xref: /openbmc/linux/net/mac80211/mesh_ps.c (revision afc98d90)
1 /*
2  * Copyright 2012-2013, Marco Porsch <marco.porsch@s2005.tu-chemnitz.de>
3  * Copyright 2012-2013, cozybit Inc.
4  *
5  * This program is free software; you can redistribute it and/or modify
6  * it under the terms of the GNU General Public License version 2 as
7  * published by the Free Software Foundation.
8  */
9 
10 #include "mesh.h"
11 #include "wme.h"
12 
13 
14 /* mesh PS management */
15 
16 /**
17  * mps_qos_null_get - create pre-addressed QoS Null frame for mesh powersave
18  */
19 static struct sk_buff *mps_qos_null_get(struct sta_info *sta)
20 {
21 	struct ieee80211_sub_if_data *sdata = sta->sdata;
22 	struct ieee80211_local *local = sdata->local;
23 	struct ieee80211_hdr *nullfunc; /* use 4addr header */
24 	struct sk_buff *skb;
25 	int size = sizeof(*nullfunc);
26 	__le16 fc;
27 
28 	skb = dev_alloc_skb(local->hw.extra_tx_headroom + size + 2);
29 	if (!skb)
30 		return NULL;
31 	skb_reserve(skb, local->hw.extra_tx_headroom);
32 
33 	nullfunc = (struct ieee80211_hdr *) skb_put(skb, size);
34 	fc = cpu_to_le16(IEEE80211_FTYPE_DATA | IEEE80211_STYPE_QOS_NULLFUNC);
35 	ieee80211_fill_mesh_addresses(nullfunc, &fc, sta->sta.addr,
36 				      sdata->vif.addr);
37 	nullfunc->frame_control = fc;
38 	nullfunc->duration_id = 0;
39 	/* no address resolution for this frame -> set addr 1 immediately */
40 	memcpy(nullfunc->addr1, sta->sta.addr, ETH_ALEN);
41 	memset(skb_put(skb, 2), 0, 2); /* append QoS control field */
42 	ieee80211_mps_set_frame_flags(sdata, sta, nullfunc);
43 
44 	return skb;
45 }
46 
47 /**
48  * mps_qos_null_tx - send a QoS Null to indicate link-specific power mode
49  */
50 static void mps_qos_null_tx(struct sta_info *sta)
51 {
52 	struct sk_buff *skb;
53 
54 	skb = mps_qos_null_get(sta);
55 	if (!skb)
56 		return;
57 
58 	mps_dbg(sta->sdata, "announcing peer-specific power mode to %pM\n",
59 		sta->sta.addr);
60 
61 	/* don't unintentionally start a MPSP */
62 	if (!test_sta_flag(sta, WLAN_STA_PS_STA)) {
63 		u8 *qc = ieee80211_get_qos_ctl((void *) skb->data);
64 
65 		qc[0] |= IEEE80211_QOS_CTL_EOSP;
66 	}
67 
68 	ieee80211_tx_skb(sta->sdata, skb);
69 }
70 
71 /**
72  * ieee80211_mps_local_status_update - track status of local link-specific PMs
73  *
74  * @sdata: local mesh subif
75  *
76  * sets the non-peer power mode and triggers the driver PS (re-)configuration
77  * Return BSS_CHANGED_BEACON if a beacon update is necessary.
78  */
79 u32 ieee80211_mps_local_status_update(struct ieee80211_sub_if_data *sdata)
80 {
81 	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
82 	struct sta_info *sta;
83 	bool peering = false;
84 	int light_sleep_cnt = 0;
85 	int deep_sleep_cnt = 0;
86 	u32 changed = 0;
87 	enum nl80211_mesh_power_mode nonpeer_pm;
88 
89 	rcu_read_lock();
90 	list_for_each_entry_rcu(sta, &sdata->local->sta_list, list) {
91 		if (sdata != sta->sdata)
92 			continue;
93 
94 		switch (sta->plink_state) {
95 		case NL80211_PLINK_OPN_SNT:
96 		case NL80211_PLINK_OPN_RCVD:
97 		case NL80211_PLINK_CNF_RCVD:
98 			peering = true;
99 			break;
100 		case NL80211_PLINK_ESTAB:
101 			if (sta->local_pm == NL80211_MESH_POWER_LIGHT_SLEEP)
102 				light_sleep_cnt++;
103 			else if (sta->local_pm == NL80211_MESH_POWER_DEEP_SLEEP)
104 				deep_sleep_cnt++;
105 			break;
106 		default:
107 			break;
108 		}
109 	}
110 	rcu_read_unlock();
111 
112 	/*
113 	 * Set non-peer mode to active during peering/scanning/authentication
114 	 * (see IEEE802.11-2012 13.14.8.3). The non-peer mesh power mode is
115 	 * deep sleep if the local STA is in light or deep sleep towards at
116 	 * least one mesh peer (see 13.14.3.1). Otherwise, set it to the
117 	 * user-configured default value.
