Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost
[cris-mirror.git] / net / mac80211 / ht.c
blobd7523530d3f80cb1b64a7f7a3b530460ef71fc5e
1 /*
2 * HT handling
4 * Copyright 2003, Jouni Malinen <jkmaline@cc.hut.fi>
5 * Copyright 2002-2005, Instant802 Networks, Inc.
6 * Copyright 2005-2006, Devicescape Software, Inc.
7 * Copyright 2006-2007 Jiri Benc <jbenc@suse.cz>
8 * Copyright 2007, Michael Wu <flamingice@sourmilk.net>
9 * Copyright 2007-2010, Intel Corporation
10 * Copyright 2017 Intel Deutschland GmbH
12 * This program is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License version 2 as
14 * published by the Free Software Foundation.
17 #include <linux/ieee80211.h>
18 #include <linux/export.h>
19 #include <net/mac80211.h>
20 #include "ieee80211_i.h"
21 #include "rate.h"
23 static void __check_htcap_disable(struct ieee80211_ht_cap *ht_capa,
24 struct ieee80211_ht_cap *ht_capa_mask,
25 struct ieee80211_sta_ht_cap *ht_cap,
26 u16 flag)
28 __le16 le_flag = cpu_to_le16(flag);
29 if (ht_capa_mask->cap_info & le_flag) {
30 if (!(ht_capa->cap_info & le_flag))
31 ht_cap->cap &= ~flag;
35 static void __check_htcap_enable(struct ieee80211_ht_cap *ht_capa,
36 struct ieee80211_ht_cap *ht_capa_mask,
37 struct ieee80211_sta_ht_cap *ht_cap,
38 u16 flag)
40 __le16 le_flag = cpu_to_le16(flag);
42 if ((ht_capa_mask->cap_info & le_flag) &&
43 (ht_capa->cap_info & le_flag))
44 ht_cap->cap |= flag;
47 void ieee80211_apply_htcap_overrides(struct ieee80211_sub_if_data *sdata,
48 struct ieee80211_sta_ht_cap *ht_cap)
50 struct ieee80211_ht_cap *ht_capa, *ht_capa_mask;
51 u8 *scaps, *smask;
52 int i;
54 if (!ht_cap->ht_supported)
55 return;
57 switch (sdata->vif.type) {
58 case NL80211_IFTYPE_STATION:
59 ht_capa = &sdata->u.mgd.ht_capa;
60 ht_capa_mask = &sdata->u.mgd.ht_capa_mask;
61 break;
62 case NL80211_IFTYPE_ADHOC:
63 ht_capa = &sdata->u.ibss.ht_capa;
64 ht_capa_mask = &sdata->u.ibss.ht_capa_mask;
65 break;
66 default:
67 WARN_ON_ONCE(1);
68 return;
71 scaps = (u8 *)(&ht_capa->mcs.rx_mask);
72 smask = (u8 *)(&ht_capa_mask->mcs.rx_mask);
74 /* NOTE: If you add more over-rides here, update register_hw
75 * ht_capa_mod_mask logic in main.c as well.
76 * And, if this method can ever change ht_cap.ht_supported, fix
77 * the check in ieee80211_add_ht_ie.
