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

   1 /******************************************************************************
   2  *
   3  * GPL LICENSE SUMMARY
   4  *
   5  * Copyright(c) 2008 - 2010 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/types.h>
  29 #include <linux/etherdevice.h>
  30 #include <net/mac80211.h>
  31
  32 #include "iwl-eeprom.h"
  33 #include "iwl-dev.h"
  34 #include "iwl-core.h"
  35 #include "iwl-sta.h"
  36 #include "iwl-io.h"
  37 #include "iwl-helpers.h"
  38
  39 /* For active scan, listen ACTIVE_DWELL_TIME (msec) on each channel after
  40  * sending probe req.  This should be set long enough to hear probe responses
  41  * from more than one AP.  */
  42 #define IWL_ACTIVE_DWELL_TIME_24    (30)       /* all times in msec */
  43 #define IWL_ACTIVE_DWELL_TIME_52    (20)
  44
  45 #define IWL_ACTIVE_DWELL_FACTOR_24GHZ (3)
  46 #define IWL_ACTIVE_DWELL_FACTOR_52GHZ (2)
  47
  48 /* For passive scan, listen PASSIVE_DWELL_TIME (msec) on each channel.
  49  * Must be set longer than active dwell time.
  50  * For the most reliable scan, set > AP beacon interval (typically 100msec). */
  51 #define IWL_PASSIVE_DWELL_TIME_24   (20)       /* all times in msec */
  52 #define IWL_PASSIVE_DWELL_TIME_52   (10)
  53 #define IWL_PASSIVE_DWELL_BASE      (100)
  54 #define IWL_CHANNEL_TUNE_TIME       5
  55
  56
  57
  58 /**
  59  * iwl_scan_cancel - Cancel any currently executing HW scan
  60  *
  61  * NOTE: priv->mutex is not required before calling this function
  62  */
  63 int iwl_scan_cancel(struct iwl_priv *priv)
  64 {
  65         if (!test_bit(STATUS_SCAN_HW, &priv->status)) {
  66                 clear_bit(STATUS_SCANNING, &priv->status);
  67                 return 0;
  68         }
  69
  70         if (test_bit(STATUS_SCANNING, &priv->status)) {
  71                 if (!test_and_set_bit(STATUS_SCAN_ABORTING, &priv->status)) {
  72                         IWL_DEBUG_SCAN(priv, "Queuing scan abort.\n");
  73                         queue_work(priv->workqueue, &priv->abort_scan);
  74
  75                 } else
  76                         IWL_DEBUG_SCAN(priv, "Scan abort already in progress.\n");
  77
  78                 return test_bit(STATUS_SCANNING, &priv->status);
  79         }
  80
  81         return 0;
  82 }
  83 EXPORT_SYMBOL(iwl_scan_cancel);
  84 /**
  85  * iwl_scan_cancel_timeout - Cancel any currently executing HW scan
  86  * @ms: amount of time to wait (in milliseconds) for scan to abort
  87  *
  88  * NOTE: priv->mutex must be held before calling this function
  89  */
  90 int iwl_scan_cancel_timeout(struct iwl_priv *priv, unsigned long ms)
  91 {
  92         unsigned long now = jiffies;
  93         int ret;
  94
  95         ret = iwl_scan_cancel(priv);
  96         if (ret && ms) {
  97                 mutex_unlock(&priv->mutex);
  98                 while (!time_after(jiffies, now + msecs_to_jiffies(ms)) &&
  99                                 test_bit(STATUS_SCANNING, &priv->status))
 100                         msleep(1);
 101                 mutex_lock(&priv->mutex);
 102
 103                 return test_bit(STATUS_SCANNING, &priv->status);
 104         }
 105
 106         return ret;
 107 }
 108 EXPORT_SYMBOL(iwl_scan_cancel_timeout);
 109
 110 static int iwl_send_scan_abort(struct iwl_priv *priv)
 111 {
 112         int ret = 0;
 113         struct iwl_rx_packet *pkt;
 114         struct iwl_host_cmd cmd = {
 115                 .id = REPLY_SCAN_ABORT_CMD,
 116                 .flags = CMD_WANT_SKB,
 117         };
 118
 119         /* If there isn't a scan actively going on in the hardware
 120          * then we are in between scan bands and not actually
 121          * actively scanning, so don't send the abort command */
 122         if (!test_bit(STATUS_SCAN_HW, &priv->status)) {
 123                 clear_bit(STATUS_SCAN_ABORTING, &priv->status);
 124                 return 0;
 125         }
 126
 127         ret = iwl_send_cmd_sync(priv, &cmd);
 128         if (ret) {
 129                 clear_bit(STATUS_SCAN_ABORTING, &priv->status);
 130                 return ret;
 131         }
 132
 133         pkt = (struct iwl_rx_packet *)cmd.reply_page;
 134         if (pkt->u.status != CAN_ABORT_STATUS) {
 135                 /* The scan abort will return 1 for success or
 136                  * 2 for "failure".  A failure condition can be
