Pileus Git - ~andy/linux/blob - 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         if (WARN_ON(wl->role_id == WL12XX_INVALID_ROLE_ID)) {
 160                 ret = -EINVAL;
 161                 goto out;
 162         }
 163         cmd->params.role_id = wl->role_id;
 164         cmd->params.scan_options = cpu_to_le16(scan_options);
 165
 166         cmd->params.n_ch = wl1271_get_scan_channels(wl, wl->scan.req,
 167                                                     cmd->channels,
 168                                                     band, passive);
 169         if (cmd->params.n_ch == 0) {
 170                 ret = WL1271_NOTHING_TO_SCAN;
 171                 goto out;
 172         }
 173
 174         cmd->params.tx_rate = cpu_to_le32(basic_rate);
 175         cmd->params.n_probe_reqs = wl->conf.scan.num_probe_reqs;
 176         cmd->params.tx_rate = cpu_to_le32(basic_rate);
 177         cmd->params.tid_trigger = 0;
 178         cmd->params.scan_tag = WL1271_SCAN_DEFAULT_TAG;
 179
 180         if (band == IEEE80211_BAND_2GHZ)
 181                 cmd->params.band = WL1271_SCAN_BAND_2_4_GHZ;
 182         else
 183                 cmd->params.band = WL1271_SCAN_BAND_5_GHZ;
 184
 185         if (wl->scan.ssid_len && wl->scan.ssid) {
 186                 cmd->params.ssid_len = wl->scan.ssid_len;
 187                 memcpy(cmd->params.ssid, wl->scan.ssid, wl->scan.ssid_len);
 188         }
 189
 190         memcpy(cmd->addr, wl->mac_addr, ETH_ALEN);
 191
 192         ret = wl1271_cmd_build_probe_req(wl, wl->scan.ssid, wl->scan.ssid_len,
 193                                          wl->scan.req->ie, wl->scan.req->ie_len,
 194                                          band);
 195         if (ret < 0) {
 196                 wl1271_error("PROBE request template failed");
 197                 goto out;
 198         }
 199
 200         /* disable the timeout */
 201         trigger->timeout = 0;
 202         ret = wl1271_cmd_send(wl, CMD_TRIGGER_SCAN_TO, trigger,
 203                               sizeof(*trigger), 0);
 204         if (ret < 0) {
 205                 wl1271_error("trigger scan to failed for hw scan");
 206                 goto out;
 207         }
 208
 209         wl1271_dump(DEBUG_SCAN, "SCAN: ", cmd, sizeof(*cmd));
 210
 211         ret = wl1271_cmd_send(wl, CMD_SCAN, cmd, sizeof(*cmd), 0);
 212         if (ret < 0) {
 213                 wl1271_error("SCAN failed");
 214                 goto out;
 215         }
 216
 217 out:
 218         kfree(cmd);
 219         kfree(trigger);
 220         return ret;
 221 }
 222
 223 void wl1271_scan_stm(struct wl1271 *wl)
 224 {
 225         int ret = 0;
 226
 227         switch (wl->scan.state) {
 228         case WL1271_SCAN_STATE_IDLE:
 229                 break;
 230
 231         case WL1271_SCAN_STATE_2GHZ_ACTIVE:
 232                 ret = wl1271_scan_send(wl, IEEE80211_BAND_2GHZ, false,
 233                                        wl->conf.tx.basic_rate);
 234                 if (ret == WL1271_NOTHING_TO_SCAN) {
 235                         wl->scan.state = WL1271_SCAN_STATE_2GHZ_PASSIVE;
 236                         wl1271_scan_stm(wl);
 237                 }
 238
 239                 break;
 240
 241         case WL1271_SCAN_STATE_2GHZ_PASSIVE:
 242                 ret = wl1271_scan_send(wl, IEEE80211_BAND_2GHZ, true,
 243                                        wl->conf.tx.basic_rate);
 244                 if (ret == WL1271_NOTHING_TO_SCAN) {
 245                         if (wl->enable_11a)
 246                                 wl->scan.state = WL1271_SCAN_STATE_5GHZ_ACTIVE;
 247                         else
 248                                 wl->scan.state = WL1271_SCAN_STATE_DONE;
 249                         wl1271_scan_stm(wl);
 250                 }
 251
 252                 break;
 253
