drivers/net/wireless/iwlwifi/iwl-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 "iwl-eeprom.h"
  34 #include "iwl-dev.h"
  35 #include "iwl-io.h"
  36 #include "iwl-agn.h"
  37 #include "iwl-trans.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 #define MAX_SCAN_CHANNEL            50
  56
  57 static int iwl_send_scan_abort(struct iwl_priv *priv)
  58 {
  59         int ret;
  60         struct iwl_host_cmd cmd = {
  61                 .id = REPLY_SCAN_ABORT_CMD,
  62                 .flags = CMD_SYNC | CMD_WANT_SKB,
  63         };
  64         __le32 *status;
  65
  66         /* Exit instantly with error when device is not ready
  67          * to receive scan abort command or it does not perform
  68          * hardware scan currently */
  69         if (!test_bit(STATUS_READY, &priv->status) ||
  70             !test_bit(STATUS_GEO_CONFIGURED, &priv->status) ||
  71             !test_bit(STATUS_SCAN_HW, &priv->status) ||
  72             test_bit(STATUS_FW_ERROR, &priv->status))
  73                 return -EIO;
  74
  75         ret = iwl_dvm_send_cmd(priv, &cmd);
  76         if (ret)
  77                 return ret;
  78
  79         status = (void *)cmd.resp_pkt->data;
  80         if (*status != CAN_ABORT_STATUS) {
  81                 /* The scan abort will return 1 for success or
  82                  * 2 for "failure".  A failure condition can be
  83                  * due to simply not being in an active scan which
  84                  * can occur if we send the scan abort before we
  85                  * the microcode has notified us that a scan is
  86                  * completed. */
  87                 IWL_DEBUG_SCAN(priv, "SCAN_ABORT ret %d.\n",
  88                                le32_to_cpu(*status));
  89                 ret = -EIO;
  90         }
  91
  92         iwl_free_resp(&cmd);
  93         return ret;
  94 }
  95
  96 static void iwl_complete_scan(struct iwl_priv *priv, bool aborted)
  97 {
  98         /* check if scan was requested from mac80211 */
  99         if (priv->scan_request) {
 100                 IWL_DEBUG_SCAN(priv, "Complete scan in mac80211\n");
 101                 ieee80211_scan_completed(priv->hw, aborted);
 102         }
 103
 104         if (priv->scan_type == IWL_SCAN_ROC) {
 105                 ieee80211_remain_on_channel_expired(priv->hw);
 106                 priv->hw_roc_channel = NULL;
 107                 schedule_delayed_work(&priv->hw_roc_disable_work, 10 * HZ);
 108         }
 109
 110         priv->scan_type = IWL_SCAN_NORMAL;
 111         priv->scan_vif = NULL;
 112         priv->scan_request = NULL;
 113 }
 114
 115 static void iwl_process_scan_complete(struct iwl_priv *priv)
 116 {
 117         bool aborted;
 118
 119         lockdep_assert_held(&priv->mutex);
 120
 121         if (!test_and_clear_bit(STATUS_SCAN_COMPLETE, &priv->status))
 122                 return;
 123
 124         IWL_DEBUG_SCAN(priv, "Completed scan.\n");
 125
 126         cancel_delayed_work(&priv->scan_check);
 127
 128         aborted = test_and_clear_bit(STATUS_SCAN_ABORTING, &priv->status);
 129         if (aborted)
 130                 IWL_DEBUG_SCAN(priv, "Aborted scan completed.\n");
 131
 132         if (!test_and_clear_bit(STATUS_SCANNING, &priv->status)) {
 133                 IWL_DEBUG_SCAN(priv, "Scan already completed.\n");
 134                 goto out_settings;
 135         }
 136
 137         if (priv->scan_type == IWL_SCAN_ROC) {
 138                 ieee80211_remain_on_channel_expired(priv->hw);
 139                 priv->hw_roc_channel = NULL;
 140                 schedule_delayed_work(&priv->hw_roc_disable_work, 10 * HZ);
 141         }
 142
 143         if (priv->scan_type != IWL_SCAN_NORMAL && !aborted) {
 144                 int err;
 145
 146                 /* Check if mac80211 requested scan during our internal scan */
 147                 if (priv->scan_request == NULL)
 148                         goto out_complete;
 149
 150                 /* If so request a new scan */
 151                 err = iwl_scan_initiate(priv, priv->scan_vif, IWL_SCAN_NORMAL,
 152                                         priv->scan_request->channels[0]->band);
 153                 if (err) {
 154                         IWL_DEBUG_SCAN(priv,
 155                                 "failed to initiate pending scan: %d\n", err);
 156                         aborted = true;
 157                         goto out_complete;
 158                 }
 159
 160                 return;
 161         }
 162
 163 out_complete:
 164         iwl_complete_scan(priv, aborted);
 165
 166 out_settings:
 167         /* Can we still talk to firmware ? */
 168         if (!iwl_is_ready_rf(priv))
 169                 return;
 170
 171         iwlagn_post_scan(priv);
 172 }
 173
 174 void iwl_force_scan_end(struct iwl_priv *priv)
 175 {
 176         lockdep_assert_held(&priv->mutex);
 177
 178         if (!test_bit(STATUS_SCANNING, &priv->status)) {
 179                 IWL_DEBUG_SCAN(priv, "Forcing scan end while not scanning\n");
 180                 return;
 181         }
 182
 183         IWL_DEBUG_SCAN(priv, "Forcing scan end\n");
 184         clear_bit(STATUS_SCANNING, &priv->status);
 185         clear_bit(STATUS_SCAN_HW, &priv->status);
 186         clear_bit(STATUS_SCAN_ABORTING, &priv->status);
 187         clear_bit(STATUS_SCAN_COMPLETE, &priv->status);
 188         iwl_complete_scan(priv, true);
 189 }
 190
 191 static void iwl_do_scan_abort(struct iwl_priv *priv)
 192 {
 193         int ret;
 194
 195         lockdep_assert_held(&priv->mutex);
 196
 197         if (!test_bit(STATUS_SCANNING, &priv->status)) {
 198                 IWL_DEBUG_SCAN(priv, "Not performing scan to abort\n");
 199                 return;
 200         }
 201
 202         if (test_and_set_bit(STATUS_SCAN_ABORTING, &priv->status)) {
 203                 IWL_DEBUG_SCAN(priv, "Scan abort in progress\n");
 204                 return;
 205         }
 206
 207         ret = iwl_send_scan_abort(priv);
 208         if (ret) {
 209                 IWL_DEBUG_SCAN(priv, "Send scan abort failed %d\n", ret);
