Merge branch 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git...
[linux-2.6.git] / drivers / net / wireless / iwlwifi / iwl-scan.c
1 /******************************************************************************
2  *
3  * GPL LICENSE SUMMARY
4  *
5  * Copyright(c) 2008 - 2011 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 #include "iwl-agn.h"
40 #include "iwl-trans.h"
41
42 /* For active scan, listen ACTIVE_DWELL_TIME (msec) on each channel after
43  * sending probe req.  This should be set long enough to hear probe responses
44  * from more than one AP.  */
45 #define IWL_ACTIVE_DWELL_TIME_24    (30)       /* all times in msec */
46 #define IWL_ACTIVE_DWELL_TIME_52    (20)
47
48 #define IWL_ACTIVE_DWELL_FACTOR_24GHZ (3)
49 #define IWL_ACTIVE_DWELL_FACTOR_52GHZ (2)
50
51 /* For passive scan, listen PASSIVE_DWELL_TIME (msec) on each channel.
52  * Must be set longer than active dwell time.
53  * For the most reliable scan, set > AP beacon interval (typically 100msec). */
54 #define IWL_PASSIVE_DWELL_TIME_24   (20)       /* all times in msec */
55 #define IWL_PASSIVE_DWELL_TIME_52   (10)
56 #define IWL_PASSIVE_DWELL_BASE      (100)
57 #define IWL_CHANNEL_TUNE_TIME       5
58
59 static int iwl_send_scan_abort(struct iwl_priv *priv)
60 {
61         int ret;
62         struct iwl_rx_packet *pkt;
63         struct iwl_host_cmd cmd = {
64                 .id = REPLY_SCAN_ABORT_CMD,
65                 .flags = CMD_SYNC | CMD_WANT_SKB,
66         };
67
68         /* Exit instantly with error when device is not ready
69          * to receive scan abort command or it does not perform
70          * hardware scan currently */
71         if (!test_bit(STATUS_READY, &priv->status) ||
72             !test_bit(STATUS_GEO_CONFIGURED, &priv->status) ||
73             !test_bit(STATUS_SCAN_HW, &priv->status) ||
74             test_bit(STATUS_FW_ERROR, &priv->status) ||
75             test_bit(STATUS_EXIT_PENDING, &priv->status))
76                 return -EIO;
77
78         ret = trans_send_cmd(priv, &cmd);
79         if (ret)
80                 return ret;
81
82         pkt = (struct iwl_rx_packet *)cmd.reply_page;
83         if (pkt->u.status != CAN_ABORT_STATUS) {
84                 /* The scan abort will return 1 for success or
85                  * 2 for "failure".  A failure condition can be
86                  * due to simply not being in an active scan which
87                  * can occur if we send the scan abort before we
88                  * the microcode has notified us that a scan is
89                  * completed. */
90                 IWL_DEBUG_SCAN(priv, "SCAN_ABORT ret %d.\n", pkt->u.status);
91                 ret = -EIO;
92         }
93
94         iwl_free_pages(priv, cmd.reply_page);
95         return ret;
96 }
97
98 static void iwl_complete_scan(struct iwl_priv *priv, bool aborted)
99 {
100         /* check if scan was requested from mac80211 */
101         if (priv->scan_request) {
102                 IWL_DEBUG_SCAN(priv, "Complete scan in mac80211\n");
103                 ieee80211_scan_completed(priv->hw, aborted);
104         }
105
106         priv->scan_type = IWL_SCAN_NORMAL;
107         priv->scan_vif = NULL;
108         priv->scan_request = NULL;
109 }
110
111 void iwl_force_scan_end(struct iwl_priv *priv)
112 {
113         lockdep_assert_held(&priv->mutex);
114
115         if (!test_bit(STATUS_SCANNING, &priv->status)) {
116                 IWL_DEBUG_SCAN(priv, "Forcing scan end while not scanning\n");
117                 return;
118         }
119
120         IWL_DEBUG_SCAN(priv, "Forcing scan end\n");
121         clear_bit(STATUS_SCANNING, &priv->status);
122         clear_bit(STATUS_SCAN_HW, &priv->status);
123         clear_bit(STATUS_SCAN_ABORTING, &priv->status);