 254         case WL1271_SCAN_STATE_5GHZ_ACTIVE:
 255                 ret = wl1271_scan_send(wl, IEEE80211_BAND_5GHZ, false,
 256                                        wl->conf.tx.basic_rate_5);
 257                 if (ret == WL1271_NOTHING_TO_SCAN) {
 258                         wl->scan.state = WL1271_SCAN_STATE_5GHZ_PASSIVE;
 259                         wl1271_scan_stm(wl);
 260                 }
 261
 262                 break;
 263
 264         case WL1271_SCAN_STATE_5GHZ_PASSIVE:
 265                 ret = wl1271_scan_send(wl, IEEE80211_BAND_5GHZ, true,
 266                                        wl->conf.tx.basic_rate_5);
 267                 if (ret == WL1271_NOTHING_TO_SCAN) {
 268                         wl->scan.state = WL1271_SCAN_STATE_DONE;
 269                         wl1271_scan_stm(wl);
 270                 }
 271
 272                 break;
 273
 274         case WL1271_SCAN_STATE_DONE:
 275                 wl->scan.failed = false;
 276                 cancel_delayed_work(&wl->scan_complete_work);
 277                 ieee80211_queue_delayed_work(wl->hw, &wl->scan_complete_work,
 278                                              msecs_to_jiffies(0));
 279                 break;
 280
 281         default:
 282                 wl1271_error("invalid scan state");
 283                 break;
 284         }
 285
 286         if (ret < 0) {
 287                 cancel_delayed_work(&wl->scan_complete_work);
 288                 ieee80211_queue_delayed_work(wl->hw, &wl->scan_complete_work,
 289                                              msecs_to_jiffies(0));
 290         }
 291 }
 292
 293 int wl1271_scan(struct wl1271 *wl, const u8 *ssid, size_t ssid_len,
 294                 struct cfg80211_scan_request *req)
 295 {
 296         /*
 297          * cfg80211 should guarantee that we don't get more channels
 298          * than what we have registered.
 299          */
 300         BUG_ON(req->n_channels > WL1271_MAX_CHANNELS);
 301
 302         if (wl->scan.state != WL1271_SCAN_STATE_IDLE)
 303                 return -EBUSY;
 304
 305         wl->scan.state = WL1271_SCAN_STATE_2GHZ_ACTIVE;
 306
 307         if (ssid_len && ssid) {
 308                 wl->scan.ssid_len = ssid_len;
 309                 memcpy(wl->scan.ssid, ssid, ssid_len);
 310         } else {
 311                 wl->scan.ssid_len = 0;
 312         }
 313
 314         wl->scan.req = req;
 315         memset(wl->scan.scanned_ch, 0, sizeof(wl->scan.scanned_ch));
 316
 317         /* we assume failure so that timeout scenarios are handled correctly */
 318         wl->scan.failed = true;
 319         ieee80211_queue_delayed_work(wl->hw, &wl->scan_complete_work,
 320                                      msecs_to_jiffies(WL1271_SCAN_TIMEOUT));
 321
 322         wl1271_scan_stm(wl);
 323
 324         return 0;
 325 }
 326
 327 int wl1271_scan_stop(struct wl1271 *wl)
 328 {
 329         struct wl1271_cmd_header *cmd = NULL;
 330         int ret = 0;
 331
 332         if (WARN_ON(wl->scan.state == WL1271_SCAN_STATE_IDLE))
 333                 return -EINVAL;
 334
 335         wl1271_debug(DEBUG_CMD, "cmd scan stop");
 336
 337         cmd = kzalloc(sizeof(*cmd), GFP_KERNEL);
 338         if (!cmd) {
 339                 ret = -ENOMEM;
 340                 goto out;
 341         }
 342
 343         ret = wl1271_cmd_send(wl, CMD_STOP_SCAN, cmd,
 344                               sizeof(*cmd), 0);
 345         if (ret < 0) {
 346                 wl1271_error("cmd stop_scan failed");
 347                 goto out;
 348         }
 349 out:
 350         kfree(cmd);
 351         return ret;
 352 }
 353
 354 static int
 355 wl1271_scan_get_sched_scan_channels(struct wl1271 *wl,
 356                                     struct cfg80211_sched_scan_request *req,
 357                                     struct conn_scan_ch_params *channels,
