch (priv->scan_type) {
 899         case IWL_SCAN_RADIO_RESET:
 900                 scan->channel_count =
 901                         iwl_get_single_channel_for_scan(priv, vif, band,
 902                                 (void *)&scan->data[cmd_len]);
 903                 break;
 904         case IWL_SCAN_NORMAL:
 905                 scan->channel_count =
 906                         iwl_get_channels_for_scan(priv, vif, band,
 907                                 is_active, n_probes,
 908                                 (void *)&scan->data[cmd_len]);
 909                 break;
 910         case IWL_SCAN_ROC: {
 911                 struct iwl_scan_channel *scan_ch;
 912                 int n_chan, i;
 913                 u16 dwell;
 914
 915                 dwell = iwl_limit_dwell(priv, priv->hw_roc_duration);
 916                 n_chan = DIV_ROUND_UP(priv->hw_roc_duration, dwell);
 917
 918                 scan->channel_count = n_chan;
 919
 920                 scan_ch = (void *)&scan->data[cmd_len];
 921
 922                 for (i = 0; i < n_chan; i++) {
 923                         scan_ch->type = SCAN_CHANNEL_TYPE_PASSIVE;
 924                         scan_ch->channel =
 925                                 cpu_to_le16(priv->hw_roc_channel->hw_value);
 926
 927                         if (i == n_chan - 1)
 928                                 dwell = priv->hw_roc_duration - i * dwell;
 929
 930                         scan_ch->active_dwell =
 931                         scan_ch->passive_dwell = cpu_to_le16(dwell);
 932
 933                         /* Set txpower levels to defaults */
 934                         scan_ch->dsp_atten = 110;
 935
 936                         /* NOTE: if we were doing 6Mb OFDM for scans we'd use
 937                          * power level:
 938                          * scan_ch->tx_gain = ((1 << 5) | (2 << 3)) | 3;
 939                          */
 940                         if (priv->hw_roc_channel->band == IEEE80211_BAND_5GHZ)
 941                                 scan_ch->tx_gain = ((1 << 5) | (3 << 3)) | 3;
 942                         else
 943                                 scan_ch->tx_gain = ((1 << 5) | (5 << 3));
 944
 945                         scan_ch++;
 946                 }
 947                 }
 948
 949                 break;
 950         }
 951
 952         if (scan->channel_count == 0) {
 953                 IWL_DEBUG_SCAN(priv, "channel count %d\n", scan->channel_count);
 954                 return -EIO;
 955         }
 956
 957         cmd.len[0] += le16_to_cpu(scan->tx_cmd.len) +
 958             scan->channel_count * sizeof(struct iwl_scan_channel);
 959         cmd.data[0] = scan;
 960         cmd.dataflags[0] = IWL_HCMD_DFL_NOCOPY;
 961         scan->len = cpu_to_le16(cmd.len[0]);
 962
 963         /* set scan bit here for PAN params */
 964         set_bit(STATUS_SCAN_HW, &priv->status);
 965
 966         ret = iwlagn_set_pan_params(priv);
 967         if (ret) {
 968                 clear_bit(STATUS_SCAN_HW, &priv->status);
 969                 return ret;
 970         }
 971
 972         ret = iwl_dvm_send_cmd(priv, &cmd);
 973         if (ret) {
 974                 clear_bit(STATUS_SCAN_HW, &priv->status);
 975                 iwlagn_set_pan_params(priv);
 976         }
 977
 978         return ret;
 979 }
 980
 981 void iwl_init_scan_params(struct iwl_priv *priv)
 982 {
 983         u8 ant_idx = fls(priv->hw_params.valid_tx_ant) - 1;
 984         if (!priv->scan_tx_ant[IEEE80211_BAND_5GHZ])