 137                  * due to simply not being in an active scan which
 138                  * can occur if we send the scan abort before we
 139                  * the microcode has notified us that a scan is
 140                  * completed. */
 141                 IWL_DEBUG_INFO(priv, "SCAN_ABORT returned %d.\n", pkt->u.status);
 142                 clear_bit(STATUS_SCAN_ABORTING, &priv->status);
 143                 clear_bit(STATUS_SCAN_HW, &priv->status);
 144         }
 145
 146         iwl_free_pages(priv, cmd.reply_page);
 147
 148         return ret;
 149 }
 150
 151 /* Service response to REPLY_SCAN_CMD (0x80) */
 152 static void iwl_rx_reply_scan(struct iwl_priv *priv,
 153                               struct iwl_rx_mem_buffer *rxb)
 154 {
 155 #ifdef CONFIG_IWLWIFI_DEBUG
 156         struct iwl_rx_packet *pkt = rxb_addr(rxb);
 157         struct iwl_scanreq_notification *notif =
 158             (struct iwl_scanreq_notification *)pkt->u.raw;
 159
 160         IWL_DEBUG_RX(priv, "Scan request status = 0x%x\n", notif->status);
 161 #endif
 162 }
 163
 164 /* Service SCAN_START_NOTIFICATION (0x82) */
 165 static void iwl_rx_scan_start_notif(struct iwl_priv *priv,
 166                                     struct iwl_rx_mem_buffer *rxb)
 167 {
 168         struct iwl_rx_packet *pkt = rxb_addr(rxb);
 169         struct iwl_scanstart_notification *notif =
 170             (struct iwl_scanstart_notification *)pkt->u.raw;
 171         priv->scan_start_tsf = le32_to_cpu(notif->tsf_low);
 172         IWL_DEBUG_SCAN(priv, "Scan start: "
 173                        "%d [802.11%s] "
 174                        "(TSF: 0x%08X:%08X) - %d (beacon timer %u)\n",
 175                        notif->channel,
 176                        notif->band ? "bg" : "a",
 177                        le32_to_cpu(notif->tsf_high),
 178                        le32_to_cpu(notif->tsf_low),
 179                        notif->status, notif->beacon_timer);
 180 }
 181
 182 /* Service SCAN_RESULTS_NOTIFICATION (0x83) */
 183 static void iwl_rx_scan_results_notif(struct iwl_priv *priv,
 184                                       struct iwl_rx_mem_buffer *rxb)
 185 {
 186 #ifdef CONFIG_IWLWIFI_DEBUG
 187         struct iwl_rx_packet *pkt = rxb_addr(rxb);
 188         struct iwl_scanresults_notification *notif =
 189             (struct iwl_scanresults_notification *)pkt->u.raw;
 190
 191         IWL_DEBUG_SCAN(priv, "Scan ch.res: "
 192                        "%d [802.11%s] "
 193                        "(TSF: 0x%08X:%08X) - %d "
 194                        "elapsed=%lu usec\n",
 195                        notif->channel,
 196                        notif->band ? "bg" : "a",
 197                        le32_to_cpu(notif->tsf_high),
 198                        le32_to_cpu(notif->tsf_low),
 199                        le32_to_cpu(notif->statistics[0]),
 200                        le32_to_cpu(notif->tsf_low) - priv->scan_start_tsf);
 201 #endif
 202 }
 203
 204 /* Service SCAN_COMPLETE_NOTIFICATION (0x84) */
 205 static void iwl_rx_scan_complete_notif(struct iwl_priv *priv,
 206                                        struct iwl_rx_mem_buffer *rxb)
 207 {
 208 #ifdef CONFIG_IWLWIFI_DEBUG
 209         struct iwl_rx_packet *pkt = rxb_addr(rxb);
 210         struct iwl_scancomplete_notification *scan_notif = (void *)pkt->u.raw;
 211
 212         IWL_DEBUG_SCAN(priv, "Scan complete: %d channels (TSF 0x%08X:%08X) - %d\n",
 213                        scan_notif->scanned_channels,
 214                        scan_notif->tsf_low,
 215                        scan_notif->tsf_high, scan_notif->status);
 216 #endif
 217
 218         /* The HW is no longer scanning */
 219         clear_bit(STATUS_SCAN_HW, &priv->status);
 220
 221         IWL_DEBUG_INFO(priv, "Scan pass on %sGHz took %dms\n",
 222                        (priv->scan_band == IEEE80211_BAND_2GHZ) ? "2.4" : "5.2",
 223                        jiffies_to_msecs(elapsed_jiffies
 224                                         (priv->scan_pass_start, jiffies)));
 225
 226         /*
 227          * If a request to abort was given, or the scan did not succeed
 228          * then we reset the scan state machine and terminate,
 229          * re-queuing another scan if one has been requested
 230          */
 231         if (test_and_clear_bit(STATUS_SCAN_ABORTING, &priv->status))
 232                 IWL_DEBUG_INFO(priv, "Aborted scan completed.\n");
