drivers/net/wireless/wl12xx/scan.c

   1 /*
   2  * This file is part of wl1271
   3  *
   4  * Copyright (C) 2009-2010 Nokia Corporation
   5  *
   6  * Contact: Luciano Coelho <luciano.coelho@nokia.com>
   7  *
   8  * This program is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU General Public License
  10  * version 2 as published by the Free Software Foundation.
  11  *
  12  * This program is distributed in the hope that it will be useful, but
  13  * WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
  20  * 02110-1301 USA
  21  *
  22  */
  23
  24 #include <linux/ieee80211.h>
  25
  26 #include "wl12xx.h"
  27 #include "cmd.h"
  28 #include "scan.h"
  29 #include "acx.h"
  30 #include "ps.h"
  31
  32 void wl1271_scan_complete_work(struct work_struct *work)
  33 {
  34         struct delayed_work *dwork;
  35         struct wl1271 *wl;
  36
  37         dwork = container_of(work, struct delayed_work, work);
  38         wl = container_of(dwork, struct wl1271, scan_complete_work);
  39
  40         wl1271_debug(DEBUG_SCAN, "Scanning complete");
  41
  42         mutex_lock(&wl->mutex);
  43
  44         if (wl->state == WL1271_STATE_OFF)
  45                 goto out;
  46
  47         if (wl->scan.state == WL1271_SCAN_STATE_IDLE)
  48                 goto out;
  49
  50         wl->scan.state = WL1271_SCAN_STATE_IDLE;
  51         memset(wl->scan.scanned_ch, 0, sizeof(wl->scan.scanned_ch));
  52         wl->scan.req = NULL;
  53         ieee80211_scan_completed(wl->hw, false);
  54
  55         /* restore hardware connection monitoring template */
  56         if (test_bit(WL1271_FLAG_STA_ASSOCIATED, &wl->flags)) {
  57                 if (wl1271_ps_elp_wakeup(wl) == 0) {
  58                         wl1271_cmd_build_ap_probe_req(wl, wl->probereq);
  59                         wl1271_ps_elp_sleep(wl);
  60                 }
  61         }
  62
  63         if (wl->scan.failed) {
  64                 wl1271_info("Scan completed due to error.");
  65                 wl12xx_queue_recovery_work(wl);
  66         }
  67
  68 out:
  69         mutex_unlock(&wl->mutex);
  70
  71 }
  72
  73
  74 static int wl1271_get_scan_channels(struct wl1271 *wl,
  75                                     struct cfg80211_scan_request *req,
  76                                     struct basic_scan_channel_params *channels,
  77                                     enum ieee80211_band band, bool passive)
  78 {
  79         struct conf_scan_settings *c = &wl->conf.scan;
  80         int i, j;
  81         u32 flags;
  82
  83         for (i = 0, j = 0;
  84              i < req->n_channels && j < WL1271_SCAN_MAX_CHANNELS;
  85              i++) {
  86
  87                 flags = req->channels[i]->flags;
  88
  89                 if (!test_bit(i, wl->scan.scanned_ch) &&
  90                     !(flags & IEEE80211_CHAN_DISABLED) &&
  91                     ((!!(flags & IEEE80211_CHAN_PASSIVE_SCAN)) == passive) &&
  92                     (req->channels[i]->band == band)) {
  93
  94                         wl1271_debug(DEBUG_SCAN, "band %d, center_freq %d ",
  95                                      req->channels[i]->band,
  96                                      req->channels[i]->center_freq);
  97                         wl1271_debug(DEBUG_SCAN, "hw_value %d, flags %X",
  98                                      req->channels[i]->hw_value,
  99                                      req->channels[i]->flags);
 100                         wl1271_debug(DEBUG_SCAN,
 101                                      "max_antenna_gain %d, max_power %d",
 102                                      req->channels[i]->max_antenna_gain,
 103                                      req->channels[i]->max_power);
 104                         wl1271_debug(DEBUG_SCAN, "beacon_found %d",
 105                                      req->channels[i]->beacon_found);
 106
