1 /*
2 * HT handling
3 *
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 *
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License version 2 as
13 * published by the Free Software Foundation.
14 */
15
16 #include <linux/ieee80211.h>
17 #include <linux/export.h>
18 #include <net/mac80211.h>
19 #include "ieee80211_i.h"
20 #include "rate.h"
21
__check_htcap_disable(struct ieee80211_ht_cap * ht_capa,struct ieee80211_ht_cap * ht_capa_mask,struct ieee80211_sta_ht_cap * ht_cap,u16 flag)22 static void __check_htcap_disable(struct ieee80211_ht_cap *ht_capa,
23 struct ieee80211_ht_cap *ht_capa_mask,
24 struct ieee80211_sta_ht_cap *ht_cap,
25 u16 flag)
26 {
27 __le16 le_flag = cpu_to_le16(flag);
28 if (ht_capa_mask->cap_info & le_flag) {
29 if (!(ht_capa->cap_info & le_flag))
30 ht_cap->cap &= ~flag;
31 }
32 }
33
__check_htcap_enable(struct ieee80211_ht_cap * ht_capa,struct ieee80211_ht_cap * ht_capa_mask,struct ieee80211_sta_ht_cap * ht_cap,u16 flag)34 static void __check_htcap_enable(struct ieee80211_ht_cap *ht_capa,
35 struct ieee80211_ht_cap *ht_capa_mask,
36 struct ieee80211_sta_ht_cap *ht_cap,
37 u16 flag)
38 {
39 __le16 le_flag = cpu_to_le16(flag);
40
41 if ((ht_capa_mask->cap_info & le_flag) &&
42 (ht_capa->cap_info & le_flag))
43 ht_cap->cap |= flag;
44 }
45
ieee80211_apply_htcap_overrides(struct ieee80211_sub_if_data * sdata,struct ieee80211_sta_ht_cap * ht_cap)46 void ieee80211_apply_htcap_overrides(struct ieee80211_sub_if_data *sdata,
47 struct ieee80211_sta_ht_cap *ht_cap)
48 {
49 struct ieee80211_ht_cap *ht_capa, *ht_capa_mask;
50 u8 *scaps, *smask;
51 int i;
52
53 if (!ht_cap->ht_supported)
54 return;
55
56 switch (sdata->vif.type) {
57 case NL80211_IFTYPE_STATION:
58 ht_capa = &sdata->u.mgd.ht_capa;
59 ht_capa_mask = &sdata->u.mgd.ht_capa_mask;
60 break;
61 case NL80211_IFTYPE_ADHOC:
62 ht_capa = &sdata->u.ibss.ht_capa;
63 ht_capa_mask = &sdata->u.ibss.ht_capa_mask;
64 break;
65 default:
66 WARN_ON_ONCE(1);
67 return;
68 }
69
70 scaps = (u8 *)(&ht_capa->mcs.rx_mask);
71 smask = (u8 *)(&ht_capa_mask->mcs.rx_mask);
72
73 /* NOTE: If you add more over-rides here, update register_hw
74 * ht_capa_mod_mask logic in main.c as well.
75 * And, if this method can ever change ht_cap.ht_supported, fix
76 * the check in ieee80211_add_ht_ie.