 233
 234         IWL_DEBUG_INFO(priv, "Setting scan to off\n");
 235
 236         clear_bit(STATUS_SCANNING, &priv->status);
 237
 238         IWL_DEBUG_INFO(priv, "Scan took %dms\n",
 239                 jiffies_to_msecs(elapsed_jiffies(priv->scan_start, jiffies)));
 240
 241         queue_work(priv->workqueue, &priv->scan_completed);
 242 }
 243
 244 void iwl_setup_rx_scan_handlers(struct iwl_priv *priv)
 245 {
 246         /* scan handlers */
 247         priv->rx_handlers[REPLY_SCAN_CMD] = iwl_rx_reply_scan;
 248         priv->rx_handlers[SCAN_START_NOTIFICATION] = iwl_rx_scan_start_notif;
 249         priv->rx_handlers[SCAN_RESULTS_NOTIFICATION] =
 250                                         iwl_rx_scan_results_notif;
 251         priv->rx_handlers[SCAN_COMPLETE_NOTIFICATION] =
 252                                         iwl_rx_scan_complete_notif;
 253 }
 254 EXPORT_SYMBOL(iwl_setup_rx_scan_handlers);
 255
 256 inline u16 iwl_get_active_dwell_time(struct iwl_priv *priv,
 257                                      enum ieee80211_band band,
 258                                      u8 n_probes)
 259 {
 260         if (band == IEEE80211_BAND_5GHZ)
 261                 return IWL_ACTIVE_DWELL_TIME_52 +
 262                         IWL_ACTIVE_DWELL_FACTOR_52GHZ * (n_probes + 1);
 263         else
 264                 return IWL_ACTIVE_DWELL_TIME_24 +
 265                         IWL_ACTIVE_DWELL_FACTOR_24GHZ * (n_probes + 1);
 266 }
 267 EXPORT_SYMBOL(iwl_get_active_dwell_time);
 268
 269 u16 iwl_get_passive_dwell_time(struct iwl_priv *priv,
 270                                enum ieee80211_band band)
 271 {
 272         u16 passive = (band == IEEE80211_BAND_2GHZ) ?
 273             IWL_PASSIVE_DWELL_BASE + IWL_PASSIVE_DWELL_TIME_24 :
 274             IWL_PASSIVE_DWELL_BASE + IWL_PASSIVE_DWELL_TIME_52;
 275
 276         if (iwl_is_associated(priv)) {
 277                 /* If we're associated, we clamp the maximum passive
 278                  * dwell time to be 98% of the beacon interval (minus
 279                  * 2 * channel tune time) */
 280                 passive = priv->beacon_int;
 281                 if ((passive > IWL_PASSIVE_DWELL_BASE) || !passive)
 282                         passive = IWL_PASSIVE_DWELL_BASE;
 283                 passive = (passive * 98) / 100 - IWL_CHANNEL_TUNE_TIME * 2;
 284         }
 285
 286         return passive;
 287 }
 288 EXPORT_SYMBOL(iwl_get_passive_dwell_time);
 289
 290 static int iwl_get_single_channel_for_scan(struct iwl_priv *priv,
 291                                      enum ieee80211_band band,
 292                                      struct iwl_scan_channel *scan_ch)
 293 {
 294         const struct ieee80211_supported_band *sband;
 295         const struct iwl_channel_info *ch_info;
 296         u16 passive_dwell = 0;
 297         u16 active_dwell = 0;
 298         int i, added = 0;
 299         u16 channel = 0;
 300
 301         sband = iwl_get_hw_mode(priv, band);
 302         if (!sband) {
 303                 IWL_ERR(priv, "invalid band\n");
 304                 return added;
 305         }
 306
 307         active_dwell = iwl_get_active_dwell_time(priv, band, 0);
 308         passive_dwell = iwl_get_passive_dwell_time(priv, band);
 309
 310         if (passive_dwell <= active_dwell)
 311                 passive_dwell = active_dwell + 1;
 312
 313         /* only scan single channel, good enough to reset the RF */
 314         /* pick the first valid not in-use channel */
 315         if (band == IEEE80211_BAND_5GHZ) {
 316                 for (i = 14; i < priv->channel_count; i++) {
 317                         if (priv->channel_info[i].channel !=
 318                             le16_to_cpu(priv->staging_rxon.channel)) {
 319                                 channel = priv->channel_info[i].channel;
 320                                 ch_info = iwl_get_channel_info(priv,
 321                                         band, channel);
 322                                 if (is_channel_valid(ch_info))
 323                                         break;
 324                         }
 325                 }
 326         } else {
 327                 for (i = 0; i < 14; i++) {
 328                         if (priv->channel_info[i].channel !=
 329                             le16_to_cpu(priv->staging_rxon.channel)) {
 330                                         channel =
