2 * This file contains helper code to handle channel
3 * settings and keeping track of what is possible at
6 * Copyright 2009 Johannes Berg <johannes@sipsolutions.net>
7 * Copyright 2013-2014 Intel Mobile Communications GmbH
10 #include <linux/export.h>
11 #include <net/cfg80211.h>
15 void cfg80211_chandef_create(struct cfg80211_chan_def *chandef,
16 struct ieee80211_channel *chan,
17 enum nl80211_channel_type chan_type)
23 chandef->center_freq2 = 0;
26 case NL80211_CHAN_NO_HT:
27 chandef->width = NL80211_CHAN_WIDTH_20_NOHT;
28 chandef->center_freq1 = chan->center_freq;
30 case NL80211_CHAN_HT20:
31 chandef->width = NL80211_CHAN_WIDTH_20;
32 chandef->center_freq1 = chan->center_freq;
34 case NL80211_CHAN_HT40PLUS:
35 chandef->width = NL80211_CHAN_WIDTH_40;
36 chandef->center_freq1 = chan->center_freq + 10;
38 case NL80211_CHAN_HT40MINUS:
39 chandef->width = NL80211_CHAN_WIDTH_40;
40 chandef->center_freq1 = chan->center_freq - 10;
46 EXPORT_SYMBOL(cfg80211_chandef_create);
48 bool cfg80211_chandef_valid(const struct cfg80211_chan_def *chandef)
55 control_freq = chandef->chan->center_freq;
57 switch (chandef->width) {
58 case NL80211_CHAN_WIDTH_5:
59 case NL80211_CHAN_WIDTH_10:
60 case NL80211_CHAN_WIDTH_20:
61 case NL80211_CHAN_WIDTH_20_NOHT:
62 if (chandef->center_freq1 != control_freq)
64 if (chandef->center_freq2)
67 case NL80211_CHAN_WIDTH_40:
68 if (chandef->center_freq1 != control_freq + 10 &&
69 chandef->center_freq1 != control_freq - 10)
71 if (chandef->center_freq2)
74 case NL80211_CHAN_WIDTH_80P80:
75 if (chandef->center_freq1 != control_freq + 30 &&
76 chandef->center_freq1 != control_freq + 10 &&
77 chandef->center_freq1 != control_freq - 10 &&
78 chandef->center_freq1 != control_freq - 30)
80 if (!chandef->center_freq2)
82 /* adjacent is not allowed -- that's a 160 MHz channel */
83 if (chandef->center_freq1 - chandef->center_freq2 == 80 ||
84 chandef->center_freq2 - chandef->center_freq1 == 80)
87 case NL80211_CHAN_WIDTH_80:
88 if (chandef->center_freq1 != control_freq + 30 &&
89 chandef->center_freq1 != control_freq + 10 &&
90 chandef->center_freq1 != control_freq - 10 &&
91 chandef->center_freq1 != control_freq - 30)
93 if (chandef->center_freq2)
96 case NL80211_CHAN_WIDTH_160:
97 if (chandef->center_freq1 != control_freq + 70 &&
98 chandef->center_freq1 != control_freq + 50 &&
99 chandef->center_freq1 != control_freq + 30 &&
100 chandef->center_freq1 != control_freq + 10 &&
101 chandef->center_freq1 != control_freq - 10 &&
102 chandef->center_freq1 != control_freq - 30 &&
103 chandef->center_freq1 != control_freq - 50 &&
104 chandef->center_freq1 != control_freq - 70)
106 if (chandef->center_freq2)
115 EXPORT_SYMBOL(cfg80211_chandef_valid);
117 static void chandef_primary_freqs(const struct cfg80211_chan_def *c,
118 int *pri40, int *pri80)
123 case NL80211_CHAN_WIDTH_40:
124 *pri40 = c->center_freq1;
127 case NL80211_CHAN_WIDTH_80:
128 case NL80211_CHAN_WIDTH_80P80:
129 *pri80 = c->center_freq1;
131 tmp = (30 + c->chan->center_freq - c->center_freq1)/20;
135 *pri40 = c->center_freq1 - 20 + 40 * tmp;
137 case NL80211_CHAN_WIDTH_160:
139 tmp = (70 + c->chan->center_freq - c->center_freq1)/20;
143 *pri40 = c->center_freq1 - 60 + 40 * tmp;
146 *pri80 = c->center_freq1 - 40 + 80 * tmp;
153 static int cfg80211_chandef_get_width(const struct cfg80211_chan_def *c)
158 case NL80211_CHAN_WIDTH_5:
161 case NL80211_CHAN_WIDTH_10:
164 case NL80211_CHAN_WIDTH_20:
165 case NL80211_CHAN_WIDTH_20_NOHT:
168 case NL80211_CHAN_WIDTH_40:
171 case NL80211_CHAN_WIDTH_80P80:
172 case NL80211_CHAN_WIDTH_80:
175 case NL80211_CHAN_WIDTH_160:
185 const struct cfg80211_chan_def *
186 cfg80211_chandef_compatible(const struct cfg80211_chan_def *c1,
187 const struct cfg80211_chan_def *c2)
189 u32 c1_pri40, c1_pri80, c2_pri40, c2_pri80;
191 /* If they are identical, return */
192 if (cfg80211_chandef_identical(c1, c2))
195 /* otherwise, must have same control channel */
196 if (c1->chan != c2->chan)
200 * If they have the same width, but aren't identical,
201 * then they can't be compatible.
