1/*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 2002-2008 Sam Leffler, Errno Consulting
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 */
27
28#include <sys/cdefs.h>
29__FBSDID("$FreeBSD: releng/12.0/sys/net80211/ieee80211_power.c 326272 2017-11-27 15:23:17Z pfg $");
30
31/*
32 * IEEE 802.11 power save support.
33 */
34#include "opt_wlan.h"
35
36#include <sys/param.h>
37#include <sys/systm.h>
38#include <sys/kernel.h>
39#include <sys/malloc.h>
40
41#include <sys/socket.h>
42
43#include <net/if.h>
44#include <net/if_var.h>
45#include <net/if_media.h>
46#include <net/ethernet.h>
47
48#include <net80211/ieee80211_var.h>
49
50#include <net/bpf.h>
51
52static void ieee80211_update_ps(struct ieee80211vap *, int);
53static int ieee80211_set_tim(struct ieee80211_node *, int);
54
55static MALLOC_DEFINE(M_80211_POWER, "80211power", "802.11 power save state");
56
57void
58ieee80211_power_attach(struct ieee80211com *ic)
59{
60}
61
62void
63ieee80211_power_detach(struct ieee80211com *ic)
64{
65}
66
67void
68ieee80211_power_vattach(struct ieee80211vap *vap)
69{
70	if (vap->iv_opmode == IEEE80211_M_HOSTAP ||
71	    vap->iv_opmode == IEEE80211_M_IBSS) {
72		/* NB: driver should override */
73		vap->iv_update_ps = ieee80211_update_ps;
74		vap->iv_set_tim = ieee80211_set_tim;
75	}
76	vap->iv_node_ps = ieee80211_node_pwrsave;
77	vap->iv_sta_ps = ieee80211_sta_pwrsave;
78}
79
80void
81ieee80211_power_latevattach(struct ieee80211vap *vap)
82{
83	/*
84	 * Allocate these only if needed.  Beware that we
85	 * know adhoc mode doesn't support ATIM yet...
86	 */
87	if (vap->iv_opmode == IEEE80211_M_HOSTAP) {
88		vap->iv_tim_len = howmany(vap->iv_max_aid,8) * sizeof(uint8_t);
89		vap->iv_tim_bitmap = (uint8_t *) IEEE80211_MALLOC(vap->iv_tim_len,
90			M_80211_POWER,
91			IEEE80211_M_NOWAIT | IEEE80211_M_ZERO);
92		if (vap->iv_tim_bitmap == NULL) {
93			printf("%s: no memory for TIM bitmap!\n", __func__);
94			/* XXX good enough to keep from crashing? */
95			vap->iv_tim_len = 0;
96		}
97	}
98}
99
100void
101ieee80211_power_vdetach(struct ieee80211vap *vap)
102{
103	if (vap->iv_tim_bitmap != NULL) {
104		IEEE80211_FREE(vap->iv_tim_bitmap, M_80211_POWER);
105		vap->iv_tim_bitmap = NULL;
106	}
107}
108
109void
110ieee80211_psq_init(struct ieee80211_psq *psq, const char *name)
111{
112	memset(psq, 0, sizeof(*psq));
113	psq->psq_maxlen = IEEE80211_PS_MAX_QUEUE;
114	IEEE80211_PSQ_INIT(psq, name);		/* OS-dependent setup */
115}
116
117void
118ieee80211_psq_cleanup(struct ieee80211_psq *psq)
119{
120#if 0
121	psq_drain(psq);				/* XXX should not be needed? */
122#else
123	KASSERT(psq->psq_len == 0, ("%d frames on ps q", psq->psq_len));
124#endif
125	IEEE80211_PSQ_DESTROY(psq);		/* OS-dependent cleanup */
126}
127
128/*
129 * Return the highest priority frame in the ps queue.
