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iwlwifi: fix scan races
[deliverable/linux.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/types.h>
29 #include <linux/etherdevice.h>
30 #include <net/mac80211.h>
31
32 #include "iwl-eeprom.h"
33 #include "iwl-dev.h"
34 #include "iwl-core.h"
35 #include "iwl-sta.h"
36 #include "iwl-io.h"
37 #include "iwl-helpers.h"
38
39 /* For active scan, listen ACTIVE_DWELL_TIME (msec) on each channel after
40 * sending probe req. This should be set long enough to hear probe responses
41 * from more than one AP. */
42 #define IWL_ACTIVE_DWELL_TIME_24 (30) /* all times in msec */
43 #define IWL_ACTIVE_DWELL_TIME_52 (20)
44
45 #define IWL_ACTIVE_DWELL_FACTOR_24GHZ (3)
46 #define IWL_ACTIVE_DWELL_FACTOR_52GHZ (2)
47
48 /* For passive scan, listen PASSIVE_DWELL_TIME (msec) on each channel.
49 * Must be set longer than active dwell time.
50 * For the most reliable scan, set > AP beacon interval (typically 100msec). */
51 #define IWL_PASSIVE_DWELL_TIME_24 (20) /* all times in msec */
52 #define IWL_PASSIVE_DWELL_TIME_52 (10)
53 #define IWL_PASSIVE_DWELL_BASE (100)
54 #define IWL_CHANNEL_TUNE_TIME 5
55
56
57
58 /**
59 * iwl_scan_cancel - Cancel any currently executing HW scan
60 *
61 * NOTE: priv->mutex is not required before calling this function
62 */
63 int iwl_scan_cancel(struct iwl_priv *priv)
64 {
65 if (!test_bit(STATUS_SCAN_HW, &priv->status)) {
66 clear_bit(STATUS_SCANNING, &priv->status);
67 return 0;
68 }
69
70 if (test_bit(STATUS_SCANNING, &priv->status)) {
71 if (!test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
72 IWL_DEBUG_SCAN(priv, "Queuing scan abort.\n");
73 set_bit(STATUS_SCAN_ABORTING, &priv->status);
74 queue_work(priv->workqueue, &priv->abort_scan);
75
76 } else
77 IWL_DEBUG_SCAN(priv, "Scan abort already in progress.\n");
78
79 return test_bit(STATUS_SCANNING, &priv->status);
80 }
81
82 return 0;
83 }
84 EXPORT_SYMBOL(iwl_scan_cancel);
85 /**
86 * iwl_scan_cancel_timeout - Cancel any currently executing HW scan
87 * @ms: amount of time to wait (in milliseconds) for scan to abort
88 *
89 * NOTE: priv->mutex must be held before calling this function
90 */
91 int iwl_scan_cancel_timeout(struct iwl_priv *priv, unsigned long ms)
92 {
93 unsigned long now = jiffies;
94 int ret;
95
96 ret = iwl_scan_cancel(priv);
97 if (ret && ms) {
98 mutex_unlock(&priv->mutex);
99 while (!time_after(jiffies, now + msecs_to_jiffies(ms)) &&
100 test_bit(STATUS_SCANNING, &priv->status))
101 msleep(1);
102 mutex_lock(&priv->mutex);
103
104 return test_bit(STATUS_SCANNING, &priv->status);
105 }
106
107 return ret;
108 }
109 EXPORT_SYMBOL(iwl_scan_cancel_timeout);
110
111 static int iwl_send_scan_abort(struct iwl_priv *priv)
112 {
113 int ret = 0;
114 struct iwl_rx_packet *pkt;
115 struct iwl_host_cmd cmd = {
116 .id = REPLY_SCAN_ABORT_CMD,
117 .flags = CMD_WANT_SKB,
118 };
119
120 /* If there isn't a scan actively going on in the hardware
121 * then we are in between scan bands and not actually
122 * actively scanning, so don't send the abort command */
123 if (!test_bit(STATUS_SCAN_HW, &priv->status)) {
124 clear_bit(STATUS_SCAN_ABORTING, &priv->status);
125 return 0;
126 }
127