 331                                                 priv->channel_info[i].channel;
 332                                         ch_info = iwl_get_channel_info(priv,
 333                                                 band, channel);
 334                                         if (is_channel_valid(ch_info))
 335                                                 break;
 336                         }
 337                 }
 338         }
 339         if (channel) {
 340                 scan_ch->channel = cpu_to_le16(channel);
 341                 scan_ch->type = SCAN_CHANNEL_TYPE_PASSIVE;
 342                 scan_ch->active_dwell = cpu_to_le16(active_dwell);
 343                 scan_ch->passive_dwell = cpu_to_le16(passive_dwell);
 344                 /* Set txpower levels to defaults */
 345                 scan_ch->dsp_atten = 110;
 346                 if (band == IEEE80211_BAND_5GHZ)
 347                         scan_ch->tx_gain = ((1 << 5) | (3 << 3)) | 3;
 348                 else
 349                         scan_ch->tx_gain = ((1 << 5) | (5 << 3));
 350                 added++;
 351         } else
 352                 IWL_ERR(priv, "no valid channel found\n");
 353         return added;
 354 }
 355
 356 static int iwl_get_channels_for_scan(struct iwl_priv *priv,
 357                                      enum ieee80211_band band,
 358                                      u8 is_active, u8 n_probes,
 359                                      struct iwl_scan_channel *scan_ch)
 360 {
 361         struct ieee80211_channel *chan;
 362         const struct ieee80211_supported_band *sband;
 363         const struct iwl_channel_info *ch_info;
 364         u16 passive_dwell = 0;
 365         u16 active_dwell = 0;
 366         int added, i;
 367         u16 channel;
 368
 369         sband = iwl_get_hw_mode(priv, band);
 370         if (!sband)
 371                 return 0;
 372
 373         active_dwell = iwl_get_active_dwell_time(priv, band, n_probes);
 374         passive_dwell = iwl_get_passive_dwell_time(priv, band);
 375
 376         if (passive_dwell <= active_dwell)
 377                 passive_dwell = active_dwell + 1;
 378
 379         for (i = 0, added = 0; i < priv->scan_request->n_channels; i++) {
 380                 chan = priv->scan_request->channels[i];
 381
 382                 if (chan->band != band)
 383                         continue;
 384
 385                 channel = ieee80211_frequency_to_channel(chan->center_freq);
 386                 scan_ch->channel = cpu_to_le16(channel);
 387
 388                 ch_info = iwl_get_channel_info(priv, band, channel);
 389                 if (!is_channel_valid(ch_info)) {
 390                         IWL_DEBUG_SCAN(priv, "Channel %d is INVALID for this band.\n",
 391                                         channel);
 392                         continue;
 393                 }
 394
 395                 if (!is_active || is_channel_passive(ch_info) ||
 396                     (chan->flags & IEEE80211_CHAN_PASSIVE_SCAN))
 397                         scan_ch->type = SCAN_CHANNEL_TYPE_PASSIVE;
 398                 else
 399                         scan_ch->type = SCAN_CHANNEL_TYPE_ACTIVE;
 400
 401                 if (n_probes)
 402                         scan_ch->type |= IWL_SCAN_PROBE_MASK(n_probes);
 403
 404                 scan_ch->active_dwell = cpu_to_le16(active_dwell);
 405                 scan_ch->passive_dwell = cpu_to_le16(passive_dwell);
 406
 407                 /* Set txpower levels to defaults */
 408                 scan_ch->dsp_atten = 110;
 409
 410                 /* NOTE: if we were doing 6Mb OFDM for scans we'd use
 411                  * power level:
 412                  * scan_ch->tx_gain = ((1 << 5) | (2 << 3)) | 3;
 413                  */
 414                 if (band == IEEE80211_BAND_5GHZ)
 415                         scan_ch->tx_gain = ((1 << 5) | (3 << 3)) | 3;
 416                 else
 417                         scan_ch->tx_gain = ((1 << 5) | (5 << 3));
 418
 419                 IWL_DEBUG_SCAN(priv, "Scanning ch=%d prob=0x%X [%s %d]\n",
 420                                channel, le32_to_cpu(scan_ch->type),
 421                                (scan_ch->type & SCAN_CHANNEL_TYPE_ACTIVE) ?
 422                                 "ACTIVE" : "PASSIVE",
 423                                (scan_ch->type & SCAN_CHANNEL_TYPE_ACTIVE) ?
