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