124         iwl_complete_scan(priv, true);
125 }
126
127 static void iwl_do_scan_abort(struct iwl_priv *priv)
128 {
129         int ret;
130
131         lockdep_assert_held(&priv->mutex);
132
133         if (!test_bit(STATUS_SCANNING, &priv->status)) {
134                 IWL_DEBUG_SCAN(priv, "Not performing scan to abort\n");
135                 return;
136         }
137
138         if (test_and_set_bit(STATUS_SCAN_ABORTING, &priv->status)) {
139                 IWL_DEBUG_SCAN(priv, "Scan abort in progress\n");
140                 return;
141         }
142
143         ret = iwl_send_scan_abort(priv);
144         if (ret) {
145                 IWL_DEBUG_SCAN(priv, "Send scan abort failed %d\n", ret);
146                 iwl_force_scan_end(priv);
147         } else
148                 IWL_DEBUG_SCAN(priv, "Successfully send scan abort\n");
149 }
150
151 /**
152  * iwl_scan_cancel - Cancel any currently executing HW scan
153  */
154 int iwl_scan_cancel(struct iwl_priv *priv)
155 {
156         IWL_DEBUG_SCAN(priv, "Queuing abort scan\n");
157         queue_work(priv->workqueue, &priv->abort_scan);
158         return 0;
159 }
160
161 /**
162  * iwl_scan_cancel_timeout - Cancel any currently executing HW scan
163  * @ms: amount of time to wait (in milliseconds) for scan to abort
164  *
165  */
166 int iwl_scan_cancel_timeout(struct iwl_priv *priv, unsigned long ms)
167 {
168         unsigned long timeout = jiffies + msecs_to_jiffies(ms);
169
170         lockdep_assert_held(&priv->mutex);
171
172         IWL_DEBUG_SCAN(priv, "Scan cancel timeout\n");
173
174         iwl_do_scan_abort(priv);
175
176         while (time_before_eq(jiffies, timeout)) {
177                 if (!test_bit(STATUS_SCAN_HW, &priv->status))
178                         break;
179                 msleep(20);
180         }
181
182         return test_bit(STATUS_SCAN_HW, &priv->status);
183 }
184
185 /* Service response to REPLY_SCAN_CMD (0x80) */
186 static void iwl_rx_reply_scan(struct iwl_priv *priv,
187                               struct iwl_rx_mem_buffer *rxb)
188 {
189 #ifdef CONFIG_IWLWIFI_DEBUG
190         struct iwl_rx_packet *pkt = rxb_addr(rxb);
191         struct iwl_scanreq_notification *notif =
192             (struct iwl_scanreq_notification *)pkt->u.raw;
193
194         IWL_DEBUG_SCAN(priv, "Scan request status = 0x%x\n", notif->status);
195 #endif
196 }
197
198 /* Service SCAN_START_NOTIFICATION (0x82) */
199 static void iwl_rx_scan_start_notif(struct iwl_priv *priv,
200                                     struct iwl_rx_mem_buffer *rxb)
201 {
202         struct iwl_rx_packet *pkt = rxb_addr(rxb);
203         struct iwl_scanstart_notification *notif =
204             (struct iwl_scanstart_notification *)pkt->u.raw;
205         priv->scan_start_tsf = le32_to_cpu(notif->tsf_low);
206         IWL_DEBUG_SCAN(priv, "Scan start: "
207                        "%d [802.11%s] "
208                        "(TSF: 0x%08X:%08X) - %d (beacon timer %u)\n",
209                        notif->channel,
210                        notif->band ? "bg" : "a",
211                        le32_to_cpu(notif->tsf_high),
212                        le32_to_cpu(notif->tsf_low),
213                        notif->status, notif->beacon_timer);
214 }
215
216 /* Service SCAN_RESULTS_NOTIFICATION (0x83) */
217 static void iwl_rx_scan_results_notif(struct iwl_priv *priv,
218                                       struct iwl_rx_mem_buffer *rxb)
219 {
220 #ifdef CONFIG_IWLWIFI_DEBUG
221         struct iwl_rx_packet *pkt = rxb_addr(rxb);
222         struct iwl_scanresults_notification *notif =
223             (struct iwl_scanresults_notification *)pkt->u.raw;
224
225         IWL_DEBUG_SCAN(priv, "Scan ch.res: "
226                        "%d [802.11%s] "
227                        "(TSF: 0x%08X:%08X) - %d "