 424                                active_dwell : passive_dwell);
 425
 426                 scan_ch++;
 427                 added++;
 428         }
 429
 430         IWL_DEBUG_SCAN(priv, "total channels to scan %d\n", added);
 431         return added;
 432 }
 433
 434 void iwl_init_scan_params(struct iwl_priv *priv)
 435 {
 436         u8 ant_idx = fls(priv->hw_params.valid_tx_ant) - 1;
 437         if (!priv->scan_tx_ant[IEEE80211_BAND_5GHZ])
 438                 priv->scan_tx_ant[IEEE80211_BAND_5GHZ] = ant_idx;
 439         if (!priv->scan_tx_ant[IEEE80211_BAND_2GHZ])
 440                 priv->scan_tx_ant[IEEE80211_BAND_2GHZ] = ant_idx;
 441 }
 442 EXPORT_SYMBOL(iwl_init_scan_params);
 443
 444 static int iwl_scan_initiate(struct iwl_priv *priv)
 445 {
 446         WARN_ON(!mutex_is_locked(&priv->mutex));
 447
 448         IWL_DEBUG_INFO(priv, "Starting scan...\n");
 449         set_bit(STATUS_SCANNING, &priv->status);
 450         priv->is_internal_short_scan = false;
 451         priv->scan_start = jiffies;
 452         priv->scan_pass_start = priv->scan_start;
 453
 454         queue_work(priv->workqueue, &priv->request_scan);
 455
 456         return 0;
 457 }
 458
 459 int iwl_mac_hw_scan(struct ieee80211_hw *hw,
 460                      struct cfg80211_scan_request *req)
 461 {
 462         unsigned long flags;
 463         struct iwl_priv *priv = hw->priv;
 464         int ret;
 465
 466         IWL_DEBUG_MAC80211(priv, "enter\n");
 467
 468         if (req->n_channels == 0)
 469                 return -EINVAL;
 470
 471         mutex_lock(&priv->mutex);
 472         spin_lock_irqsave(&priv->lock, flags);
 473
 474         if (!iwl_is_ready_rf(priv)) {
 475                 ret = -EIO;
 476                 IWL_DEBUG_MAC80211(priv, "leave - not ready or exit pending\n");
 477                 goto out_unlock;
 478         }
 479
 480         if (test_bit(STATUS_SCANNING, &priv->status)) {
 481                 IWL_DEBUG_SCAN(priv, "Scan already in progress.\n");
 482                 ret = -EAGAIN;
 483                 goto out_unlock;
 484         }
 485
 486         if (test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
 487                 IWL_DEBUG_SCAN(priv, "Scan request while abort pending\n");
 488                 ret = -EAGAIN;
 489                 goto out_unlock;
 490         }
 491
 492         /* mac80211 will only ask for one band at a time */
 493         priv->scan_band = req->channels[0]->band;
 494         priv->scan_request = req;
 495
 496         ret = iwl_scan_initiate(priv);
 497
 498         IWL_DEBUG_MAC80211(priv, "leave\n");
 499
 500 out_unlock:
 501         spin_unlock_irqrestore(&priv->lock, flags);
 502         mutex_unlock(&priv->mutex);
 503
 504         return ret;
 505 }
 506 EXPORT_SYMBOL(iwl_mac_hw_scan);
 507
 508 /*
 509  * internal short scan, this function should only been called while associated.
 510  * It will reset and tune the radio to prevent possible RF related problem
 511  */
 512 void iwl_internal_short_hw_scan(struct iwl_priv *priv)
 513 {
 514         queue_work(priv->workqueue, &priv->start_internal_scan);
 515 }
 516
 517 static void iwl_bg_start_internal_scan(struct work_struct *work)
 518 {
 519         struct iwl_priv *priv =
 520                 container_of(work, struct iwl_priv, start_internal_scan);
 521
 522         mutex_lock(&priv->mutex);
 523
 524         if (!iwl_is_ready_rf(priv)) {
 525                 IWL_DEBUG_SCAN(priv, "not ready or exit pending\n");
 526                 goto unlock;
 527         }
 528
 529         if (test_bit(STATUS_SCANNING, &priv->status)) {
 530                 IWL_DEBUG_SCAN(priv, "Scan already in progress.\n");
 531                 goto unlock;
 532         }
 533
 534         if (test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
 535                 IWL_DEBUG_SCAN(priv, "Scan request while abort pending\n");
 536                 goto unlock;
 537         }
 538
 539         priv->scan_band = priv->band;
 540
 541         IWL_DEBUG_SCAN(priv, "Start internal short scan...\n");
 542         set_bit(STATUS_SCANNING, &priv->status);
 543         priv->is_internal_short_scan = true;
 544         queue_work(priv->workqueue, &priv->request_scan);
 545  unlock:
 546         mutex_unlock(&priv->mutex);
 547 }
 548
 549 #define IWL_SCAN_CHECK_WATCHDOG (7 * HZ)
 550
 551 void iwl_bg_scan_check(struct work_struct *data)
 552 {
 553         struct iwl_priv *priv =
 554             container_of(data, struct iwl_priv, scan_check.work);
 555
 556         if (test_bit(STATUS_EXIT_PENDING, &priv->status))
 557                 return;
 558
 559         mutex_lock(&priv->mutex);
 560         if (test_bit(STATUS_SCANNING, &priv->status) ||
 561             test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
 562                 IWL_DEBUG_SCAN(priv, "Scan completion watchdog resetting "
 563                         "adapter (%dms)\n",
 564                         jiffies_to_msecs(IWL_SCAN_CHECK_WATCHDOG));
 565
 566                 if (!test_bit(STATUS_EXIT_PENDING, &priv->status))