118 	 */
119 	if (peering) {
120 		mps_dbg(sdata, "setting non-peer PM to active for peering\n");
121 		nonpeer_pm = NL80211_MESH_POWER_ACTIVE;
122 	} else if (light_sleep_cnt || deep_sleep_cnt) {
123 		mps_dbg(sdata, "setting non-peer PM to deep sleep\n");
124 		nonpeer_pm = NL80211_MESH_POWER_DEEP_SLEEP;
125 	} else {
126 		mps_dbg(sdata, "setting non-peer PM to user value\n");
127 		nonpeer_pm = ifmsh->mshcfg.power_mode;
128 	}
129 
130 	/* need update if sleep counts move between 0 and non-zero */
131 	if (ifmsh->nonpeer_pm != nonpeer_pm ||
132 	    !ifmsh->ps_peers_light_sleep != !light_sleep_cnt ||
133 	    !ifmsh->ps_peers_deep_sleep != !deep_sleep_cnt)
134 		changed = BSS_CHANGED_BEACON;
135 
136 	ifmsh->nonpeer_pm = nonpeer_pm;
137 	ifmsh->ps_peers_light_sleep = light_sleep_cnt;
138 	ifmsh->ps_peers_deep_sleep = deep_sleep_cnt;
139 
140 	return changed;
141 }
142 
143 /**
144  * ieee80211_mps_set_sta_local_pm - set local PM towards a mesh STA
145  *
146  * @sta: mesh STA
147  * @pm: the power mode to set
148  * Return BSS_CHANGED_BEACON if a beacon update is in order.
149  */
150 u32 ieee80211_mps_set_sta_local_pm(struct sta_info *sta,
151 				   enum nl80211_mesh_power_mode pm)
152 {
153 	struct ieee80211_sub_if_data *sdata = sta->sdata;
154 
155 	if (sta->local_pm == pm)
156 		return 0;
157 
158 	mps_dbg(sdata, "local STA operates in mode %d with %pM\n",
159 		pm, sta->sta.addr);
160 
161 	sta->local_pm = pm;
162 
163 	/*
164 	 * announce peer-specific power mode transition
165 	 * (see IEEE802.11-2012 13.14.3.2 and 13.14.3.3)
166 	 */
167 	if (sta->plink_state == NL80211_PLINK_ESTAB)
168 		mps_qos_null_tx(sta);
169 
170 	return ieee80211_mps_local_status_update(sdata);
171 }
172 
173 /**
174  * ieee80211_mps_set_frame_flags - set mesh PS flags in FC (and QoS Control)
175  *
176  * @sdata: local mesh subif
177  * @sta: mesh STA
178  * @hdr: 802.11 frame header
179  *
180  * see IEEE802.11-2012 8.2.4.1.7 and 8.2.4.5.11
181  *
182  * NOTE: sta must be given when an individually-addressed QoS frame header
183  * is handled, for group-addressed and management frames it is not used
184  */
185 void ieee80211_mps_set_frame_flags(struct ieee80211_sub_if_data *sdata,
186 				   struct sta_info *sta,
187 				   struct ieee80211_hdr *hdr)
188 {
189 	enum nl80211_mesh_power_mode pm;
190 	u8 *qc;
191 
192 	if (WARN_ON(is_unicast_ether_addr(hdr->addr1) &&
193 		    ieee80211_is_data_qos(hdr->frame_control) &&
194 		    !sta))
195 		return;
196 
197 	if (is_unicast_ether_addr(hdr->addr1) &&
198 	    ieee80211_is_data_qos(hdr->frame_control) &&
199 	    sta->plink_state == NL80211_PLINK_ESTAB)
200 		pm = sta->local_pm;
201 	else
202 		pm = sdata->u.mesh.nonpeer_pm;
203 
204 	if (pm == NL80211_MESH_POWER_ACTIVE)
205 		hdr->frame_control &= cpu_to_le16(~IEEE80211_FCTL_PM);
206 	else
207 		hdr->frame_control |= cpu_to_le16(IEEE80211_FCTL_PM);
208 
209 	if (!ieee80211_is_data_qos(hdr->frame_control))
210 		return;
211 