228                        "elapsed=%lu usec\n",
229                        notif->channel,
230                        notif->band ? "bg" : "a",
231                        le32_to_cpu(notif->tsf_high),
232                        le32_to_cpu(notif->tsf_low),
233                        le32_to_cpu(notif->statistics[0]),
234                        le32_to_cpu(notif->tsf_low) - priv->scan_start_tsf);
235 #endif
236 }
237
238 /* Service SCAN_COMPLETE_NOTIFICATION (0x84) */
239 static void iwl_rx_scan_complete_notif(struct iwl_priv *priv,
240                                        struct iwl_rx_mem_buffer *rxb)
241 {
242         struct iwl_rx_packet *pkt = rxb_addr(rxb);
243         struct iwl_scancomplete_notification *scan_notif = (void *)pkt->u.raw;
244
245         IWL_DEBUG_SCAN(priv, "Scan complete: %d channels (TSF 0x%08X:%08X) - %d\n",
246                        scan_notif->scanned_channels,
247                        scan_notif->tsf_low,
248                        scan_notif->tsf_high, scan_notif->status);
249
250         /* The HW is no longer scanning */
251         clear_bit(STATUS_SCAN_HW, &priv->status);
252
253         IWL_DEBUG_SCAN(priv, "Scan on %sGHz took %dms\n",
254                        (priv->scan_band == IEEE80211_BAND_2GHZ) ? "2.4" : "5.2",
255                        jiffies_to_msecs(jiffies - priv->scan_start));
256
257         queue_work(priv->workqueue, &priv->scan_completed);
258
259         if (priv->iw_mode != NL80211_IFTYPE_ADHOC &&
260             iwl_advanced_bt_coexist(priv) &&
261             priv->bt_status != scan_notif->bt_status) {
262                 if (scan_notif->bt_status) {
263                         /* BT on */
264                         if (!priv->bt_ch_announce)
265                                 priv->bt_traffic_load =
266                                         IWL_BT_COEX_TRAFFIC_LOAD_HIGH;
267                         /*
268                          * otherwise, no traffic load information provided
269                          * no changes made
270                          */
271                 } else {
272                         /* BT off */
273                         priv->bt_traffic_load =
274                                 IWL_BT_COEX_TRAFFIC_LOAD_NONE;
275                 }
276                 priv->bt_status = scan_notif->bt_status;
277                 queue_work(priv->workqueue, &priv->bt_traffic_change_work);
278         }
279 }
280
281 void iwl_setup_rx_scan_handlers(struct iwl_priv *priv)
282 {
283         /* scan handlers */
284         priv->rx_handlers[REPLY_SCAN_CMD] = iwl_rx_reply_scan;
285         priv->rx_handlers[SCAN_START_NOTIFICATION] = iwl_rx_scan_start_notif;
286         priv->rx_handlers[SCAN_RESULTS_NOTIFICATION] =
287                                         iwl_rx_scan_results_notif;
288         priv->rx_handlers[SCAN_COMPLETE_NOTIFICATION] =
289                                         iwl_rx_scan_complete_notif;
290 }
291
292 inline u16 iwl_get_active_dwell_time(struct iwl_priv *priv,
293                                      enum ieee80211_band band,
294                                      u8 n_probes)
295 {
296         if (band == IEEE80211_BAND_5GHZ)
297                 return IWL_ACTIVE_DWELL_TIME_52 +
298                         IWL_ACTIVE_DWELL_FACTOR_52GHZ * (n_probes + 1);
299         else
300                 return IWL_ACTIVE_DWELL_TIME_24 +
301                         IWL_ACTIVE_DWELL_FACTOR_24GHZ * (n_probes + 1);
302 }
303
304 u16 iwl_get_passive_dwell_time(struct iwl_priv *priv,
305                                enum ieee80211_band band,
306                                struct ieee80211_vif *vif)
307 {
308         struct iwl_rxon_context *ctx;
309         u16 passive = (band == IEEE80211_BAND_2GHZ) ?