77 */
78
79 /* check for HT over-rides, MCS rates first. */
80 for (i = 0; i < IEEE80211_HT_MCS_MASK_LEN; i++) {
81 u8 m = smask[i];
82 ht_cap->mcs.rx_mask[i] &= ~m; /* turn off all masked bits */
83 /* Add back rates that are supported */
84 ht_cap->mcs.rx_mask[i] |= (m & scaps[i]);
85 }
86
87 /* Force removal of HT-40 capabilities? */
88 __check_htcap_disable(ht_capa, ht_capa_mask, ht_cap,
89 IEEE80211_HT_CAP_SUP_WIDTH_20_40);
90 __check_htcap_disable(ht_capa, ht_capa_mask, ht_cap,
91 IEEE80211_HT_CAP_SGI_40);
92
93 /* Allow user to disable SGI-20 (SGI-40 is handled above) */
94 __check_htcap_disable(ht_capa, ht_capa_mask, ht_cap,
95 IEEE80211_HT_CAP_SGI_20);
96
97 /* Allow user to disable the max-AMSDU bit. */
98 __check_htcap_disable(ht_capa, ht_capa_mask, ht_cap,
99 IEEE80211_HT_CAP_MAX_AMSDU);
100
101 /* Allow user to disable LDPC */
102 __check_htcap_disable(ht_capa, ht_capa_mask, ht_cap,
103 IEEE80211_HT_CAP_LDPC_CODING);
104
105 /* Allow user to enable 40 MHz intolerant bit. */
106 __check_htcap_enable(ht_capa, ht_capa_mask, ht_cap,
107 IEEE80211_HT_CAP_40MHZ_INTOLERANT);
108
109 /* Allow user to decrease AMPDU factor */
110 if (ht_capa_mask->ampdu_params_info &
111 IEEE80211_HT_AMPDU_PARM_FACTOR) {
112 u8 n = ht_capa->ampdu_params_info &
113 IEEE80211_HT_AMPDU_PARM_FACTOR;
114 if (n < ht_cap->ampdu_factor)
115 ht_cap->ampdu_factor = n;
116 }
117
118 /* Allow the user to increase AMPDU density. */
119 if (ht_capa_mask->ampdu_params_info &
120 IEEE80211_HT_AMPDU_PARM_DENSITY) {
121 u8 n = (ht_capa->ampdu_params_info &
122 IEEE80211_HT_AMPDU_PARM_DENSITY)
123 >> IEEE80211_HT_AMPDU_PARM_DENSITY_SHIFT;
124 if (n > ht_cap->ampdu_density)
125 ht_cap->ampdu_density = n;
126 }
127 }
128
129
ieee80211_ht_cap_ie_to_sta_ht_cap(struct ieee80211_sub_if_data * sdata,struct ieee80211_supported_band * sband,const struct ieee80211_ht_cap * ht_cap_ie,struct sta_info * sta)130 bool ieee80211_ht_cap_ie_to_sta_ht_cap(struct ieee80211_sub_if_data *sdata,
131 struct ieee80211_supported_band *sband,
132 const struct ieee80211_ht_cap *ht_cap_ie,
133 struct sta_info *sta)
134 {
135 struct ieee80211_sta_ht_cap ht_cap, own_cap;
136 u8 ampdu_info, tx_mcs_set_cap;
137 int i, max_tx_streams;
138 bool changed;
139 enum ieee80211_sta_rx_bandwidth bw;
140 enum ieee80211_smps_mode smps_mode;
141
142 memset(&ht_cap, 0, sizeof(ht_cap));
143
144 if (!ht_cap_ie || !sband->ht_cap.ht_supported)
145 goto apply;
146
147 ht_cap.ht_supported = true;
148
149 own_cap = sband->ht_cap;
150
151 /*
152 * If user has specified capability over-rides, take care
153 * of that if the station we're setting up is the AP or TDLS peer that
154 * we advertised a restricted capability set to. Override
155 * our own capabilities and then use those below.
156 */
157 if (sdata->vif.type == NL80211_IFTYPE_STATION ||
158 sdata->vif.type == NL80211_IFTYPE_ADHOC)
159 ieee80211_apply_htcap_overrides(sdata, &own_cap);
160
161 /*
162 * The bits listed in this expression should be
163 * the same for the peer and us, if the station
164 * advertises more then we can't use those thus
165 * we mask them out.
166 */
167 ht_cap.cap = le16_to_cpu(ht_cap_ie->cap_info) &
168 (own_cap.cap | ~(IEEE80211_HT_CAP_LDPC_CODING |
169 IEEE80211_HT_CAP_SUP_WIDTH_20_40 |
170 IEEE80211_HT_CAP_GRN_FLD |
171 IEEE80211_HT_CAP_SGI_20 |
172 IEEE80211_HT_CAP_SGI_40 |
173 IEEE80211_HT_CAP_DSSSCCK40));
174
175 /*
176 * The STBC bits are asymmetric -- if we don't have
177 * TX then mask out the peer's RX and vice versa.