 567                         iwl_send_scan_abort(priv);
 568         }
 569         mutex_unlock(&priv->mutex);
 570 }
 571 EXPORT_SYMBOL(iwl_bg_scan_check);
 572
 573 /**
 574  * iwl_fill_probe_req - fill in all required fields and IE for probe request
 575  */
 576
 577 u16 iwl_fill_probe_req(struct iwl_priv *priv, struct ieee80211_mgmt *frame,
 578                        const u8 *ies, int ie_len, int left)
 579 {
 580         int len = 0;
 581         u8 *pos = NULL;
 582
 583         /* Make sure there is enough space for the probe request,
 584          * two mandatory IEs and the data */
 585         left -= 24;
 586         if (left < 0)
 587                 return 0;
 588
 589         frame->frame_control = cpu_to_le16(IEEE80211_STYPE_PROBE_REQ);
 590         memcpy(frame->da, iwl_bcast_addr, ETH_ALEN);
 591         memcpy(frame->sa, priv->mac_addr, ETH_ALEN);
 592         memcpy(frame->bssid, iwl_bcast_addr, ETH_ALEN);
 593         frame->seq_ctrl = 0;
 594
 595         len += 24;
 596
 597         /* ...next IE... */
 598         pos = &frame->u.probe_req.variable[0];
 599
 600         /* fill in our indirect SSID IE */
 601         left -= 2;
 602         if (left < 0)
 603                 return 0;
 604         *pos++ = WLAN_EID_SSID;
 605         *pos++ = 0;
 606
 607         len += 2;
 608
 609         if (WARN_ON(left < ie_len))
 610                 return len;
 611
 612         if (ies)
 613                 memcpy(pos, ies, ie_len);
 614         len += ie_len;
 615         left -= ie_len;
 616
 617         return (u16)len;
 618 }
 619 EXPORT_SYMBOL(iwl_fill_probe_req);
 620
 621 static void iwl_bg_request_scan(struct work_struct *data)
 622 {
 623         struct iwl_priv *priv =
 624             container_of(data, struct iwl_priv, request_scan);
 625         struct iwl_host_cmd cmd = {
 626                 .id = REPLY_SCAN_CMD,
 627                 .len = sizeof(struct iwl_scan_cmd),
 628                 .flags = CMD_SIZE_HUGE,
 629         };
 630         struct iwl_scan_cmd *scan;
 631         struct ieee80211_conf *conf = NULL;
 632         u32 rate_flags = 0;
 633         u16 cmd_len;
 634         u16 rx_chain = 0;
 635         enum ieee80211_band band;
 636         u8 n_probes = 0;
 637         u8 rx_ant = priv->hw_params.valid_rx_ant;
 638         u8 rate;
 639         bool is_active = false;
 640         int  chan_mod;
 641         u8 active_chains;
 642
 643         conf = ieee80211_get_hw_conf(priv->hw);
 644
 645         mutex_lock(&priv->mutex);
 646
 647         cancel_delayed_work(&priv->scan_check);
 648
 649         if (!iwl_is_ready(priv)) {
 650                 IWL_WARN(priv, "request scan called when driver not ready.\n");
 651                 goto done;
 652         }
 653
 654         /* Make sure the scan wasn't canceled before this queued work
 655          * was given the chance to run... */
 656         if (!test_bit(STATUS_SCANNING, &priv->status))
 657                 goto done;
 658
 659         /* This should never be called or scheduled if there is currently
 660          * a scan active in the hardware. */
 661         if (test_bit(STATUS_SCAN_HW, &priv->status)) {
 662                 IWL_DEBUG_INFO(priv, "Multiple concurrent scan requests in parallel. "
 663                                "Ignoring second request.\n");
 664                 goto done;
 665         }
 666
 667         if (test_bit(STATUS_EXIT_PENDING, &priv->status)) {
 668                 IWL_DEBUG_SCAN(priv, "Aborting scan due to device shutdown\n");
 669                 goto done;
 670         }
 671
 672         if (test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
 673                 IWL_DEBUG_HC(priv, "Scan request while abort pending.  Queuing.\n");
 674                 goto done;
 675         }
 676
 677         if (iwl_is_rfkill(priv)) {
 678                 IWL_DEBUG_HC(priv, "Aborting scan due to RF Kill activation\n");
 679                 goto done;
 680         }
 681
 682         if (!test_bit(STATUS_READY, &priv->status)) {
 683                 IWL_DEBUG_HC(priv, "Scan request while uninitialized.  Queuing.\n");
 684                 goto done;
 685         }
 686
 687         if (!priv->scan) {
 688                 priv->scan = kmalloc(sizeof(struct iwl_scan_cmd) +
 689                                      IWL_MAX_SCAN_SIZE, GFP_KERNEL);
 690                 if (!priv->scan) {
 691                         IWL_DEBUG_SCAN(priv,
 692                                        "fail to allocate memory for scan\n");
 693                         goto done;
 694                 }
 695         }
 696         scan = priv->scan;
 697         memset(scan, 0, sizeof(struct iwl_scan_cmd) + IWL_MAX_SCAN_SIZE);
 698
 699         scan->quiet_plcp_th = IWL_PLCP_QUIET_THRESH;
 700         scan->quiet_time = IWL_ACTIVE_QUIET_TIME;
 701
 702         if (iwl_is_associated(priv)) {
 703                 u16 interval = 0;
 704                 u32 extra;
 705                 u32 suspend_time = 100;
 706                 u32 scan_suspend_time = 100;
 707                 unsigned long flags;
 708