80 /* check for HT over-rides, MCS rates first. */
81 for (i = 0; i < IEEE80211_HT_MCS_MASK_LEN; i++) {
82 u8 m = smask[i];
83 ht_cap->mcs.rx_mask[i] &= ~m; /* turn off all masked bits */
84 /* Add back rates that are supported */
85 ht_cap->mcs.rx_mask[i] |= (m & scaps[i]);
88 /* Force removal of HT-40 capabilities? */
89 __check_htcap_disable(ht_capa, ht_capa_mask, ht_cap,
90 IEEE80211_HT_CAP_SUP_WIDTH_20_40);
91 __check_htcap_disable(ht_capa, ht_capa_mask, ht_cap,
92 IEEE80211_HT_CAP_SGI_40);
94 /* Allow user to disable SGI-20 (SGI-40 is handled above) */
95 __check_htcap_disable(ht_capa, ht_capa_mask, ht_cap,
96 IEEE80211_HT_CAP_SGI_20);
98 /* Allow user to disable the max-AMSDU bit. */
99 __check_htcap_disable(ht_capa, ht_capa_mask, ht_cap,
100 IEEE80211_HT_CAP_MAX_AMSDU);
102 /* Allow user to disable LDPC */
103 __check_htcap_disable(ht_capa, ht_capa_mask, ht_cap,
104 IEEE80211_HT_CAP_LDPC_CODING);
106 /* Allow user to enable 40 MHz intolerant bit. */
107 __check_htcap_enable(ht_capa, ht_capa_mask, ht_cap,
108 IEEE80211_HT_CAP_40MHZ_INTOLERANT);
110 /* Allow user to decrease AMPDU factor */
111 if (ht_capa_mask->ampdu_params_info &
112 IEEE80211_HT_AMPDU_PARM_FACTOR) {
113 u8 n = ht_capa->ampdu_params_info &
114 IEEE80211_HT_AMPDU_PARM_FACTOR;
115 if (n < ht_cap->ampdu_factor)
116 ht_cap->ampdu_factor = n;
119 /* Allow the user to increase AMPDU density. */
120 if (ht_capa_mask->ampdu_params_info &
121 IEEE80211_HT_AMPDU_PARM_DENSITY) {
122 u8 n = (ht_capa->ampdu_params_info &
123 IEEE80211_HT_AMPDU_PARM_DENSITY)
124 >> IEEE80211_HT_AMPDU_PARM_DENSITY_SHIFT;
125 if (n > ht_cap->ampdu_density)
126 ht_cap->ampdu_density = n;
131 bool ieee80211_ht_cap_ie_to_sta_ht_cap(struct ieee80211_sub_if_data *sdata,
132 struct ieee80211_supported_band *sband,
133 const struct ieee80211_ht_cap *ht_cap_ie,
134 struct sta_info *sta)
136 struct ieee80211_sta_ht_cap ht_cap, own_cap;
137 u8 ampdu_info, tx_mcs_set_cap;
138 int i, max_tx_streams;
139 bool changed;
140 enum ieee80211_sta_rx_bandwidth bw;
141 enum ieee80211_smps_mode smps_mode;
143 memset(&ht_cap, 0, sizeof(ht_cap));
145 if (!ht_cap_ie || !sband->ht_cap.ht_supported)
146 goto apply;
148 ht_cap.ht_supported = true;
150 own_cap = sband->ht_cap;
153 * If user has specified capability over-rides, take care
154 * of that if the station we're setting up is the AP or TDLS peer that
155 * we advertised a restricted capability set to. Override
156 * our own capabilities and then use those below.
158 if (sdata->vif.type == NL80211_IFTYPE_STATION ||
159 sdata->vif.type == NL80211_IFTYPE_ADHOC)
160 ieee80211_apply_htcap_overrides(sdata, &own_cap);
163 * The bits listed in this expression should be
164 * the same for the peer and us, if the station
165 * advertises more then we can't use those thus
166 * we mask them out.
168 ht_cap.cap = le16_to_cpu(ht_cap_ie->cap_info) &
169 (own_cap.cap | ~(IEEE80211_HT_CAP_LDPC_CODING |
170 IEEE80211_HT_CAP_SUP_WIDTH_20_40 |
171 IEEE80211_HT_CAP_GRN_FLD |
172 IEEE80211_HT_CAP_SGI_20 |
173 IEEE80211_HT_CAP_SGI_40 |
174 IEEE80211_HT_CAP_DSSSCCK40));
177 * The STBC bits are asymmetric -- if we don't have
178 * TX then mask out the peer's RX and vice versa.