178 */
179 if (!(own_cap.cap & IEEE80211_HT_CAP_TX_STBC))
180 ht_cap.cap &= ~IEEE80211_HT_CAP_RX_STBC;
181 if (!(own_cap.cap & IEEE80211_HT_CAP_RX_STBC))
182 ht_cap.cap &= ~IEEE80211_HT_CAP_TX_STBC;
183
184 ampdu_info = ht_cap_ie->ampdu_params_info;
185 ht_cap.ampdu_factor =
186 ampdu_info & IEEE80211_HT_AMPDU_PARM_FACTOR;
187 ht_cap.ampdu_density =
188 (ampdu_info & IEEE80211_HT_AMPDU_PARM_DENSITY) >> 2;
189
190 /* own MCS TX capabilities */
191 tx_mcs_set_cap = own_cap.mcs.tx_params;
192
193 /* Copy peer MCS TX capabilities, the driver might need them. */
194 ht_cap.mcs.tx_params = ht_cap_ie->mcs.tx_params;
195
196 /* can we TX with MCS rates? */
197 if (!(tx_mcs_set_cap & IEEE80211_HT_MCS_TX_DEFINED))
198 goto apply;
199
200 /* Counting from 0, therefore +1 */
201 if (tx_mcs_set_cap & IEEE80211_HT_MCS_TX_RX_DIFF)
202 max_tx_streams =
203 ((tx_mcs_set_cap & IEEE80211_HT_MCS_TX_MAX_STREAMS_MASK)
204 >> IEEE80211_HT_MCS_TX_MAX_STREAMS_SHIFT) + 1;
205 else
206 max_tx_streams = IEEE80211_HT_MCS_TX_MAX_STREAMS;
207
208 /*
209 * 802.11n-2009 20.3.5 / 20.6 says:
210 * - indices 0 to 7 and 32 are single spatial stream
211 * - 8 to 31 are multiple spatial streams using equal modulation
212 * [8..15 for two streams, 16..23 for three and 24..31 for four]
213 * - remainder are multiple spatial streams using unequal modulation
214 */
215 for (i = 0; i < max_tx_streams; i++)
216 ht_cap.mcs.rx_mask[i] =
217 own_cap.mcs.rx_mask[i] & ht_cap_ie->mcs.rx_mask[i];
218
219 if (tx_mcs_set_cap & IEEE80211_HT_MCS_TX_UNEQUAL_MODULATION)
220 for (i = IEEE80211_HT_MCS_UNEQUAL_MODULATION_START_BYTE;
221 i < IEEE80211_HT_MCS_MASK_LEN; i++)
222 ht_cap.mcs.rx_mask[i] =
223 own_cap.mcs.rx_mask[i] &
224 ht_cap_ie->mcs.rx_mask[i];
225
226 /* handle MCS rate 32 too */
227 if (own_cap.mcs.rx_mask[32/8] & ht_cap_ie->mcs.rx_mask[32/8] & 1)
228 ht_cap.mcs.rx_mask[32/8] |= 1;
229
230 /* set Rx highest rate */
231 ht_cap.mcs.rx_highest = ht_cap_ie->mcs.rx_highest;
232
233 apply:
234 changed = memcmp(&sta->sta.ht_cap, &ht_cap, sizeof(ht_cap));
235
236 memcpy(&sta->sta.ht_cap, &ht_cap, sizeof(ht_cap));
237
238 switch (sdata->vif.bss_conf.chandef.width) {
239 default:
240 WARN_ON_ONCE(1);
241 /* fall through */
242 case NL80211_CHAN_WIDTH_20_NOHT:
243 case NL80211_CHAN_WIDTH_20:
244 bw = IEEE80211_STA_RX_BW_20;
245 break;
246 case NL80211_CHAN_WIDTH_40:
247 case NL80211_CHAN_WIDTH_80:
248 case NL80211_CHAN_WIDTH_80P80:
249 case NL80211_CHAN_WIDTH_160:
250 bw = ht_cap.cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40 ?
251 IEEE80211_STA_RX_BW_40 : IEEE80211_STA_RX_BW_20;
252 break;
253 }
254
255 if (bw != sta->sta.bandwidth)
256 changed = true;
257 sta->sta.bandwidth = bw;
258
259 sta->cur_max_bandwidth =
260 ht_cap.cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40 ?