 107                         if (!passive) {
 108                                 channels[j].min_duration =
 109                                         cpu_to_le32(c->min_dwell_time_active);
 110                                 channels[j].max_duration =
 111                                         cpu_to_le32(c->max_dwell_time_active);
 112                         } else {
 113                                 channels[j].min_duration =
 114                                         cpu_to_le32(c->min_dwell_time_passive);
 115                                 channels[j].max_duration =
 116                                         cpu_to_le32(c->max_dwell_time_passive);
 117                         }
 118                         channels[j].early_termination = 0;
 119                         channels[j].tx_power_att = req->channels[i]->max_power;
 120                         channels[j].channel = req->channels[i]->hw_value;
 121
 122                         memset(&channels[j].bssid_lsb, 0xff, 4);
 123                         memset(&channels[j].bssid_msb, 0xff, 2);
 124
 125                         /* Mark the channels we already used */
 126                         set_bit(i, wl->scan.scanned_ch);
 127
 128                         j++;
 129                 }
 130         }
 131
 132         return j;
 133 }
 134
 135 #define WL1271_NOTHING_TO_SCAN 1
 136
 137 static int wl1271_scan_send(struct wl1271 *wl, enum ieee80211_band band,
 138                              bool passive, u32 basic_rate)
 139 {
 140         struct wl1271_cmd_scan *cmd;
 141         struct wl1271_cmd_trigger_scan_to *trigger;
 142         int ret;
 143         u16 scan_options = 0;
 144
 145         cmd = kzalloc(sizeof(*cmd), GFP_KERNEL);
 146         trigger = kzalloc(sizeof(*trigger), GFP_KERNEL);
 147         if (!cmd || !trigger) {
 148                 ret = -ENOMEM;
 149                 goto out;
 150         }
 151
 152         /* We always use high priority scans */
 153         scan_options = WL1271_SCAN_OPT_PRIORITY_HIGH;
 154
 155         /* No SSIDs means that we have a forced passive scan */
 156         if (passive || wl->scan.req->n_ssids == 0)
 157                 scan_options |= WL1271_SCAN_OPT_PASSIVE;
 158
 159         cmd->params.scan_options = cpu_to_le16(scan_options);
 160
 161         cmd->params.n_ch = wl1271_get_scan_channels(wl, wl->scan.req,
 162                                                     cmd->channels,
 163                                                     band, passive);
 164         if (cmd->params.n_ch == 0) {
 165                 ret = WL1271_NOTHING_TO_SCAN;
 166                 goto out;
 167         }
 168
 169         cmd->params.tx_rate = cpu_to_le32(basic_rate);
 170         cmd->params.rx_config_options = cpu_to_le32(CFG_RX_ALL_GOOD);
 171         cmd->params.rx_filter_options =
 172                 cpu_to_le32(CFG_RX_PRSP_EN | CFG_RX_MGMT_EN | CFG_RX_BCN_EN);
 173
 174         cmd->params.n_probe_reqs = wl->conf.scan.num_probe_reqs;
 175         cmd->params.tx_rate = cpu_to_le32(basic_rate);
 176         cmd->params.tid_trigger = 0;
 177         cmd->params.scan_tag = WL1271_SCAN_DEFAULT_TAG;
 178
 179         if (band == IEEE80211_BAND_2GHZ)
 180                 cmd->params.band = WL1271_SCAN_BAND_2_4_GHZ;
 181         else
 182                 cmd->params.band = WL1271_SCAN_BAND_5_GHZ;
 183
 184         if (wl->scan.ssid_len && wl->scan.ssid) {
 185                 cmd->params.ssid_len = wl->scan.ssid_len;
 186                 memcpy(cmd->params.ssid, wl->scan.ssid, wl->scan.ssid_len);
 187         }
 188
 189         ret = wl1271_cmd_build_probe_req(wl, wl->scan.ssid, wl->scan.ssid_len,
 190                                          wl->scan.req->ie, wl->scan.req->ie_len,
 191                                          band);
 192         if (ret < 0) {
 193                 wl1271_error("PROBE request template failed");