128 ret = iwl_send_cmd_sync(priv, &cmd);
129 if (ret) {
130 clear_bit(STATUS_SCAN_ABORTING, &priv->status);
131 return ret;
132 }
133
134 pkt = (struct iwl_rx_packet *)cmd.reply_page;
135 if (pkt->u.status != CAN_ABORT_STATUS) {
136 /* The scan abort will return 1 for success or
137 * 2 for "failure". A failure condition can be
138 * due to simply not being in an active scan which
139 * can occur if we send the scan abort before we
140 * the microcode has notified us that a scan is
141 * completed. */
142 IWL_DEBUG_INFO(priv, "SCAN_ABORT returned %d.\n", pkt->u.status);
143 clear_bit(STATUS_SCAN_ABORTING, &priv->status);
144 clear_bit(STATUS_SCAN_HW, &priv->status);
145 }
146
147 iwl_free_pages(priv, cmd.reply_page);
148
149 return ret;
150 }
151
152 /* Service response to REPLY_SCAN_CMD (0x80) */
153 static void iwl_rx_reply_scan(struct iwl_priv *priv,
154 struct iwl_rx_mem_buffer *rxb)
155 {
156 #ifdef CONFIG_IWLWIFI_DEBUG
157 struct iwl_rx_packet *pkt = rxb_addr(rxb);
158 struct iwl_scanreq_notification *notif =
159 (struct iwl_scanreq_notification *)pkt->u.raw;
160
161 IWL_DEBUG_RX(priv, "Scan request status = 0x%x\n", notif->status);
162 #endif
163 }
164
165 /* Service SCAN_START_NOTIFICATION (0x82) */
166 static void iwl_rx_scan_start_notif(struct iwl_priv *priv,
167 struct iwl_rx_mem_buffer *rxb)
168 {
169 struct iwl_rx_packet *pkt = rxb_addr(rxb);
170 struct iwl_scanstart_notification *notif =
171 (struct iwl_scanstart_notification *)pkt->u.raw;
172 priv->scan_start_tsf = le32_to_cpu(notif->tsf_low);
173 IWL_DEBUG_SCAN(priv, "Scan start: "
174 "%d [802.11%s] "
175 "(TSF: 0x%08X:%08X) - %d (beacon timer %u)\n",
176 notif->channel,
177 notif->band ? "bg" : "a",
178 le32_to_cpu(notif->tsf_high),
179 le32_to_cpu(notif->tsf_low),
180 notif->status, notif->beacon_timer);
181 }
182
183 /* Service SCAN_RESULTS_NOTIFICATION (0x83) */
184 static void iwl_rx_scan_results_notif(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_scanresults_notification *notif =
190 (struct iwl_scanresults_notification *)pkt->u.raw;
191
192 IWL_DEBUG_SCAN(priv, "Scan ch.res: "
193 "%d [802.11%s] "
194 "(TSF: 0x%08X:%08X) - %d "
195 "elapsed=%lu usec\n",
196 notif->channel,
197 notif->band ? "bg" : "a",
198 le32_to_cpu(notif->tsf_high),
199 le32_to_cpu(notif->tsf_low),
200 le32_to_cpu(notif->statistics[0]),
201 le32_to_cpu(notif->tsf_low) - priv->scan_start_tsf);
202 #endif
203
204 if (!priv->is_internal_short_scan)
205 priv->next_scan_jiffies = 0;
206 }
207
208 /* Service SCAN_COMPLETE_NOTIFICATION (0x84) */
209 static void iwl_rx_scan_complete_notif(struct iwl_priv *priv,
210 struct iwl_rx_mem_buffer *rxb)
211 {
212 #ifdef CONFIG_IWLWIFI_DEBUG
213 struct iwl_rx_packet *pkt = rxb_addr(rxb);
214 struct iwl_scancomplete_notification *scan_notif = (void *)pkt->u.raw;
215
216 IWL_DEBUG_SCAN(priv, "Scan complete: %d channels (TSF 0x%08X:%08X) - %d\n",
217 scan_notif->scanned_channels,
218 scan_notif->tsf_low,
219 scan_notif->tsf_high, scan_notif->status);
220 #endif
221
222 /* The HW is no longer scanning */
223 clear_bit(STATUS_SCAN_HW, &priv->status);
224
225 IWL_DEBUG_INFO(priv, "Scan pass on %sGHz took %dms\n",
226 (priv->scan_bands & BIT(IEEE80211_BAND_2GHZ)) ?
