Merge branch 'for-linville' of git://git.kernel.org/pub/scm/linux/kernel/git/luca...
[pandora-kernel.git] / drivers / net / wireless / iwlwifi / iwl-scan.c
1 /******************************************************************************
2  *
3  * GPL LICENSE SUMMARY
4  *
5  * Copyright(c) 2008 - 2010 Intel Corporation. All rights reserved.
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of version 2 of the GNU General Public License as
9  * published by the Free Software Foundation.
10  *
11  * This program is distributed in the hope that it will be useful, but
12  * WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14  * General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110,
19  * USA
20  *
21  * The full GNU General Public License is included in this distribution
22  * in the file called LICENSE.GPL.
23  *
24  * Contact Information:
25  *  Intel Linux Wireless <ilw@linux.intel.com>
26  * Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
27  *****************************************************************************/
28 #include <linux/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-core.h"
36 #include "iwl-sta.h"
37 #include "iwl-io.h"
38 #include "iwl-helpers.h"
39
40 /* For active scan, listen ACTIVE_DWELL_TIME (msec) on each channel after
41  * sending probe req.  This should be set long enough to hear probe responses
42  * from more than one AP.  */
43 #define IWL_ACTIVE_DWELL_TIME_24    (30)       /* all times in msec */
44 #define IWL_ACTIVE_DWELL_TIME_52    (20)
45
46 #define IWL_ACTIVE_DWELL_FACTOR_24GHZ (3)
47 #define IWL_ACTIVE_DWELL_FACTOR_52GHZ (2)
48
49 /* For passive scan, listen PASSIVE_DWELL_TIME (msec) on each channel.
50  * Must be set longer than active dwell time.
51  * For the most reliable scan, set > AP beacon interval (typically 100msec). */
52 #define IWL_PASSIVE_DWELL_TIME_24   (20)       /* all times in msec */
53 #define IWL_PASSIVE_DWELL_TIME_52   (10)
54 #define IWL_PASSIVE_DWELL_BASE      (100)
55 #define IWL_CHANNEL_TUNE_TIME       5
56
57 static int iwl_send_scan_abort(struct iwl_priv *priv)
58 {
59         int ret;
60         struct iwl_rx_packet *pkt;
61         struct iwl_host_cmd cmd = {
62                 .id = REPLY_SCAN_ABORT_CMD,
63                 .flags = CMD_WANT_SKB,
64         };
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             test_bit(STATUS_EXIT_PENDING, &priv->status))
74                 return -EIO;
75
76         ret = iwl_send_cmd_sync(priv, &cmd);
77         if (ret)
78                 return ret;
79
80         pkt = (struct iwl_rx_packet *)cmd.reply_page;
81         if (pkt->u.status != CAN_ABORT_STATUS) {
82                 /* The scan abort will return 1 for success or
83                  * 2 for "failure".  A failure condition can be
84                  * due to simply not being in an active scan which
85                  * can occur if we send the scan abort before we
86                  * the microcode has notified us that a scan is
87                  * completed. */
88                 IWL_DEBUG_SCAN(priv, "SCAN_ABORT ret %d.\n", pkt->u.status);
89                 ret = -EIO;
90         }
91
92         iwl_free_pages(priv, cmd.reply_page);
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         priv->is_internal_short_scan = false;
105         priv->scan_vif = NULL;
106         priv->scan_request = NULL;
107 }
108
109 void iwl_force_scan_end(struct iwl_priv *priv)
110 {
111         lockdep_assert_held(&priv->mutex);
112
113         if (!test_bit(STATUS_SCANNING, &priv->status)) {
114                 IWL_DEBUG_SCAN(priv, "Forcing scan end while not scanning\n");
115                 return;
116         }
117
118         IWL_DEBUG_SCAN(priv, "Forcing scan end\n");
119         clear_bit(STATUS_SCANNING, &priv->status);
120         clear_bit(STATUS_SCAN_HW, &priv->status);