 358                                     u32 band, bool radar, bool passive,
 359                                     int start, int max_channels)
 360 {
 361         struct conf_sched_scan_settings *c = &wl->conf.sched_scan;
 362         int i, j;
 363         u32 flags;
 364         bool force_passive = !req->n_ssids;
 365
 366         for (i = 0, j = start;
 367              i < req->n_channels && j < max_channels;
 368              i++) {
 369                 flags = req->channels[i]->flags;
 370
 371                 if (force_passive)
 372                         flags |= IEEE80211_CHAN_PASSIVE_SCAN;
 373
 374                 if ((req->channels[i]->band == band) &&
 375                     !(flags & IEEE80211_CHAN_DISABLED) &&
 376                     (!!(flags & IEEE80211_CHAN_RADAR) == radar) &&
 377                     /* if radar is set, we ignore the passive flag */
 378                     (radar ||
 379                      !!(flags & IEEE80211_CHAN_PASSIVE_SCAN) == passive)) {
 380                         wl1271_debug(DEBUG_SCAN, "band %d, center_freq %d ",
 381                                      req->channels[i]->band,
 382                                      req->channels[i]->center_freq);
 383                         wl1271_debug(DEBUG_SCAN, "hw_value %d, flags %X",
 384                                      req->channels[i]->hw_value,
 385                                      req->channels[i]->flags);
 386                         wl1271_debug(DEBUG_SCAN, "max_power %d",
 387                                      req->channels[i]->max_power);
 388
 389                         if (flags & IEEE80211_CHAN_RADAR) {
 390                                 channels[j].flags |= SCAN_CHANNEL_FLAGS_DFS;
 391                                 channels[j].passive_duration =
 392                                         cpu_to_le16(c->dwell_time_dfs);
 393                         }
 394                         else if (flags & IEEE80211_CHAN_PASSIVE_SCAN) {
 395                                 channels[j].passive_duration =
 396                                         cpu_to_le16(c->dwell_time_passive);
 397                         } else {
 398                                 channels[j].min_duration =
 399                                         cpu_to_le16(c->min_dwell_time_active);
 400                                 channels[j].max_duration =
 401                                         cpu_to_le16(c->max_dwell_time_active);
 402                         }
 403                         channels[j].tx_power_att = req->channels[i]->max_power;
 404                         channels[j].channel = req->channels[i]->hw_value;
 405
 406                         j++;
 407                 }
 408         }
 409
 410         return j - start;
 411 }
 412
 413 static bool
 414 wl1271_scan_sched_scan_channels(struct wl1271 *wl,
 415                                 struct cfg80211_sched_scan_request *req,
 416                                 struct wl1271_cmd_sched_scan_config *cfg)
 417 {
 418         cfg->passive[0] =
 419                 wl1271_scan_get_sched_scan_channels(wl, req, cfg->channels_2,
 420                                                     IEEE80211_BAND_2GHZ,
 421                                                     false, true, 0,
 422                                                     MAX_CHANNELS_2GHZ);
 423         cfg->active[0] =
 424                 wl1271_scan_get_sched_scan_channels(wl, req, cfg->channels_2,
 425                                                     IEEE80211_BAND_2GHZ,
 426                                                     false, false,
 427                                                     cfg->passive[0],
 428                                                     MAX_CHANNELS_2GHZ);
 429         cfg->passive[1] =