203 if (c1->width == c2->width)
207 * can't be compatible if one of them is 5 or 10 MHz,
208 * but they don't have the same width.
210 if (c1->width == NL80211_CHAN_WIDTH_5 ||
211 c1->width == NL80211_CHAN_WIDTH_10 ||
212 c2->width == NL80211_CHAN_WIDTH_5 ||
213 c2->width == NL80211_CHAN_WIDTH_10)
216 if (c1->width == NL80211_CHAN_WIDTH_20_NOHT ||
217 c1->width == NL80211_CHAN_WIDTH_20)
220 if (c2->width == NL80211_CHAN_WIDTH_20_NOHT ||
221 c2->width == NL80211_CHAN_WIDTH_20)
224 chandef_primary_freqs(c1, &c1_pri40, &c1_pri80);
225 chandef_primary_freqs(c2, &c2_pri40, &c2_pri80);
227 if (c1_pri40 != c2_pri40)
230 WARN_ON(!c1_pri80 && !c2_pri80);
231 if (c1_pri80 && c2_pri80 && c1_pri80 != c2_pri80)
234 if (c1->width > c2->width)
238 EXPORT_SYMBOL(cfg80211_chandef_compatible);
240 static void cfg80211_set_chans_dfs_state(struct wiphy *wiphy, u32 center_freq,
242 enum nl80211_dfs_state dfs_state)
244 struct ieee80211_channel *c;
247 for (freq = center_freq - bandwidth/2 + 10;
248 freq <= center_freq + bandwidth/2 - 10;
250 c = ieee80211_get_channel(wiphy, freq);
251 if (!c || !(c->flags & IEEE80211_CHAN_RADAR))
254 c->dfs_state = dfs_state;
255 c->dfs_state_entered = jiffies;
259 void cfg80211_set_dfs_state(struct wiphy *wiphy,
260 const struct cfg80211_chan_def *chandef,
261 enum nl80211_dfs_state dfs_state)
265 if (WARN_ON(!cfg80211_chandef_valid(chandef)))
268 width = cfg80211_chandef_get_width(chandef);
272 cfg80211_set_chans_dfs_state(wiphy, chandef->center_freq1,
275 if (!chandef->center_freq2)
277 cfg80211_set_chans_dfs_state(wiphy, chandef->center_freq2,
281 static u32 cfg80211_get_start_freq(u32 center_freq,
287 start_freq = center_freq;
289 start_freq = center_freq - bandwidth/2 + 10;
294 static u32 cfg80211_get_end_freq(u32 center_freq,
300 end_freq = center_freq;
302 end_freq = center_freq + bandwidth/2 - 10;
307 static int cfg80211_get_chans_dfs_required(struct wiphy *wiphy,
311 struct ieee80211_channel *c;
312 u32 freq, start_freq, end_freq;
314 start_freq = cfg80211_get_start_freq(center_freq, bandwidth);
315 end_freq = cfg80211_get_end_freq(center_freq, bandwidth);
317 for (freq = start_freq; freq <= end_freq; freq += 20) {
318 c = ieee80211_get_channel(wiphy, freq);
322 if (c->flags & IEEE80211_CHAN_RADAR)
329 int cfg80211_chandef_dfs_required(struct wiphy *wiphy,
330 const struct cfg80211_chan_def *chandef,
331 enum nl80211_iftype iftype)