130 */
131struct mbuf *
132ieee80211_node_psq_dequeue(struct ieee80211_node *ni, int *qlen)
133{
134	struct ieee80211_psq *psq = &ni->ni_psq;
135	struct ieee80211_psq_head *qhead;
136	struct mbuf *m;
137
138	IEEE80211_PSQ_LOCK(psq);
139	qhead = &psq->psq_head[0];
140again:
141	if ((m = qhead->head) != NULL) {
142		if ((qhead->head = m->m_nextpkt) == NULL)
143			qhead->tail = NULL;
144		KASSERT(qhead->len > 0, ("qhead len %d", qhead->len));
145		qhead->len--;
146		KASSERT(psq->psq_len > 0, ("psq len %d", psq->psq_len));
147		psq->psq_len--;
148		m->m_nextpkt = NULL;
149	}
150	if (m == NULL && qhead == &psq->psq_head[0]) {
151		/* Algol-68 style for loop */
152		qhead = &psq->psq_head[1];
153		goto again;
154	}
155	if (qlen != NULL)
156		*qlen = psq->psq_len;
157	IEEE80211_PSQ_UNLOCK(psq);
158	return m;
159}
160
161/*
162 * Reclaim an mbuf from the ps q.  If marked with M_ENCAP
163 * we assume there is a node reference that must be relcaimed.
164 */
165static void
166psq_mfree(struct mbuf *m)
167{
168	if (m->m_flags & M_ENCAP) {
169		struct ieee80211_node *ni = (void *) m->m_pkthdr.rcvif;
170		ieee80211_free_node(ni);
171	}
172	m->m_nextpkt = NULL;
173	m_freem(m);
174}
175
176/*
177 * Clear any frames queued in the power save queue.
178 * The number of frames that were present is returned.
179 */
180static int
181psq_drain(struct ieee80211_psq *psq)
182{
183	struct ieee80211_psq_head *qhead;
184	struct mbuf *m;
185	int qlen;
186
187	IEEE80211_PSQ_LOCK(psq);
188	qlen = psq->psq_len;
189	qhead = &psq->psq_head[0];
190again:
191	while ((m = qhead->head) != NULL) {
192		qhead->head = m->m_nextpkt;
193		psq_mfree(m);
194	}
195	qhead->tail = NULL;
196	qhead->len = 0;
197	if (qhead == &psq->psq_head[0]) {	/* Algol-68 style for loop */
198		qhead = &psq->psq_head[1];
199		goto again;
200	}
201	psq->psq_len = 0;
202	IEEE80211_PSQ_UNLOCK(psq);
203
204	return qlen;
205}
206
207/*
208 * Clear any frames queued in the power save queue.
209 * The number of frames that were present is returned.
210 */
211int
212ieee80211_node_psq_drain(struct ieee80211_node *ni)
213{
214	return psq_drain(&ni->ni_psq);
215}
216
217/*
218 * Age frames on the power save queue. The aging interval is
219 * 4 times the listen interval specified by the station.  This
220 * number is factored into the age calculations when the frame
221 * is placed on the queue.  We store ages as time differences
222 * so we can check and/or adjust only the head of the list.
223 * If a frame's age exceeds the threshold then discard it.
224 * The number of frames discarded is returned so the caller
225 * can check if it needs to adjust the tim.
226 */
227int
228ieee80211_node_psq_age(struct ieee80211_node *ni)
229{
230	struct ieee80211_psq *psq = &ni->ni_psq;
231	int discard = 0;
232
233	if (psq->psq_len != 0) {
234#ifdef IEEE80211_DEBUG
235		struct ieee80211vap *vap = ni->ni_vap;
236#endif
237		struct ieee80211_psq_head *qhead;
238		struct mbuf *m;
239
240		IEEE80211_PSQ_LOCK(psq);
241		qhead = &psq->psq_head[0];
242	again:
243		while ((m = qhead->head) != NULL &&
244		    M_AGE_GET(m) < IEEE80211_INACT_WAIT) {
245			IEEE80211_NOTE(vap, IEEE80211_MSG_POWER, ni,
246			     "discard frame, age %u", M_AGE_GET(m));
247			if ((qhead->head = m->m_nextpkt) == NULL)
248				qhead->tail = NULL;
249			KASSERT(qhead->len > 0, ("qhead len %d", qhead->len));
250			qhead->len--;
251			KASSERT(psq->psq_len > 0, ("psq len %d", psq->psq_len));
252			psq->psq_len--;
253			psq_mfree(m);
254			discard++;
255		}
256		if (qhead == &psq->psq_head[0]) { /* Algol-68 style for loop */
257			qhead = &psq->psq_head[1];
258			goto again;
259		}
260		if (m != NULL)
261			M_AGE_SUB(m, IEEE80211_INACT_WAIT);
262		IEEE80211_PSQ_UNLOCK(psq);
263
264		IEEE80211_NOTE(vap, IEEE80211_MSG_POWER, ni,
265		    "discard %u frames for age", discard);
266		IEEE80211_NODE_STAT_ADD(ni, ps_discard, discard);
267	}
268	return discard;
269}
270
271/*
272 * Handle a change in the PS station occupancy.