212 	qc = ieee80211_get_qos_ctl(hdr);
213 
214 	if ((is_unicast_ether_addr(hdr->addr1) &&
215 	     pm == NL80211_MESH_POWER_DEEP_SLEEP) ||
216 	    (is_multicast_ether_addr(hdr->addr1) &&
217 	     sdata->u.mesh.ps_peers_deep_sleep > 0))
218 		qc[1] |= (IEEE80211_QOS_CTL_MESH_PS_LEVEL >> 8);
219 	else
220 		qc[1] &= ~(IEEE80211_QOS_CTL_MESH_PS_LEVEL >> 8);
221 }
222 
223 /**
224  * ieee80211_mps_sta_status_update - update buffering status of neighbor STA
225  *
226  * @sta: mesh STA
227  *
228  * called after change of peering status or non-peer/peer-specific power mode
229  */
230 void ieee80211_mps_sta_status_update(struct sta_info *sta)
231 {
232 	enum nl80211_mesh_power_mode pm;
233 	bool do_buffer;
234 
235 	/* For non-assoc STA, prevent buffering or frame transmission */
236 	if (sta->sta_state < IEEE80211_STA_ASSOC)
237 		return;
238 
239 	/*
240 	 * use peer-specific power mode if peering is established and the
241 	 * peer's power mode is known
242 	 */
243 	if (sta->plink_state == NL80211_PLINK_ESTAB &&
244 	    sta->peer_pm != NL80211_MESH_POWER_UNKNOWN)
245 		pm = sta->peer_pm;
246 	else
247 		pm = sta->nonpeer_pm;
248 
249 	do_buffer = (pm != NL80211_MESH_POWER_ACTIVE);
250 
251 	/* clear the MPSP flags for non-peers or active STA */
252 	if (sta->plink_state != NL80211_PLINK_ESTAB) {
253 		clear_sta_flag(sta, WLAN_STA_MPSP_OWNER);
254 		clear_sta_flag(sta, WLAN_STA_MPSP_RECIPIENT);
255 	} else if (!do_buffer) {
256 		clear_sta_flag(sta, WLAN_STA_MPSP_OWNER);
257 	}
258 
259 	/* Don't let the same PS state be set twice */
260 	if (test_sta_flag(sta, WLAN_STA_PS_STA) == do_buffer)
261 		return;
262 
263 	if (do_buffer) {
264 		set_sta_flag(sta, WLAN_STA_PS_STA);
265 		atomic_inc(&sta->sdata->u.mesh.ps.num_sta_ps);
266 		mps_dbg(sta->sdata, "start PS buffering frames towards %pM\n",
267 			sta->sta.addr);
268 	} else {
269 		ieee80211_sta_ps_deliver_wakeup(sta);
270 	}
271 }
272 
273 static void mps_set_sta_peer_pm(struct sta_info *sta,
274 				struct ieee80211_hdr *hdr)
275 {
276 	enum nl80211_mesh_power_mode pm;
277 	u8 *qc = ieee80211_get_qos_ctl(hdr);
278 
279 	/*
280 	 * Test Power Management field of frame control (PW) and
281 	 * mesh power save level subfield of QoS control field (PSL)
282 	 *
283 	 * | PM | PSL| Mesh PM |
284 	 * +----+----+---------+
285 	 * | 0  |Rsrv|  Active |
286 	 * | 1  | 0  |  Light  |
287 	 * | 1  | 1  |  Deep   |
288 	 */
289 	if (ieee80211_has_pm(hdr->frame_control)) {
290 		if (qc[1] & (IEEE80211_QOS_CTL_MESH_PS_LEVEL >> 8))
291 			pm = NL80211_MESH_POWER_DEEP_SLEEP;
292 		else
293 			pm = NL80211_MESH_POWER_LIGHT_SLEEP;
294 	} else {
295 		pm = NL80211_MESH_POWER_ACTIVE;
296 	}
297 
298 	if (sta->peer_pm == pm)
299 		return;
300 
301 	mps_dbg(sta->sdata, "STA %pM enters mode %d\n",
302 		sta->sta.addr, pm);
303 
304 	sta->peer_pm = pm;
305 
306 	ieee80211_mps_sta_status_update(sta);
307 }
308 
309 static void mps_set_sta_nonpeer_pm(struct sta_info *sta,
310 				   struct ieee80211_hdr *hdr)