227 "2.4" : "5.2",
228 jiffies_to_msecs(elapsed_jiffies
229 (priv->scan_pass_start, jiffies)));
230
231 /* Remove this scanned band from the list of pending
232 * bands to scan, band G precedes A in order of scanning
233 * as seen in iwl_bg_request_scan */
234 if (priv->scan_bands & BIT(IEEE80211_BAND_2GHZ))
235 priv->scan_bands &= ~BIT(IEEE80211_BAND_2GHZ);
236 else if (priv->scan_bands & BIT(IEEE80211_BAND_5GHZ))
237 priv->scan_bands &= ~BIT(IEEE80211_BAND_5GHZ);
238
239 /* If a request to abort was given, or the scan did not succeed
240 * then we reset the scan state machine and terminate,
241 * re-queuing another scan if one has been requested */
242 if (test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
243 IWL_DEBUG_INFO(priv, "Aborted scan completed.\n");
244 clear_bit(STATUS_SCAN_ABORTING, &priv->status);
245 } else {
246 /* If there are more bands on this scan pass reschedule */
247 if (priv->scan_bands)
248 goto reschedule;
249 }
250
251 if (!priv->is_internal_short_scan)
252 priv->next_scan_jiffies = 0;
253
254 IWL_DEBUG_INFO(priv, "Setting scan to off\n");
255
256 clear_bit(STATUS_SCANNING, &priv->status);
257
258 IWL_DEBUG_INFO(priv, "Scan took %dms\n",
259 jiffies_to_msecs(elapsed_jiffies(priv->scan_start, jiffies)));
260
261 queue_work(priv->workqueue, &priv->scan_completed);
262
263 return;
264
265 reschedule:
266 priv->scan_pass_start = jiffies;
267 queue_work(priv->workqueue, &priv->request_scan);
268 }
269
270 void iwl_setup_rx_scan_handlers(struct iwl_priv *priv)
271 {
272 /* scan handlers */
273 priv->rx_handlers[REPLY_SCAN_CMD] = iwl_rx_reply_scan;
274 priv->rx_handlers[SCAN_START_NOTIFICATION] = iwl_rx_scan_start_notif;
275 priv->rx_handlers[SCAN_RESULTS_NOTIFICATION] =
276 iwl_rx_scan_results_notif;
277 priv->rx_handlers[SCAN_COMPLETE_NOTIFICATION] =
278 iwl_rx_scan_complete_notif;
279 }
280 EXPORT_SYMBOL(iwl_setup_rx_scan_handlers);
281
282 inline u16 iwl_get_active_dwell_time(struct iwl_priv *priv,
283 enum ieee80211_band band,
284 u8 n_probes)
285 {
286 if (band == IEEE80211_BAND_5GHZ)
287 return IWL_ACTIVE_DWELL_TIME_52 +
288 IWL_ACTIVE_DWELL_FACTOR_52GHZ * (n_probes + 1);
289 else
290 return IWL_ACTIVE_DWELL_TIME_24 +
291 IWL_ACTIVE_DWELL_FACTOR_24GHZ * (n_probes + 1);
292 }
293 EXPORT_SYMBOL(iwl_get_active_dwell_time);
294
295 u16 iwl_get_passive_dwell_time(struct iwl_priv *priv,
296 enum ieee80211_band band)
297 {
298 u16 passive = (band == IEEE80211_BAND_2GHZ) ?
299 IWL_PASSIVE_DWELL_BASE + IWL_PASSIVE_DWELL_TIME_24 :
300 IWL_PASSIVE_DWELL_BASE + IWL_PASSIVE_DWELL_TIME_52;
301
302 if (iwl_is_associated(priv)) {
303 /* If we're associated, we clamp the maximum passive
304 * dwell time to be 98% of the beacon interval (minus
305 * 2 * channel tune time) */
306 passive = priv->beacon_int;
307 if ((passive > IWL_PASSIVE_DWELL_BASE) || !passive)
308 passive = IWL_PASSIVE_DWELL_BASE;
309 passive = (passive * 98) / 100 - IWL_CHANNEL_TUNE_TIME * 2;
310 }
311
312 return passive;
313 }
314 EXPORT_SYMBOL(iwl_get_passive_dwell_time);
315
316 static int iwl_get_single_channel_for_scan(struct iwl_priv *priv,
317 enum ieee80211_band band,
318 struct iwl_scan_channel *scan_ch)
319 {
320 const struct ieee80211_supported_band *sband;
321 const struct iwl_channel_info *ch_info;
322 u16 passive_dwell = 0;
323 u16 active_dwell = 0;
324 int i, added = 0;
325 u16 channel = 0;
326
327 sband = iwl_get_hw_mode(priv, band);
328 if (!sband) {
329 IWL_ERR(priv, "invalid band\n");
330 return added;
331 }
332
333 active_dwell = iwl_get_active_dwell_time(priv, band, 0);
334 passive_dwell = iwl_get_passive_dwell_time(priv, band);
335
336 if (passive_dwell <= active_dwell)
337 passive_dwell = active_dwell + 1;
338
339 /* only scan single channel, good enough to reset the RF */
340 /* pick the first valid not in-use channel */
341 if (band == IEEE80211_BAND_5GHZ) {
342 for (i = 14; i < priv->channel_count; i++) {
343 if (priv->channel_info[i].channel !=
344 le16_to_cpu(priv->staging_rxon.channel)) {
345 channel = priv->channel_info[i].channel;
346 ch_info = iwl_get_channel_info(priv,
347 band, channel);
348 if (is_channel_valid(ch_info))
349 break;
350 }
351 }
352 } else {
353 for (i = 0; i < 14; i++) {
354 if (priv->channel_info[i].channel !=
355 le16_to_cpu(priv->staging_rxon.channel)) {
356 channel =
357 priv->channel_info[i].channel;
358 ch_info = iwl_get_channel_info(priv,
359 band, channel);
360 if (is_channel_valid(ch_info))
361 break;
362 }
363 }
364 }
365 if (channel) {