273 */
274static void
275ieee80211_update_ps(struct ieee80211vap *vap, int nsta)
276{
277
278	KASSERT(vap->iv_opmode == IEEE80211_M_HOSTAP ||
279		vap->iv_opmode == IEEE80211_M_IBSS,
280		("operating mode %u", vap->iv_opmode));
281}
282
283/*
284 * Indicate whether there are frames queued for a station in power-save mode.
285 */
286static int
287ieee80211_set_tim(struct ieee80211_node *ni, int set)
288{
289	struct ieee80211vap *vap = ni->ni_vap;
290	struct ieee80211com *ic = ni->ni_ic;
291	uint16_t aid;
292	int changed;
293
294	KASSERT(vap->iv_opmode == IEEE80211_M_HOSTAP ||
295		vap->iv_opmode == IEEE80211_M_IBSS,
296		("operating mode %u", vap->iv_opmode));
297
298	aid = IEEE80211_AID(ni->ni_associd);
299	KASSERT(aid < vap->iv_max_aid,
300		("bogus aid %u, max %u", aid, vap->iv_max_aid));
301
302	IEEE80211_LOCK(ic);
303	changed = (set != (isset(vap->iv_tim_bitmap, aid) != 0));
304	if (changed) {
305		if (set) {
306			setbit(vap->iv_tim_bitmap, aid);
307			vap->iv_ps_pending++;
308		} else {
309			clrbit(vap->iv_tim_bitmap, aid);
310			vap->iv_ps_pending--;
311		}
312		/* NB: we know vap is in RUN state so no need to check */
313		vap->iv_update_beacon(vap, IEEE80211_BEACON_TIM);
314	}
315	IEEE80211_UNLOCK(ic);
316
317	return changed;
318}
319
320/*
321 * Save an outbound packet for a node in power-save sleep state.
322 * The new packet is placed on the node's saved queue, and the TIM
323 * is changed, if necessary.
324 */
325int
326ieee80211_pwrsave(struct ieee80211_node *ni, struct mbuf *m)
327{
328	struct ieee80211_psq *psq = &ni->ni_psq;
329	struct ieee80211vap *vap = ni->ni_vap;
330	struct ieee80211com *ic = ni->ni_ic;
331	struct ieee80211_psq_head *qhead;
332	int qlen, age;
333
334	IEEE80211_PSQ_LOCK(psq);
335	if (psq->psq_len >= psq->psq_maxlen) {
336		psq->psq_drops++;
337		IEEE80211_PSQ_UNLOCK(psq);
338		IEEE80211_NOTE(vap, IEEE80211_MSG_ANY, ni,
339		    "pwr save q overflow, drops %d (size %d)",
340		    psq->psq_drops, psq->psq_len);
341#ifdef IEEE80211_DEBUG
342		if (ieee80211_msg_dumppkts(vap))
343			ieee80211_dump_pkt(ni->ni_ic, mtod(m, caddr_t),
344			    m->m_len, -1, -1);
345#endif
346		psq_mfree(m);
347		return ENOSPC;
348	}
349	/*
350	 * Tag the frame with it's expiry time and insert it in
351	 * the appropriate queue.  The aging interval is 4 times
352	 * the listen interval specified by the station. Frames
353	 * that sit around too long are reclaimed using this
354	 * information.