261 IEEE80211_STA_RX_BW_40 : IEEE80211_STA_RX_BW_20;
262
263 switch ((ht_cap.cap & IEEE80211_HT_CAP_SM_PS)
264 >> IEEE80211_HT_CAP_SM_PS_SHIFT) {
265 case WLAN_HT_CAP_SM_PS_INVALID:
266 case WLAN_HT_CAP_SM_PS_STATIC:
267 smps_mode = IEEE80211_SMPS_STATIC;
268 break;
269 case WLAN_HT_CAP_SM_PS_DYNAMIC:
270 smps_mode = IEEE80211_SMPS_DYNAMIC;
271 break;
272 case WLAN_HT_CAP_SM_PS_DISABLED:
273 smps_mode = IEEE80211_SMPS_OFF;
274 break;
275 }
276
277 if (smps_mode != sta->sta.smps_mode)
278 changed = true;
279 sta->sta.smps_mode = smps_mode;
280
281 return changed;
282 }
283
ieee80211_sta_tear_down_BA_sessions(struct sta_info * sta,enum ieee80211_agg_stop_reason reason)284 void ieee80211_sta_tear_down_BA_sessions(struct sta_info *sta,
285 enum ieee80211_agg_stop_reason reason)
286 {
287 int i;
288
289 cancel_work_sync(&sta->ampdu_mlme.work);
290
291 for (i = 0; i < IEEE80211_NUM_TIDS; i++) {
292 __ieee80211_stop_tx_ba_session(sta, i, reason);
293 __ieee80211_stop_rx_ba_session(sta, i, WLAN_BACK_RECIPIENT,
294 WLAN_REASON_QSTA_LEAVE_QBSS,
295 reason != AGG_STOP_DESTROY_STA &&
296 reason != AGG_STOP_PEER_REQUEST);
297 }
298 }
299
ieee80211_ba_session_work(struct work_struct * work)300 void ieee80211_ba_session_work(struct work_struct *work)
301 {
302 struct sta_info *sta =
303 container_of(work, struct sta_info, ampdu_mlme.work);
304 struct tid_ampdu_tx *tid_tx;
305 int tid;
306
307 /*
308 * When this flag is set, new sessions should be
309 * blocked, and existing sessions will be torn
310 * down by the code that set the flag, so this
311 * need not run.
312 */
313 if (test_sta_flag(sta, WLAN_STA_BLOCK_BA))
314 return;
315
316 mutex_lock(&sta->ampdu_mlme.mtx);
317 for (tid = 0; tid < IEEE80211_NUM_TIDS; tid++) {
318 if (test_and_clear_bit(tid, sta->ampdu_mlme.tid_rx_timer_expired))
319 ___ieee80211_stop_rx_ba_session(
320 sta, tid, WLAN_BACK_RECIPIENT,
321 WLAN_REASON_QSTA_TIMEOUT, true);
322
323 if (test_and_clear_bit(tid,
324 sta->ampdu_mlme.tid_rx_stop_requested))
325 ___ieee80211_stop_rx_ba_session(
326 sta, tid, WLAN_BACK_RECIPIENT,
327 WLAN_REASON_UNSPECIFIED, true);
328
329 spin_lock_bh(&sta->lock);
330
331 tid_tx = sta->ampdu_mlme.tid_start_tx[tid];
332 if (tid_tx) {
333 /*
334 * Assign it over to the normal tid_tx array
335 * where it "goes live".