121         clear_bit(STATUS_SCAN_ABORTING, &priv->status);
122         iwl_complete_scan(priv, true);
123 }
124
125 static void iwl_do_scan_abort(struct iwl_priv *priv)
126 {
127         int ret;
128
129         lockdep_assert_held(&priv->mutex);
130
131         if (!test_bit(STATUS_SCANNING, &priv->status)) {
132                 IWL_DEBUG_SCAN(priv, "Not performing scan to abort\n");
133                 return;
134         }
135
136         if (test_and_set_bit(STATUS_SCAN_ABORTING, &priv->status)) {
137                 IWL_DEBUG_SCAN(priv, "Scan abort in progress\n");
138                 return;
139         }
140
141         ret = iwl_send_scan_abort(priv);
142         if (ret) {
143                 IWL_DEBUG_SCAN(priv, "Send scan abort failed %d\n", ret);
144                 iwl_force_scan_end(priv);
145         } else
146                 IWL_DEBUG_SCAN(priv, "Sucessfully send scan abort\n");
147 }
148
149 /**
150  * iwl_scan_cancel - Cancel any currently executing HW scan
151  */
152 int iwl_scan_cancel(struct iwl_priv *priv)
153 {
154         IWL_DEBUG_SCAN(priv, "Queuing abort scan\n");
155         queue_work(priv->workqueue, &priv->abort_scan);
156         return 0;
157 }
158
159 /**
160  * iwl_scan_cancel_timeout - Cancel any currently executing HW scan
161  * @ms: amount of time to wait (in milliseconds) for scan to abort
162  *
163  */
164 int iwl_scan_cancel_timeout(struct iwl_priv *priv, unsigned long ms)
165 {
166         unsigned long timeout = jiffies + msecs_to_jiffies(ms);
167
168         lockdep_assert_held(&priv->mutex);
169
170         IWL_DEBUG_SCAN(priv, "Scan cancel timeout\n");
171
172         iwl_do_scan_abort(priv);
173
174         while (time_before_eq(jiffies, timeout)) {
175                 if (!test_bit(STATUS_SCAN_HW, &priv->status))
176                         break;
177                 msleep(20);
178         }
179
180         return test_bit(STATUS_SCAN_HW, &priv->status);
181 }
182
183 /* Service response to REPLY_SCAN_CMD (0x80) */
184 static void iwl_rx_reply_scan(struct iwl_priv *priv,
185                               struct iwl_rx_mem_buffer *rxb)
186 {
187 #ifdef CONFIG_IWLWIFI_DEBUG
188         struct iwl_rx_packet *pkt = rxb_addr(rxb);
189         struct iwl_scanreq_notification *notif =
190             (struct iwl_scanreq_notification *)pkt->u.raw;
191
192         IWL_DEBUG_SCAN(priv, "Scan request status = 0x%x\n", notif->status);
193 #endif
194 }
195
196 /* Service SCAN_START_NOTIFICATION (0x82) */
197 static void iwl_rx_scan_start_notif(struct iwl_priv *priv,
198                                     struct iwl_rx_mem_buffer *rxb)
199 {
200         struct iwl_rx_packet *pkt = rxb_addr(rxb);
201         struct iwl_scanstart_notification *notif =
202             (struct iwl_scanstart_notification *)pkt->u.raw;
203         priv->scan_start_tsf = le32_to_cpu(notif->tsf_low);
204         IWL_DEBUG_SCAN(priv, "Scan start: "
205                        "%d [802.11%s] "
206                        "(TSF: 0x%08X:%08X) - %d (beacon timer %u)\n",
207                        notif->channel,
208                        notif->band ? "bg" : "a",
209                        le32_to_cpu(notif->tsf_high),
210                        le32_to_cpu(notif->tsf_low),
211                        notif->status, notif->beacon_timer);
212 }
213
214 /* Service SCAN_RESULTS_NOTIFICATION (0x83) */
215 static void iwl_rx_scan_results_notif(struct iwl_priv *priv,
216                                       struct iwl_rx_mem_buffer *rxb)
217 {
218 #ifdef CONFIG_IWLWIFI_DEBUG
219         struct iwl_rx_packet *pkt = rxb_addr(rxb);
220         struct iwl_scanresults_notification *notif =
221             (struct iwl_scanresults_notification *)pkt->u.raw;
222
223         IWL_DEBUG_SCAN(priv, "Scan ch.res: "
224                        "%d [802.11%s] "