311 {
312 	enum nl80211_mesh_power_mode pm;
313 
314 	if (ieee80211_has_pm(hdr->frame_control))
315 		pm = NL80211_MESH_POWER_DEEP_SLEEP;
316 	else
317 		pm = NL80211_MESH_POWER_ACTIVE;
318 
319 	if (sta->nonpeer_pm == pm)
320 		return;
321 
322 	mps_dbg(sta->sdata, "STA %pM sets non-peer mode to %d\n",
323 		sta->sta.addr, pm);
324 
325 	sta->nonpeer_pm = pm;
326 
327 	ieee80211_mps_sta_status_update(sta);
328 }
329 
330 /**
331  * ieee80211_mps_rx_h_sta_process - frame receive handler for mesh powersave
332  *
333  * @sta: STA info that transmitted the frame
334  * @hdr: IEEE 802.11 (QoS) Header
335  */
336 void ieee80211_mps_rx_h_sta_process(struct sta_info *sta,
337 				    struct ieee80211_hdr *hdr)
338 {
339 	if (is_unicast_ether_addr(hdr->addr1) &&
340 	    ieee80211_is_data_qos(hdr->frame_control)) {
341 		/*
342 		 * individually addressed QoS Data/Null frames contain
343 		 * peer link-specific PS mode towards the local STA
344 		 */
345 		mps_set_sta_peer_pm(sta, hdr);
346 
347 		/* check for mesh Peer Service Period trigger frames */
348 		ieee80211_mpsp_trigger_process(ieee80211_get_qos_ctl(hdr),
349 					       sta, false, false);
350 	} else {
351 		/*
352 		 * can only determine non-peer PS mode
353 		 * (see IEEE802.11-2012 8.2.4.1.7)
354 		 */
355 		mps_set_sta_nonpeer_pm(sta, hdr);
356 	}
357 }
358 
359 
360 /* mesh PS frame release */
361 
362 static void mpsp_trigger_send(struct sta_info *sta, bool rspi, bool eosp)
363 {
364 	struct ieee80211_sub_if_data *sdata = sta->sdata;
365 	struct sk_buff *skb;
366 	struct ieee80211_hdr *nullfunc;
367 	struct ieee80211_tx_info *info;
368 	u8 *qc;
369 
370 	skb = mps_qos_null_get(sta);
371 	if (!skb)
372 		return;
373 
374 	nullfunc = (struct ieee80211_hdr *) skb->data;
375 	if (!eosp)
376 		nullfunc->frame_control |=
377 				cpu_to_le16(IEEE80211_FCTL_MOREDATA);
378 	/*
379 	 * | RSPI | EOSP |  MPSP triggering   |
380 	 * +------+------+--------------------+
381 	 * |  0   |  0   | local STA is owner |
382 	 * |  0   |  1   | no MPSP (MPSP end) |
383 	 * |  1   |  0   | both STA are owner |
384 	 * |  1   |  1   | peer STA is owner  | see IEEE802.11-2012 13.14.9.2
385 	 */
386 	qc = ieee80211_get_qos_ctl(nullfunc);
387 	if (rspi)
388 		qc[1] |= (IEEE80211_QOS_CTL_RSPI >> 8);
389 	if (eosp)
390 		qc[0] |= IEEE80211_QOS_CTL_EOSP;
391 
392 	info = IEEE80211_SKB_CB(skb);
393 
394 	info->flags |= IEEE80211_TX_CTL_NO_PS_BUFFER |
395 		       IEEE80211_TX_CTL_REQ_TX_STATUS;
396 
397 	mps_dbg(sdata, "sending MPSP trigger%s%s to %pM\n",
398 		rspi ? " RSPI" : "", eosp ? " EOSP" : "", sta->sta.addr);
399 
400 	ieee80211_tx_skb(sdata, skb);
401 }
402 
403 /**
404  * mpsp_qos_null_append - append QoS Null frame to MPSP skb queue if needed
405  *
406  * To properly end a mesh MPSP the last transmitted frame has to set the EOSP
407  * flag in the QoS Control field. In case the current tailing frame is not a
408  * QoS Data frame, append a QoS Null to carry the flag.