366 scan_ch->channel = cpu_to_le16(channel);
367 scan_ch->type = SCAN_CHANNEL_TYPE_PASSIVE;
368 scan_ch->active_dwell = cpu_to_le16(active_dwell);
369 scan_ch->passive_dwell = cpu_to_le16(passive_dwell);
370 /* Set txpower levels to defaults */
371 scan_ch->dsp_atten = 110;
372 if (band == IEEE80211_BAND_5GHZ)
373 scan_ch->tx_gain = ((1 << 5) | (3 << 3)) | 3;
374 else
375 scan_ch->tx_gain = ((1 << 5) | (5 << 3));
376 added++;
377 } else
378 IWL_ERR(priv, "no valid channel found\n");
379 return added;
380 }
381
382 static int iwl_get_channels_for_scan(struct iwl_priv *priv,
383 enum ieee80211_band band,
384 u8 is_active, u8 n_probes,
385 struct iwl_scan_channel *scan_ch)
386 {
387 struct ieee80211_channel *chan;
388 const struct ieee80211_supported_band *sband;
389 const struct iwl_channel_info *ch_info;
390 u16 passive_dwell = 0;
391 u16 active_dwell = 0;
392 int added, i;
393 u16 channel;
394
395 sband = iwl_get_hw_mode(priv, band);
396 if (!sband)
397 return 0;
398
399 active_dwell = iwl_get_active_dwell_time(priv, band, n_probes);
400 passive_dwell = iwl_get_passive_dwell_time(priv, band);
401
402 if (passive_dwell <= active_dwell)
403 passive_dwell = active_dwell + 1;
404
405 for (i = 0, added = 0; i < priv->scan_request->n_channels; i++) {
406 chan = priv->scan_request->channels[i];
407
408 if (chan->band != band)
409 continue;
410
411 channel = ieee80211_frequency_to_channel(chan->center_freq);
412 scan_ch->channel = cpu_to_le16(channel);
413
414 ch_info = iwl_get_channel_info(priv, band, channel);
415 if (!is_channel_valid(ch_info)) {
416 IWL_DEBUG_SCAN(priv, "Channel %d is INVALID for this band.\n",
417 channel);
418 continue;
419 }
420
421 if (!is_active || is_channel_passive(ch_info) ||
422 (chan->flags & IEEE80211_CHAN_PASSIVE_SCAN))
423 scan_ch->type = SCAN_CHANNEL_TYPE_PASSIVE;
424 else
425 scan_ch->type = SCAN_CHANNEL_TYPE_ACTIVE;
426
427 if (n_probes)
428 scan_ch->type |= IWL_SCAN_PROBE_MASK(n_probes);
429
430 scan_ch->active_dwell = cpu_to_le16(active_dwell);
431 scan_ch->passive_dwell = cpu_to_le16(passive_dwell);
432
433 /* Set txpower levels to defaults */
434 scan_ch->dsp_atten = 110;
435
436 /* NOTE: if we were doing 6Mb OFDM for scans we'd use
437 * power level:
438 * scan_ch->tx_gain = ((1 << 5) | (2 << 3)) | 3;
439 */
440 if (band == IEEE80211_BAND_5GHZ)
441 scan_ch->tx_gain = ((1 << 5) | (3 << 3)) | 3;
442 else
443 scan_ch->tx_gain = ((1 << 5) | (5 << 3));
444
445 IWL_DEBUG_SCAN(priv, "Scanning ch=%d prob=0x%X [%s %d]\n",
446 channel, le32_to_cpu(scan_ch->type),
447 (scan_ch->type & SCAN_CHANNEL_TYPE_ACTIVE) ?
448 "ACTIVE" : "PASSIVE",
449 (scan_ch->type & SCAN_CHANNEL_TYPE_ACTIVE) ?
450 active_dwell : passive_dwell);
451
452 scan_ch++;
453 added++;
454 }
455
456 IWL_DEBUG_SCAN(priv, "total channels to scan %d \n", added);
457 return added;
458 }
459
460 void iwl_init_scan_params(struct iwl_priv *priv)
461 {
462 u8 ant_idx = fls(priv->hw_params.valid_tx_ant) - 1;
463 if (!priv->scan_tx_ant[IEEE80211_BAND_5GHZ])
464 priv->scan_tx_ant[IEEE80211_BAND_5GHZ] = ant_idx;
465 if (!priv->scan_tx_ant[IEEE80211_BAND_2GHZ])
466 priv->scan_tx_ant[IEEE80211_BAND_2GHZ] = ant_idx;
467 }
468 EXPORT_SYMBOL(iwl_init_scan_params);
469
470 static int iwl_scan_initiate(struct iwl_priv *priv)
471 {
472 WARN_ON(!mutex_is_locked(&priv->mutex));
473
474 IWL_DEBUG_INFO(priv, "Starting scan...\n");
475 set_bit(STATUS_SCANNING, &priv->status);
476 priv->is_internal_short_scan = false;
477 priv->scan_start = jiffies;
478 priv->scan_pass_start = priv->scan_start;
479
480 queue_work(priv->workqueue, &priv->request_scan);
481
482 return 0;
483 }
484
485 #define IWL_DELAY_NEXT_SCAN (HZ*2)
486
487 int iwl_mac_hw_scan(struct ieee80211_hw *hw,
488 struct cfg80211_scan_request *req)
489 {
490 unsigned long flags;
491 struct iwl_priv *priv = hw->priv;
492 int ret, i;
493
494 IWL_DEBUG_MAC80211(priv, "enter\n");
495
496 mutex_lock(&priv->mutex);
497 spin_lock_irqsave(&priv->lock, flags);
498
499 if (!iwl_is_ready_rf(priv)) {
500 ret = -EIO;
501 IWL_DEBUG_MAC80211(priv, "leave - not ready or exit pending\n");
502 goto out_unlock;
503 }
504
505 if (test_bit(STATUS_SCANNING, &priv->status)) {
506 IWL_DEBUG_SCAN(priv, "Scan already in progress.\n");
507 ret = -EAGAIN;
508 goto out_unlock;
509 }
510
511 if (test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
512 IWL_DEBUG_SCAN(priv, "Scan request while abort pending\n");
513 ret = -EAGAIN;
514 goto out_unlock;
515 }
516
517 /* We don't schedule scan within next_scan_jiffies period.