 194                 goto out;
 195         }
 196
 197         /* disable the timeout */
 198         trigger->timeout = 0;
 199         ret = wl1271_cmd_send(wl, CMD_TRIGGER_SCAN_TO, trigger,
 200                               sizeof(*trigger), 0);
 201         if (ret < 0) {
 202                 wl1271_error("trigger scan to failed for hw scan");
 203                 goto out;
 204         }
 205
 206         wl1271_dump(DEBUG_SCAN, "SCAN: ", cmd, sizeof(*cmd));
 207
 208         ret = wl1271_cmd_send(wl, CMD_SCAN, cmd, sizeof(*cmd), 0);
 209         if (ret < 0) {
 210                 wl1271_error("SCAN failed");
 211                 goto out;
 212         }
 213
 214 out:
 215         kfree(cmd);
 216         kfree(trigger);
 217         return ret;
 218 }
 219
 220 void wl1271_scan_stm(struct wl1271 *wl)
 221 {
 222         int ret = 0;
 223
 224         switch (wl->scan.state) {
 225         case WL1271_SCAN_STATE_IDLE:
 226                 break;
 227
 228         case WL1271_SCAN_STATE_2GHZ_ACTIVE:
 229                 ret = wl1271_scan_send(wl, IEEE80211_BAND_2GHZ, false,
 230                                        wl->conf.tx.basic_rate);
 231                 if (ret == WL1271_NOTHING_TO_SCAN) {
 232                         wl->scan.state = WL1271_SCAN_STATE_2GHZ_PASSIVE;
 233                         wl1271_scan_stm(wl);
 234                 }
 235
 236                 break;
 237
 238         case WL1271_SCAN_STATE_2GHZ_PASSIVE:
 239                 ret = wl1271_scan_send(wl, IEEE80211_BAND_2GHZ, true,
 240                                        wl->conf.tx.basic_rate);
 241                 if (ret == WL1271_NOTHING_TO_SCAN) {
 242                         if (wl->enable_11a)
 243                                 wl->scan.state = WL1271_SCAN_STATE_5GHZ_ACTIVE;
 244                         else
 245                                 wl->scan.state = WL1271_SCAN_STATE_DONE;
 246                         wl1271_scan_stm(wl);
 247                 }
 248
 249                 break;
 250
 251         case WL1271_SCAN_STATE_5GHZ_ACTIVE:
 252                 ret = wl1271_scan_send(wl, IEEE80211_BAND_5GHZ, false,
 253                                        wl->conf.tx.basic_rate_5);
 254                 if (ret == WL1271_NOTHING_TO_SCAN) {
 255                         wl->scan.state = WL1271_SCAN_STATE_5GHZ_PASSIVE;
 256                         wl1271_scan_stm(wl);
 257                 }
 258
 259                 break;
 260
 261         case WL1271_SCAN_STATE_5GHZ_PASSIVE:
 262                 ret = wl1271_scan_send(wl, IEEE80211_BAND_5GHZ, true,
 263                                        wl->conf.tx.basic_rate_5);
 264                 if (ret == WL1271_NOTHING_TO_SCAN) {
 265                         wl->scan.state = WL1271_SCAN_STATE_DONE;
 266                         wl1271_scan_stm(wl);
 267                 }
 268
 269                 break;
 270
 271         case WL1271_SCAN_STATE_DONE:
 272                 wl->scan.failed = false;
 273                 cancel_delayed_work(&wl->scan_complete_work);
 274                 ieee80211_queue_delayed_work(wl->hw, &wl->scan_complete_work,
 275                                              msecs_to_jiffies(0));
 276                 break;
 277
 278         default:
 279                 wl1271_error("invalid scan state");
 280                 break;
 281         }
 282
 283         if (ret < 0) {
 284                 cancel_delayed_work(&wl->scan_complete_work);
 285                 ieee80211_queue_delayed_work(wl->hw, &wl->scan_complete_work,
 286                                              msecs_to_jiffies(0));
 287         }
 288 }
 289
 290 int wl1271_scan(struct wl1271 *wl, const u8 *ssid, size_t ssid_len,
 291                 struct cfg80211_scan_request *req)
 292 {
 293         /*
 294          * cfg80211 should guarantee that we don't get more channels
 295          * than what we have registered.