225                        "(TSF: 0x%08X:%08X) - %d "
226                        "elapsed=%lu usec\n",
227                        notif->channel,
228                        notif->band ? "bg" : "a",
229                        le32_to_cpu(notif->tsf_high),
230                        le32_to_cpu(notif->tsf_low),
231                        le32_to_cpu(notif->statistics[0]),
232                        le32_to_cpu(notif->tsf_low) - priv->scan_start_tsf);
233 #endif
234 }
235
236 /* Service SCAN_COMPLETE_NOTIFICATION (0x84) */
237 static void iwl_rx_scan_complete_notif(struct iwl_priv *priv,
238                                        struct iwl_rx_mem_buffer *rxb)
239 {
240         struct iwl_rx_packet *pkt = rxb_addr(rxb);
241         struct iwl_scancomplete_notification *scan_notif = (void *)pkt->u.raw;
242
243         IWL_DEBUG_SCAN(priv, "Scan complete: %d channels (TSF 0x%08X:%08X) - %d\n",
244                        scan_notif->scanned_channels,
245                        scan_notif->tsf_low,
246                        scan_notif->tsf_high, scan_notif->status);
247
248         /* The HW is no longer scanning */
249         clear_bit(STATUS_SCAN_HW, &priv->status);
250
251         IWL_DEBUG_SCAN(priv, "Scan on %sGHz took %dms\n",
252                        (priv->scan_band == IEEE80211_BAND_2GHZ) ? "2.4" : "5.2",
253                        jiffies_to_msecs(jiffies - priv->scan_start));
254
255         queue_work(priv->workqueue, &priv->scan_completed);
256
257         if (priv->iw_mode != NL80211_IFTYPE_ADHOC &&
258             iwl_advanced_bt_coexist(priv) &&
259             priv->bt_status != scan_notif->bt_status) {
260                 if (scan_notif->bt_status) {
261                         /* BT on */
262                         if (!priv->bt_ch_announce)
263                                 priv->bt_traffic_load =
264                                         IWL_BT_COEX_TRAFFIC_LOAD_HIGH;
265                         /*
266                          * otherwise, no traffic load information provided
267                          * no changes made
268                          */
269                 } else {
270                         /* BT off */
271                         priv->bt_traffic_load =
272                                 IWL_BT_COEX_TRAFFIC_LOAD_NONE;
273                 }
274                 priv->bt_status = scan_notif->bt_status;
275                 queue_work(priv->workqueue, &priv->bt_traffic_change_work);
276         }
277 }
278
279 void iwl_setup_rx_scan_handlers(struct iwl_priv *priv)
280 {
281         /* scan handlers */
282         priv->rx_handlers[REPLY_SCAN_CMD] = iwl_rx_reply_scan;
283         priv->rx_handlers[SCAN_START_NOTIFICATION] = iwl_rx_scan_start_notif;
284         priv->rx_handlers[SCAN_RESULTS_NOTIFICATION] =
285                                         iwl_rx_scan_results_notif;
286         priv->rx_handlers[SCAN_COMPLETE_NOTIFICATION] =
287                                         iwl_rx_scan_complete_notif;
288 }
289
290 inline u16 iwl_get_active_dwell_time(struct iwl_priv *priv,
291                                      enum ieee80211_band band,
292                                      u8 n_probes)
293 {
294         if (band == IEEE80211_BAND_5GHZ)
295                 return IWL_ACTIVE_DWELL_TIME_52 +
296                         IWL_ACTIVE_DWELL_FACTOR_52GHZ * (n_probes + 1);
297         else
298                 return IWL_ACTIVE_DWELL_TIME_24 +
299                         IWL_ACTIVE_DWELL_FACTOR_24GHZ * (n_probes + 1);
300 }
301
302 u16 iwl_get_passive_dwell_time(struct iwl_priv *priv,
303                                enum ieee80211_band band,
304                                struct ieee80211_vif *vif)
305 {
306         struct iwl_rxon_context *ctx;
307         u16 passive = (band == IEEE80211_BAND_2GHZ) ?