518 * Avoid scanning during possible EAPOL exchange, return
519 * success immediately.
520 */
521 if (priv->next_scan_jiffies &&
522 time_after(priv->next_scan_jiffies, jiffies)) {
523 IWL_DEBUG_SCAN(priv, "scan rejected: within next scan period\n");
524 queue_work(priv->workqueue, &priv->scan_completed);
525 ret = 0;
526 goto out_unlock;
527 }
528
529 priv->scan_bands = 0;
530 for (i = 0; i < req->n_channels; i++)
531 priv->scan_bands |= BIT(req->channels[i]->band);
532
533 priv->scan_request = req;
534
535 ret = iwl_scan_initiate(priv);
536
537 IWL_DEBUG_MAC80211(priv, "leave\n");
538
539 out_unlock:
540 spin_unlock_irqrestore(&priv->lock, flags);
541 mutex_unlock(&priv->mutex);
542
543 return ret;
544 }
545 EXPORT_SYMBOL(iwl_mac_hw_scan);
546
547 /*
548 * internal short scan, this function should only been called while associated.
549 * It will reset and tune the radio to prevent possible RF related problem
550 */
551 void iwl_internal_short_hw_scan(struct iwl_priv *priv)
552 {
553 queue_work(priv->workqueue, &priv->start_internal_scan);
554 }
555
556 static void iwl_bg_start_internal_scan(struct work_struct *work)
557 {
558 struct iwl_priv *priv =
559 container_of(work, struct iwl_priv, start_internal_scan);
560
561 mutex_lock(&priv->mutex);
562
563 if (!iwl_is_ready_rf(priv)) {
564 IWL_DEBUG_SCAN(priv, "not ready or exit pending\n");
565 goto unlock;
566 }
567
568 if (test_bit(STATUS_SCANNING, &priv->status)) {
569 IWL_DEBUG_SCAN(priv, "Scan already in progress.\n");
570 goto unlock;
571 }
572
573 if (test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
574 IWL_DEBUG_SCAN(priv, "Scan request while abort pending\n");
575 goto unlock;
576 }
577
578 priv->scan_bands = 0;
579 if (priv->band == IEEE80211_BAND_5GHZ)
580 priv->scan_bands |= BIT(IEEE80211_BAND_5GHZ);
581 else
582 priv->scan_bands |= BIT(IEEE80211_BAND_2GHZ);
583
584 IWL_DEBUG_SCAN(priv, "Start internal short scan...\n");
585 set_bit(STATUS_SCANNING, &priv->status);
586 priv->is_internal_short_scan = true;
587 queue_work(priv->workqueue, &priv->request_scan);
588 unlock:
589 mutex_unlock(&priv->mutex);
590 }
591 EXPORT_SYMBOL(iwl_internal_short_hw_scan);
592
593 #define IWL_SCAN_CHECK_WATCHDOG (7 * HZ)
594
595 void iwl_bg_scan_check(struct work_struct *data)
596 {
597 struct iwl_priv *priv =
598 container_of(data, struct iwl_priv, scan_check.work);
599
600 if (test_bit(STATUS_EXIT_PENDING, &priv->status))
601 return;
602
603 mutex_lock(&priv->mutex);
604 if (test_bit(STATUS_SCANNING, &priv->status) ||
605 test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
606 IWL_DEBUG_SCAN(priv, "Scan completion watchdog resetting "
607 "adapter (%dms)\n",
608 jiffies_to_msecs(IWL_SCAN_CHECK_WATCHDOG));
609
610 if (!test_bit(STATUS_EXIT_PENDING, &priv->status))
611 iwl_send_scan_abort(priv);
612 }
613 mutex_unlock(&priv->mutex);
614 }
615 EXPORT_SYMBOL(iwl_bg_scan_check);
616
617 /**
618 * iwl_fill_probe_req - fill in all required fields and IE for probe request
619 */
620
621 u16 iwl_fill_probe_req(struct iwl_priv *priv, struct ieee80211_mgmt *frame,
622 const u8 *ies, int ie_len, int left)
623 {
624 int len = 0;
625 u8 *pos = NULL;
626
627 /* Make sure there is enough space for the probe request,
628 * two mandatory IEs and the data */
629 left -= 24;
630 if (left < 0)
631 return 0;
632
633 frame->frame_control = cpu_to_le16(IEEE80211_STYPE_PROBE_REQ);
634 memcpy(frame->da, iwl_bcast_addr, ETH_ALEN);
635 memcpy(frame->sa, priv->mac_addr, ETH_ALEN);
636 memcpy(frame->bssid, iwl_bcast_addr, ETH_ALEN);