 210                 iwl_force_scan_end(priv);
 211         } else
 212                 IWL_DEBUG_SCAN(priv, "Successfully send scan abort\n");
 213 }
 214
 215 /**
 216  * iwl_scan_cancel - Cancel any currently executing HW scan
 217  */
 218 int iwl_scan_cancel(struct iwl_priv *priv)
 219 {
 220         IWL_DEBUG_SCAN(priv, "Queuing abort scan\n");
 221         queue_work(priv->workqueue, &priv->abort_scan);
 222         return 0;
 223 }
 224
 225 /**
 226  * iwl_scan_cancel_timeout - Cancel any currently executing HW scan
 227  * @ms: amount of time to wait (in milliseconds) for scan to abort
 228  *
 229  */
 230 void iwl_scan_cancel_timeout(struct iwl_priv *priv, unsigned long ms)
 231 {
 232         unsigned long timeout = jiffies + msecs_to_jiffies(ms);
 233
 234         lockdep_assert_held(&priv->mutex);
 235
 236         IWL_DEBUG_SCAN(priv, "Scan cancel timeout\n");
 237
 238         iwl_do_scan_abort(priv);
 239
 240         while (time_before_eq(jiffies, timeout)) {
 241                 if (!test_bit(STATUS_SCAN_HW, &priv->status))
 242                         goto finished;
 243                 msleep(20);
 244         }
 245
 246         return;
 247
 248  finished:
 249         /*
 250          * Now STATUS_SCAN_HW is clear. This means that the
 251          * device finished, but the background work is going
 252          * to execute at best as soon as we release the mutex.
 253          * Since we need to be able to issue a new scan right
 254          * after this function returns, run the complete here.
 255          * The STATUS_SCAN_COMPLETE bit will then be cleared
 256          * and prevent the background work from "completing"
 257          * a possible new scan.
 258          */
 259         iwl_process_scan_complete(priv);
 260 }
 261
 262 /* Service response to REPLY_SCAN_CMD (0x80) */
 263 static int iwl_rx_reply_scan(struct iwl_priv *priv,
 264                               struct iwl_rx_cmd_buffer *rxb,
 265                               struct iwl_device_cmd *cmd)
 266 {
 267 #ifdef CONFIG_IWLWIFI_DEBUG
 268         struct iwl_rx_packet *pkt = rxb_addr(rxb);
 269         struct iwl_scanreq_notification *notif = (void *)pkt->data;
 270
 271         IWL_DEBUG_SCAN(priv, "Scan request status = 0x%x\n", notif->status);
 272 #endif
 273         return 0;
 274 }
 275
 276 /* Service SCAN_START_NOTIFICATION (0x82) */
 277 static int iwl_rx_scan_start_notif(struct iwl_priv *priv,
 278                                     struct iwl_rx_cmd_buffer *rxb,
 279                                     struct iwl_device_cmd *cmd)
 280 {
 281         struct iwl_rx_packet *pkt = rxb_addr(rxb);
 282         struct iwl_scanstart_notification *notif = (void *)pkt->data;
 283
 284         priv->scan_start_tsf = le32_to_cpu(notif->tsf_low);
 285         IWL_DEBUG_SCAN(priv, "Scan start: "
 286                        "%d [802.11%s] "
 287                        "(TSF: 0x%08X:%08X) - %d (beacon timer %u)\n",
 288                        notif->channel,
 289                        notif->band ? "bg" : "a",
 290                        le32_to_cpu(notif->tsf_high),
 291                        le32_to_cpu(notif->tsf_low),
 292                        notif->status, notif->beacon_timer);
 293
 294         if (priv->scan_type == IWL_SCAN_ROC &&
 295             !priv->hw_roc_start_notified) {
 296                 ieee80211_ready_on_channel(priv->hw);
 297                 priv->hw_roc_start_notified = true;
 298         }
 299
 300         return 0;
 301 }
 302
 303 /* Service SCAN_RESULTS_NOTIFICATION (0x83) */
 304 static int iwl_rx_scan_results_notif(struct iwl_priv *priv,
 305                                       struct iwl_rx_cmd_buffer *rxb,
 306                                       struct iwl_device_cmd *cmd)
 307 {
 308 #ifdef CONFIG_IWLWIFI_DEBUG
 309         struct iwl_rx_packet *pkt = rxb_addr(rxb);
 310         struct iwl_scanresults_notification *notif = (void *)pkt->data;
 311
 312         IWL_DEBUG_SCAN(priv, "Scan ch.res: "
 313                        "%d [802.11%s] "
 314                        "probe status: %u:%u "
 315                        "(TSF: 0x%08X:%08X) - %d "
 316                        "elapsed=%lu usec\n",
 317                        notif->channel,
 318                        notif->band ? "bg" : "a",
 319                        notif->probe_status, notif->num_probe_not_sent,
 320                        le32_to_cpu(notif->tsf_high),
 321                        le32_to_cpu(notif->tsf_low),
 322                        le32_to_cpu(notif->statistics[0]),
 323                        le32_to_cpu(notif->tsf_low) - priv->scan_start_tsf);
 324 #endif
 325         return 0;
 326 }
 327
 328 /* Service SCAN_COMPLETE_NOTIFICATION (0x84) */
 329 static int iwl_rx_scan_complete_notif(struct iwl_priv *priv,
 330                                        struct iwl_rx_cmd_buffer *rxb,
 331                                        struct iwl_device_cmd *cmd)
 332 {
 333         struct iwl_rx_packet *pkt = rxb_addr(rxb);
 334         struct iwl_scancomplete_notification *scan_notif = (void *)pkt->data;
 335
 336         IWL_DEBUG_SCAN(priv, "Scan complete: %d channels (TSF 0x%08X:%08X) - %d\n",
 337                        scan_notif->scanned_channels,
 338                        scan_notif->tsf_low,
 339                        scan_notif->tsf_high, scan_notif->status);
 340
 341         IWL_DEBUG_SCAN(priv, "Scan on %sGHz took %dms\n",
 342                        (priv->scan_band == IEEE80211_BAND_2GHZ) ? "2.4" : "5.2",
 343                        jiffies_to_msecs(jiffies - priv->scan_start));
 344
 345         /*
 346          * When aborting, we run the scan completed background work inline
 347          * and the background work must then do nothing. The SCAN_COMPLETE
 348          * bit helps implement that logic and thus needs to be set before
 349          * queueing the work. Also, since the scan abort waits for SCAN_HW
 350          * to clear, we need to set SCAN_COMPLETE before clearing SCAN_HW
 351          * to avoid a race there.