180 if (!(own_cap.cap & IEEE80211_HT_CAP_TX_STBC))
181 ht_cap.cap &= ~IEEE80211_HT_CAP_RX_STBC;
182 if (!(own_cap.cap & IEEE80211_HT_CAP_RX_STBC))
183 ht_cap.cap &= ~IEEE80211_HT_CAP_TX_STBC;
185 ampdu_info = ht_cap_ie->ampdu_params_info;
186 ht_cap.ampdu_factor =
187 ampdu_info & IEEE80211_HT_AMPDU_PARM_FACTOR;
188 ht_cap.ampdu_density =
189 (ampdu_info & IEEE80211_HT_AMPDU_PARM_DENSITY) >> 2;
191 /* own MCS TX capabilities */
192 tx_mcs_set_cap = own_cap.mcs.tx_params;
194 /* Copy peer MCS TX capabilities, the driver might need them. */
195 ht_cap.mcs.tx_params = ht_cap_ie->mcs.tx_params;
197 /* can we TX with MCS rates? */
198 if (!(tx_mcs_set_cap & IEEE80211_HT_MCS_TX_DEFINED))
199 goto apply;
201 /* Counting from 0, therefore +1 */
202 if (tx_mcs_set_cap & IEEE80211_HT_MCS_TX_RX_DIFF)
203 max_tx_streams =
204 ((tx_mcs_set_cap & IEEE80211_HT_MCS_TX_MAX_STREAMS_MASK)
205 >> IEEE80211_HT_MCS_TX_MAX_STREAMS_SHIFT) + 1;
206 else
207 max_tx_streams = IEEE80211_HT_MCS_TX_MAX_STREAMS;
210 * 802.11n-2009 20.3.5 / 20.6 says:
211 * - indices 0 to 7 and 32 are single spatial stream
212 * - 8 to 31 are multiple spatial streams using equal modulation
213 * [8..15 for two streams, 16..23 for three and 24..31 for four]
214 * - remainder are multiple spatial streams using unequal modulation
216 for (i = 0; i < max_tx_streams; i++)
217 ht_cap.mcs.rx_mask[i] =
218 own_cap.mcs.rx_mask[i] & ht_cap_ie->mcs.rx_mask[i];
220 if (tx_mcs_set_cap & IEEE80211_HT_MCS_TX_UNEQUAL_MODULATION)
221 for (i = IEEE80211_HT_MCS_UNEQUAL_MODULATION_START_BYTE;
222 i < IEEE80211_HT_MCS_MASK_LEN; i++)
223 ht_cap.mcs.rx_mask[i] =
224 own_cap.mcs.rx_mask[i] &
225 ht_cap_ie->mcs.rx_mask[i];
227 /* handle MCS rate 32 too */
228 if (own_cap.mcs.rx_mask[32/8] & ht_cap_ie->mcs.rx_mask[32/8] & 1)
229 ht_cap.mcs.rx_mask[32/8] |= 1;
231 /* set Rx highest rate */
232 ht_cap.mcs.rx_highest = ht_cap_ie->mcs.rx_highest;
234 if (ht_cap.cap & IEEE80211_HT_CAP_MAX_AMSDU)
235 sta->sta.max_amsdu_len = IEEE80211_MAX_MPDU_LEN_HT_7935;
236 else
237 sta->sta.max_amsdu_len = IEEE80211_MAX_MPDU_LEN_HT_3839;
239 apply:
240 changed = memcmp(&sta->sta.ht_cap, &ht_cap, sizeof(ht_cap));
242 memcpy(&sta->sta.ht_cap, &ht_cap, sizeof(ht_cap));
244 switch (sdata->vif.bss_conf.chandef.width) {
245 default:
246 WARN_ON_ONCE(1);
247 /* fall through */
248 case NL80211_CHAN_WIDTH_20_NOHT:
249 case NL80211_CHAN_WIDTH_20:
250 bw = IEEE80211_STA_RX_BW_20;
251 break;
252 case NL80211_CHAN_WIDTH_40:
253 case NL80211_CHAN_WIDTH_80:
254 case NL80211_CHAN_WIDTH_80P80:
255 case NL80211_CHAN_WIDTH_160:
256 bw = ht_cap.cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40 ?
257 IEEE80211_STA_RX_BW_40 : IEEE80211_STA_RX_BW_20;
258 break;
261 sta->sta.bandwidth = bw;
263 sta->cur_max_bandwidth =
264 ht_cap.cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40 ?