 430                 wl1271_scan_get_sched_scan_channels(wl, req, cfg->channels_5,
 431                                                     IEEE80211_BAND_5GHZ,
 432                                                     false, true, 0,
 433                                                     MAX_CHANNELS_5GHZ);
 434         cfg->dfs =
 435                 wl1271_scan_get_sched_scan_channels(wl, req, cfg->channels_5,
 436                                                     IEEE80211_BAND_5GHZ,
 437                                                     true, true,
 438                                                     cfg->passive[1],
 439                                                     MAX_CHANNELS_5GHZ);
 440         cfg->active[1] =
 441                 wl1271_scan_get_sched_scan_channels(wl, req, cfg->channels_5,
 442                                                     IEEE80211_BAND_5GHZ,
 443                                                     false, false,
 444                                                     cfg->passive[1] + cfg->dfs,
 445                                                     MAX_CHANNELS_5GHZ);
 446         /* 802.11j channels are not supported yet */
 447         cfg->passive[2] = 0;
 448         cfg->active[2] = 0;
 449
 450         wl1271_debug(DEBUG_SCAN, "    2.4GHz: active %d passive %d",
 451                      cfg->active[0], cfg->passive[0]);
 452         wl1271_debug(DEBUG_SCAN, "    5GHz: active %d passive %d",
 453                      cfg->active[1], cfg->passive[1]);
 454         wl1271_debug(DEBUG_SCAN, "    DFS: %d", cfg->dfs);
 455
 456         return  cfg->passive[0] || cfg->active[0] ||
 457                 cfg->passive[1] || cfg->active[1] || cfg->dfs ||
 458                 cfg->passive[2] || cfg->active[2];
 459 }
 460
 461 int wl1271_scan_sched_scan_config(struct wl1271 *wl,
 462                                   struct cfg80211_sched_scan_request *req,
 463                                   struct ieee80211_sched_scan_ies *ies)
 464 {
 465         struct wl1271_cmd_sched_scan_config *cfg = NULL;
 466         struct conf_sched_scan_settings *c = &wl->conf.sched_scan;
 467         int i, ret;
 468         bool force_passive = !req->n_ssids;
 469
 470         wl1271_debug(DEBUG_CMD, "cmd sched_scan scan config");
 471
 472         cfg = kzalloc(sizeof(*cfg), GFP_KERNEL);
 473         if (!cfg)
 474                 return -ENOMEM;
 475
 476         cfg->rssi_threshold = c->rssi_threshold;
 477         cfg->snr_threshold  = c->snr_threshold;
 478         cfg->n_probe_reqs = c->num_probe_reqs;
 479         /* cycles set to 0 it means infinite (until manually stopped) */
 480         cfg->cycles = 0;
 481         /* report APs when at least 1 is found */
 482         cfg->report_after = 1;
 483         /* don't stop scanning automatically when something is found */
 484         cfg->terminate = 0;
 485         cfg->tag = WL1271_SCAN_DEFAULT_TAG;
 486         /* don't filter on BSS type */
 487         cfg->bss_type = SCAN_BSS_TYPE_ANY;
 488         /* currently NL80211 supports only a single interval */
 489         for (i = 0; i < SCAN_MAX_CYCLE_INTERVALS; i++)
 490                 cfg->intervals[i] = cpu_to_le32(req->interval);
 491
 492         if (!force_passive && req->ssids[0].ssid_len && req->ssids[0].ssid) {
 493                 cfg->filter_type = SCAN_SSID_FILTER_SPECIFIC;
 494                 cfg->ssid_len = req->ssids[0].ssid_len;
 495                 memcpy(cfg->ssid, req->ssids[0].ssid,
 496                        req->ssids[0].ssid_len);
 497         } else {
 498                 cfg->filter_type = SCAN_SSID_FILTER_ANY;
 499                 cfg->ssid_len = 0;
 500         }
 501
 502         if (!wl1271_scan_sched_scan_channels(wl, req, cfg)) {
 503                 wl1271_error("scan channel list is empty");
 504                 ret = -EINVAL;