 352          */
 353         set_bit(STATUS_SCAN_COMPLETE, &priv->status);
 354         clear_bit(STATUS_SCAN_HW, &priv->status);
 355         queue_work(priv->workqueue, &priv->scan_completed);
 356
 357         if (priv->iw_mode != NL80211_IFTYPE_ADHOC &&
 358             iwl_advanced_bt_coexist(priv) &&
 359             priv->bt_status != scan_notif->bt_status) {
 360                 if (scan_notif->bt_status) {
 361                         /* BT on */
 362                         if (!priv->bt_ch_announce)
 363                                 priv->bt_traffic_load =
 364                                         IWL_BT_COEX_TRAFFIC_LOAD_HIGH;
 365                         /*
 366                          * otherwise, no traffic load information provided
 367                          * no changes made
 368                          */
 369                 } else {
 370                         /* BT off */
 371                         priv->bt_traffic_load =
 372                                 IWL_BT_COEX_TRAFFIC_LOAD_NONE;
 373                 }
 374                 priv->bt_status = scan_notif->bt_status;
 375                 queue_work(priv->workqueue,
 376                            &priv->bt_traffic_change_work);
 377         }
 378         return 0;
 379 }
 380
 381 void iwl_setup_rx_scan_handlers(struct iwl_priv *priv)
 382 {
 383         /* scan handlers */
 384         priv->rx_handlers[REPLY_SCAN_CMD] = iwl_rx_reply_scan;
 385         priv->rx_handlers[SCAN_START_NOTIFICATION] = iwl_rx_scan_start_notif;
 386         priv->rx_handlers[SCAN_RESULTS_NOTIFICATION] =
 387                                         iwl_rx_scan_results_notif;
 388         priv->rx_handlers[SCAN_COMPLETE_NOTIFICATION] =
 389                                         iwl_rx_scan_complete_notif;
 390 }
 391
 392 static u16 iwl_get_active_dwell_time(struct iwl_priv *priv,
 393                                      enum ieee80211_band band, u8 n_probes)
 394 {
 395         if (band == IEEE80211_BAND_5GHZ)
 396                 return IWL_ACTIVE_DWELL_TIME_52 +
 397                         IWL_ACTIVE_DWELL_FACTOR_52GHZ * (n_probes + 1);
 398         else
 399                 return IWL_ACTIVE_DWELL_TIME_24 +
 400                         IWL_ACTIVE_DWELL_FACTOR_24GHZ * (n_probes + 1);
 401 }
 402
 403 static u16 iwl_limit_dwell(struct iwl_priv *priv, u16 dwell_time)
 404 {
 405         struct iwl_rxon_context *ctx;
 406
 407         /*
 408          * If we're associated, we clamp the dwell time 98%
 409          * of the smallest beacon interval (minus 2 * channel
 410          * tune time)
 411          */
 412         for_each_context(priv, ctx) {
 413                 u16 value;
 414
 415                 switch (ctx->staging.dev_type) {
 416                 case RXON_DEV_TYPE_P2P:
 417                         /* no timing constraints */
 418                         continue;
 419                 case RXON_DEV_TYPE_ESS:
 420                 default:
 421                         /* timing constraints if associated */
 422                         if (!iwl_is_associated_ctx(ctx))
 423                                 continue;
 424                         break;
 425                 case RXON_DEV_TYPE_CP:
 426                 case RXON_DEV_TYPE_2STA:
 427                         /*
 428                          * These seem to always have timers for TBTT
 429                          * active in uCode even when not associated yet.
 430                          */
 431                         break;
 432                 }
 433
 434                 value = ctx->beacon_int;
 435                 if (!value)
 436                         value = IWL_PASSIVE_DWELL_BASE;
 437                 value = (value * 98) / 100 - IWL_CHANNEL_TUNE_TIME * 2;
 438                 dwell_time = min(value, dwell_time);
 439         }
 440
 441         return dwell_time;
 442 }
 443
 444 static u16 iwl_get_passive_dwell_time(struct iwl_priv *priv,
 445                                       enum ieee80211_band band)
 446 {
 447         u16 passive = (band == IEEE80211_BAND_2GHZ) ?