409  */
410 static void mpsp_qos_null_append(struct sta_info *sta,
411 				 struct sk_buff_head *frames)
412 {
413 	struct ieee80211_sub_if_data *sdata = sta->sdata;
414 	struct sk_buff *new_skb, *skb = skb_peek_tail(frames);
415 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
416 	struct ieee80211_tx_info *info;
417 
418 	if (ieee80211_is_data_qos(hdr->frame_control))
419 		return;
420 
421 	new_skb = mps_qos_null_get(sta);
422 	if (!new_skb)
423 		return;
424 
425 	mps_dbg(sdata, "appending QoS Null in MPSP towards %pM\n",
426 		sta->sta.addr);
427 	/*
428 	 * This frame has to be transmitted last. Assign lowest priority to
429 	 * make sure it cannot pass other frames when releasing multiple ACs.
430 	 */
431 	new_skb->priority = 1;
432 	skb_set_queue_mapping(new_skb, IEEE80211_AC_BK);
433 	ieee80211_set_qos_hdr(sdata, new_skb);
434 
435 	info = IEEE80211_SKB_CB(new_skb);
436 	info->control.vif = &sdata->vif;
437 	info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING;
438 
439 	__skb_queue_tail(frames, new_skb);
440 }
441 
442 /**
443  * mps_frame_deliver - transmit frames during mesh powersave
444  *
445  * @sta: STA info to transmit to
446  * @n_frames: number of frames to transmit. -1 for all
447  */
448 static void mps_frame_deliver(struct sta_info *sta, int n_frames)
449 {
450 	struct ieee80211_local *local = sta->sdata->local;
451 	int ac;
452 	struct sk_buff_head frames;
453 	struct sk_buff *skb;
454 	bool more_data = false;
455 
456 	skb_queue_head_init(&frames);
457 
458 	/* collect frame(s) from buffers */
459 	for (ac = 0; ac < IEEE80211_NUM_ACS; ac++) {
460 		while (n_frames != 0) {
461 			skb = skb_dequeue(&sta->tx_filtered[ac]);
462 			if (!skb) {
463 				skb = skb_dequeue(
464 					&sta->ps_tx_buf[ac]);
465 				if (skb)
466 					local->total_ps_buffered--;
467 			}
468 			if (!skb)
469 				break;
470 			n_frames--;
471 			__skb_queue_tail(&frames, skb);
472 		}
473 
474 		if (!skb_queue_empty(&sta->tx_filtered[ac]) ||
475 		    !skb_queue_empty(&sta->ps_tx_buf[ac]))
476 			more_data = true;
477 	}
478 
479 	/* nothing to send? -> EOSP */
480 	if (skb_queue_empty(&frames)) {
481 		mpsp_trigger_send(sta, false, true);
482 		return;
483 	}
484 
485 	/* in a MPSP make sure the last skb is a QoS Data frame */
486 	if (test_sta_flag(sta, WLAN_STA_MPSP_OWNER))
487 		mpsp_qos_null_append(sta, &frames);
488 
489 	mps_dbg(sta->sdata, "sending %d frames to PS STA %pM\n",
490 		skb_queue_len(&frames), sta->sta.addr);
491 
492 	/* prepare collected frames for transmission */
493 	skb_queue_walk(&frames, skb) {
494 		struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
495 		struct ieee80211_hdr *hdr = (void *) skb->data;
496 
497 		/*
498 		 * Tell TX path to send this frame even though the
499 		 * STA may still remain is PS mode after this frame
500 		 * exchange.