336 */
337
338 sta->ampdu_mlme.tid_start_tx[tid] = NULL;
339 /* could there be a race? */
340 if (sta->ampdu_mlme.tid_tx[tid])
341 kfree(tid_tx);
342 else
343 ieee80211_assign_tid_tx(sta, tid, tid_tx);
344 spin_unlock_bh(&sta->lock);
345
346 ieee80211_tx_ba_session_handle_start(sta, tid);
347 continue;
348 }
349 spin_unlock_bh(&sta->lock);
350
351 tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
352 if (tid_tx && test_and_clear_bit(HT_AGG_STATE_WANT_STOP,
353 &tid_tx->state))
354 ___ieee80211_stop_tx_ba_session(sta, tid,
355 AGG_STOP_LOCAL_REQUEST);
356 }
357 mutex_unlock(&sta->ampdu_mlme.mtx);
358 }
359
ieee80211_send_delba(struct ieee80211_sub_if_data * sdata,const u8 * da,u16 tid,u16 initiator,u16 reason_code)360 void ieee80211_send_delba(struct ieee80211_sub_if_data *sdata,
361 const u8 *da, u16 tid,
362 u16 initiator, u16 reason_code)
363 {
364 struct ieee80211_local *local = sdata->local;
365 struct sk_buff *skb;
366 struct ieee80211_mgmt *mgmt;
367 u16 params;
368
369 skb = dev_alloc_skb(sizeof(*mgmt) + local->hw.extra_tx_headroom);
370 if (!skb)
371 return;
372
373 skb_reserve(skb, local->hw.extra_tx_headroom);
374 mgmt = (struct ieee80211_mgmt *) skb_put(skb, 24);
375 memset(mgmt, 0, 24);
376 memcpy(mgmt->da, da, ETH_ALEN);
377 memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
378 if (sdata->vif.type == NL80211_IFTYPE_AP ||
379 sdata->vif.type == NL80211_IFTYPE_AP_VLAN ||
380 sdata->vif.type == NL80211_IFTYPE_MESH_POINT)
381 memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
382 else if (sdata->vif.type == NL80211_IFTYPE_STATION)
383 memcpy(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN);
384 else if (sdata->vif.type == NL80211_IFTYPE_ADHOC)
385 memcpy(mgmt->bssid, sdata->u.ibss.bssid, ETH_ALEN);
386
387 mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
388 IEEE80211_STYPE_ACTION);
389
390 skb_put(skb, 1 + sizeof(mgmt->u.action.u.delba));
391
392 mgmt->u.action.category = WLAN_CATEGORY_BACK;
393 mgmt->u.action.u.delba.action_code = WLAN_ACTION_DELBA;
394 params = (u16)(initiator << 11); /* bit 11 initiator */
395 params |= (u16)(tid << 12); /* bit 15:12 TID number */
396
397 mgmt->u.action.u.delba.params = cpu_to_le16(params);
398 mgmt->u.action.u.delba.reason_code = cpu_to_le16(reason_code);
399
400 ieee80211_tx_skb(sdata, skb);
401 }
402
ieee80211_process_delba(struct ieee80211_sub_if_data * sdata,struct sta_info * sta,struct ieee80211_mgmt * mgmt,size_t len)403 void ieee80211_process_delba(struct ieee80211_sub_if_data *sdata,
404 struct sta_info *sta,
405 struct ieee80211_mgmt *mgmt, size_t len)
406 {
407 u16 tid, params;
408 u16 initiator;
409
410 params = le16_to_cpu(mgmt->u.action.u.delba.params);
411 tid = (params & IEEE80211_DELBA_PARAM_TID_MASK) >> 12;
412 initiator = (params & IEEE80211_DELBA_PARAM_INITIATOR_MASK) >> 11;
413
414 ht_dbg_ratelimited(sdata, "delba from %pM (%s) tid %d reason code %d\n",
415 mgmt->sa, initiator ? "initiator" : "recipient",
416 tid,
417 le16_to_cpu(mgmt->u.action.u.delba.reason_code));
418
419 if (initiator == WLAN_BACK_INITIATOR)
420 __ieee80211_stop_rx_ba_session(sta, tid, WLAN_BACK_INITIATOR, 0,
421 true);
422 else
423 __ieee80211_stop_tx_ba_session(sta, tid, AGG_STOP_PEER_REQUEST);
424 }
425
ieee80211_send_smps_action(struct ieee80211_sub_if_data * sdata,enum ieee80211_smps_mode smps,const u8 * da,const u8 * bssid)426 int ieee80211_send_smps_action(struct ieee80211_sub_if_data *sdata,