 448             IWL_PASSIVE_DWELL_BASE + IWL_PASSIVE_DWELL_TIME_24 :
 449             IWL_PASSIVE_DWELL_BASE + IWL_PASSIVE_DWELL_TIME_52;
 450
 451         return iwl_limit_dwell(priv, passive);
 452 }
 453
 454 /* Return valid, unused, channel for a passive scan to reset the RF */
 455 static u8 iwl_get_single_channel_number(struct iwl_priv *priv,
 456                                  enum ieee80211_band band)
 457 {
 458         const struct iwl_channel_info *ch_info;
 459         int i;
 460         u8 channel = 0;
 461         u8 min, max;
 462         struct iwl_rxon_context *ctx;
 463
 464         if (band == IEEE80211_BAND_5GHZ) {
 465                 min = 14;
 466                 max = priv->channel_count;
 467         } else {
 468                 min = 0;
 469                 max = 14;
 470         }
 471
 472         for (i = min; i < max; i++) {
 473                 bool busy = false;
 474
 475                 for_each_context(priv, ctx) {
 476                         busy = priv->channel_info[i].channel ==
 477                                 le16_to_cpu(ctx->staging.channel);
 478                         if (busy)
 479                                 break;
 480                 }
 481
 482                 if (busy)
 483                         continue;
 484
 485                 channel = priv->channel_info[i].channel;
 486                 ch_info = iwl_get_channel_info(priv, band, channel);
 487                 if (is_channel_valid(ch_info))
 488                         break;
 489         }
 490
 491         return channel;
 492 }
 493
 494 static int iwl_get_single_channel_for_scan(struct iwl_priv *priv,
 495                                            struct ieee80211_vif *vif,
 496                                            enum ieee80211_band band,
 497                                            struct iwl_scan_channel *scan_ch)
 498 {
 499         const struct ieee80211_supported_band *sband;
 500         u16 passive_dwell = 0;
 501         u16 active_dwell = 0;
 502         int added = 0;
 503         u16 channel = 0;
 504
 505         sband = iwl_get_hw_mode(priv, band);
 506         if (!sband) {
 507                 IWL_ERR(priv, "invalid band\n");
 508                 return added;
 509         }
 510
 511         active_dwell = iwl_get_active_dwell_time(priv, band, 0);
 512         passive_dwell = iwl_get_passive_dwell_time(priv, band);
 513
 514         if (passive_dwell <= active_dwell)
 515                 passive_dwell = active_dwell + 1;
 516
 517         channel = iwl_get_single_channel_number(priv, band);
 518         if (channel) {
 519                 scan_ch->channel = cpu_to_le16(channel);
 520                 scan_ch->type = SCAN_CHANNEL_TYPE_PASSIVE;
 521                 scan_ch->active_dwell = cpu_to_le16(active_dwell);
 522                 scan_ch->passive_dwell = cpu_to_le16(passive_dwell);
 523                 /* Set txpower levels to defaults */
 524                 scan_ch->dsp_atten = 110;
 525                 if (band == IEEE80211_BAND_5GHZ)
 526                         scan_ch->tx_gain = ((1 << 5) | (3 << 3)) | 3;
 527                 else
 528                         scan_ch->tx_gain = ((1 << 5) | (5 << 3));
 529                 added++;
 530         } else
 531                 IWL_ERR(priv, "no valid channel found\n");
 532         return added;
 533 }
 534
 535 static int iwl_get_channels_for_scan(struct iwl_priv *priv,
 536                                      struct ieee80211_vif *vif,
 537                                      enum ieee80211_band band,
 538                                      u8 is_active, u8 n_probes,
 539                                      struct iwl_scan_channel *scan_ch)
 540 {
 541         struct ieee80211_channel *chan;
 542         const struct ieee80211_supported_band *sband;
 543         const struct iwl_channel_info *ch_info;
 544         u16 passive_dwell = 0;
 545         u16 active_dwell = 0;
 546         int added, i;
 547         u16 channel;
 548
 549         sband = iwl_get_hw_mode(priv, band);
 550         if (!sband)
 551                 return 0;
 552
 553         active_dwell = iwl_get_active_dwell_time(priv, band, n_probes);
 554         passive_dwell = iwl_get_passive_dwell_time(priv, band);
 555
 556         if (passive_dwell <= active_dwell)
 557                 passive_dwell = active_dwell + 1;
 558
 559         for (i = 0, added = 0; i < priv->scan_request->n_channels; i++) {
 560                 chan = priv->scan_request->channels[i];
 561
 562                 if (chan->band != band)
 563                         continue;
 564
 565                 channel = chan->hw_value;
 566                 scan_ch->channel = cpu_to_le16(channel);
 567
 568                 ch_info = iwl_get_channel_info(priv, band, channel);
 569                 if (!is_channel_valid(ch_info)) {
 570                         IWL_DEBUG_SCAN(priv,
 571                                        "Channel %d is INVALID for this band.\n",
 572                                        channel);
 573                         continue;
 574                 }
 575
 576                 if (!is_active || is_channel_passive(ch_info) ||
 577                     (chan->flags & IEEE80211_CHAN_PASSIVE_SCAN))
 578                         scan_ch->type = SCAN_CHANNEL_TYPE_PASSIVE;
 579                 else
 580                         scan_ch->type = SCAN_CHANNEL_TYPE_ACTIVE;
 581
 582                 if (n_probes)
 583                         scan_ch->type |= IWL_SCAN_PROBE_MASK(n_probes);
 584
 585                 scan_ch->active_dwell = cpu_to_le16(active_dwell);
 586                 scan_ch->passive_dwell = cpu_to_le16(passive_dwell);
 587
 588                 /* Set txpower levels to defaults */
 589                 scan_ch->dsp_atten = 110;
 590
 591                 /* NOTE: if we were doing 6Mb OFDM for scans we'd use
 592                  * power level:
 593                  * scan_ch->tx_gain = ((1 << 5) | (2 << 3)) | 3;
 594                  */
 595                 if (band == IEEE80211_BAND_5GHZ)
 596                         scan_ch->tx_gain = ((1 << 5) | (3 << 3)) | 3;
 597                 else
 598                         scan_ch->tx_gain = ((1 << 5) | (5 << 3));
 599
 600                 IWL_DEBUG_SCAN(priv, "Scanning ch=%d prob=0x%X [%s %d]\n",
 601                                channel, le32_to_cpu(scan_ch->type),
 602                                (scan_ch->type & SCAN_CHANNEL_TYPE_ACTIVE) ?
 603                                 "ACTIVE" : "PASSIVE",
 604                                (scan_ch->type & SCAN_CHANNEL_TYPE_ACTIVE) ?