265 IEEE80211_STA_RX_BW_40 : IEEE80211_STA_RX_BW_20;
267 switch ((ht_cap.cap & IEEE80211_HT_CAP_SM_PS)
268 >> IEEE80211_HT_CAP_SM_PS_SHIFT) {
269 case WLAN_HT_CAP_SM_PS_INVALID:
270 case WLAN_HT_CAP_SM_PS_STATIC:
271 smps_mode = IEEE80211_SMPS_STATIC;
272 break;
273 case WLAN_HT_CAP_SM_PS_DYNAMIC:
274 smps_mode = IEEE80211_SMPS_DYNAMIC;
275 break;
276 case WLAN_HT_CAP_SM_PS_DISABLED:
277 smps_mode = IEEE80211_SMPS_OFF;
278 break;
281 if (smps_mode != sta->sta.smps_mode)
282 changed = true;
283 sta->sta.smps_mode = smps_mode;
285 return changed;
288 void ieee80211_sta_tear_down_BA_sessions(struct sta_info *sta,
289 enum ieee80211_agg_stop_reason reason)
291 int i;
293 mutex_lock(&sta->ampdu_mlme.mtx);
294 for (i = 0; i < IEEE80211_NUM_TIDS; i++)
295 ___ieee80211_stop_rx_ba_session(sta, i, WLAN_BACK_RECIPIENT,
296 WLAN_REASON_QSTA_LEAVE_QBSS,
297 reason != AGG_STOP_DESTROY_STA &&
298 reason != AGG_STOP_PEER_REQUEST);
300 for (i = 0; i < IEEE80211_NUM_TIDS; i++)
301 ___ieee80211_stop_tx_ba_session(sta, i, reason);
302 mutex_unlock(&sta->ampdu_mlme.mtx);
304 /* stopping might queue the work again - so cancel only afterwards */
305 cancel_work_sync(&sta->ampdu_mlme.work);
308 * In case the tear down is part of a reconfigure due to HW restart
309 * request, it is possible that the low level driver requested to stop
310 * the BA session, so handle it to properly clean tid_tx data.
312 mutex_lock(&sta->ampdu_mlme.mtx);
313 for (i = 0; i < IEEE80211_NUM_TIDS; i++) {
314 struct tid_ampdu_tx *tid_tx =
315 rcu_dereference_protected_tid_tx(sta, i);
317 if (!tid_tx)
318 continue;
320 if (test_and_clear_bit(HT_AGG_STATE_STOP_CB, &tid_tx->state))
321 ieee80211_stop_tx_ba_cb(sta, i, tid_tx);
323 mutex_unlock(&sta->ampdu_mlme.mtx);
326 void ieee80211_ba_session_work(struct work_struct *work)
328 struct sta_info *sta =
329 container_of(work, struct sta_info, ampdu_mlme.work);
330 struct tid_ampdu_tx *tid_tx;
331 int tid;
334 * When this flag is set, new sessions should be
335 * blocked, and existing sessions will be torn
336 * down by the code that set the flag, so this
337 * need not run.
339 if (test_sta_flag(sta, WLAN_STA_BLOCK_BA))
340 return;
342 mutex_lock(&sta->ampdu_mlme.mtx);
343 for (tid = 0; tid < IEEE80211_NUM_TIDS; tid++) {
344 if (test_and_clear_bit(tid, sta->ampdu_mlme.tid_rx_timer_expired))
345 ___ieee80211_stop_rx_ba_session(
346 sta, tid, WLAN_BACK_RECIPIENT,
347 WLAN_REASON_QSTA_TIMEOUT, true);
349 if (test_and_clear_bit(tid,
350 sta->ampdu_mlme.tid_rx_stop_requested))
351 ___ieee80211_stop_rx_ba_session(
352 sta, tid, WLAN_BACK_RECIPIENT,
353 WLAN_REASON_UNSPECIFIED, true);
355 if (test_and_clear_bit(tid,
356 sta->ampdu_mlme.tid_rx_manage_offl))
357 ___ieee80211_start_rx_ba_session(sta, 0, 0, 0, 1, tid,
358 IEEE80211_MAX_AMPDU_BUF,
359 false, true);
361 if (test_and_clear_bit(tid + IEEE80211_NUM_TIDS,
362 sta->ampdu_mlme.tid_rx_manage_offl))
363 ___ieee80211_stop_rx_ba_session(
364 sta, tid, WLAN_BACK_RECIPIENT,
365 0, false);
367 spin_lock_bh(&sta->lock);
369 tid_tx = sta->ampdu_mlme.tid_start_tx[tid];
370 if (tid_tx) {
372 * Assign it over to the normal tid_tx array
373 * where it "goes live".