 985                 priv->scan_tx_ant[IEEE80211_BAND_5GHZ] = ant_idx;
 986         if (!priv->scan_tx_ant[IEEE80211_BAND_2GHZ])
 987                 priv->scan_tx_ant[IEEE80211_BAND_2GHZ] = ant_idx;
 988 }
 989
 990 int __must_check iwl_scan_initiate(struct iwl_priv *priv,
 991                                    struct ieee80211_vif *vif,
 992                                    enum iwl_scan_type scan_type,
 993                                    enum ieee80211_band band)
 994 {
 995         int ret;
 996
 997         lockdep_assert_held(&priv->mutex);
 998
 999         cancel_delayed_work(&priv->scan_check);
1000
1001         if (!iwl_is_ready_rf(priv)) {
1002                 IWL_WARN(priv, "Request scan called when driver not ready.\n");
1003                 return -EIO;
1004         }
1005
1006         if (test_bit(STATUS_SCAN_HW, &priv->status)) {
1007                 IWL_DEBUG_SCAN(priv,
1008                         "Multiple concurrent scan requests in parallel.\n");
1009                 return -EBUSY;
1010         }
1011
1012         if (test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
1013                 IWL_DEBUG_SCAN(priv, "Scan request while abort pending.\n");
1014                 return -EBUSY;
1015         }
1016
1017         IWL_DEBUG_SCAN(priv, "Starting %sscan...\n",
1018                         scan_type == IWL_SCAN_NORMAL ? "" :
1019                         scan_type == IWL_SCAN_ROC ? "remain-on-channel " :
1020                         "internal short ");
1021
1022         set_bit(STATUS_SCANNING, &priv->status);
1023         priv->scan_type = scan_type;
1024         priv->scan_start = jiffies;
1025         priv->scan_band = band;
1026
1027         ret = iwlagn_request_scan(priv, vif);
1028         if (ret) {
1029                 clear_bit(STATUS_SCANNING, &priv->status);
1030                 priv->scan_type = IWL_SCAN_NORMAL;
1031                 return ret;
1032         }
1033
1034         queue_delayed_work(priv->workqueue, &priv->scan_check,
1035                            IWL_SCAN_CHECK_WATCHDOG);
1036
1037         return 0;
1038 }
1039
1040
1041 /*
1042  * internal short scan, this function should only been called while associated.
1043  * It will reset and tune the radio to prevent possible RF related problem
1044  */
1045 void iwl_internal_short_hw_scan(struct iwl_priv *priv)
1046 {
1047         queue_work(priv->workqueue, &priv->start_internal_scan);
1048 }
1049
1050 static void iwl_bg_start_internal_scan(struct work_struct *work)
1051 {
1052         struct iwl_priv *priv =
1053                 container_of(work, struct iwl_priv, start_internal_scan);
1054
1055         IWL_DEBUG_SCAN(priv, "Start internal scan\n");
1056
1057         mutex_lock(&priv->mutex);
1058
1059         if (priv->scan_type == IWL_SCAN_RADIO_RESET) {
1060                 IWL_DEBUG_SCAN(priv, "Internal scan already in progress\n");
1061                 goto unlock;
1062         }
1063
1064         if (test_bit(STATUS_SCANNING, &priv->status)) {
1065                 IWL_DEBUG_SCAN(priv, "Scan already in progress.\n");
1066                 goto unlock;
1067         }
1068
1069         if (iwl_scan_initiate(priv, NULL, IWL_SCAN_RADIO_RESET, priv->band))
1070                 IWL_DEBUG_SCAN(priv, "failed to start internal short scan\n");
1071  unlock:
1072         mutex_unlock(&priv->mutex);
1073 }
1074
1075 static void iwl_bg_scan_check(struct work_struct *data)
1076 {
1077         struct iwl_priv *priv =
1078             container_of(data, struct iwl_priv, scan_check.work);
1079
1080         IWL_DEBUG_SCAN(priv, "Scan check work\n");