355	 */
356	/* TU -> secs.  XXX handle overflow? */
357	age = IEEE80211_TU_TO_MS((ni->ni_intval * ic->ic_bintval) << 2) / 1000;
358	/*
359	 * Encapsulated frames go on the high priority queue,
360	 * other stuff goes on the low priority queue.  We use
361	 * this to order frames returned out of the driver
362	 * ahead of frames we collect in ieee80211_start.
363	 */
364	if (m->m_flags & M_ENCAP)
365		qhead = &psq->psq_head[0];
366	else
367		qhead = &psq->psq_head[1];
368	if (qhead->tail == NULL) {
369		struct mbuf *mh;
370
371		qhead->head = m;
372		/*
373		 * Take care to adjust age when inserting the first
374		 * frame of a queue and the other queue already has
375		 * frames.  We need to preserve the age difference
376		 * relationship so ieee80211_node_psq_age works.
377		 */
378		if (qhead == &psq->psq_head[1]) {
379			mh = psq->psq_head[0].head;
380			if (mh != NULL)
381				age-= M_AGE_GET(mh);
382		} else {
383			mh = psq->psq_head[1].head;
384			if (mh != NULL) {
385				int nage = M_AGE_GET(mh) - age;
386				/* XXX is clamping to zero good 'nuf? */
387				M_AGE_SET(mh, nage < 0 ? 0 : nage);
388			}
389		}
390	} else {
391		qhead->tail->m_nextpkt = m;
392		age -= M_AGE_GET(qhead->head);
393	}
394	KASSERT(age >= 0, ("age %d", age));
395	M_AGE_SET(m, age);
396	m->m_nextpkt = NULL;
397	qhead->tail = m;
398	qhead->len++;
399	qlen = ++(psq->psq_len);
400	IEEE80211_PSQ_UNLOCK(psq);
401
402	IEEE80211_NOTE(vap, IEEE80211_MSG_POWER, ni,
403	    "save frame with age %d, %u now queued", age, qlen);
404
405	if (qlen == 1 && vap->iv_set_tim != NULL)
406		vap->iv_set_tim(ni, 1);
407
408	return 0;
409}
410
411/*
412 * Move frames from the ps q to the vap's send queue
413 * and/or the driver's send queue; and kick the start
414 * method for each, as appropriate.  Note we're careful
415 * to preserve packet ordering here.
416 */
417static void
418pwrsave_flushq(struct ieee80211_node *ni)
419{
420	struct ieee80211_psq *psq = &ni->ni_psq;
421	struct ieee80211com *ic = ni->ni_ic;
422	struct ieee80211vap *vap = ni->ni_vap;
423	struct ieee80211_psq_head *qhead;
424	struct mbuf *parent_q = NULL, *ifp_q = NULL;
425	struct mbuf *m;
426
427	IEEE80211_NOTE(vap, IEEE80211_MSG_POWER, ni,
428	    "flush ps queue, %u packets queued", psq->psq_len);
429
430	IEEE80211_PSQ_LOCK(psq);
431	qhead = &psq->psq_head[0];	/* 802.11 frames */
432	if (qhead->head != NULL) {
433		/* XXX could dispatch through vap and check M_ENCAP */
434		/* XXX need different driver interface */
435		/* XXX bypasses q max and OACTIVE */
436		parent_q = qhead->head;
437		qhead->head = qhead->tail = NULL;
438		qhead->len = 0;
439	}
440
441	qhead = &psq->psq_head[1];	/* 802.3 frames */
442	if (qhead->head != NULL) {
443		/* XXX need different driver interface */
444		/* XXX bypasses q max and OACTIVE */
445		ifp_q = qhead->head;
446		qhead->head = qhead->tail = NULL;
447		qhead->len = 0;
448	}
449	psq->psq_len = 0;
450	IEEE80211_PSQ_UNLOCK(psq);
451
452	/* NB: do this outside the psq lock */
453	/* XXX packets might get reordered if parent is OACTIVE */
454	/* parent frames, should be encapsulated */
455	while (parent_q != NULL) {
456		m = parent_q;
457		parent_q = m->m_nextpkt;
458		m->m_nextpkt = NULL;
459		/* must be encapsulated */
460		KASSERT((m->m_flags & M_ENCAP),
461		    ("%s: parentq with non-M_ENCAP frame!\n",
462		    __func__));
463		(void) ieee80211_parent_xmitpkt(ic, m);
464	}
465
466	/* VAP frames, aren't encapsulated */
467	while (ifp_q != NULL) {
468		m = ifp_q;
469		ifp_q = m->m_nextpkt;
470		m->m_nextpkt = NULL;
471		KASSERT((!(m->m_flags & M_ENCAP)),
472		    ("%s: vapq with M_ENCAP frame!\n", __func__));
473		(void) ieee80211_vap_xmitpkt(vap, m);
474	}
475}
476
477/*
478 * Handle station power-save state change.