 296          */
 297         BUG_ON(req->n_channels > WL1271_MAX_CHANNELS);
 298
 299         if (wl->scan.state != WL1271_SCAN_STATE_IDLE)
 300                 return -EBUSY;
 301
 302         wl->scan.state = WL1271_SCAN_STATE_2GHZ_ACTIVE;
 303
 304         if (ssid_len && ssid) {
 305                 wl->scan.ssid_len = ssid_len;
 306                 memcpy(wl->scan.ssid, ssid, ssid_len);
 307         } else {
 308                 wl->scan.ssid_len = 0;
 309         }
 310
 311         wl->scan.req = req;
 312         memset(wl->scan.scanned_ch, 0, sizeof(wl->scan.scanned_ch));
 313
 314         /* we assume failure so that timeout scenarios are handled correctly */
 315         wl->scan.failed = true;
 316         ieee80211_queue_delayed_work(wl->hw, &wl->scan_complete_work,
 317                                      msecs_to_jiffies(WL1271_SCAN_TIMEOUT));
 318
 319         wl1271_scan_stm(wl);
 320
 321         return 0;
 322 }
 323
 324 int wl1271_scan_stop(struct wl1271 *wl)
 325 {
 326         struct wl1271_cmd_header *cmd = NULL;
 327         int ret = 0;
 328
 329         if (WARN_ON(wl->scan.state == WL1271_SCAN_STATE_IDLE))
 330                 return -EINVAL;
 331
 332         wl1271_debug(DEBUG_CMD, "cmd scan stop");
 333
 334         cmd = kzalloc(sizeof(*cmd), GFP_KERNEL);
 335         if (!cmd) {
 336                 ret = -ENOMEM;
 337                 goto out;
 338         }
 339
 340         ret = wl1271_cmd_send(wl, CMD_STOP_SCAN, cmd,
 341                               sizeof(*cmd), 0);
 342         if (ret < 0) {
 343                 wl1271_error("cmd stop_scan failed");
 344                 goto out;
 345         }
 346 out:
 347         kfree(cmd);
 348         return ret;
 349 }
 350
 351 static int
 352 wl1271_scan_get_sched_scan_channels(struct wl1271 *wl,
 353                                     struct cfg80211_sched_scan_request *req,
 354                                     struct conn_scan_ch_params *channels,
 355                                     u32 band, bool radar, bool passive,
 356                                     int start, int max_channels)
 357 {
 358         struct conf_sched_scan_settings *c = &wl->conf.sched_scan;
 359         int i, j;
 360         u32 flags;
 361         bool force_passive = !req->n_ssids;
 362
 363         for (i = 0, j = start;
 364              i < req->n_channels && j < max_channels;
 365              i++) {
 366                 flags = req->channels[i]->flags;
 367
 368                 if (force_passive)
 369                         flags |= IEEE80211_CHAN_PASSIVE_SCAN;
 370
 371                 if ((req->channels[i]->band == band) &&
 372                     !(flags & IEEE80211_CHAN_DISABLED) &&
 373                     (!!(flags & IEEE80211_CHAN_RADAR) == radar) &&
 374                     /* if radar is set, we ignore the passive flag */
 375                     (radar ||
 376                      !!(flags & IEEE80211_CHAN_PASSIVE_SCAN) == passive)) {
 377                         wl1271_debug(DEBUG_SCAN, "band %d, center_freq %d ",
 378                                      req->channels[i]->band,
 379                                      req->channels[i]->center_freq);
 380                         wl1271_debug(DEBUG_SCAN, "hw_value %d, flags %X",
 381                                      req->channels[i]->hw_value,
 382                                      req->channels[i]->flags);
 383                         wl1271_debug(DEBUG_SCAN, "max_power %d",
 384                                      req->channels[i]->max_power);
 385
 386                         if (flags & IEEE80211_CHAN_RADAR) {
 387                                 channels[j].flags |= SCAN_CHANNEL_FLAGS_DFS;
 388                                 channels[j].passive_duration =
 389                                         cpu_to_le16(c->dwell_time_dfs);
 390                         }
 391                         else if (flags & IEEE80211_CHAN_PASSIVE_SCAN) {
 392                                 channels[j].passive_duration =
 393                                         cpu_to_le16(c->dwell_time_passive);
 394                         } else {
 395                                 channels[j].min_duration =
 396                                         cpu_to_le16(c->min_dwell_time_active);
 397                                 channels[j].max_duration =
 398                                         cpu_to_le16(c->max_dwell_time_active);
 399                         }