427 enum ieee80211_smps_mode smps, const u8 *da,
428 const u8 *bssid)
429 {
430 struct ieee80211_local *local = sdata->local;
431 struct sk_buff *skb;
432 struct ieee80211_mgmt *action_frame;
433
434 /* 27 = header + category + action + smps mode */
435 skb = dev_alloc_skb(27 + local->hw.extra_tx_headroom);
436 if (!skb)
437 return -ENOMEM;
438
439 skb_reserve(skb, local->hw.extra_tx_headroom);
440 action_frame = (void *)skb_put(skb, 27);
441 memcpy(action_frame->da, da, ETH_ALEN);
442 memcpy(action_frame->sa, sdata->dev->dev_addr, ETH_ALEN);
443 memcpy(action_frame->bssid, bssid, ETH_ALEN);
444 action_frame->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
445 IEEE80211_STYPE_ACTION);
446 action_frame->u.action.category = WLAN_CATEGORY_HT;
447 action_frame->u.action.u.ht_smps.action = WLAN_HT_ACTION_SMPS;
448 switch (smps) {
449 case IEEE80211_SMPS_AUTOMATIC:
450 case IEEE80211_SMPS_NUM_MODES:
451 WARN_ON(1);
452 case IEEE80211_SMPS_OFF:
453 action_frame->u.action.u.ht_smps.smps_control =
454 WLAN_HT_SMPS_CONTROL_DISABLED;
455 break;
456 case IEEE80211_SMPS_STATIC:
457 action_frame->u.action.u.ht_smps.smps_control =
458 WLAN_HT_SMPS_CONTROL_STATIC;
459 break;
460 case IEEE80211_SMPS_DYNAMIC:
461 action_frame->u.action.u.ht_smps.smps_control =
462 WLAN_HT_SMPS_CONTROL_DYNAMIC;
463 break;
464 }
465
466 /* we'll do more on status of this frame */
467 IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_CTL_REQ_TX_STATUS;
468 ieee80211_tx_skb(sdata, skb);
469
470 return 0;
471 }
472
ieee80211_request_smps_mgd_work(struct work_struct * work)473 void ieee80211_request_smps_mgd_work(struct work_struct *work)
474 {
475 struct ieee80211_sub_if_data *sdata =
476 container_of(work, struct ieee80211_sub_if_data,
477 u.mgd.request_smps_work);
478
479 sdata_lock(sdata);
480 __ieee80211_request_smps_mgd(sdata, sdata->u.mgd.driver_smps_mode);
481 sdata_unlock(sdata);
482 }
483
ieee80211_request_smps_ap_work(struct work_struct * work)484 void ieee80211_request_smps_ap_work(struct work_struct *work)
485 {
486 struct ieee80211_sub_if_data *sdata =
487 container_of(work, struct ieee80211_sub_if_data,
488 u.ap.request_smps_work);
489
490 sdata_lock(sdata);
491 if (sdata_dereference(sdata->u.ap.beacon, sdata))
492 __ieee80211_request_smps_ap(sdata,
493 sdata->u.ap.driver_smps_mode);
494 sdata_unlock(sdata);
495 }
496
ieee80211_request_smps(struct ieee80211_vif * vif,enum ieee80211_smps_mode smps_mode)497 void ieee80211_request_smps(struct ieee80211_vif *vif,
498 enum ieee80211_smps_mode smps_mode)
499 {
500 struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
501
502 if (WARN_ON_ONCE(vif->type != NL80211_IFTYPE_STATION &&
503 vif->type != NL80211_IFTYPE_AP))
504 return;
505
506 if (vif->type == NL80211_IFTYPE_STATION) {
507 if (sdata->u.mgd.driver_smps_mode == smps_mode)
508 return;
509 sdata->u.mgd.driver_smps_mode = smps_mode;
510 ieee80211_queue_work(&sdata->local->hw,
511 &sdata->u.mgd.request_smps_work);
512 } else {
513 /* AUTOMATIC is meaningless in AP mode */
514 if (WARN_ON_ONCE(smps_mode == IEEE80211_SMPS_AUTOMATIC))
515 return;
516 if (sdata->u.ap.driver_smps_mode == smps_mode)
517 return;
518 sdata->u.ap.driver_smps_mode = smps_mode;
519 ieee80211_queue_work(&sdata->local->hw,
520 &sdata->u.ap.request_smps_work);
521 }
522 }
523 /* this might change ... don't want non-open drivers using it */
524 EXPORT_SYMBOL_GPL(ieee80211_request_smps);
525