308             IWL_PASSIVE_DWELL_BASE + IWL_PASSIVE_DWELL_TIME_24 :
309             IWL_PASSIVE_DWELL_BASE + IWL_PASSIVE_DWELL_TIME_52;
310
311         if (iwl_is_any_associated(priv)) {
312                 /*
313                  * If we're associated, we clamp the maximum passive
314                  * dwell time to be 98% of the smallest beacon interval
315                  * (minus 2 * channel tune time)
316                  */
317                 for_each_context(priv, ctx) {
318                         u16 value;
319
320                         if (!iwl_is_associated_ctx(ctx))
321                                 continue;
322                         value = ctx->vif ? ctx->vif->bss_conf.beacon_int : 0;
323                         if ((value > IWL_PASSIVE_DWELL_BASE) || !value)
324                                 value = IWL_PASSIVE_DWELL_BASE;
325                         value = (value * 98) / 100 - IWL_CHANNEL_TUNE_TIME * 2;
326                         passive = min(value, passive);
327                 }
328         }
329
330         return passive;
331 }
332
333 void iwl_init_scan_params(struct iwl_priv *priv)
334 {
335         u8 ant_idx = fls(priv->hw_params.valid_tx_ant) - 1;
336         if (!priv->scan_tx_ant[IEEE80211_BAND_5GHZ])
337                 priv->scan_tx_ant[IEEE80211_BAND_5GHZ] = ant_idx;
338         if (!priv->scan_tx_ant[IEEE80211_BAND_2GHZ])
339                 priv->scan_tx_ant[IEEE80211_BAND_2GHZ] = ant_idx;
340 }
341
342 static int __must_check iwl_scan_initiate(struct iwl_priv *priv,
343                                           struct ieee80211_vif *vif,
344                                           bool internal,
345                                           enum ieee80211_band band)
346 {
347         int ret;
348
349         lockdep_assert_held(&priv->mutex);
350
351         if (WARN_ON(!priv->cfg->ops->utils->request_scan))
352                 return -EOPNOTSUPP;
353
354         cancel_delayed_work(&priv->scan_check);
355
356         if (!iwl_is_ready_rf(priv)) {
357                 IWL_WARN(priv, "Request scan called when driver not ready.\n");
358                 return -EIO;
359         }
360
361         if (test_bit(STATUS_SCAN_HW, &priv->status)) {
362                 IWL_DEBUG_SCAN(priv,
363                         "Multiple concurrent scan requests in parallel.\n");
364                 return -EBUSY;
365         }
366
367         if (test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
368                 IWL_DEBUG_SCAN(priv, "Scan request while abort pending.\n");
369                 return -EBUSY;
370         }
371
372         IWL_DEBUG_SCAN(priv, "Starting %sscan...\n",
373                         internal ? "internal short " : "");
374
375         set_bit(STATUS_SCANNING, &priv->status);
376         priv->is_internal_short_scan = internal;
377         priv->scan_start = jiffies;
378         priv->scan_band = band;
379
380         ret = priv->cfg->ops->utils->request_scan(priv, vif);
381         if (ret) {
382                 clear_bit(STATUS_SCANNING, &priv->status);
383                 priv->is_internal_short_scan = false;
384                 return ret;
385         }
386
387         queue_delayed_work(priv->workqueue, &priv->scan_check,
388                            IWL_SCAN_CHECK_WATCHDOG);
389
390         return 0;
391 }
392
393 int iwl_mac_hw_scan(struct ieee80211_hw *hw,
394                     struct ieee80211_vif *vif,
395                     struct cfg80211_scan_request *req)
396 {
397         struct iwl_priv *priv = hw->priv;
398         int ret;
399
400         IWL_DEBUG_MAC80211(priv, "enter\n");
401
402         if (req->n_channels == 0)
403                 return -EINVAL;
404
405         mutex_lock(&priv->mutex);
406
407         if (test_bit(STATUS_SCANNING, &priv->status) &&
408             !priv->is_internal_short_scan) {
409                 IWL_DEBUG_SCAN(priv, "Scan already in progress.\n");
410                 ret = -EAGAIN;
411                 goto out_unlock;
412         }
413
414         /* mac80211 will only ask for one band at a time */
415         priv->scan_request = req;
416         priv->scan_vif = vif;
417
418         /*
419          * If an internal scan is in progress, just set
420          * up the scan_request as per above.