1081
1082         /* Since we are here firmware does not finish scan and
1083          * most likely is in bad shape, so we don't bother to
1084          * send abort command, just force scan complete to mac80211 */
1085         mutex_lock(&priv->mutex);
1086         iwl_force_scan_end(priv);
1087         mutex_unlock(&priv->mutex);
1088 }
1089
1090 static void iwl_bg_abort_scan(struct work_struct *work)
1091 {
1092         struct iwl_priv *priv = container_of(work, struct iwl_priv, abort_scan);
1093
1094         IWL_DEBUG_SCAN(priv, "Abort scan work\n");
1095
1096         /* We keep scan_check work queued in case when firmware will not
1097          * report back scan completed notification */
1098         mutex_lock(&priv->mutex);
1099         iwl_scan_cancel_timeout(priv, 200);
1100         mutex_unlock(&priv->mutex);
1101 }
1102
1103 static void iwl_bg_scan_completed(struct work_struct *work)
1104 {
1105         struct iwl_priv *priv =
1106                 container_of(work, struct iwl_priv, scan_completed);
1107
1108         mutex_lock(&priv->mutex);
1109         iwl_process_scan_complete(priv);
1110         mutex_unlock(&priv->mutex);
1111 }
1112
1113 void iwl_setup_scan_deferred_work(struct iwl_priv *priv)
1114 {
1115         INIT_WORK(&priv->scan_completed, iwl_bg_scan_completed);
1116         INIT_WORK(&priv->abort_scan, iwl_bg_abort_scan);
1117         INIT_WORK(&priv->start_internal_scan, iwl_bg_start_internal_scan);
1118         INIT_DELAYED_WORK(&priv->scan_check, iwl_bg_scan_check);
1119 }
1120
1121 void iwl_cancel_scan_deferred_work(struct iwl_priv *priv)
1122 {
1123         cancel_work_sync(&priv->start_internal_scan);
1124         cancel_work_sync(&priv->abort_scan);
1125         cancel_work_sync(&priv->scan_completed);
1126
1127         if (cancel_delayed_work_sync(&priv->scan_check)) {
1128                 mutex_lock(&priv->mutex);
1129                 iwl_force_scan_end(priv);
1130                 mutex_unlock(&priv->mutex);
1131         }
1132 }
1133
1134 void iwl_scan_roc_expired(struct iwl_priv *priv)
1135 {
1136         /*
1137          * The status bit should be set here, to prevent a race
1138          * where the atomic_read returns 1, but before the execution continues
1139          * iwl_scan_offchannel_skb_status() checks if the status bit is set
1140          */
1141         set_bit(STATUS_SCAN_ROC_EXPIRED, &priv->status);
1142
1143         if (atomic_read(&priv->num_aux_in_flight) == 0) {
1144                 ieee80211_remain_on_channel_expired(priv->hw);
1145                 priv->hw_roc_channel = NULL;
1146                 schedule_delayed_work(&priv->hw_roc_disable_work,
1147                                       10 * HZ);
1148
1149                 clear_bit(STATUS_SCAN_ROC_EXPIRED, &priv->status);
1150         } else {
1151                 IWL_DEBUG_SCAN(priv, "ROC done with %d frames in aux\n",
1152                                atomic_read(&priv->num_aux_in_flight));
1153         }
1154 }
1155
1156 void iwl_scan_offchannel_skb(struct iwl_priv *priv)
1157 {
1158         WARN_ON(!priv->hw_roc_start_notified);
1159         atomic_inc(&priv->num_aux_in_flight);
1160 }
1161
1162 void iwl_scan_offchannel_skb_status(struct iwl_priv *priv)
1163 {
1164         if (atomic_dec_return(&priv->num_aux_in_flight) == 0 &&
1165             test_bit(STATUS_SCAN_ROC_EXPIRED, &priv->status)) {
1166                 IWL_DEBUG_SCAN(priv, "0 aux frames. Calling ROC expired\n");
1167                 iwl_scan_roc_expired(priv);
1168         }
1169 }