479 */
480void
481ieee80211_node_pwrsave(struct ieee80211_node *ni, int enable)
482{
483	struct ieee80211vap *vap = ni->ni_vap;
484	int update;
485
486	update = 0;
487	if (enable) {
488		if ((ni->ni_flags & IEEE80211_NODE_PWR_MGT) == 0) {
489			vap->iv_ps_sta++;
490			update = 1;
491		}
492		ni->ni_flags |= IEEE80211_NODE_PWR_MGT;
493		IEEE80211_NOTE(vap, IEEE80211_MSG_POWER, ni,
494		    "power save mode on, %u sta's in ps mode", vap->iv_ps_sta);
495
496		if (update)
497			vap->iv_update_ps(vap, vap->iv_ps_sta);
498	} else {
499		if (ni->ni_flags & IEEE80211_NODE_PWR_MGT) {
500			vap->iv_ps_sta--;
501			update = 1;
502		}
503		ni->ni_flags &= ~IEEE80211_NODE_PWR_MGT;
504		IEEE80211_NOTE(vap, IEEE80211_MSG_POWER, ni,
505		    "power save mode off, %u sta's in ps mode", vap->iv_ps_sta);
506
507		/* NB: order here is intentional so TIM is clear before flush */
508		if (vap->iv_set_tim != NULL)
509			vap->iv_set_tim(ni, 0);
510		if (update) {
511			/* NB if no sta's in ps, driver should flush mc q */
512			vap->iv_update_ps(vap, vap->iv_ps_sta);
513		}
514		if (ni->ni_psq.psq_len != 0)
515			pwrsave_flushq(ni);
516	}
517}
518
519/*
520 * Handle power-save state change in station mode.
521 */
522void
523ieee80211_sta_pwrsave(struct ieee80211vap *vap, int enable)
524{
525	struct ieee80211_node *ni = vap->iv_bss;
526
527	if (!((enable != 0) ^ ((ni->ni_flags & IEEE80211_NODE_PWR_MGT) != 0)))
528		return;
529
530	IEEE80211_NOTE(vap, IEEE80211_MSG_POWER, ni,
531	    "sta power save mode %s", enable ? "on" : "off");
532	if (!enable) {
533		ni->ni_flags &= ~IEEE80211_NODE_PWR_MGT;
534		ieee80211_send_nulldata(ieee80211_ref_node(ni));
535		/*
536		 * Flush any queued frames; we can do this immediately
537		 * because we know they'll be queued behind the null
538		 * data frame we send the ap.
539		 * XXX can we use a data frame to take us out of ps?
540		 */
541		if (ni->ni_psq.psq_len != 0)
542			pwrsave_flushq(ni);
543	} else {
544		ni->ni_flags |= IEEE80211_NODE_PWR_MGT;
545		ieee80211_send_nulldata(ieee80211_ref_node(ni));
546	}
547}
548
549/*
550 * Handle being notified that we have data available for us in a TIM/ATIM.
551 *
552 * This may schedule a transition from _SLEEP -> _RUN if it's appropriate.