637 frame->seq_ctrl = 0;
638
639 len += 24;
640
641 /* ...next IE... */
642 pos = &frame->u.probe_req.variable[0];
643
644 /* fill in our indirect SSID IE */
645 left -= 2;
646 if (left < 0)
647 return 0;
648 *pos++ = WLAN_EID_SSID;
649 *pos++ = 0;
650
651 len += 2;
652
653 if (WARN_ON(left < ie_len))
654 return len;
655
656 if (ies)
657 memcpy(pos, ies, ie_len);
658 len += ie_len;
659 left -= ie_len;
660
661 return (u16)len;
662 }
663 EXPORT_SYMBOL(iwl_fill_probe_req);
664
665 static void iwl_bg_request_scan(struct work_struct *data)
666 {
667 struct iwl_priv *priv =
668 container_of(data, struct iwl_priv, request_scan);
669 struct iwl_host_cmd cmd = {
670 .id = REPLY_SCAN_CMD,
671 .len = sizeof(struct iwl_scan_cmd),
672 .flags = CMD_SIZE_HUGE,
673 };
674 struct iwl_scan_cmd *scan;
675 struct ieee80211_conf *conf = NULL;
676 int ret = 0;
677 u32 rate_flags = 0;
678 u16 cmd_len;
679 u16 rx_chain = 0;
680 enum ieee80211_band band;
681 u8 n_probes = 0;
682 u8 rx_ant = priv->hw_params.valid_rx_ant;
683 u8 rate;
684 bool is_active = false;
685 int chan_mod;
686 u8 active_chains;
687
688 conf = ieee80211_get_hw_conf(priv->hw);
689
690 mutex_lock(&priv->mutex);
691
692 cancel_delayed_work(&priv->scan_check);
693
694 if (!iwl_is_ready(priv)) {
695 IWL_WARN(priv, "request scan called when driver not ready.\n");
696 goto done;
697 }
698
699 /* Make sure the scan wasn't canceled before this queued work
700 * was given the chance to run... */
701 if (!test_bit(STATUS_SCANNING, &priv->status))
702 goto done;
703
704 /* This should never be called or scheduled if there is currently
705 * a scan active in the hardware. */
706 if (test_bit(STATUS_SCAN_HW, &priv->status)) {
707 IWL_DEBUG_INFO(priv, "Multiple concurrent scan requests in parallel. "
708 "Ignoring second request.\n");
709 ret = -EIO;
710 goto done;
711 }
712
713 if (test_bit(STATUS_EXIT_PENDING, &priv->status)) {
714 IWL_DEBUG_SCAN(priv, "Aborting scan due to device shutdown\n");
715 goto done;
716 }
717
718 if (test_bit(STATUS_SCAN_ABORTING, &priv->status)) {
719 IWL_DEBUG_HC(priv, "Scan request while abort pending. Queuing.\n");
720 goto done;
721 }
722
723 if (iwl_is_rfkill(priv)) {
724 IWL_DEBUG_HC(priv, "Aborting scan due to RF Kill activation\n");
725 goto done;
726 }
727
728 if (!test_bit(STATUS_READY, &priv->status)) {
729 IWL_DEBUG_HC(priv, "Scan request while uninitialized. Queuing.\n");
730 goto done;
731 }
732
733 if (!priv->scan_bands) {
734 IWL_DEBUG_HC(priv, "Aborting scan due to no requested bands\n");
735 goto done;
736 }
737
738 if (!priv->scan) {
739 priv->scan = kmalloc(sizeof(struct iwl_scan_cmd) +
740 IWL_MAX_SCAN_SIZE, GFP_KERNEL);
741 if (!priv->scan) {
742 ret = -ENOMEM;
743 goto done;
744 }
745 }
746 scan = priv->scan;
747 memset(scan, 0, sizeof(struct iwl_scan_cmd) + IWL_MAX_SCAN_SIZE);
748
749 scan->quiet_plcp_th = IWL_PLCP_QUIET_THRESH;
750 scan->quiet_time = IWL_ACTIVE_QUIET_TIME;
751
752 if (iwl_is_associated(priv)) {
753 u16 interval = 0;
754 u32 extra;
755 u32 suspend_time = 100;
756 u32 scan_suspend_time = 100;
757 unsigned long flags;
758
759 IWL_DEBUG_INFO(priv, "Scanning while associated...\n");
760 spin_lock_irqsave(&priv->lock, flags);
761 interval = priv->beacon_int;
762 spin_unlock_irqrestore(&priv->lock, flags);
763
764 scan->suspend_time = 0;
765 scan->max_out_time = cpu_to_le32(200 * 1024);
766 if (!interval)
767 interval = suspend_time;
768
769 extra = (suspend_time / interval) << 22;
770 scan_suspend_time = (extra |