336 if (WARN_ON(!cfg80211_chandef_valid(chandef)))
340 case NL80211_IFTYPE_ADHOC:
341 case NL80211_IFTYPE_AP:
342 case NL80211_IFTYPE_P2P_GO:
343 case NL80211_IFTYPE_MESH_POINT:
344 width = cfg80211_chandef_get_width(chandef);
348 ret = cfg80211_get_chans_dfs_required(wiphy,
349 chandef->center_freq1,
354 return BIT(chandef->width);
356 if (!chandef->center_freq2)
359 ret = cfg80211_get_chans_dfs_required(wiphy,
360 chandef->center_freq2,
365 return BIT(chandef->width);
368 case NL80211_IFTYPE_STATION:
369 case NL80211_IFTYPE_P2P_CLIENT:
370 case NL80211_IFTYPE_MONITOR:
371 case NL80211_IFTYPE_AP_VLAN:
372 case NL80211_IFTYPE_WDS:
373 case NL80211_IFTYPE_P2P_DEVICE:
375 case NL80211_IFTYPE_UNSPECIFIED:
376 case NUM_NL80211_IFTYPES:
382 EXPORT_SYMBOL(cfg80211_chandef_dfs_required);
384 static int cfg80211_get_chans_dfs_usable(struct wiphy *wiphy,
388 struct ieee80211_channel *c;
389 u32 freq, start_freq, end_freq;
392 start_freq = cfg80211_get_start_freq(center_freq, bandwidth);
393 end_freq = cfg80211_get_end_freq(center_freq, bandwidth);
396 * Check entire range of channels for the bandwidth.
397 * Check all channels are DFS channels (DFS_USABLE or
398 * DFS_AVAILABLE). Return number of usable channels
399 * (require CAC). Allow DFS and non-DFS channel mix.
401 for (freq = start_freq; freq <= end_freq; freq += 20) {
402 c = ieee80211_get_channel(wiphy, freq);
406 if (c->flags & IEEE80211_CHAN_DISABLED)
409 if (c->flags & IEEE80211_CHAN_RADAR) {
410 if (c->dfs_state == NL80211_DFS_UNAVAILABLE)
413 if (c->dfs_state == NL80211_DFS_USABLE)
421 bool cfg80211_chandef_dfs_usable(struct wiphy *wiphy,
422 const struct cfg80211_chan_def *chandef)
427 if (WARN_ON(!cfg80211_chandef_valid(chandef)))
430 width = cfg80211_chandef_get_width(chandef);
434 r1 = cfg80211_get_chans_dfs_usable(wiphy, chandef->center_freq1,
440 switch (chandef->width) {
441 case NL80211_CHAN_WIDTH_80P80:
442 WARN_ON(!chandef->center_freq2);
443 r2 = cfg80211_get_chans_dfs_usable(wiphy,
444 chandef->center_freq2,
450 WARN_ON(chandef->center_freq2);
454 return (r1 + r2 > 0);
458 static bool cfg80211_get_chans_dfs_available(struct wiphy *wiphy,
462 struct ieee80211_channel *c;
463 u32 freq, start_freq, end_freq;
465 start_freq = cfg80211_get_start_freq(center_freq, bandwidth);
466 end_freq = cfg80211_get_end_freq(center_freq, bandwidth);
469 * Check entire range of channels for the bandwidth.