310             IWL_PASSIVE_DWELL_BASE + IWL_PASSIVE_DWELL_TIME_24 :
311             IWL_PASSIVE_DWELL_BASE + IWL_PASSIVE_DWELL_TIME_52;
312
313         if (iwl_is_any_associated(priv)) {
314                 /*
315                  * If we're associated, we clamp the maximum passive
316                  * dwell time to be 98% of the smallest beacon interval
317                  * (minus 2 * channel tune time)
318                  */
319                 for_each_context(priv, ctx) {
320                         u16 value;
321
322                         if (!iwl_is_associated_ctx(ctx))
323                                 continue;
324                         value = ctx->vif ? ctx->vif->bss_conf.beacon_int : 0;
325                         if ((value > IWL_PASSIVE_DWELL_BASE) || !value)
326                                 value = IWL_PASSIVE_DWELL_BASE;
327                         value = (value * 98) / 100 - IWL_CHANNEL_TUNE_TIME * 2;
328                         passive = min(value, passive);
329                 }
330         }
331
332         return passive;
333 }
334
335 void iwl_init_scan_params(struct iwl_priv *priv)
336 {
337         u8 ant_idx = fls(priv->hw_params.valid_tx_ant) - 1;
338         if (!priv->scan_tx_ant[IEEE80211_BAND_5GHZ])
339                 priv->scan_tx_ant[IEEE80211_BAND_5GHZ] = ant_idx;
340         if (!priv->scan_tx_ant[IEEE80211_BAND_2GHZ])
341                 priv->scan_tx_ant[IEEE80211_BAND_2GHZ] = ant_idx;
342 }
343
344 int __must_check iwl_scan_initiate(struct iwl_priv *priv,
345                                    struct ieee80211_vif *vif,
346                                    enum iwl_scan_type scan_type,
347                                    enum ieee80211_band band)
348 {
349         int ret;
350
351         lockdep_assert_held(&priv->mutex);
352
353         cancel_delayed_work(&priv->scan_check);
354
355         if (!iwl_is_ready_rf(priv)) {
356                 IWL_WARN(priv, "Request scan called when driver not ready.\n");
357                 return -EIO;
358         }
359
360         if (test_bit(STATUS_SCAN_HW, &priv->status)) {
361                 IWL_DEBUG_SCAN(priv,
362                         "Multiple concurrent scan requests in parallel.\n");
363                 return -EBUSY;
364         }
365
366         if (test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
367                 IWL_DEBUG_SCAN(priv, "Scan request while abort pending.\n");
368                 return -EBUSY;
369         }
370
371         IWL_DEBUG_SCAN(priv, "Starting %sscan...\n",
372                         scan_type == IWL_SCAN_NORMAL ? "" :
373                         scan_type == IWL_SCAN_OFFCH_TX ? "offchan TX " :
374                         "internal short ");
375
376         set_bit(STATUS_SCANNING, &priv->status);
377         priv->scan_type = scan_type;
378         priv->scan_start = jiffies;
379         priv->scan_band = band;
380
381         ret = iwlagn_request_scan(priv, vif);
382         if (ret) {
383                 clear_bit(STATUS_SCANNING, &priv->status);
384                 priv->scan_type = IWL_SCAN_NORMAL;
385                 return ret;
386         }
387
388         queue_delayed_work(priv->workqueue, &priv->scan_check,
389                            IWL_SCAN_CHECK_WATCHDOG);
390
391         return 0;
392 }
393
394 int iwl_mac_hw_scan(struct ieee80211_hw *hw,
395                     struct ieee80211_vif *vif,
396                     struct cfg80211_scan_request *req)
397 {
398         struct iwl_priv *priv = hw->priv;
399         int ret;
400
401         IWL_DEBUG_MAC80211(priv, "enter\n");
402
403         if (req->n_channels == 0)
404                 return -EINVAL;
405
406         mutex_lock(&priv->mutex);
407
408         if (test_bit(STATUS_SCANNING, &priv->status) &&
409             priv->scan_type != IWL_SCAN_NORMAL) {
410                 IWL_DEBUG_SCAN(priv, "Scan already in progress.\n");
411                 ret = -EAGAIN;
412                 goto out_unlock;
413         }
414
415         /* mac80211 will only ask for one band at a time */
416         priv->scan_request = req;
417         priv->scan_vif = vif;
418
419         /*
420          * If an internal scan is in progress, just set
421          * up the scan_request as per above.