421          */
422         if (priv->is_internal_short_scan) {
423                 IWL_DEBUG_SCAN(priv, "SCAN request during internal scan\n");
424                 ret = 0;
425         } else
426                 ret = iwl_scan_initiate(priv, vif, false,
427                                         req->channels[0]->band);
428
429         IWL_DEBUG_MAC80211(priv, "leave\n");
430
431 out_unlock:
432         mutex_unlock(&priv->mutex);
433
434         return ret;
435 }
436
437 /*
438  * internal short scan, this function should only been called while associated.
439  * It will reset and tune the radio to prevent possible RF related problem
440  */
441 void iwl_internal_short_hw_scan(struct iwl_priv *priv)
442 {
443         queue_work(priv->workqueue, &priv->start_internal_scan);
444 }
445
446 static void iwl_bg_start_internal_scan(struct work_struct *work)
447 {
448         struct iwl_priv *priv =
449                 container_of(work, struct iwl_priv, start_internal_scan);
450
451         IWL_DEBUG_SCAN(priv, "Start internal scan\n");
452
453         mutex_lock(&priv->mutex);
454
455         if (priv->is_internal_short_scan == true) {
456                 IWL_DEBUG_SCAN(priv, "Internal scan already in progress\n");
457                 goto unlock;
458         }
459
460         if (test_bit(STATUS_SCANNING, &priv->status)) {
461                 IWL_DEBUG_SCAN(priv, "Scan already in progress.\n");
462                 goto unlock;
463         }
464
465         if (iwl_scan_initiate(priv, NULL, true, priv->band))
466                 IWL_DEBUG_SCAN(priv, "failed to start internal short scan\n");
467  unlock:
468         mutex_unlock(&priv->mutex);
469 }
470
471 static void iwl_bg_scan_check(struct work_struct *data)
472 {
473         struct iwl_priv *priv =
474             container_of(data, struct iwl_priv, scan_check.work);
475
476         IWL_DEBUG_SCAN(priv, "Scan check work\n");
477
478         /* Since we are here firmware does not finish scan and
479          * most likely is in bad shape, so we don't bother to
480          * send abort command, just force scan complete to mac80211 */
481         mutex_lock(&priv->mutex);
482         iwl_force_scan_end(priv);
483         mutex_unlock(&priv->mutex);
484 }
485
486 /**
487  * iwl_fill_probe_req - fill in all required fields and IE for probe request
488  */
489
490 u16 iwl_fill_probe_req(struct iwl_priv *priv, struct ieee80211_mgmt *frame,
491                        const u8 *ta, const u8 *ies, int ie_len, int left)
492 {
493         int len = 0;
494         u8 *pos = NULL;
495
496         /* Make sure there is enough space for the probe request,
497          * two mandatory IEs and the data */
498         left -= 24;
499         if (left < 0)
500                 return 0;
501
502         frame->frame_control = cpu_to_le16(IEEE80211_STYPE_PROBE_REQ);
503         memcpy(frame->da, iwl_bcast_addr, ETH_ALEN);
504         memcpy(frame->sa, ta, ETH_ALEN);
505         memcpy(frame->bssid, iwl_bcast_addr, ETH_ALEN);
506         frame->seq_ctrl = 0;
507
508         len += 24;
509
510         /* ...next IE... */
511         pos = &frame->u.probe_req.variable[0];
512
513         /* fill in our indirect SSID IE */
514         left -= 2;
515         if (left < 0)
516                 return 0;
517         *pos++ = WLAN_EID_SSID;
518         *pos++ = 0;
519
520         len += 2;
521
522         if (WARN_ON(left < ie_len))
523                 return len;
524
525         if (ies && ie_len) {
526                 memcpy(pos, ies, ie_len);
527                 len += ie_len;
528         }
529