 605                                active_dwell : passive_dwell);
 606
 607                 scan_ch++;
 608                 added++;
 609         }
 610
 611         IWL_DEBUG_SCAN(priv, "total channels to scan %d\n", added);
 612         return added;
 613 }
 614
 615 /**
 616  * iwl_fill_probe_req - fill in all required fields and IE for probe request
 617  */
 618
 619 static u16 iwl_fill_probe_req(struct ieee80211_mgmt *frame, const u8 *ta,
 620                               const u8 *ies, int ie_len, const u8 *ssid,
 621                               u8 ssid_len, int left)
 622 {
 623         int len = 0;
 624         u8 *pos = NULL;
 625
 626         /* Make sure there is enough space for the probe request,
 627          * two mandatory IEs and the data */
 628         left -= 24;
 629         if (left < 0)
 630                 return 0;
 631
 632         frame->frame_control = cpu_to_le16(IEEE80211_STYPE_PROBE_REQ);
 633         memcpy(frame->da, iwl_bcast_addr, ETH_ALEN);
 634         memcpy(frame->sa, ta, ETH_ALEN);
 635         memcpy(frame->bssid, iwl_bcast_addr, ETH_ALEN);
 636         frame->seq_ctrl = 0;
 637
 638         len += 24;
 639
 640         /* ...next IE... */
 641         pos = &frame->u.probe_req.variable[0];
 642
 643         /* fill in our SSID IE */
 644         left -= ssid_len + 2;
 645         if (left < 0)
 646                 return 0;
 647         *pos++ = WLAN_EID_SSID;
 648         *pos++ = ssid_len;
 649         if (ssid && ssid_len) {
 650                 memcpy(pos, ssid, ssid_len);
 651                 pos += ssid_len;
 652         }
 653
 654         len += ssid_len + 2;
 655
 656         if (WARN_ON(left < ie_len))
 657                 return len;
 658
 659         if (ies && ie_len) {
 660                 memcpy(pos, ies, ie_len);
 661                 len += ie_len;
 662         }
 663
 664         return (u16)len;
 665 }
 666
 667 static int iwlagn_request_scan(struct iwl_priv *priv, struct ieee80211_vif *vif)
 668 {
 669         struct iwl_host_cmd cmd = {
 670                 .id = REPLY_SCAN_CMD,
 671                 .len = { sizeof(struct iwl_scan_cmd), },
 672                 .flags = CMD_SYNC,
 673         };
 674         struct iwl_scan_cmd *scan;
 675         struct iwl_rxon_context *ctx = &priv->contexts[IWL_RXON_CTX_BSS];
 676         u32 rate_flags = 0;
 677         u16 cmd_len = 0;
 678         u16 rx_chain = 0;
 679         enum ieee80211_band band;
 680         u8 n_probes = 0;
 681         u8 rx_ant = priv->hw_params.valid_rx_ant;
 682         u8 rate;
 683         bool is_active = false;
 684         int  chan_mod;
 685         u8 active_chains;
 686         u8 scan_tx_antennas = priv->hw_params.valid_tx_ant;
 687         int ret;
 688         int scan_cmd_size = sizeof(struct iwl_scan_cmd) +
 689                             MAX_SCAN_CHANNEL * sizeof(struct iwl_scan_channel) +
 690                             priv->fw->ucode_capa.max_probe_length;
 691         const u8 *ssid = NULL;
 692         u8 ssid_len = 0;
 693
 694         if (WARN_ON_ONCE(priv->scan_request &&
 695                          priv->scan_request->n_channels > MAX_SCAN_CHANNEL))
 696                 return -EINVAL;
 697
 698         lockdep_assert_held(&priv->mutex);
 699
 700         if (vif)
 701                 ctx = iwl_rxon_ctx_from_vif(vif);
 702
 703         if (!priv->scan_cmd) {
 704                 priv->scan_cmd = kmalloc(scan_cmd_size, GFP_KERNEL);
 705                 if (!priv->scan_cmd) {
 706                         IWL_DEBUG_SCAN(priv,
 707                                        "fail to allocate memory for scan\n");
 708                         return -ENOMEM;
 709                 }
 710         }
 711         scan = priv->scan_cmd;
 712         memset(scan, 0, scan_cmd_size);
 713
 714         scan->quiet_plcp_th = IWL_PLCP_QUIET_THRESH;
 715         scan->quiet_time = IWL_ACTIVE_QUIET_TIME;
 716
 717         if (priv->scan_type != IWL_SCAN_ROC &&
 718             iwl_is_any_associated(priv)) {
 719                 u16 interval = 0;
 720                 u32 extra;
 721                 u32 suspend_time = 100;
 722                 u32 scan_suspend_time = 100;
 723
 724                 IWL_DEBUG_INFO(priv, "Scanning while associated...\n");
 725                 switch (priv->scan_type) {
 726                 case IWL_SCAN_ROC:
 727                         WARN_ON(1);
 728                         break;
 729                 case IWL_SCAN_RADIO_RESET:
 730                         interval = 0;
 731                         break;
 732                 case IWL_SCAN_NORMAL:
 733                         interval = vif->bss_conf.beacon_int;
 734                         break;
 735                 }
 736
 737                 scan->suspend_time = 0;
 738                 scan->max_out_time = cpu_to_le32(200 * 1024);
 739                 if (!interval)
 740                         interval = suspend_time;
 741
 742                 extra = (suspend_time / interval) << 22;
 743                 scan_suspend_time = (extra |
 744                     ((suspend_time % interval) * 1024));
 745                 scan->suspend_time = cpu_to_le32(scan_suspend_time);
 746                 IWL_DEBUG_SCAN(priv, "suspend_time 0x%X beacon interval %d\n",
 747                                scan_suspend_time, interval);
 748         } else if (priv->scan_type == IWL_SCAN_ROC) {
 749                 scan->suspend_time = 0;
 750                 scan->max_out_time = 0;
 751                 scan->quiet_time = 0;
 752                 scan->quiet_plcp_th = 0;
 753         }
 754
 755         switch (priv->scan_type) {
 756         case IWL_SCAN_RADIO_RESET:
 757                 IWL_DEBUG_SCAN(priv, "Start internal passive scan.\n");
 758                 break;
 759         case IWL_SCAN_NORMAL:
 760                 if (priv->scan_request->n_ssids) {
 761                         int i, p = 0;
 762                         IWL_DEBUG_SCAN(priv, "Kicking off active scan\n");
 763                         /*
 764                          * The highest priority SSID is inserted to the
 765                          * probe request template.