501 		 */
502 		info->flags |= IEEE80211_TX_CTL_NO_PS_BUFFER;
503 
504 		if (more_data || !skb_queue_is_last(&frames, skb))
505 			hdr->frame_control |=
506 				cpu_to_le16(IEEE80211_FCTL_MOREDATA);
507 		else
508 			hdr->frame_control &=
509 				cpu_to_le16(~IEEE80211_FCTL_MOREDATA);
510 
511 		if (skb_queue_is_last(&frames, skb) &&
512 		    ieee80211_is_data_qos(hdr->frame_control)) {
513 			u8 *qoshdr = ieee80211_get_qos_ctl(hdr);
514 
515 			/* MPSP trigger frame ends service period */
516 			*qoshdr |= IEEE80211_QOS_CTL_EOSP;
517 			info->flags |= IEEE80211_TX_CTL_REQ_TX_STATUS;
518 		}
519 	}
520 
521 	ieee80211_add_pending_skbs(local, &frames);
522 	sta_info_recalc_tim(sta);
523 }
524 
525 /**
526  * ieee80211_mpsp_trigger_process - track status of mesh Peer Service Periods
527  *
528  * @qc: QoS Control field
529  * @sta: peer to start a MPSP with
530  * @tx: frame was transmitted by the local STA
531  * @acked: frame has been transmitted successfully
532  *
533  * NOTE: active mode STA may only serve as MPSP owner
534  */
535 void ieee80211_mpsp_trigger_process(u8 *qc, struct sta_info *sta,
536 				    bool tx, bool acked)
537 {
538 	u8 rspi = qc[1] & (IEEE80211_QOS_CTL_RSPI >> 8);
539 	u8 eosp = qc[0] & IEEE80211_QOS_CTL_EOSP;
540 
541 	if (tx) {
542 		if (rspi && acked)
543 			set_sta_flag(sta, WLAN_STA_MPSP_RECIPIENT);
544 
545 		if (eosp)
546 			clear_sta_flag(sta, WLAN_STA_MPSP_OWNER);
547 		else if (acked &&
548 			 test_sta_flag(sta, WLAN_STA_PS_STA) &&
549 			 !test_and_set_sta_flag(sta, WLAN_STA_MPSP_OWNER))
550 			mps_frame_deliver(sta, -1);
551 	} else {
552 		if (eosp)
553 			clear_sta_flag(sta, WLAN_STA_MPSP_RECIPIENT);
554 		else if (sta->local_pm != NL80211_MESH_POWER_ACTIVE)
555 			set_sta_flag(sta, WLAN_STA_MPSP_RECIPIENT);
556 
557 		if (rspi && !test_and_set_sta_flag(sta, WLAN_STA_MPSP_OWNER))
558 			mps_frame_deliver(sta, -1);
559 	}
560 }
561 
562 /**
563  * ieee80211_mps_frame_release - release frames buffered due to mesh power save
564  *
565  * @sta: mesh STA
566  * @elems: IEs of beacon or probe response
567  *
568  * For peers if we have individually-addressed frames buffered or the peer
569  * indicates buffered frames, send a corresponding MPSP trigger frame. Since
570  * we do not evaluate the awake window duration, QoS Nulls are used as MPSP
571  * trigger frames. If the neighbour STA is not a peer, only send single frames.
572  */
573 void ieee80211_mps_frame_release(struct sta_info *sta,
574 				 struct ieee802_11_elems *elems)
575 {
576 	int ac, buffer_local = 0;
577 	bool has_buffered = false;
578 
579 	if (sta->plink_state == NL80211_PLINK_ESTAB)
580 		has_buffered = ieee80211_check_tim(elems->tim, elems->tim_len,
581 						   sta->llid);
582 
583 	if (has_buffered)
584 		mps_dbg(sta->sdata, "%pM indicates buffered frames\n",
585 			sta->sta.addr);
586 
587 	/* only transmit to PS STA with announced, non-zero awake window */
588 	if (test_sta_flag(sta, WLAN_STA_PS_STA) &&
589 	    (!elems->awake_window || !le16_to_cpu(*elems->awake_window)))
590 		return;
591 
592 	if (!test_sta_flag(sta, WLAN_STA_MPSP_OWNER))
593 		for (ac = 0; ac < IEEE80211_NUM_ACS; ac++)
594 			buffer_local += skb_queue_len(&sta->ps_tx_buf[ac]) +
595 					skb_queue_len(&sta->tx_filtered[ac]);
596 
597 	if (!has_buffered && !buffer_local)
598 		return;
599 
600 	if (sta->plink_state == NL80211_PLINK_ESTAB)
601 		mpsp_trigger_send(sta, has_buffered, !buffer_local);
602 	else
603 		mps_frame_deliver(sta, 1);
604 }
605