376 sta->ampdu_mlme.tid_start_tx[tid] = NULL;
377 /* could there be a race? */
378 if (sta->ampdu_mlme.tid_tx[tid])
379 kfree(tid_tx);
380 else
381 ieee80211_assign_tid_tx(sta, tid, tid_tx);
382 spin_unlock_bh(&sta->lock);
384 ieee80211_tx_ba_session_handle_start(sta, tid);
385 continue;
387 spin_unlock_bh(&sta->lock);
389 tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
390 if (!tid_tx)
391 continue;
393 if (test_and_clear_bit(HT_AGG_STATE_START_CB, &tid_tx->state))
394 ieee80211_start_tx_ba_cb(sta, tid, tid_tx);
395 if (test_and_clear_bit(HT_AGG_STATE_WANT_STOP, &tid_tx->state))
396 ___ieee80211_stop_tx_ba_session(sta, tid,
397 AGG_STOP_LOCAL_REQUEST);
398 if (test_and_clear_bit(HT_AGG_STATE_STOP_CB, &tid_tx->state))
399 ieee80211_stop_tx_ba_cb(sta, tid, tid_tx);
401 mutex_unlock(&sta->ampdu_mlme.mtx);
404 void ieee80211_send_delba(struct ieee80211_sub_if_data *sdata,
405 const u8 *da, u16 tid,
406 u16 initiator, u16 reason_code)
408 struct ieee80211_local *local = sdata->local;
409 struct sk_buff *skb;
410 struct ieee80211_mgmt *mgmt;
411 u16 params;
413 skb = dev_alloc_skb(sizeof(*mgmt) + local->hw.extra_tx_headroom);
414 if (!skb)
415 return;
417 skb_reserve(skb, local->hw.extra_tx_headroom);
418 mgmt = skb_put_zero(skb, 24);
419 memcpy(mgmt->da, da, ETH_ALEN);
420 memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
421 if (sdata->vif.type == NL80211_IFTYPE_AP ||
422 sdata->vif.type == NL80211_IFTYPE_AP_VLAN ||
423 sdata->vif.type == NL80211_IFTYPE_MESH_POINT)
424 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
425 else if (sdata->vif.type == NL80211_IFTYPE_STATION)
426 memcpy(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN);
427 else if (sdata->vif.type == NL80211_IFTYPE_ADHOC)
428 memcpy(mgmt->bssid, sdata->u.ibss.bssid, ETH_ALEN);
430 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
431 IEEE80211_STYPE_ACTION);
433 skb_put(skb, 1 + sizeof(mgmt->u.action.u.delba));
435 mgmt->u.action.category = WLAN_CATEGORY_BACK;
436 mgmt->u.action.u.delba.action_code = WLAN_ACTION_DELBA;
437 params = (u16)(initiator << 11); /* bit 11 initiator */
438 params |= (u16)(tid << 12); /* bit 15:12 TID number */
440 mgmt->u.action.u.delba.params = cpu_to_le16(params);
441 mgmt->u.action.u.delba.reason_code = cpu_to_le16(reason_code);
443 ieee80211_tx_skb(sdata, skb);
446 void ieee80211_process_delba(struct ieee80211_sub_if_data *sdata,
447 struct sta_info *sta,
448 struct ieee80211_mgmt *mgmt, size_t len)
450 u16 tid, params;
451 u16 initiator;
453 params = le16_to_cpu(mgmt->u.action.u.delba.params);
454 tid = (params & IEEE80211_DELBA_PARAM_TID_MASK) >> 12;
455 initiator = (params & IEEE80211_DELBA_PARAM_INITIATOR_MASK) >> 11;
457 ht_dbg_ratelimited(sdata, "delba from %pM (%s) tid %d reason code %d\n",
458 mgmt->sa, initiator ? "initiator" : "recipient",
459 tid,
460 le16_to_cpu(mgmt->u.action.u.delba.reason_code));
462 if (initiator == WLAN_BACK_INITIATOR)
463 __ieee80211_stop_rx_ba_session(sta, tid, WLAN_BACK_INITIATOR, 0,
464 true);
465 else
466 __ieee80211_stop_tx_ba_session(sta, tid, AGG_STOP_PEER_REQUEST);
469 int ieee80211_send_smps_action(struct ieee80211_sub_if_data *sdata,