470 * If any channel in between is disabled or has not
471 * had gone through CAC return false
473 for (freq = start_freq; freq <= end_freq; freq += 20) {
474 c = ieee80211_get_channel(wiphy, freq);
478 if (c->flags & IEEE80211_CHAN_DISABLED)
481 if ((c->flags & IEEE80211_CHAN_RADAR) &&
482 (c->dfs_state != NL80211_DFS_AVAILABLE))
489 static bool cfg80211_chandef_dfs_available(struct wiphy *wiphy,
490 const struct cfg80211_chan_def *chandef)
495 if (WARN_ON(!cfg80211_chandef_valid(chandef)))
498 width = cfg80211_chandef_get_width(chandef);
502 r = cfg80211_get_chans_dfs_available(wiphy, chandef->center_freq1,
505 /* If any of channels unavailable for cf1 just return */
509 switch (chandef->width) {
510 case NL80211_CHAN_WIDTH_80P80:
511 WARN_ON(!chandef->center_freq2);
512 r = cfg80211_get_chans_dfs_available(wiphy,
513 chandef->center_freq2,
516 WARN_ON(chandef->center_freq2);
523 static unsigned int cfg80211_get_chans_dfs_cac_time(struct wiphy *wiphy,
527 struct ieee80211_channel *c;
528 u32 start_freq, end_freq, freq;
529 unsigned int dfs_cac_ms = 0;
531 start_freq = cfg80211_get_start_freq(center_freq, bandwidth);
532 end_freq = cfg80211_get_end_freq(center_freq, bandwidth);
534 for (freq = start_freq; freq <= end_freq; freq += 20) {
535 c = ieee80211_get_channel(wiphy, freq);
539 if (c->flags & IEEE80211_CHAN_DISABLED)
542 if (!(c->flags & IEEE80211_CHAN_RADAR))
545 if (c->dfs_cac_ms > dfs_cac_ms)
546 dfs_cac_ms = c->dfs_cac_ms;
553 cfg80211_chandef_dfs_cac_time(struct wiphy *wiphy,
554 const struct cfg80211_chan_def *chandef)
557 unsigned int t1 = 0, t2 = 0;
559 if (WARN_ON(!cfg80211_chandef_valid(chandef)))
562 width = cfg80211_chandef_get_width(chandef);
566 t1 = cfg80211_get_chans_dfs_cac_time(wiphy,
567 chandef->center_freq1,
570 if (!chandef->center_freq2)
573 t2 = cfg80211_get_chans_dfs_cac_time(wiphy,
574 chandef->center_freq2,
580 static bool cfg80211_secondary_chans_ok(struct wiphy *wiphy,
581 u32 center_freq, u32 bandwidth,
582 u32 prohibited_flags)
584 struct ieee80211_channel *c;
585 u32 freq, start_freq, end_freq;
587 start_freq = cfg80211_get_start_freq(center_freq, bandwidth);
588 end_freq = cfg80211_get_end_freq(center_freq, bandwidth);
590 for (freq = start_freq; freq <= end_freq; freq += 20) {
591 c = ieee80211_get_channel(wiphy, freq);
592 if (!c || c->flags & prohibited_flags)
599 bool cfg80211_chandef_usable(struct wiphy *wiphy,
600 const struct cfg80211_chan_def *chandef,
601 u32 prohibited_flags)
603 struct ieee80211_sta_ht_cap *ht_cap;
604 struct ieee80211_sta_vht_cap *vht_cap;
605 u32 width, control_freq;
607 if (WARN_ON(!cfg80211_chandef_valid(chandef)))
610 ht_cap = &wiphy->bands[chandef->chan->band]->ht_cap;
611 vht_cap = &wiphy->bands[chandef->chan->band]->vht_cap;
613 control_freq = chandef->chan->center_freq;
615 switch (chandef->width) {
616 case NL80211_CHAN_WIDTH_5:
619 case NL80211_CHAN_WIDTH_10:
620 prohibited_flags |= IEEE80211_CHAN_NO_10MHZ;
623 case NL80211_CHAN_WIDTH_20:
624 if (!ht_cap->ht_supported)
626 case NL80211_CHAN_WIDTH_20_NOHT:
627 prohibited_flags |= IEEE80211_CHAN_NO_20MHZ;
630 case NL80211_CHAN_WIDTH_40:
632 if (!ht_cap->ht_supported)
634 if (!(ht_cap->cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40) ||
635 ht_cap->cap & IEEE80211_HT_CAP_40MHZ_INTOLERANT)
637 if (chandef->center_freq1 < control_freq &&
638 chandef->chan->flags & IEEE80211_CHAN_NO_HT40MINUS)
640 if (chandef->center_freq1 > control_freq &&
641 chandef->chan->flags & IEEE80211_CHAN_NO_HT40PLUS)
644 case NL80211_CHAN_WIDTH_80P80:
645 if (!(vht_cap->cap & IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160_80PLUS80MHZ))
647 case NL80211_CHAN_WIDTH_80:
648 if (!vht_cap->vht_supported)
650 prohibited_flags |= IEEE80211_CHAN_NO_80MHZ;
653 case NL80211_CHAN_WIDTH_160:
654 if (!vht_cap->vht_supported)
656 if (!(vht_cap->cap & IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160MHZ))
658 prohibited_flags |= IEEE80211_CHAN_NO_160MHZ;
667 * TODO: What if there are only certain 80/160/80+80 MHz channels
668 * allowed by the driver, or only certain combinations?