 709                 IWL_DEBUG_INFO(priv, "Scanning while associated...\n");
 710                 spin_lock_irqsave(&priv->lock, flags);
 711                 interval = priv->beacon_int;
 712                 spin_unlock_irqrestore(&priv->lock, flags);
 713
 714                 scan->suspend_time = 0;
 715                 scan->max_out_time = cpu_to_le32(200 * 1024);
 716                 if (!interval)
 717                         interval = suspend_time;
 718
 719                 extra = (suspend_time / interval) << 22;
 720                 scan_suspend_time = (extra |
 721                     ((suspend_time % interval) * 1024));
 722                 scan->suspend_time = cpu_to_le32(scan_suspend_time);
 723                 IWL_DEBUG_SCAN(priv, "suspend_time 0x%X beacon interval %d\n",
 724                                scan_suspend_time, interval);
 725         }
 726
 727         if (priv->is_internal_short_scan) {
 728                 IWL_DEBUG_SCAN(priv, "Start internal passive scan.\n");
 729         } else if (priv->scan_request->n_ssids) {
 730                 int i, p = 0;
 731                 IWL_DEBUG_SCAN(priv, "Kicking off active scan\n");
 732                 for (i = 0; i < priv->scan_request->n_ssids; i++) {
 733                         /* always does wildcard anyway */
 734                         if (!priv->scan_request->ssids[i].ssid_len)
 735                                 continue;
 736                         scan->direct_scan[p].id = WLAN_EID_SSID;
 737                         scan->direct_scan[p].len =
 738                                 priv->scan_request->ssids[i].ssid_len;
 739                         memcpy(scan->direct_scan[p].ssid,
 740                                priv->scan_request->ssids[i].ssid,
 741                                priv->scan_request->ssids[i].ssid_len);
 742                         n_probes++;
 743                         p++;
 744                 }
 745                 is_active = true;
 746         } else
 747                 IWL_DEBUG_SCAN(priv, "Start passive scan.\n");
 748
 749         scan->tx_cmd.tx_flags = TX_CMD_FLG_SEQ_CTL_MSK;
 750         scan->tx_cmd.sta_id = priv->hw_params.bcast_sta_id;
 751         scan->tx_cmd.stop_time.life_time = TX_CMD_LIFE_TIME_INFINITE;
 752
 753         switch (priv->scan_band) {
 754         case IEEE80211_BAND_2GHZ:
 755                 scan->flags = RXON_FLG_BAND_24G_MSK | RXON_FLG_AUTO_DETECT_MSK;
 756                 chan_mod = le32_to_cpu(priv->active_rxon.flags & RXON_FLG_CHANNEL_MODE_MSK)
 757                                        >> RXON_FLG_CHANNEL_MODE_POS;
 758                 if (chan_mod == CHANNEL_MODE_PURE_40) {
 759                         rate = IWL_RATE_6M_PLCP;
 760                 } else {
 761                         rate = IWL_RATE_1M_PLCP;
 762                         rate_flags = RATE_MCS_CCK_MSK;
 763                 }
 764                 scan->good_CRC_th = 0;
 765                 break;
 766         case IEEE80211_BAND_5GHZ:
 767                 rate = IWL_RATE_6M_PLCP;
 768                 /*
 769                  * If active scaning is requested but a certain channel
 770                  * is marked passive, we can do active scanning if we
 771                  * detect transmissions.
 772                  */
 773                 scan->good_CRC_th = is_active ? IWL_GOOD_CRC_TH : 0;
 774
 775                 /* Force use of chains B and C (0x6) for scan Rx
 776                  * Avoid A (0x1) for the device has off-channel reception
 777                  * on A-band.
 778                  */
 779                 if (priv->cfg->off_channel_workaround)
 780                         rx_ant = ANT_BC;
 781                 break;
 782         default:
 783                 IWL_WARN(priv, "Invalid scan band count\n");
 784                 goto done;
 785         }
 786
 787         band = priv->scan_band;
 788
 789         priv->scan_tx_ant[band] =
 790                         iwl_toggle_tx_ant(priv, priv->scan_tx_ant[band]);
 791         rate_flags |= iwl_ant_idx_to_flags(priv->scan_tx_ant[band]);
 792         scan->tx_cmd.rate_n_flags = iwl_hw_set_rate_n_flags(rate, rate_flags);
 793
 794         /* In power save mode use one chain, otherwise use all chains */
 795         if (test_bit(STATUS_POWER_PMI, &priv->status)) {
 796                 /* rx_ant has been set to all valid chains previously */
 797                 active_chains = rx_ant &
 798                                 ((u8)(priv->chain_noise_data.active_chains));
 799                 if (!active_chains)
 800                         active_chains = rx_ant;
 801
 802                 IWL_DEBUG_SCAN(priv, "chain_noise_data.active_chains: %u\n",
 803                                 priv->chain_noise_data.active_chains);
 804
 805                 rx_ant = first_antenna(active_chains);
 806         }
 807         /* MIMO is not used here, but value is required */
 808         rx_chain |= priv->hw_params.valid_rx_ant << RXON_RX_CHAIN_VALID_POS;
 809         rx_chain |= rx_ant << RXON_RX_CHAIN_FORCE_MIMO_SEL_POS;
 810         rx_chain |= rx_ant << RXON_RX_CHAIN_FORCE_SEL_POS;