470 enum ieee80211_smps_mode smps, const u8 *da,
471 const u8 *bssid)
473 struct ieee80211_local *local = sdata->local;
474 struct sk_buff *skb;
475 struct ieee80211_mgmt *action_frame;
477 /* 27 = header + category + action + smps mode */
478 skb = dev_alloc_skb(27 + local->hw.extra_tx_headroom);
479 if (!skb)
480 return -ENOMEM;
482 skb_reserve(skb, local->hw.extra_tx_headroom);
483 action_frame = skb_put(skb, 27);
484 memcpy(action_frame->da, da, ETH_ALEN);
485 memcpy(action_frame->sa, sdata->dev->dev_addr, ETH_ALEN);
486 memcpy(action_frame->bssid, bssid, ETH_ALEN);
487 action_frame->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
488 IEEE80211_STYPE_ACTION);
489 action_frame->u.action.category = WLAN_CATEGORY_HT;
490 action_frame->u.action.u.ht_smps.action = WLAN_HT_ACTION_SMPS;
491 switch (smps) {
492 case IEEE80211_SMPS_AUTOMATIC:
493 case IEEE80211_SMPS_NUM_MODES:
494 WARN_ON(1);
495 /* fall through */
496 case IEEE80211_SMPS_OFF:
497 action_frame->u.action.u.ht_smps.smps_control =
498 WLAN_HT_SMPS_CONTROL_DISABLED;
499 break;
500 case IEEE80211_SMPS_STATIC:
501 action_frame->u.action.u.ht_smps.smps_control =
502 WLAN_HT_SMPS_CONTROL_STATIC;
503 break;
504 case IEEE80211_SMPS_DYNAMIC:
505 action_frame->u.action.u.ht_smps.smps_control =
506 WLAN_HT_SMPS_CONTROL_DYNAMIC;
507 break;
510 /* we'll do more on status of this frame */
511 IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_CTL_REQ_TX_STATUS;
512 ieee80211_tx_skb(sdata, skb);
514 return 0;
517 void ieee80211_request_smps_mgd_work(struct work_struct *work)
519 struct ieee80211_sub_if_data *sdata =
520 container_of(work, struct ieee80211_sub_if_data,
521 u.mgd.request_smps_work);
523 sdata_lock(sdata);
524 __ieee80211_request_smps_mgd(sdata, sdata->u.mgd.driver_smps_mode);
525 sdata_unlock(sdata);
528 void ieee80211_request_smps_ap_work(struct work_struct *work)
530 struct ieee80211_sub_if_data *sdata =
531 container_of(work, struct ieee80211_sub_if_data,
532 u.ap.request_smps_work);
534 sdata_lock(sdata);
535 if (sdata_dereference(sdata->u.ap.beacon, sdata))
536 __ieee80211_request_smps_ap(sdata,
537 sdata->u.ap.driver_smps_mode);
538 sdata_unlock(sdata);
541 void ieee80211_request_smps(struct ieee80211_vif *vif,
542 enum ieee80211_smps_mode smps_mode)
544 struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
546 if (WARN_ON_ONCE(vif->type != NL80211_IFTYPE_STATION &&
547 vif->type != NL80211_IFTYPE_AP))
548 return;
550 if (vif->type == NL80211_IFTYPE_STATION) {
551 if (sdata->u.mgd.driver_smps_mode == smps_mode)
552 return;
553 sdata->u.mgd.driver_smps_mode = smps_mode;
554 ieee80211_queue_work(&sdata->local->hw,
555 &sdata->u.mgd.request_smps_work);
556 } else {
557 /* AUTOMATIC is meaningless in AP mode */
558 if (WARN_ON_ONCE(smps_mode == IEEE80211_SMPS_AUTOMATIC))
559 return;
560 if (sdata->u.ap.driver_smps_mode == smps_mode)
561 return;
562 sdata->u.ap.driver_smps_mode = smps_mode;
563 ieee80211_queue_work(&sdata->local->hw,
564 &sdata->u.ap.request_smps_work);
567 /* this might change ... don't want non-open drivers using it */
568 EXPORT_SYMBOL_GPL(ieee80211_request_smps);