669 * For 40 MHz the driver can set the NO_HT40 flags, but for
670 * 80/160 MHz and in particular 80+80 MHz this isn't really
671 * feasible and we only have NO_80MHZ/NO_160MHZ so far but
672 * no way to cover 80+80 MHz or more complex restrictions.
673 * Note that such restrictions also need to be advertised to
674 * userspace, for example for P2P channel selection.
678 prohibited_flags |= IEEE80211_CHAN_NO_OFDM;
680 /* 5 and 10 MHz are only defined for the OFDM PHY */
682 prohibited_flags |= IEEE80211_CHAN_NO_OFDM;
685 if (!cfg80211_secondary_chans_ok(wiphy, chandef->center_freq1,
686 width, prohibited_flags))
689 if (!chandef->center_freq2)
691 return cfg80211_secondary_chans_ok(wiphy, chandef->center_freq2,
692 width, prohibited_flags);
694 EXPORT_SYMBOL(cfg80211_chandef_usable);
697 * For GO only, check if the channel can be used under permissive conditions
698 * mandated by the some regulatory bodies, i.e., the channel is marked with
699 * IEEE80211_CHAN_GO_CONCURRENT and there is an additional station interface
700 * associated to an AP on the same channel or on the same UNII band
701 * (assuming that the AP is an authorized master).
702 * In addition allow the GO to operate on a channel on which indoor operation is
703 * allowed, iff we are currently operating in an indoor environment.
705 static bool cfg80211_go_permissive_chan(struct cfg80211_registered_device *rdev,
706 struct ieee80211_channel *chan)
708 struct wireless_dev *wdev_iter;
709 struct wiphy *wiphy = wiphy_idx_to_wiphy(rdev->wiphy_idx);
713 if (!config_enabled(CONFIG_CFG80211_REG_RELAX_NO_IR) ||
714 !(wiphy->regulatory_flags & REGULATORY_ENABLE_RELAX_NO_IR))
717 if (regulatory_indoor_allowed() &&
718 (chan->flags & IEEE80211_CHAN_INDOOR_ONLY))
721 if (!(chan->flags & IEEE80211_CHAN_GO_CONCURRENT))
725 * Generally, it is possible to rely on another device/driver to allow
726 * the GO concurrent relaxation, however, since the device can further
727 * enforce the relaxation (by doing a similar verifications as this),
728 * and thus fail the GO instantiation, consider only the interfaces of
729 * the current registered device.
731 list_for_each_entry(wdev_iter, &rdev->wdev_list, list) {
732 struct ieee80211_channel *other_chan = NULL;
735 if (wdev_iter->iftype != NL80211_IFTYPE_STATION ||
736 !netif_running(wdev_iter->netdev))
739 wdev_lock(wdev_iter);
740 if (wdev_iter->current_bss)
741 other_chan = wdev_iter->current_bss->pub.channel;
742 wdev_unlock(wdev_iter);
747 if (chan == other_chan)
750 if (chan->band != IEEE80211_BAND_5GHZ)
753 r1 = cfg80211_get_unii(chan->center_freq);
754 r2 = cfg80211_get_unii(other_chan->center_freq);
756 if (r1 != -EINVAL && r1 == r2) {
758 * At some locations channels 149-165 are considered a
759 * bundle, but at other locations, e.g., Indonesia,
760 * channels 149-161 are considered a bundle while
761 * channel 165 is left out and considered to be in a
762 * different bundle. Thus, in case that there is a
763 * station interface connected to an AP on channel 165,
764 * it is assumed that channels 149-161 are allowed for
765 * GO operations. However, having a station interface
766 * connected to an AP on channels 149-161, does not
767 * allow GO operation on channel 165.