422          */
423         if (priv->scan_type != IWL_SCAN_NORMAL) {
424                 IWL_DEBUG_SCAN(priv, "SCAN request during internal scan\n");
425                 ret = 0;
426         } else
427                 ret = iwl_scan_initiate(priv, vif, IWL_SCAN_NORMAL,
428                                         req->channels[0]->band);
429
430         IWL_DEBUG_MAC80211(priv, "leave\n");
431
432 out_unlock:
433         mutex_unlock(&priv->mutex);
434
435         return ret;
436 }
437
438 /*
439  * internal short scan, this function should only been called while associated.
440  * It will reset and tune the radio to prevent possible RF related problem
441  */
442 void iwl_internal_short_hw_scan(struct iwl_priv *priv)
443 {
444         queue_work(priv->workqueue, &priv->start_internal_scan);
445 }
446
447 static void iwl_bg_start_internal_scan(struct work_struct *work)
448 {
449         struct iwl_priv *priv =
450                 container_of(work, struct iwl_priv, start_internal_scan);
451
452         IWL_DEBUG_SCAN(priv, "Start internal scan\n");
453
454         mutex_lock(&priv->mutex);
455
456         if (priv->scan_type == IWL_SCAN_RADIO_RESET) {
457                 IWL_DEBUG_SCAN(priv, "Internal scan already in progress\n");
458                 goto unlock;
459         }
460
461         if (test_bit(STATUS_SCANNING, &priv->status)) {
462                 IWL_DEBUG_SCAN(priv, "Scan already in progress.\n");
463                 goto unlock;
464         }
465
466         if (iwl_scan_initiate(priv, NULL, IWL_SCAN_RADIO_RESET, priv->band))
467                 IWL_DEBUG_SCAN(priv, "failed to start internal short scan\n");
468  unlock:
469         mutex_unlock(&priv->mutex);
470 }
471
472 static void iwl_bg_scan_check(struct work_struct *data)
473 {
474         struct iwl_priv *priv =
475             container_of(data, struct iwl_priv, scan_check.work);
476
477         IWL_DEBUG_SCAN(priv, "Scan check work\n");
478
479         /* Since we are here firmware does not finish scan and
480          * most likely is in bad shape, so we don't bother to
481          * send abort command, just force scan complete to mac80211 */
482         mutex_lock(&priv->mutex);
483         iwl_force_scan_end(priv);
484         mutex_unlock(&priv->mutex);
485 }
486
487 /**
488  * iwl_fill_probe_req - fill in all required fields and IE for probe request
489  */
490
491 u16 iwl_fill_probe_req(struct iwl_priv *priv, struct ieee80211_mgmt *frame,
492                        const u8 *ta, const u8 *ies, int ie_len, int left)
493 {
494         int len = 0;
495         u8 *pos = NULL;
496
497         /* Make sure there is enough space for the probe request,
498          * two mandatory IEs and the data */
499         left -= 24;
500         if (left < 0)
501                 return 0;
502
503         frame->frame_control = cpu_to_le16(IEEE80211_STYPE_PROBE_REQ);
504         memcpy(frame->da, iwl_bcast_addr, ETH_ALEN);
505         memcpy(frame->sa, ta, ETH_ALEN);
506         memcpy(frame->bssid, iwl_bcast_addr, ETH_ALEN);
507         frame->seq_ctrl = 0;
508
509         len += 24;
510
511         /* ...next IE... */
512         pos = &frame->u.probe_req.variable[0];
513
514         /* fill in our indirect SSID IE */
515         left -= 2;
516         if (left < 0)
517                 return 0;