530         return (u16)len;
531 }
532
533 static void iwl_bg_abort_scan(struct work_struct *work)
534 {
535         struct iwl_priv *priv = container_of(work, struct iwl_priv, abort_scan);
536
537         IWL_DEBUG_SCAN(priv, "Abort scan work\n");
538
539         /* We keep scan_check work queued in case when firmware will not
540          * report back scan completed notification */
541         mutex_lock(&priv->mutex);
542         iwl_scan_cancel_timeout(priv, 200);
543         mutex_unlock(&priv->mutex);
544 }
545
546 static void iwl_bg_scan_completed(struct work_struct *work)
547 {
548         struct iwl_priv *priv =
549             container_of(work, struct iwl_priv, scan_completed);
550         bool aborted;
551
552         IWL_DEBUG_SCAN(priv, "Completed %sscan.\n",
553                        priv->is_internal_short_scan ? "internal short " : "");
554
555         cancel_delayed_work(&priv->scan_check);
556
557         mutex_lock(&priv->mutex);
558
559         aborted = test_and_clear_bit(STATUS_SCAN_ABORTING, &priv->status);
560         if (aborted)
561                 IWL_DEBUG_SCAN(priv, "Aborted scan completed.\n");
562
563         if (!test_and_clear_bit(STATUS_SCANNING, &priv->status)) {
564                 IWL_DEBUG_SCAN(priv, "Scan already completed.\n");
565                 goto out_settings;
566         }
567
568         if (priv->is_internal_short_scan && !aborted) {
569                 int err;
570
571                 /* Check if mac80211 requested scan during our internal scan */
572                 if (priv->scan_request == NULL)
573                         goto out_complete;
574
575                 /* If so request a new scan */
576                 err = iwl_scan_initiate(priv, priv->scan_vif, false,
577                                         priv->scan_request->channels[0]->band);
578                 if (err) {
579                         IWL_DEBUG_SCAN(priv,
580                                 "failed to initiate pending scan: %d\n", err);
581                         aborted = true;
582                         goto out_complete;
583                 }
584
585                 goto out;
586         }
587
588 out_complete:
589         iwl_complete_scan(priv, aborted);
590
591 out_settings:
592         /* Can we still talk to firmware ? */
593         if (!iwl_is_ready_rf(priv))
594                 goto out;
595
596         /*
597          * We do not commit power settings while scan is pending,
598          * do it now if the settings changed.
599          */
600         iwl_power_set_mode(priv, &priv->power_data.sleep_cmd_next, false);
601         iwl_set_tx_power(priv, priv->tx_power_next, false);
602
603         priv->cfg->ops->utils->post_scan(priv);
604
605 out:
606         mutex_unlock(&priv->mutex);
607 }
608
609 void iwl_setup_scan_deferred_work(struct iwl_priv *priv)
610 {
611         INIT_WORK(&priv->scan_completed, iwl_bg_scan_completed);
612         INIT_WORK(&priv->abort_scan, iwl_bg_abort_scan);
613         INIT_WORK(&priv->start_internal_scan, iwl_bg_start_internal_scan);
614         INIT_DELAYED_WORK(&priv->scan_check, iwl_bg_scan_check);
615 }
616
617 void iwl_cancel_scan_deferred_work(struct iwl_priv *priv)
618 {
619         cancel_work_sync(&priv->start_internal_scan);
620         cancel_work_sync(&priv->abort_scan);
621         cancel_work_sync(&priv->scan_completed);
622
623         if (cancel_delayed_work_sync(&priv->scan_check)) {
624                 mutex_lock(&priv->mutex);
625                 iwl_force_scan_end(priv);
626                 mutex_unlock(&priv->mutex);
627         }
628 }