 766                          */
 767                         ssid_len = priv->scan_request->ssids[0].ssid_len;
 768                         ssid = priv->scan_request->ssids[0].ssid;
 769
 770                         /*
 771                          * Invert the order of ssids, the firmware will invert
 772                          * it back.
 773                          */
 774                         for (i = priv->scan_request->n_ssids - 1; i >= 1; i--) {
 775                                 scan->direct_scan[p].id = WLAN_EID_SSID;
 776                                 scan->direct_scan[p].len =
 777                                         priv->scan_request->ssids[i].ssid_len;
 778                                 memcpy(scan->direct_scan[p].ssid,
 779                                        priv->scan_request->ssids[i].ssid,
 780                                        priv->scan_request->ssids[i].ssid_len);
 781                                 n_probes++;
 782                                 p++;
 783                         }
 784                         is_active = true;
 785                 } else
 786                         IWL_DEBUG_SCAN(priv, "Start passive scan.\n");
 787                 break;
 788         case IWL_SCAN_ROC:
 789                 IWL_DEBUG_SCAN(priv, "Start ROC scan.\n");
 790                 break;
 791         }
 792
 793         scan->tx_cmd.tx_flags = TX_CMD_FLG_SEQ_CTL_MSK;
 794         scan->tx_cmd.sta_id = ctx->bcast_sta_id;
 795         scan->tx_cmd.stop_time.life_time = TX_CMD_LIFE_TIME_INFINITE;
 796
 797         switch (priv->scan_band) {
 798         case IEEE80211_BAND_2GHZ:
 799                 scan->flags = RXON_FLG_BAND_24G_MSK | RXON_FLG_AUTO_DETECT_MSK;
 800                 chan_mod = le32_to_cpu(
 801                         priv->contexts[IWL_RXON_CTX_BSS].active.flags &
 802                                                 RXON_FLG_CHANNEL_MODE_MSK)
 803                                        >> RXON_FLG_CHANNEL_MODE_POS;
 804                 if ((priv->scan_request && priv->scan_request->no_cck) ||
 805                     chan_mod == CHANNEL_MODE_PURE_40) {
 806                         rate = IWL_RATE_6M_PLCP;
 807                 } else {
 808                         rate = IWL_RATE_1M_PLCP;
 809                         rate_flags = RATE_MCS_CCK_MSK;
 810                 }
 811                 /*
 812                  * Internal scans are passive, so we can indiscriminately set
 813                  * the BT ignore flag on 2.4 GHz since it applies to TX only.
 814                  */
 815                 if (priv->cfg->bt_params &&
 816                     priv->cfg->bt_params->advanced_bt_coexist)
 817                         scan->tx_cmd.tx_flags |= TX_CMD_FLG_IGNORE_BT;
 818                 break;
 819         case IEEE80211_BAND_5GHZ:
 820                 rate = IWL_RATE_6M_PLCP;
 821                 break;
 822         default:
 823                 IWL_WARN(priv, "Invalid scan band\n");
 824                 return -EIO;
 825         }
 826
 827         /*
 828          * If active scanning is requested but a certain channel is
 829          * marked passive, we can do active scanning if we detect
 830          * transmissions.
 831          *
 832          * There is an issue with some firmware versions that triggers
 833          * a sysassert on a "good CRC threshold" of zero (== disabled),
 834          * on a radar channel even though this means that we should NOT
 835          * send probes.
 836          *
 837          * The "good CRC threshold" is the number of frames that we
 838          * need to receive during our dwell time on a channel before
 839          * sending out probes -- setting this to a huge value will
 840          * mean we never reach it, but at the same time work around
 841          * the aforementioned issue. Thus use IWL_GOOD_CRC_TH_NEVER
 842          * here instead of IWL_GOOD_CRC_TH_DISABLED.
 843          *
 844          * This was fixed in later versions along with some other
 845          * scan changes, and the threshold behaves as a flag in those
 846          * versions.
 847          */
 848         if (priv->new_scan_threshold_behaviour)
 849                 scan->good_CRC_th = is_active ? IWL_GOOD_CRC_TH_DEFAULT :
 850                                                 IWL_GOOD_CRC_TH_DISABLED;
 851         else
 852                 scan->good_CRC_th = is_active ? IWL_GOOD_CRC_TH_DEFAULT :
 853                                                 IWL_GOOD_CRC_TH_NEVER;
 854
 855         band = priv->scan_band;
 856
 857         if (band == IEEE80211_BAND_2GHZ &&
 858             priv->cfg->bt_params &&
 859             priv->cfg->bt_params->advanced_bt_coexist) {
 860                 /* transmit 2.4 GHz probes only on first antenna */
 861                 scan_tx_antennas = first_antenna(scan_tx_antennas);
 862         }
 863
 864         priv->scan_tx_ant[band] = iwl_toggle_tx_ant(priv,
 865                                                     priv->scan_tx_ant[band],
 866                                                     scan_tx_antennas);
 867         rate_flags |= iwl_ant_idx_to_flags(priv->scan_tx_ant[band]);
 868         scan->tx_cmd.rate_n_flags = iwl_hw_set_rate_n_flags(rate, rate_flags);
 869
 870         /*
 871          * In power save mode while associated use one chain,
 872          * otherwise use all chains
 873          */
 874         if (test_bit(STATUS_POWER_PMI, &priv->status) &&
 875             !(priv->hw->conf.flags & IEEE80211_CONF_IDLE)) {
 876                 /* rx_ant has been set to all valid chains previously */
 877                 active_chains = rx_ant &
 878                                 ((u8)(priv->chain_noise_data.active_chains));