 505                 goto out;
 506         }
 507
 508         if (!force_passive && cfg->active[0]) {
 509                 ret = wl1271_cmd_build_probe_req(wl, req->ssids[0].ssid,
 510                                                  req->ssids[0].ssid_len,
 511                                                  ies->ie[IEEE80211_BAND_2GHZ],
 512                                                  ies->len[IEEE80211_BAND_2GHZ],
 513                                                  IEEE80211_BAND_2GHZ);
 514                 if (ret < 0) {
 515                         wl1271_error("2.4GHz PROBE request template failed");
 516                         goto out;
 517                 }
 518         }
 519
 520         if (!force_passive && cfg->active[1]) {
 521                 ret = wl1271_cmd_build_probe_req(wl,  req->ssids[0].ssid,
 522                                                  req->ssids[0].ssid_len,
 523                                                  ies->ie[IEEE80211_BAND_5GHZ],
 524                                                  ies->len[IEEE80211_BAND_5GHZ],
 525                                                  IEEE80211_BAND_5GHZ);
 526                 if (ret < 0) {
 527                         wl1271_error("5GHz PROBE request template failed");
 528                         goto out;
 529                 }
 530         }
 531
 532         wl1271_dump(DEBUG_SCAN, "SCAN_CFG: ", cfg, sizeof(*cfg));
 533
 534         ret = wl1271_cmd_send(wl, CMD_CONNECTION_SCAN_CFG, cfg,
 535                               sizeof(*cfg), 0);
 536         if (ret < 0) {
 537                 wl1271_error("SCAN configuration failed");
 538                 goto out;
 539         }
 540 out:
 541         kfree(cfg);
 542         return ret;
 543 }
 544
 545 int wl1271_scan_sched_scan_start(struct wl1271 *wl)
 546 {
 547         struct wl1271_cmd_sched_scan_start *start;
 548         int ret = 0;
 549
 550         wl1271_debug(DEBUG_CMD, "cmd periodic scan start");
 551
 552         if (wl->bss_type != BSS_TYPE_STA_BSS)
 553                 return -EOPNOTSUPP;
 554
 555         if (!test_bit(WL1271_FLAG_IDLE, &wl->flags))
 556                 return -EBUSY;
 557
 558         start = kzalloc(sizeof(*start), GFP_KERNEL);
 559         if (!start)
 560                 return -ENOMEM;
 561
 562         start->tag = WL1271_SCAN_DEFAULT_TAG;
 563
 564         ret = wl1271_cmd_send(wl, CMD_START_PERIODIC_SCAN, start,
 565                               sizeof(*start), 0);
 566         if (ret < 0) {
 567                 wl1271_error("failed to send scan start command");
 568                 goto out_free;
 569         }
 570
 571 out_free:
 572         kfree(start);
 573         return ret;
 574 }
 575
 576 void wl1271_scan_sched_scan_results(struct wl1271 *wl)
 577 {
 578         wl1271_debug(DEBUG_SCAN, "got periodic scan results");
 579
 580         ieee80211_sched_scan_results(wl->hw);
 581 }
 582
 583 void wl1271_scan_sched_scan_stop(struct wl1271 *wl)
 584 {
 585         struct wl1271_cmd_sched_scan_stop *stop;
 586         int ret = 0;
 587
 588         wl1271_debug(DEBUG_CMD, "cmd periodic scan stop");
 589
 590         /* FIXME: what to do if alloc'ing to stop fails? */
 591         stop = kzalloc(sizeof(*stop), GFP_KERNEL);
 592         if (!stop) {
 593                 wl1271_error("failed to alloc memory to send sched scan stop");
 594                 return;
 595         }
 596
 597         stop->tag = WL1271_SCAN_DEFAULT_TAG;
 598
 599         ret = wl1271_cmd_send(wl, CMD_STOP_PERIODIC_SCAN, stop,
 600                               sizeof(*stop), 0);
 601         if (ret < 0) {
 602                 wl1271_error("failed to send sched scan stop command");
 603                 goto out_free;
 604         }
 605         wl->sched_scanning = false;
 606
 607 out_free:
 608         kfree(stop);
 609 }