771 ((suspend_time % interval) * 1024));
772 scan->suspend_time = cpu_to_le32(scan_suspend_time);
773 IWL_DEBUG_SCAN(priv, "suspend_time 0x%X beacon interval %d\n",
774 scan_suspend_time, interval);
775 }
776
777 if (priv->is_internal_short_scan) {
778 IWL_DEBUG_SCAN(priv, "Start internal passive scan.\n");
779 } else if (priv->scan_request->n_ssids) {
780 int i, p = 0;
781 IWL_DEBUG_SCAN(priv, "Kicking off active scan\n");
782 for (i = 0; i < priv->scan_request->n_ssids; i++) {
783 /* always does wildcard anyway */
784 if (!priv->scan_request->ssids[i].ssid_len)
785 continue;
786 scan->direct_scan[p].id = WLAN_EID_SSID;
787 scan->direct_scan[p].len =
788 priv->scan_request->ssids[i].ssid_len;
789 memcpy(scan->direct_scan[p].ssid,
790 priv->scan_request->ssids[i].ssid,
791 priv->scan_request->ssids[i].ssid_len);
792 n_probes++;
793 p++;
794 }
795 is_active = true;
796 } else
797 IWL_DEBUG_SCAN(priv, "Start passive scan.\n");
798
799 scan->tx_cmd.tx_flags = TX_CMD_FLG_SEQ_CTL_MSK;
800 scan->tx_cmd.sta_id = priv->hw_params.bcast_sta_id;
801 scan->tx_cmd.stop_time.life_time = TX_CMD_LIFE_TIME_INFINITE;
802
803
804 if (priv->scan_bands & BIT(IEEE80211_BAND_2GHZ)) {
805 band = IEEE80211_BAND_2GHZ;
806 scan->flags = RXON_FLG_BAND_24G_MSK | RXON_FLG_AUTO_DETECT_MSK;
807 chan_mod = le32_to_cpu(priv->active_rxon.flags & RXON_FLG_CHANNEL_MODE_MSK)
808 >> RXON_FLG_CHANNEL_MODE_POS;
809 if (chan_mod == CHANNEL_MODE_PURE_40) {
810 rate = IWL_RATE_6M_PLCP;
811 } else {
812 rate = IWL_RATE_1M_PLCP;
813 rate_flags = RATE_MCS_CCK_MSK;
814 }
815 scan->good_CRC_th = 0;
816 } else if (priv->scan_bands & BIT(IEEE80211_BAND_5GHZ)) {
817 band = IEEE80211_BAND_5GHZ;
818 rate = IWL_RATE_6M_PLCP;
819 /*
820 * If active scaning is requested but a certain channel
821 * is marked passive, we can do active scanning if we
822 * detect transmissions.
823 */
824 scan->good_CRC_th = is_active ? IWL_GOOD_CRC_TH : 0;
825
826 /* Force use of chains B and C (0x6) for scan Rx for 4965
827 * Avoid A (0x1) because of its off-channel reception on A-band.
828 */
829 if ((priv->hw_rev & CSR_HW_REV_TYPE_MSK) == CSR_HW_REV_TYPE_4965)
830 rx_ant = ANT_BC;
831 } else {
832 IWL_WARN(priv, "Invalid scan band count\n");
833 goto done;
834 }
835
836 priv->scan_tx_ant[band] =
837 iwl_toggle_tx_ant(priv, priv->scan_tx_ant[band]);
838 rate_flags |= iwl_ant_idx_to_flags(priv->scan_tx_ant[band]);
839 scan->tx_cmd.rate_n_flags = iwl_hw_set_rate_n_flags(rate, rate_flags);
840
841 /* In power save mode use one chain, otherwise use all chains */
842 if (test_bit(STATUS_POWER_PMI, &priv->status)) {
843 /* rx_ant has been set to all valid chains previously */
844 active_chains = rx_ant &
845 ((u8)(priv->chain_noise_data.active_chains));
846 if (!active_chains)
847 active_chains = rx_ant;
848
849 IWL_DEBUG_SCAN(priv, "chain_noise_data.active_chains: %u\n",
850 priv->chain_noise_data.active_chains);
851
852 rx_ant = first_antenna(active_chains);
853 }
854 /* MIMO is not used here, but value is required */
855 rx_chain |= priv->hw_params.valid_rx_ant << RXON_RX_CHAIN_VALID_POS;
856 rx_chain |= rx_ant << RXON_RX_CHAIN_FORCE_MIMO_SEL_POS;
857 rx_chain |= rx_ant << RXON_RX_CHAIN_FORCE_SEL_POS;
858 rx_chain |= 0x1 << RXON_RX_CHAIN_DRIVER_FORCE_POS;
859 scan->rx_chain = cpu_to_le16(rx_chain);
860 if (!priv->is_internal_short_scan) {
861 cmd_len = iwl_fill_probe_req(priv,
862 (struct ieee80211_mgmt *)scan->data,
863 priv->scan_request->ie,
864 priv->scan_request->ie_len,
865 IWL_MAX_SCAN_SIZE - sizeof(*scan));
866 } else {