 879                 if (!active_chains)
 880                         active_chains = rx_ant;
 881
 882                 IWL_DEBUG_SCAN(priv, "chain_noise_data.active_chains: %u\n",
 883                                 priv->chain_noise_data.active_chains);
 884
 885                 rx_ant = first_antenna(active_chains);
 886         }
 887         if (priv->cfg->bt_params &&
 888             priv->cfg->bt_params->advanced_bt_coexist &&
 889             priv->bt_full_concurrent) {
 890                 /* operated as 1x1 in full concurrency mode */
 891                 rx_ant = first_antenna(rx_ant);
 892         }
 893
 894         /* MIMO is not used here, but value is required */
 895         rx_chain |=
 896                 priv->hw_params.valid_rx_ant << RXON_RX_CHAIN_VALID_POS;
 897         rx_chain |= rx_ant << RXON_RX_CHAIN_FORCE_MIMO_SEL_POS;
 898         rx_chain |= rx_ant << RXON_RX_CHAIN_FORCE_SEL_POS;
 899         rx_chain |= 0x1 << RXON_RX_CHAIN_DRIVER_FORCE_POS;
 900         scan->rx_chain = cpu_to_le16(rx_chain);
 901         switch (priv->scan_type) {
 902         case IWL_SCAN_NORMAL:
 903                 cmd_len = iwl_fill_probe_req(
 904                                         (struct ieee80211_mgmt *)scan->data,
 905                                         vif->addr,
 906                                         priv->scan_request->ie,
 907                                         priv->scan_request->ie_len,
 908                                         ssid, ssid_len,
 909                                         scan_cmd_size - sizeof(*scan));
 910                 break;
 911         case IWL_SCAN_RADIO_RESET:
 912         case IWL_SCAN_ROC:
 913                 /* use bcast addr, will not be transmitted but must be valid */
 914                 cmd_len = iwl_fill_probe_req(
 915                                         (struct ieee80211_mgmt *)scan->data,
 916                                         iwl_bcast_addr, NULL, 0,
 917                                         NULL, 0,
 918                                         scan_cmd_size - sizeof(*scan));
 919                 break;
 920         default:
 921                 BUG();
 922         }
 923         scan->tx_cmd.len = cpu_to_le16(cmd_len);
 924
 925         scan->filter_flags |= (RXON_FILTER_ACCEPT_GRP_MSK |
 926                                RXON_FILTER_BCON_AWARE_MSK);
 927
 928         switch (priv->scan_type) {
 929         case IWL_SCAN_RADIO_RESET:
 930                 scan->channel_count =
 931                         iwl_get_single_channel_for_scan(priv, vif, band,
 932                                 (void *)&scan->data[cmd_len]);
 933                 break;
 934         case IWL_SCAN_NORMAL:
 935                 scan->channel_count =
 936                         iwl_get_channels_for_scan(priv, vif, band,
 937                                 is_active, n_probes,
 938                                 (void *)&scan->data[cmd_len]);
 939                 break;
 940         case IWL_SCAN_ROC: {
 941                 struct iwl_scan_channel *scan_ch;
 942                 int n_chan, i;
 943                 u16 dwell;
 944
 945                 dwell = iwl_limit_dwell(priv, priv->hw_roc_duration);
 946                 n_chan = DIV_ROUND_UP(priv->hw_roc_duration, dwell);
 947
 948                 scan->channel_count = n_chan;
 949
 950                 scan_ch = (void *)&scan->data[cmd_len];
 951
 952                 for (i = 0; i < n_chan; i++) {
 953                         scan_ch->type = SCAN_CHANNEL_TYPE_PASSIVE;
 954                         scan_ch->channel =
 955                                 cpu_to_le16(priv->hw_roc_channel->hw_value);
 956
 957                         if (i == n_chan - 1)
 958                                 dwell = priv->hw_roc_duration - i * dwell;
 959
 960                         scan_ch->active_dwell =
 961                         scan_ch->passive_dwell = cpu_to_le16(dwell);
 962
 963                         /* Set txpower levels to defaults */
 964                         scan_ch->dsp_atten = 110;
 965
 966                         /* NOTE: if we were doing 6Mb OFDM for scans we'd use
 967                          * power level:
 968                          * scan_ch->tx_gain = ((1 << 5) | (2 << 3)) | 3;
 969                          */
 970                         if (priv->hw_roc_channel->band == IEEE80211_BAND_5GHZ)
 971                                 scan_ch->tx_gain = ((1 << 5) | (3 << 3)) | 3;
 972                         else
 973                                 scan_ch->tx_gain = ((1 << 5) | (5 << 3));
 974
 975                         scan_ch++;
 976                 }
 977                 }
 978
 979                 break;
 980         }
 981
 982         if (scan->channel_count == 0) {
 983                 IWL_DEBUG_SCAN(priv, "channel count %d\n", scan->channel_count);
 984                 return -EIO;
 985         }
 986
 987         cmd.len[0] += le16_to_cpu(scan->tx_cmd.len) +
 988             scan->channel_count * sizeof(struct iwl_scan_channel);
 989         cmd.data[0] = scan;
 990         cmd.dataflags[0] = IWL_HCMD_DFL_NOCOPY;
 991         scan->len = cpu_to_le16(cmd.len[0]);
 992
 993         /* set scan bit here for PAN params */
 994         set_bit(STATUS_SCAN_HW, &priv->status);
 995
 996         ret = iwlagn_set_pan_params(priv);
 997         if (ret)
 998                 return ret;
 999
1000         ret = iwl_dvm_send_cmd(priv, &cmd);
1001         if (ret) {
1002                 clear_bit(STATUS_SCAN_HW, &priv->status);
1003                 iwlagn_set_pan_params(priv);
1004         }
1005
1006         return ret;
1007 }
1008
1009 void iwl_init_scan_params(struct iwl_priv *priv)