 400                         channels[j].tx_power_att = req->channels[i]->max_power;
 401                         channels[j].channel = req->channels[i]->hw_value;
 402
 403                         j++;
 404                 }
 405         }
 406
 407         return j - start;
 408 }
 409
 410 static bool
 411 wl1271_scan_sched_scan_channels(struct wl1271 *wl,
 412                                 struct cfg80211_sched_scan_request *req,
 413                                 struct wl1271_cmd_sched_scan_config *cfg)
 414 {
 415         cfg->passive[0] =
 416                 wl1271_scan_get_sched_scan_channels(wl, req, cfg->channels_2,
 417                                                     IEEE80211_BAND_2GHZ,
 418                                                     false, true, 0,
 419                                                     MAX_CHANNELS_2GHZ);
 420         cfg->active[0] =
 421                 wl1271_scan_get_sched_scan_channels(wl, req, cfg->channels_2,
 422                                                     IEEE80211_BAND_2GHZ,
 423                                                     false, false,
 424                                                     cfg->passive[0],
 425                                                     MAX_CHANNELS_2GHZ);
 426         cfg->passive[1] =
 427                 wl1271_scan_get_sched_scan_channels(wl, req, cfg->channels_5,
 428                                                     IEEE80211_BAND_5GHZ,
 429                                                     false, true, 0,
 430                                                     MAX_CHANNELS_5GHZ);
 431         cfg->dfs =
 432                 wl1271_scan_get_sched_scan_channels(wl, req, cfg->channels_5,
 433                                                     IEEE80211_BAND_5GHZ,
 434                                                     true, true,
 435                                                     cfg->passive[1],
 436                                                     MAX_CHANNELS_5GHZ);
 437         cfg->active[1] =
 438                 wl1271_scan_get_sched_scan_channels(wl, req, cfg->channels_5,
 439                                                     IEEE80211_BAND_5GHZ,
 440                                                     false, false,
 441                                                     cfg->passive[1] + cfg->dfs,
 442                                                     MAX_CHANNELS_5GHZ);
 443         /* 802.11j channels are not supported yet */
 444         cfg->passive[2] = 0;
 445         cfg->active[2] = 0;
 446
 447         wl1271_debug(DEBUG_SCAN, "    2.4GHz: active %d passive %d",
 448                      cfg->active[0], cfg->passive[0]);
 449         wl1271_debug(DEBUG_SCAN, "    5GHz: active %d passive %d",
 450                      cfg->active[1], cfg->passive[1]);
 451         wl1271_debug(DEBUG_SCAN, "    DFS: %d", cfg->dfs);
 452
 453         return  cfg->passive[0] || cfg->active[0] ||
 454                 cfg->passive[1] || cfg->active[1] || cfg->dfs ||
 455                 cfg->passive[2] || cfg->active[2];
 456 }
 457
 458 int wl1271_scan_sched_scan_config(struct wl1271 *wl,
 459                                   struct cfg80211_sched_scan_request *req,
 460                                   struct ieee80211_sched_scan_ies *ies)
 461 {
 462         struct wl1271_cmd_sched_scan_config *cfg = NULL;
 463         struct conf_sched_scan_settings *c = &wl->conf.sched_scan;
 464         int i, ret;
 465         bool force_passive = !req->n_ssids;
 466
 467         wl1271_debug(DEBUG_CMD, "cmd sched_scan scan config");
 468
 469         cfg = kzalloc(sizeof(*cfg), GFP_KERNEL);
 470         if (!cfg)
 471                 return -ENOMEM;
 472
 473         cfg->rssi_threshold = c->rssi_threshold;
 474         cfg->snr_threshold  = c->snr_threshold;
 475         cfg->n_probe_reqs = c->num_probe_reqs;
 476         /* cycles set to 0 it means infinite (until manually stopped) */
 477         cfg->cycles = 0;
 478         /* report APs when at least 1 is found */
 479         cfg->report_after = 1;
 480         /* don't stop scanning automatically when something is found */
 481         cfg->terminate = 0;
 482         cfg->tag = WL1271_SCAN_DEFAULT_TAG;
 483         /* don't filter on BSS type */
 484         cfg->bss_type = SCAN_BSS_TYPE_ANY;
 485         /* currently NL80211 supports only a single interval */
 486         for (i = 0; i < SCAN_MAX_CYCLE_INTERVALS; i++)
 487                 cfg->intervals[i] = cpu_to_le32(req->interval);