867 cmd_len = iwl_fill_probe_req(priv,
868 (struct ieee80211_mgmt *)scan->data,
869 NULL, 0,
870 IWL_MAX_SCAN_SIZE - sizeof(*scan));
871
872 }
873 scan->tx_cmd.len = cpu_to_le16(cmd_len);
874 if (iwl_is_monitor_mode(priv))
875 scan->filter_flags = RXON_FILTER_PROMISC_MSK;
876
877 scan->filter_flags |= (RXON_FILTER_ACCEPT_GRP_MSK |
878 RXON_FILTER_BCON_AWARE_MSK);
879
880 if (priv->is_internal_short_scan) {
881 scan->channel_count =
882 iwl_get_single_channel_for_scan(priv, band,
883 (void *)&scan->data[le16_to_cpu(
884 scan->tx_cmd.len)]);
885 } else {
886 scan->channel_count =
887 iwl_get_channels_for_scan(priv, band,
888 is_active, n_probes,
889 (void *)&scan->data[le16_to_cpu(
890 scan->tx_cmd.len)]);
891 }
892 if (scan->channel_count == 0) {
893 IWL_DEBUG_SCAN(priv, "channel count %d\n", scan->channel_count);
894 goto done;
895 }
896
897 cmd.len += le16_to_cpu(scan->tx_cmd.len) +
898 scan->channel_count * sizeof(struct iwl_scan_channel);
899 cmd.data = scan;
900 scan->len = cpu_to_le16(cmd.len);
901
902 set_bit(STATUS_SCAN_HW, &priv->status);
903 ret = iwl_send_cmd_sync(priv, &cmd);
904 if (ret)
905 goto done;
906
907 queue_delayed_work(priv->workqueue, &priv->scan_check,
908 IWL_SCAN_CHECK_WATCHDOG);
909
910 mutex_unlock(&priv->mutex);
911 return;
912
913 done:
914 /* Cannot perform scan. Make sure we clear scanning
915 * bits from status so next scan request can be performed.
916 * If we don't clear scanning status bit here all next scan
917 * will fail
918 */
919 clear_bit(STATUS_SCAN_HW, &priv->status);
920 clear_bit(STATUS_SCANNING, &priv->status);
921 /* inform mac80211 scan aborted */
922 queue_work(priv->workqueue, &priv->scan_completed);
923 mutex_unlock(&priv->mutex);
924 }
925
926 void iwl_bg_abort_scan(struct work_struct *work)
927 {
928 struct iwl_priv *priv = container_of(work, struct iwl_priv, abort_scan);
929
930 if (!test_bit(STATUS_READY, &priv->status) ||
931 !test_bit(STATUS_GEO_CONFIGURED, &priv->status))
932 return;
933
934 mutex_lock(&priv->mutex);
935
936 set_bit(STATUS_SCAN_ABORTING, &priv->status);
937 iwl_send_scan_abort(priv);
938
939 mutex_unlock(&priv->mutex);
940 }
941 EXPORT_SYMBOL(iwl_bg_abort_scan);
942
943 void iwl_bg_scan_completed(struct work_struct *work)
944 {
945 struct iwl_priv *priv =
946 container_of(work, struct iwl_priv, scan_completed);
947
948 IWL_DEBUG_SCAN(priv, "SCAN complete scan\n");
949
950 cancel_delayed_work(&priv->scan_check);
951
952 if (!priv->is_internal_short_scan)
953 ieee80211_scan_completed(priv->hw, false);
954 else {
955 priv->is_internal_short_scan = false;
956 IWL_DEBUG_SCAN(priv, "internal short scan completed\n");
957 }
958
959 if (test_bit(STATUS_EXIT_PENDING, &priv->status))
960 return;
961
962 /* Since setting the TXPOWER may have been deferred while
963 * performing the scan, fire one off */
964 mutex_lock(&priv->mutex);
965 iwl_set_tx_power(priv, priv->tx_power_user_lmt, true);
966 mutex_unlock(&priv->mutex);
967 }
968 EXPORT_SYMBOL(iwl_bg_scan_completed);
969
970 void iwl_setup_scan_deferred_work(struct iwl_priv *priv)
971 {
972 INIT_WORK(&priv->scan_completed, iwl_bg_scan_completed);
973 INIT_WORK(&priv->request_scan, iwl_bg_request_scan);
974 INIT_WORK(&priv->abort_scan, iwl_bg_abort_scan);
975 INIT_WORK(&priv->start_internal_scan, iwl_bg_start_internal_scan);
976 INIT_DELAYED_WORK(&priv->scan_check, iwl_bg_scan_check);
977 }
978 EXPORT_SYMBOL(iwl_setup_scan_deferred_work);
979
Linux kernel - Deliverables
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