518         *pos++ = WLAN_EID_SSID;
519         *pos++ = 0;
520
521         len += 2;
522
523         if (WARN_ON(left < ie_len))
524                 return len;
525
526         if (ies && ie_len) {
527                 memcpy(pos, ies, ie_len);
528                 len += ie_len;
529         }
530
531         return (u16)len;
532 }
533
534 static void iwl_bg_abort_scan(struct work_struct *work)
535 {
536         struct iwl_priv *priv = container_of(work, struct iwl_priv, abort_scan);
537
538         IWL_DEBUG_SCAN(priv, "Abort scan work\n");
539
540         /* We keep scan_check work queued in case when firmware will not
541          * report back scan completed notification */
542         mutex_lock(&priv->mutex);
543         iwl_scan_cancel_timeout(priv, 200);
544         mutex_unlock(&priv->mutex);
545 }
546
547 static void iwl_bg_scan_completed(struct work_struct *work)
548 {
549         struct iwl_priv *priv =
550             container_of(work, struct iwl_priv, scan_completed);
551         bool aborted;
552
553         IWL_DEBUG_SCAN(priv, "Completed scan.\n");
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->scan_type == IWL_SCAN_OFFCH_TX && priv->_agn.offchan_tx_skb) {
569                 ieee80211_tx_status_irqsafe(priv->hw,
570                                             priv->_agn.offchan_tx_skb);
571                 priv->_agn.offchan_tx_skb = NULL;
572         }
573
574         if (priv->scan_type != IWL_SCAN_NORMAL && !aborted) {
575                 int err;
576
577                 /* Check if mac80211 requested scan during our internal scan */
578                 if (priv->scan_request == NULL)
579                         goto out_complete;
580
581                 /* If so request a new scan */
582                 err = iwl_scan_initiate(priv, priv->scan_vif, IWL_SCAN_NORMAL,
583                                         priv->scan_request->channels[0]->band);
584                 if (err) {
585                         IWL_DEBUG_SCAN(priv,
586                                 "failed to initiate pending scan: %d\n", err);
587                         aborted = true;
588                         goto out_complete;
589                 }
590
591                 goto out;
592         }
593
594 out_complete:
595         iwl_complete_scan(priv, aborted);
596
597 out_settings:
598         /* Can we still talk to firmware ? */
599         if (!iwl_is_ready_rf(priv))
600                 goto out;
601
602         iwlagn_post_scan(priv);
603
604 out:
605         mutex_unlock(&priv->mutex);
606 }
607
608 void iwl_setup_scan_deferred_work(struct iwl_priv *priv)
609 {
610         INIT_WORK(&priv->scan_completed, iwl_bg_scan_completed);
611         INIT_WORK(&priv->abort_scan, iwl_bg_abort_scan);
612         INIT_WORK(&priv->start_internal_scan, iwl_bg_start_internal_scan);
613         INIT_DELAYED_WORK(&priv->scan_check, iwl_bg_scan_check);
614 }
615
616 void iwl_cancel_scan_deferred_work(struct iwl_priv *priv)
617 {
618         cancel_work_sync(&priv->start_internal_scan);
619         cancel_work_sync(&priv->abort_scan);
620         cancel_work_sync(&priv->scan_completed);
621
622         if (cancel_delayed_work_sync(&priv->scan_check)) {
623                 mutex_lock(&priv->mutex);
624                 iwl_force_scan_end(priv);
625                 mutex_unlock(&priv->mutex);
626         }
627 }