1010 {
1011         u8 ant_idx = fls(priv->hw_params.valid_tx_ant) - 1;
1012         if (!priv->scan_tx_ant[IEEE80211_BAND_5GHZ])
1013                 priv->scan_tx_ant[IEEE80211_BAND_5GHZ] = ant_idx;
1014         if (!priv->scan_tx_ant[IEEE80211_BAND_2GHZ])
1015                 priv->scan_tx_ant[IEEE80211_BAND_2GHZ] = ant_idx;
1016 }
1017
1018 int __must_check iwl_scan_initiate(struct iwl_priv *priv,
1019                                    struct ieee80211_vif *vif,
1020                                    enum iwl_scan_type scan_type,
1021                                    enum ieee80211_band band)
1022 {
1023         int ret;
1024
1025         lockdep_assert_held(&priv->mutex);
1026
1027         cancel_delayed_work(&priv->scan_check);
1028
1029         if (!iwl_is_ready_rf(priv)) {
1030                 IWL_WARN(priv, "Request scan called when driver not ready.\n");
1031                 return -EIO;
1032         }
1033
1034         if (test_bit(STATUS_SCAN_HW, &priv->status)) {
1035                 IWL_DEBUG_SCAN(priv,
1036                         "Multiple concurrent scan requests in parallel.\n");
1037                 return -EBUSY;
1038         }
1039
1040         if (test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
1041                 IWL_DEBUG_SCAN(priv, "Scan request while abort pending.\n");
1042                 return -EBUSY;
1043         }
1044
1045         IWL_DEBUG_SCAN(priv, "Starting %sscan...\n",
1046                         scan_type == IWL_SCAN_NORMAL ? "" :
1047                         scan_type == IWL_SCAN_ROC ? "remain-on-channel " :
1048                         "internal short ");
1049
1050         set_bit(STATUS_SCANNING, &priv->status);
1051         priv->scan_type = scan_type;
1052         priv->scan_start = jiffies;
1053         priv->scan_band = band;
1054
1055         ret = iwlagn_request_scan(priv, vif);
1056         if (ret) {
1057                 clear_bit(STATUS_SCANNING, &priv->status);
1058                 priv->scan_type = IWL_SCAN_NORMAL;
1059                 return ret;
1060         }
1061
1062         queue_delayed_work(priv->workqueue, &priv->scan_check,
1063                            IWL_SCAN_CHECK_WATCHDOG);
1064
1065         return 0;
1066 }
1067
1068
1069 /*
1070  * internal short scan, this function should only been called while associated.
1071  * It will reset and tune the radio to prevent possible RF related problem
1072  */
1073 void iwl_internal_short_hw_scan(struct iwl_priv *priv)
1074 {
1075         queue_work(priv->workqueue, &priv->start_internal_scan);
1076 }
1077
1078 static void iwl_bg_start_internal_scan(struct work_struct *work)
1079 {
1080         struct iwl_priv *priv =
1081                 container_of(work, struct iwl_priv, start_internal_scan);
1082
1083         IWL_DEBUG_SCAN(priv, "Start internal scan\n");
1084
1085         mutex_lock(&priv->mutex);
1086
1087         if (priv->scan_type == IWL_SCAN_RADIO_RESET) {
1088                 IWL_DEBUG_SCAN(priv, "Internal scan already in progress\n");
1089                 goto unlock;
1090         }
1091
1092         if (test_bit(STATUS_SCANNING, &priv->status)) {
1093                 IWL_DEBUG_SCAN(priv, "Scan already in progress.\n");
1094                 goto unlock;
1095         }
1096
1097         if (iwl_scan_initiate(priv, NULL, IWL_SCAN_RADIO_RESET, priv->band))
1098                 IWL_DEBUG_SCAN(priv, "failed to start internal short scan\n");
1099  unlock:
1100         mutex_unlock(&priv->mutex);
1101 }
1102
1103 static void iwl_bg_scan_check(struct work_struct *data)
1104 {
1105         struct iwl_priv *priv =
1106             container_of(data, struct iwl_priv, scan_check.work);
1107
1108         IWL_DEBUG_SCAN(priv, "Scan check work\n");
1109
1110         /* Since we are here firmware does not finish scan and
1111          * most likely is in bad shape, so we don't bother to
1112          * send abort command, just force scan complete to mac80211 */
1113         mutex_lock(&priv->mutex);
1114         iwl_force_scan_end(priv);
1115         mutex_unlock(&priv->mutex);
1116 }
1117
1118 static void iwl_bg_abort_scan(struct work_struct *work)
1119 {
1120         struct iwl_priv *priv = container_of(work, struct iwl_priv, abort_scan);
1121
1122         IWL_DEBUG_SCAN(priv, "Abort scan work\n");
1123
1124         /* We keep scan_check work queued in case when firmware will not
1125          * report back scan completed notification */
1126         mutex_lock(&priv->mutex);
1127         iwl_scan_cancel_timeout(priv, 200);
1128         mutex_unlock(&priv->mutex);
1129 }
1130
1131 static void iwl_bg_scan_completed(struct work_struct *work)
1132 {
1133         struct iwl_priv *priv =
1134                 container_of(work, struct iwl_priv, scan_completed);
1135
1136         mutex_lock(&priv->mutex);
1137         iwl_process_scan_complete(priv);
1138         mutex_unlock(&priv->mutex);
1139 }
1140
1141 void iwl_setup_scan_deferred_work(struct iwl_priv *priv)
1142 {
1143         INIT_WORK(&priv->scan_completed, iwl_bg_scan_completed);
1144         INIT_WORK(&priv->abort_scan, iwl_bg_abort_scan);
1145         INIT_WORK(&priv->start_internal_scan, iwl_bg_start_internal_scan);
1146         INIT_DELAYED_WORK(&priv->scan_check, iwl_bg_scan_check);
1147 }
1148
1149 void iwl_cancel_scan_deferred_work(struct iwl_priv *priv)
1150 {
1151         cancel_work_sync(&priv->start_internal_scan);
1152         cancel_work_sync(&priv->abort_scan);
1153         cancel_work_sync(&priv->scan_completed);
1154
1155         if (cancel_delayed_work_sync(&priv->scan_check)) {
1156                 mutex_lock(&priv->mutex);
1157                 iwl_force_scan_end(priv);
1158                 mutex_unlock(&priv->mutex);
1159         }
1160 }