 488
 489         if (!force_passive && req->ssids[0].ssid_len && req->ssids[0].ssid) {
 490                 cfg->filter_type = SCAN_SSID_FILTER_SPECIFIC;
 491                 cfg->ssid_len = req->ssids[0].ssid_len;
 492                 memcpy(cfg->ssid, req->ssids[0].ssid,
 493                        req->ssids[0].ssid_len);
 494         } else {
 495                 cfg->filter_type = SCAN_SSID_FILTER_ANY;
 496                 cfg->ssid_len = 0;
 497         }
 498
 499         if (!wl1271_scan_sched_scan_channels(wl, req, cfg)) {
 500                 wl1271_error("scan channel list is empty");
 501                 ret = -EINVAL;
 502                 goto out;
 503         }
 504
 505         if (!force_passive && cfg->active[0]) {
 506                 ret = wl1271_cmd_build_probe_req(wl, req->ssids[0].ssid,
 507                                                  req->ssids[0].ssid_len,
 508                                                  ies->ie[IEEE80211_BAND_2GHZ],
 509                                                  ies->len[IEEE80211_BAND_2GHZ],
 510                                                  IEEE80211_BAND_2GHZ);
 511                 if (ret < 0) {
 512                         wl1271_error("2.4GHz PROBE request template failed");
 513                         goto out;
 514                 }
 515         }
 516
 517         if (!force_passive && cfg->active[1]) {
 518                 ret = wl1271_cmd_build_probe_req(wl,  req->ssids[0].ssid,
 519                                                  req->ssids[0].ssid_len,
 520                                                  ies->ie[IEEE80211_BAND_5GHZ],
 521                                                  ies->len[IEEE80211_BAND_5GHZ],
 522                                                  IEEE80211_BAND_5GHZ);
 523                 if (ret < 0) {
 524                         wl1271_error("5GHz PROBE request template failed");
 525                         goto out;
 526                 }
 527         }
 528
 529         wl1271_dump(DEBUG_SCAN, "SCAN_CFG: ", cfg, sizeof(*cfg));
 530
 531         ret = wl1271_cmd_send(wl, CMD_CONNECTION_SCAN_CFG, cfg,
 532                               sizeof(*cfg), 0);
 533         if (ret < 0) {
 534                 wl1271_error("SCAN configuration failed");
 535                 goto out;
 536         }
 537 out:
 538         kfree(cfg);
 539         return ret;
 540 }
 541
 542 int wl1271_scan_sched_scan_start(struct wl1271 *wl)
 543 {
 544         struct wl1271_cmd_sched_scan_start *start;
 545         int ret = 0;
 546
 547         wl1271_debug(DEBUG_CMD, "cmd periodic scan start");
 548
 549         if (wl->bss_type != BSS_TYPE_STA_BSS)
 550                 return -EOPNOTSUPP;
 551
 552         if (!test_bit(WL1271_FLAG_IDLE, &wl->flags))
 553                 return -EBUSY;
 554
 555         start = kzalloc(sizeof(*start), GFP_KERNEL);
 556         if (!start)
 557                 return -ENOMEM;
 558
 559         start->tag = WL1271_SCAN_DEFAULT_TAG;
 560
 561         ret = wl1271_cmd_send(wl, CMD_START_PERIODIC_SCAN, start,
 562                               sizeof(*start), 0);
 563         if (ret < 0) {
 564                 wl1271_error("failed to send scan start command");
 565                 goto out_free;
 566         }
 567
 568 out_free:
 569         kfree(start);
 570         return ret;
 571 }
 572
 573 void wl1271_scan_sched_scan_results(struct wl1271 *wl)
 574 {
 575         wl1271_debug(DEBUG_SCAN, "got periodic scan results");
 576
 577         ieee80211_sched_scan_results(wl->hw);
 578 }
 579
 580 void wl1271_scan_sched_scan_stop(struct wl1271 *wl)
 581 {
 582         struct wl1271_cmd_sched_scan_stop *stop;
 583         int ret = 0;
 584
 585         wl1271_debug(DEBUG_CMD, "cmd periodic scan stop");
 586
 587         /* FIXME: what to do if alloc'ing to stop fails? */
 588         stop = kzalloc(sizeof(*stop), GFP_KERNEL);
 589         if (!stop) {
 590                 wl1271_error("failed to alloc memory to send sched scan stop");
 591                 return;
 592         }
 593
 594         stop->tag = WL1271_SCAN_DEFAULT_TAG;
 595
 596         ret = wl1271_cmd_send(wl, CMD_STOP_PERIODIC_SCAN, stop,
 597                               sizeof(*stop), 0);
 598         if (ret < 0) {
 599                 wl1271_error("failed to send sched scan stop command");
 600                 goto out_free;
 601         }
 602         wl->sched_scanning = false;
 603
 604 out_free:
 605         kfree(stop);
 606 }