553 *
554 * In STA mode, we may have put to sleep during scan and need to be dragged
555 * back out of powersave mode.
556 */
557void
558ieee80211_sta_tim_notify(struct ieee80211vap *vap, int set)
559{
560	struct ieee80211com *ic = vap->iv_ic;
561
562	/*
563	 * Schedule the driver state change.  It'll happen at some point soon.
564	 * Since the hardware shouldn't know that we're running just yet
565	 * (and thus tell the peer that we're awake before we actually wake
566	 * up said hardware), we leave the actual node state transition
567	 * up to the transition to RUN.
568	 *
569	 * XXX TODO: verify that the transition to RUN will wake up the
570	 * BSS node!
571	 */
572	IEEE80211_LOCK(vap->iv_ic);
573	if (set == 1 && vap->iv_state == IEEE80211_S_SLEEP) {
574		ieee80211_new_state_locked(vap, IEEE80211_S_RUN, 0);
575		IEEE80211_DPRINTF(vap, IEEE80211_MSG_POWER,
576		    "%s: TIM=%d; wakeup\n", __func__, set);
577	} else if ((set == 1) && (ic->ic_flags_ext & IEEE80211_FEXT_BGSCAN)) {
578		/*
579		 * XXX only do this if we're in RUN state?
580		 */
581		IEEE80211_DPRINTF(vap, IEEE80211_MSG_POWER,
582		    "%s: wake up from bgscan vap sleep\n",
583		    __func__);
584		/*
585		 * We may be in BGSCAN mode - this means the VAP is is in STA
586		 * mode powersave.  If it is, we need to wake it up so we
587		 * can process outbound traffic.
588		 */
589		vap->iv_sta_ps(vap, 0);
590	}
591	IEEE80211_UNLOCK(vap->iv_ic);
592}
593
594/*
595 * Timer check on whether the VAP has had any transmit activity.
596 *
597 * This may schedule a transition from _RUN -> _SLEEP if it's appropriate.
598 */
599void
600ieee80211_sta_ps_timer_check(struct ieee80211vap *vap)
601{
602	struct ieee80211com *ic = vap->iv_ic;
603
604	/* XXX lock assert */
605
606	/* For no, only do this in STA mode */
607	if (! (vap->iv_caps & IEEE80211_C_SWSLEEP))
608		goto out;
609
610	if (vap->iv_opmode != IEEE80211_M_STA)
611		goto out;
612
613	/* If we're not at run state, bail */
614	if (vap->iv_state != IEEE80211_S_RUN)
615		goto out;
616
617	IEEE80211_DPRINTF(vap, IEEE80211_MSG_POWER,
618	    "%s: lastdata=%llu, ticks=%llu\n",
619	    __func__, (unsigned long long) ic->ic_lastdata,
620	    (unsigned long long) ticks);
621
622	/* If powersave is disabled on the VAP, don't bother */
623	if (! (vap->iv_flags & IEEE80211_F_PMGTON))
624		goto out;
625
626	/* If we've done any data within our idle interval, bail */
627	/* XXX hard-coded to one second for now, ew! */
628	if (ieee80211_time_after(ic->ic_lastdata + 500, ticks))
629		goto out;
630
631	/*
632	 * Signify we're going into power save and transition the
633	 * node to powersave.
634	 */
635	if ((vap->iv_bss->ni_flags & IEEE80211_NODE_PWR_MGT) == 0)
636		vap->iv_sta_ps(vap, 1);
637
638	/*
639	 * XXX The driver has to handle the fact that we're going
640	 * to sleep but frames may still be transmitted;
641	 * hopefully it and/or us will do the right thing and mark any
642	 * transmitted frames with PWRMGT set to 1.
643	 */
644	ieee80211_new_state_locked(vap, IEEE80211_S_SLEEP, 0);
645
646	IEEE80211_DPRINTF(vap, IEEE80211_MSG_POWER,
647	    "%s: time delta=%d msec\n", __func__,
648	    (int) ticks_to_msecs(ticks - ic->ic_lastdata));
649
650out:
651	return;
652}
653