 811         rx_chain |= 0x1 << RXON_RX_CHAIN_DRIVER_FORCE_POS;
 812         scan->rx_chain = cpu_to_le16(rx_chain);
 813         if (!priv->is_internal_short_scan) {
 814                 cmd_len = iwl_fill_probe_req(priv,
 815                                         (struct ieee80211_mgmt *)scan->data,
 816                                         priv->scan_request->ie,
 817                                         priv->scan_request->ie_len,
 818                                         IWL_MAX_SCAN_SIZE - sizeof(*scan));
 819         } else {
 820                 cmd_len = iwl_fill_probe_req(priv,
 821                                         (struct ieee80211_mgmt *)scan->data,
 822                                         NULL, 0,
 823                                         IWL_MAX_SCAN_SIZE - sizeof(*scan));
 824
 825         }
 826         scan->tx_cmd.len = cpu_to_le16(cmd_len);
 827         if (iwl_is_monitor_mode(priv))
 828                 scan->filter_flags = RXON_FILTER_PROMISC_MSK;
 829
 830         scan->filter_flags |= (RXON_FILTER_ACCEPT_GRP_MSK |
 831                                RXON_FILTER_BCON_AWARE_MSK);
 832
 833         if (priv->is_internal_short_scan) {
 834                 scan->channel_count =
 835                         iwl_get_single_channel_for_scan(priv, band,
 836                                 (void *)&scan->data[le16_to_cpu(
 837                                 scan->tx_cmd.len)]);
 838         } else {
 839                 scan->channel_count =
 840                         iwl_get_channels_for_scan(priv, band,
 841                                 is_active, n_probes,
 842                                 (void *)&scan->data[le16_to_cpu(
 843                                 scan->tx_cmd.len)]);
 844         }
 845         if (scan->channel_count == 0) {
 846                 IWL_DEBUG_SCAN(priv, "channel count %d\n", scan->channel_count);
 847                 goto done;
 848         }
 849
 850         cmd.len += le16_to_cpu(scan->tx_cmd.len) +
 851             scan->channel_count * sizeof(struct iwl_scan_channel);
 852         cmd.data = scan;
 853         scan->len = cpu_to_le16(cmd.len);
 854
 855         set_bit(STATUS_SCAN_HW, &priv->status);
 856         if (iwl_send_cmd_sync(priv, &cmd))
 857                 goto done;
 858
 859         queue_delayed_work(priv->workqueue, &priv->scan_check,
 860                            IWL_SCAN_CHECK_WATCHDOG);
 861
 862         mutex_unlock(&priv->mutex);
 863         return;
 864
 865  done:
 866         /* Cannot perform scan. Make sure we clear scanning
 867         * bits from status so next scan request can be performed.
 868         * If we don't clear scanning status bit here all next scan
 869         * will fail
 870         */
 871         clear_bit(STATUS_SCAN_HW, &priv->status);
 872         clear_bit(STATUS_SCANNING, &priv->status);
 873         /* inform mac80211 scan aborted */
 874         queue_work(priv->workqueue, &priv->scan_completed);
 875         mutex_unlock(&priv->mutex);
 876 }
 877
 878 void iwl_bg_abort_scan(struct work_struct *work)
 879 {
 880         struct iwl_priv *priv = container_of(work, struct iwl_priv, abort_scan);
 881
 882         if (!test_bit(STATUS_READY, &priv->status) ||
 883             !test_bit(STATUS_GEO_CONFIGURED, &priv->status))
 884                 return;
 885
 886         mutex_lock(&priv->mutex);
 887
 888         set_bit(STATUS_SCAN_ABORTING, &priv->status);
 889         iwl_send_scan_abort(priv);
 890
 891         mutex_unlock(&priv->mutex);
 892 }
 893 EXPORT_SYMBOL(iwl_bg_abort_scan);
 894
 895 void iwl_bg_scan_completed(struct work_struct *work)
 896 {
 897         struct iwl_priv *priv =
 898             container_of(work, struct iwl_priv, scan_completed);
 899
 900         IWL_DEBUG_SCAN(priv, "SCAN complete scan\n");
 901
 902         cancel_delayed_work(&priv->scan_check);
 903
 904         if (!priv->is_internal_short_scan)
 905                 ieee80211_scan_completed(priv->hw, false);
 906         else {
 907                 priv->is_internal_short_scan = false;
 908                 IWL_DEBUG_SCAN(priv, "internal short scan completed\n");
 909         }
 910
 911         if (test_bit(STATUS_EXIT_PENDING, &priv->status))
 912                 return;
 913
 914         /* Since setting the TXPOWER may have been deferred while
 915          * performing the scan, fire one off */
 916         mutex_lock(&priv->mutex);
 917         iwl_set_tx_power(priv, priv->tx_power_user_lmt, true);
 918         mutex_unlock(&priv->mutex);
 919 }
 920 EXPORT_SYMBOL(iwl_bg_scan_completed);
 921
 922 void iwl_setup_scan_deferred_work(struct iwl_priv *priv)
 923 {
 924         INIT_WORK(&priv->scan_completed, iwl_bg_scan_completed);
 925         INIT_WORK(&priv->request_scan, iwl_bg_request_scan);
 926         INIT_WORK(&priv->abort_scan, iwl_bg_abort_scan);
 927         INIT_WORK(&priv->start_internal_scan, iwl_bg_start_internal_scan);
 928         INIT_DELAYED_WORK(&priv->scan_check, iwl_bg_scan_check);
 929 }
 930 EXPORT_SYMBOL(iwl_setup_scan_deferred_work);
 931