769 if (chan->center_freq == 5825 &&
770 other_chan->center_freq != 5825)
779 bool cfg80211_reg_can_beacon(struct wiphy *wiphy,
780 struct cfg80211_chan_def *chandef,
781 enum nl80211_iftype iftype)
783 struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
785 u32 prohibited_flags = IEEE80211_CHAN_DISABLED |
786 IEEE80211_CHAN_RADAR;
788 trace_cfg80211_reg_can_beacon(wiphy, chandef, iftype);
791 * Under certain conditions suggested by the some regulatory bodies
792 * a GO can operate on channels marked with IEEE80211_NO_IR
793 * so set this flag only if such relaxations are not enabled and
794 * the conditions are not met.
796 if (iftype != NL80211_IFTYPE_P2P_GO ||
797 !cfg80211_go_permissive_chan(rdev, chandef->chan))
798 prohibited_flags |= IEEE80211_CHAN_NO_IR;
800 if (cfg80211_chandef_dfs_required(wiphy, chandef, iftype) > 0 &&
801 cfg80211_chandef_dfs_available(wiphy, chandef)) {
802 /* We can skip IEEE80211_CHAN_NO_IR if chandef dfs available */
803 prohibited_flags = IEEE80211_CHAN_DISABLED;
806 res = cfg80211_chandef_usable(wiphy, chandef, prohibited_flags);
808 trace_cfg80211_return_bool(res);
811 EXPORT_SYMBOL(cfg80211_reg_can_beacon);
813 int cfg80211_set_monitor_channel(struct cfg80211_registered_device *rdev,
814 struct cfg80211_chan_def *chandef)
816 if (!rdev->ops->set_monitor_channel)
818 if (!cfg80211_has_monitors_only(rdev))
821 return rdev_set_monitor_channel(rdev, chandef);
825 cfg80211_get_chan_state(struct wireless_dev *wdev,
826 struct ieee80211_channel **chan,
827 enum cfg80211_chan_mode *chanmode,
833 *chanmode = CHAN_MODE_UNDEFINED;
835 ASSERT_WDEV_LOCK(wdev);
837 if (wdev->netdev && !netif_running(wdev->netdev))
840 switch (wdev->iftype) {
841 case NL80211_IFTYPE_ADHOC:
842 if (wdev->current_bss) {
843 *chan = wdev->current_bss->pub.channel;
844 *chanmode = (wdev->ibss_fixed &&
845 !wdev->ibss_dfs_possible)
847 : CHAN_MODE_EXCLUSIVE;
849 /* consider worst-case - IBSS can try to return to the
850 * original user-specified channel as creator */
851 if (wdev->ibss_dfs_possible)
852 *radar_detect |= BIT(wdev->chandef.width);
856 case NL80211_IFTYPE_STATION:
857 case NL80211_IFTYPE_P2P_CLIENT:
858 if (wdev->current_bss) {
859 *chan = wdev->current_bss->pub.channel;
860 *chanmode = CHAN_MODE_SHARED;
864 case NL80211_IFTYPE_AP:
865 case NL80211_IFTYPE_P2P_GO:
866 if (wdev->cac_started) {
867 *chan = wdev->chandef.chan;
868 *chanmode = CHAN_MODE_SHARED;
869 *radar_detect |= BIT(wdev->chandef.width);
870 } else if (wdev->beacon_interval) {
871 *chan = wdev->chandef.chan;
872 *chanmode = CHAN_MODE_SHARED;
874 ret = cfg80211_chandef_dfs_required(wdev->wiphy,
879 *radar_detect |= BIT(wdev->chandef.width);
882 case NL80211_IFTYPE_MESH_POINT:
883 if (wdev->mesh_id_len) {
884 *chan = wdev->chandef.chan;
885 *chanmode = CHAN_MODE_SHARED;
887 ret = cfg80211_chandef_dfs_required(wdev->wiphy,
892 *radar_detect |= BIT(wdev->chandef.width);
895 case NL80211_IFTYPE_MONITOR:
896 case NL80211_IFTYPE_AP_VLAN:
897 case NL80211_IFTYPE_WDS:
898 case NL80211_IFTYPE_P2P_DEVICE:
899 /* these interface types don't really have a channel */
901 case NL80211_IFTYPE_UNSPECIFIED:
902 case NUM_NL80211_IFTYPES: