xref: /dragonfly/sys/netproto/802_11/wlan/ieee80211_power.c (revision 4f655ef568316df0b575f05cebf37546415c0d24)
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 <netproto/802_11/ieee80211_var.h>
47 
48 #include <net/bpf.h>
49 
50 static void ieee80211_update_ps(struct ieee80211vap *, int);
51 static int ieee80211_set_tim(struct ieee80211_node *, int);
52 
53 static MALLOC_DEFINE(M_80211_POWER, "80211power", "802.11 power save state");
54 
55 void
ieee80211_power_attach(struct ieee80211com * ic)56 ieee80211_power_attach(struct ieee80211com *ic)
57 {
58 }
59 
60 void
ieee80211_power_detach(struct ieee80211com * ic)61 ieee80211_power_detach(struct ieee80211com *ic)
62 {
63 }
64 
65 void
ieee80211_power_vattach(struct ieee80211vap * vap)66 ieee80211_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 
78 void
ieee80211_power_latevattach(struct ieee80211vap * vap)79 ieee80211_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 #if defined(__DragonFly__)
88                     vap->iv_tim_bitmap = (uint8_t *) kmalloc(vap->iv_tim_len,
89                               M_80211_POWER, M_INTWAIT | M_ZERO);
90 #else
91                     vap->iv_tim_bitmap = (uint8_t *) IEEE80211_MALLOC(vap->iv_tim_len,
92                               M_80211_POWER,
93                               IEEE80211_M_NOWAIT | IEEE80211_M_ZERO);
94 #endif
95                     if (vap->iv_tim_bitmap == NULL) {
96                               kprintf("%s: no memory for TIM bitmap!\n", __func__);
97                               /* XXX good enough to keep from crashing? */
98                               vap->iv_tim_len = 0;
99                     }
100           }
101 }
102 
103 void
ieee80211_power_vdetach(struct ieee80211vap * vap)104 ieee80211_power_vdetach(struct ieee80211vap *vap)
105 {
106           if (vap->iv_tim_bitmap != NULL) {
107                     IEEE80211_FREE(vap->iv_tim_bitmap, M_80211_POWER);
108                     vap->iv_tim_bitmap = NULL;
109           }
110 }
111 
112 void
ieee80211_psq_init(struct ieee80211_psq * psq,const char * name)113 ieee80211_psq_init(struct ieee80211_psq *psq, const char *name)
114 {
115           memset(psq, 0, sizeof(*psq));
116           psq->psq_maxlen = IEEE80211_PS_MAX_QUEUE;
117           IEEE80211_PSQ_INIT(psq, name);                    /* OS-dependent setup */
118 }
119 
120 void
ieee80211_psq_cleanup(struct ieee80211_psq * psq)121 ieee80211_psq_cleanup(struct ieee80211_psq *psq)
122 {
123 #if 0
124           psq_drain(psq);                                   /* XXX should not be needed? */
125 #else
126           KASSERT(psq->psq_len == 0, ("%d frames on ps q", psq->psq_len));
127 #endif
128           IEEE80211_PSQ_DESTROY(psq);             /* OS-dependent cleanup */
129 }
130 
131 /*
132  * Return the highest priority frame in the ps queue.
133  */
134 struct mbuf *
ieee80211_node_psq_dequeue(struct ieee80211_node * ni,int * qlen)135 ieee80211_node_psq_dequeue(struct ieee80211_node *ni, int *qlen)
136 {
137           struct ieee80211_psq *psq = &ni->ni_psq;
138           struct ieee80211_psq_head *qhead;
139           struct mbuf *m;
140 
141           IEEE80211_PSQ_LOCK(psq);
142           qhead = &psq->psq_head[0];
143 again:
144           if ((m = qhead->head) != NULL) {
145                     if ((qhead->head = m->m_nextpkt) == NULL)
146                               qhead->tail = NULL;
147                     KASSERT(qhead->len > 0, ("qhead len %d", qhead->len));
148                     qhead->len--;
149                     KASSERT(psq->psq_len > 0, ("psq len %d", psq->psq_len));
150                     psq->psq_len--;
151                     m->m_nextpkt = NULL;
152           }
153           if (m == NULL && qhead == &psq->psq_head[0]) {
154                     /* Algol-68 style for loop */
155                     qhead = &psq->psq_head[1];
156                     goto again;
157           }
158           if (qlen != NULL)
159                     *qlen = psq->psq_len;
160           IEEE80211_PSQ_UNLOCK(psq);
161           return m;
162 }
163 
164 /*
165  * Reclaim an mbuf from the ps q.  If marked with M_ENCAP
166  * we assume there is a node reference that must be relcaimed.
167  */
168 static void
psq_mfree(struct mbuf * m)169 psq_mfree(struct mbuf *m)
170 {
171           if (m->m_flags & M_ENCAP) {
172                     struct ieee80211_node *ni = (void *) m->m_pkthdr.rcvif;
173                     ieee80211_free_node(ni);
174           }
175           m->m_nextpkt = NULL;
176           m_freem(m);
177 }
178 
179 /*
180  * Clear any frames queued in the power save queue.
181  * The number of frames that were present is returned.
182  */
183 static int
psq_drain(struct ieee80211_psq * psq)184 psq_drain(struct ieee80211_psq *psq)
185 {
186           struct ieee80211_psq_head *qhead;
187           struct mbuf *m;
188           int qlen;
189 
190           IEEE80211_PSQ_LOCK(psq);
191           qlen = psq->psq_len;
192           qhead = &psq->psq_head[0];
193 again:
194           while ((m = qhead->head) != NULL) {
195                     qhead->head = m->m_nextpkt;
196                     psq_mfree(m);
197           }
198           qhead->tail = NULL;
199           qhead->len = 0;
200           if (qhead == &psq->psq_head[0]) {       /* Algol-68 style for loop */
201                     qhead = &psq->psq_head[1];
202                     goto again;
203           }
204           psq->psq_len = 0;
205           IEEE80211_PSQ_UNLOCK(psq);
206 
207           return qlen;
208 }
209 
210 /*
211  * Clear any frames queued in the power save queue.
212  * The number of frames that were present is returned.
213  */
214 int
ieee80211_node_psq_drain(struct ieee80211_node * ni)215 ieee80211_node_psq_drain(struct ieee80211_node *ni)
216 {
217           return psq_drain(&ni->ni_psq);
218 }
219 
220 /*
221  * Age frames on the power save queue. The aging interval is
222  * 4 times the listen interval specified by the station.  This
223  * number is factored into the age calculations when the frame
224  * is placed on the queue.  We store ages as time differences
225  * so we can check and/or adjust only the head of the list.
226  * If a frame's age exceeds the threshold then discard it.
227  * The number of frames discarded is returned so the caller
228  * can check if it needs to adjust the tim.
229  */
230 int
ieee80211_node_psq_age(struct ieee80211_node * ni)231 ieee80211_node_psq_age(struct ieee80211_node *ni)
232 {
233           struct ieee80211_psq *psq = &ni->ni_psq;
234           int discard = 0;
235 
236           if (psq->psq_len != 0) {
237 #ifdef IEEE80211_DEBUG
238                     struct ieee80211vap *vap = ni->ni_vap;
239 #endif
240                     struct ieee80211_psq_head *qhead;
241                     struct mbuf *m;
242 
243                     IEEE80211_PSQ_LOCK(psq);
244                     qhead = &psq->psq_head[0];
245           again:
246                     while ((m = qhead->head) != NULL &&
247                         M_AGE_GET(m) < IEEE80211_INACT_WAIT) {
248                               IEEE80211_NOTE(vap, IEEE80211_MSG_POWER, ni,
249                                    "discard frame, age %u", M_AGE_GET(m));
250                               if ((qhead->head = m->m_nextpkt) == NULL)
251                                         qhead->tail = NULL;
252                               KASSERT(qhead->len > 0, ("qhead len %d", qhead->len));
253                               qhead->len--;
254                               KASSERT(psq->psq_len > 0, ("psq len %d", psq->psq_len));
255                               psq->psq_len--;
256                               psq_mfree(m);
257                               discard++;
258                     }
259                     if (qhead == &psq->psq_head[0]) { /* Algol-68 style for loop */
260                               qhead = &psq->psq_head[1];
261                               goto again;
262                     }
263                     if (m != NULL)
264                               M_AGE_SUB(m, IEEE80211_INACT_WAIT);
265                     IEEE80211_PSQ_UNLOCK(psq);
266 
267                     IEEE80211_NOTE(vap, IEEE80211_MSG_POWER, ni,
268                         "discard %u frames for age", discard);
269                     IEEE80211_NODE_STAT_ADD(ni, ps_discard, discard);
270           }
271           return discard;
272 }
273 
274 /*
275  * Handle a change in the PS station occupancy.
276  */
277 static void
ieee80211_update_ps(struct ieee80211vap * vap,int nsta)278 ieee80211_update_ps(struct ieee80211vap *vap, int nsta)
279 {
280 
281           KASSERT(vap->iv_opmode == IEEE80211_M_HOSTAP ||
282                     vap->iv_opmode == IEEE80211_M_IBSS,
283                     ("operating mode %u", vap->iv_opmode));
284 }
285 
286 /*
287  * Indicate whether there are frames queued for a station in power-save mode.
288  */
289 static int
ieee80211_set_tim(struct ieee80211_node * ni,int set)290 ieee80211_set_tim(struct ieee80211_node *ni, int set)
291 {
292           struct ieee80211vap *vap = ni->ni_vap;
293           struct ieee80211com *ic = ni->ni_ic;
294           uint16_t aid;
295           int changed;
296 
297           KASSERT(vap->iv_opmode == IEEE80211_M_HOSTAP ||
298                     vap->iv_opmode == IEEE80211_M_IBSS,
299                     ("operating mode %u", vap->iv_opmode));
300 
301           aid = IEEE80211_AID(ni->ni_associd);
302           KASSERT(aid < vap->iv_max_aid,
303                     ("bogus aid %u, max %u", aid, vap->iv_max_aid));
304 
305           IEEE80211_LOCK(ic);
306           changed = (set != (isset(vap->iv_tim_bitmap, aid) != 0));
307           if (changed) {
308                     if (set) {
309                               setbit(vap->iv_tim_bitmap, aid);
310                               vap->iv_ps_pending++;
311                     } else {
312                               clrbit(vap->iv_tim_bitmap, aid);
313                               vap->iv_ps_pending--;
314                     }
315                     /* NB: we know vap is in RUN state so no need to check */
316                     vap->iv_update_beacon(vap, IEEE80211_BEACON_TIM);
317           }
318           IEEE80211_UNLOCK(ic);
319 
320           return changed;
321 }
322 
323 /*
324  * Save an outbound packet for a node in power-save sleep state.
325  * The new packet is placed on the node's saved queue, and the TIM
326  * is changed, if necessary.
327  */
328 int
ieee80211_pwrsave(struct ieee80211_node * ni,struct mbuf * m)329 ieee80211_pwrsave(struct ieee80211_node *ni, struct mbuf *m)
330 {
331           struct ieee80211_psq *psq = &ni->ni_psq;
332           struct ieee80211vap *vap = ni->ni_vap;
333           struct ieee80211com *ic = ni->ni_ic;
334           struct ieee80211_psq_head *qhead;
335           int qlen, age;
336 
337           IEEE80211_PSQ_LOCK(psq);
338           if (psq->psq_len >= psq->psq_maxlen) {
339                     psq->psq_drops++;
340                     IEEE80211_PSQ_UNLOCK(psq);
341                     IEEE80211_NOTE(vap, IEEE80211_MSG_ANY, ni,
342                         "pwr save q overflow, drops %d (size %d)",
343                         psq->psq_drops, psq->psq_len);
344 #ifdef IEEE80211_DEBUG
345                     if (ieee80211_msg_dumppkts(vap))
346                               ieee80211_dump_pkt(ni->ni_ic, mtod(m, caddr_t),
347                                   m->m_len, -1, -1);
348 #endif
349                     psq_mfree(m);
350                     return ENOSPC;
351           }
352           /*
353            * Tag the frame with it's expiry time and insert it in
354            * the appropriate queue.  The aging interval is 4 times
355            * the listen interval specified by the station. Frames
356            * that sit around too long are reclaimed using this
357            * information.
358            */
359           /* TU -> secs.  XXX handle overflow? */
360           age = IEEE80211_TU_TO_MS((ni->ni_intval * ic->ic_bintval) << 2) / 1000;
361           /*
362            * Encapsulated frames go on the high priority queue,
363            * other stuff goes on the low priority queue.  We use
364            * this to order frames returned out of the driver
365            * ahead of frames we collect in ieee80211_start.
366            */
367           if (m->m_flags & M_ENCAP)
368                     qhead = &psq->psq_head[0];
369           else
370                     qhead = &psq->psq_head[1];
371           if (qhead->tail == NULL) {
372                     struct mbuf *mh;
373 
374                     qhead->head = m;
375                     /*
376                      * Take care to adjust age when inserting the first
377                      * frame of a queue and the other queue already has
378                      * frames.  We need to preserve the age difference
379                      * relationship so ieee80211_node_psq_age works.
380                      */
381                     if (qhead == &psq->psq_head[1]) {
382                               mh = psq->psq_head[0].head;
383                               if (mh != NULL)
384                                         age-= M_AGE_GET(mh);
385                     } else {
386                               mh = psq->psq_head[1].head;
387                               if (mh != NULL) {
388                                         int nage = M_AGE_GET(mh) - age;
389                                         /* XXX is clamping to zero good 'nuf? */
390                                         M_AGE_SET(mh, nage < 0 ? 0 : nage);
391                               }
392                     }
393           } else {
394                     qhead->tail->m_nextpkt = m;
395                     age -= M_AGE_GET(qhead->head);
396           }
397           KASSERT(age >= 0, ("age %d", age));
398           M_AGE_SET(m, age);
399           m->m_nextpkt = NULL;
400           qhead->tail = m;
401           qhead->len++;
402           qlen = ++(psq->psq_len);
403           IEEE80211_PSQ_UNLOCK(psq);
404 
405           IEEE80211_NOTE(vap, IEEE80211_MSG_POWER, ni,
406               "save frame with age %d, %u now queued", age, qlen);
407 
408           if (qlen == 1 && vap->iv_set_tim != NULL)
409                     vap->iv_set_tim(ni, 1);
410 
411           return 0;
412 }
413 
414 /*
415  * Move frames from the ps q to the vap's send queue
416  * and/or the driver's send queue; and kick the start
417  * method for each, as appropriate.  Note we're careful
418  * to preserve packet ordering here.
419  */
420 static void
pwrsave_flushq(struct ieee80211_node * ni)421 pwrsave_flushq(struct ieee80211_node *ni)
422 {
423           struct ieee80211_psq *psq = &ni->ni_psq;
424           struct ieee80211com *ic = ni->ni_ic;
425           struct ieee80211vap *vap = ni->ni_vap;
426           struct ieee80211_psq_head *qhead;
427           struct mbuf *parent_q = NULL, *ifp_q = NULL;
428           struct mbuf *m;
429 
430           IEEE80211_NOTE(vap, IEEE80211_MSG_POWER, ni,
431               "flush ps queue, %u packets queued", psq->psq_len);
432 
433           IEEE80211_PSQ_LOCK(psq);
434           qhead = &psq->psq_head[0];    /* 802.11 frames */
435           if (qhead->head != NULL) {
436                     /* XXX could dispatch through vap and check M_ENCAP */
437                     /* XXX need different driver interface */
438                     /* XXX bypasses q max and OACTIVE */
439                     parent_q = qhead->head;
440                     qhead->head = qhead->tail = NULL;
441                     qhead->len = 0;
442           }
443 
444           qhead = &psq->psq_head[1];    /* 802.3 frames */
445           if (qhead->head != NULL) {
446                     /* XXX need different driver interface */
447                     /* XXX bypasses q max and OACTIVE */
448                     ifp_q = qhead->head;
449                     qhead->head = qhead->tail = NULL;
450                     qhead->len = 0;
451           }
452           psq->psq_len = 0;
453           IEEE80211_PSQ_UNLOCK(psq);
454 
455           /* NB: do this outside the psq lock */
456           /* XXX packets might get reordered if parent is OACTIVE */
457           /* parent frames, should be encapsulated */
458           while (parent_q != NULL) {
459                     m = parent_q;
460                     parent_q = m->m_nextpkt;
461                     m->m_nextpkt = NULL;
462                     /* must be encapsulated */
463                     KASSERT((m->m_flags & M_ENCAP),
464                         ("%s: parentq with non-M_ENCAP frame!\n",
465                         __func__));
466                     (void) ieee80211_parent_xmitpkt(ic, m);
467           }
468 
469           /* VAP frames, aren't encapsulated */
470           while (ifp_q != NULL) {
471                     m = ifp_q;
472                     ifp_q = m->m_nextpkt;
473                     m->m_nextpkt = NULL;
474                     KASSERT((!(m->m_flags & M_ENCAP)),
475                         ("%s: vapq with M_ENCAP frame!\n", __func__));
476                     (void) ieee80211_vap_xmitpkt(vap, m);
477           }
478 }
479 
480 /*
481  * Handle station power-save state change.
482  */
483 void
ieee80211_node_pwrsave(struct ieee80211_node * ni,int enable)484 ieee80211_node_pwrsave(struct ieee80211_node *ni, int enable)
485 {
486           struct ieee80211vap *vap = ni->ni_vap;
487           int update;
488 
489           update = 0;
490           if (enable) {
491                     if ((ni->ni_flags & IEEE80211_NODE_PWR_MGT) == 0) {
492                               vap->iv_ps_sta++;
493                               update = 1;
494                     }
495                     ni->ni_flags |= IEEE80211_NODE_PWR_MGT;
496                     IEEE80211_NOTE(vap, IEEE80211_MSG_POWER, ni,
497                         "power save mode on, %u sta's in ps mode", vap->iv_ps_sta);
498 
499                     if (update)
500                               vap->iv_update_ps(vap, vap->iv_ps_sta);
501           } else {
502                     if (ni->ni_flags & IEEE80211_NODE_PWR_MGT) {
503                               vap->iv_ps_sta--;
504                               update = 1;
505                     }
506                     ni->ni_flags &= ~IEEE80211_NODE_PWR_MGT;
507                     IEEE80211_NOTE(vap, IEEE80211_MSG_POWER, ni,
508                         "power save mode off, %u sta's in ps mode", vap->iv_ps_sta);
509 
510                     /* NB: order here is intentional so TIM is clear before flush */
511                     if (vap->iv_set_tim != NULL)
512                               vap->iv_set_tim(ni, 0);
513                     if (update) {
514                               /* NB if no sta's in ps, driver should flush mc q */
515                               vap->iv_update_ps(vap, vap->iv_ps_sta);
516                     }
517                     if (ni->ni_psq.psq_len != 0)
518                               pwrsave_flushq(ni);
519           }
520 }
521 
522 /*
523  * Handle power-save state change in station mode.
524  */
525 void
ieee80211_sta_pwrsave(struct ieee80211vap * vap,int enable)526 ieee80211_sta_pwrsave(struct ieee80211vap *vap, int enable)
527 {
528           struct ieee80211_node *ni = vap->iv_bss;
529 
530           if (!((enable != 0) ^ ((ni->ni_flags & IEEE80211_NODE_PWR_MGT) != 0)))
531                     return;
532 
533           IEEE80211_NOTE(vap, IEEE80211_MSG_POWER, ni,
534               "sta power save mode %s", enable ? "on" : "off");
535           if (!enable) {
536                     ni->ni_flags &= ~IEEE80211_NODE_PWR_MGT;
537                     ieee80211_send_nulldata(ieee80211_ref_node(ni));
538                     /*
539                      * Flush any queued frames; we can do this immediately
540                      * because we know they'll be queued behind the null
541                      * data frame we send the ap.
542                      * XXX can we use a data frame to take us out of ps?
543                      */
544                     if (ni->ni_psq.psq_len != 0)
545                               pwrsave_flushq(ni);
546           } else {
547                     ni->ni_flags |= IEEE80211_NODE_PWR_MGT;
548                     ieee80211_send_nulldata(ieee80211_ref_node(ni));
549           }
550 }
551 
552 /*
553  * Handle being notified that we have data available for us in a TIM/ATIM.
554  *
555  * This may schedule a transition from _SLEEP -> _RUN if it's appropriate.
556  *
557  * In STA mode, we may have put to sleep during scan and need to be dragged
558  * back out of powersave mode.
559  */
560 void
ieee80211_sta_tim_notify(struct ieee80211vap * vap,int set)561 ieee80211_sta_tim_notify(struct ieee80211vap *vap, int set)
562 {
563           struct ieee80211com *ic = vap->iv_ic;
564 
565           /*
566            * Schedule the driver state change.  It'll happen at some point soon.
567            * Since the hardware shouldn't know that we're running just yet
568            * (and thus tell the peer that we're awake before we actually wake
569            * up said hardware), we leave the actual node state transition
570            * up to the transition to RUN.
571            *
572            * XXX TODO: verify that the transition to RUN will wake up the
573            * BSS node!
574            */
575           IEEE80211_LOCK(vap->iv_ic);
576           if (set == 1 && vap->iv_state == IEEE80211_S_SLEEP) {
577                     ieee80211_new_state_locked(vap, IEEE80211_S_RUN, 0);
578                     IEEE80211_DPRINTF(vap, IEEE80211_MSG_POWER,
579                         "%s: TIM=%d; wakeup\n", __func__, set);
580           } else if ((set == 1) && (ic->ic_flags_ext & IEEE80211_FEXT_BGSCAN)) {
581                     /*
582                      * XXX only do this if we're in RUN state?
583                      */
584                     IEEE80211_DPRINTF(vap, IEEE80211_MSG_POWER,
585                         "%s: wake up from bgscan vap sleep\n",
586                         __func__);
587                     /*
588                      * We may be in BGSCAN mode - this means the VAP is is in STA
589                      * mode powersave.  If it is, we need to wake it up so we
590                      * can process outbound traffic.
591                      */
592                     vap->iv_sta_ps(vap, 0);
593           }
594           IEEE80211_UNLOCK(vap->iv_ic);
595 }
596 
597 /*
598  * Timer check on whether the VAP has had any transmit activity.
599  *
600  * This may schedule a transition from _RUN -> _SLEEP if it's appropriate.
601  */
602 void
ieee80211_sta_ps_timer_check(struct ieee80211vap * vap)603 ieee80211_sta_ps_timer_check(struct ieee80211vap *vap)
604 {
605           struct ieee80211com *ic = vap->iv_ic;
606 
607           /* XXX lock assert */
608 
609           /* For no, only do this in STA mode */
610           if (! (vap->iv_caps & IEEE80211_C_SWSLEEP))
611                     goto out;
612 
613           if (vap->iv_opmode != IEEE80211_M_STA)
614                     goto out;
615 
616           /* If we're not at run state, bail */
617           if (vap->iv_state != IEEE80211_S_RUN)
618                     goto out;
619 
620           IEEE80211_DPRINTF(vap, IEEE80211_MSG_POWER,
621               "%s: lastdata=%llu, ticks=%llu\n",
622               __func__, (unsigned long long) ic->ic_lastdata,
623               (unsigned long long) ticks);
624 
625           /* If powersave is disabled on the VAP, don't bother */
626           if (! (vap->iv_flags & IEEE80211_F_PMGTON))
627                     goto out;
628 
629           /* If we've done any data within our idle interval, bail */
630           /* XXX hard-coded to one second for now, ew! */
631           if (ieee80211_time_after(ic->ic_lastdata + 500, ticks))
632                     goto out;
633 
634           /*
635            * Signify we're going into power save and transition the
636            * node to powersave.
637            */
638           if ((vap->iv_bss->ni_flags & IEEE80211_NODE_PWR_MGT) == 0)
639                     vap->iv_sta_ps(vap, 1);
640 
641           /*
642            * XXX The driver has to handle the fact that we're going
643            * to sleep but frames may still be transmitted;
644            * hopefully it and/or us will do the right thing and mark any
645            * transmitted frames with PWRMGT set to 1.
646            */
647           ieee80211_new_state_locked(vap, IEEE80211_S_SLEEP, 0);
648 
649           IEEE80211_DPRINTF(vap, IEEE80211_MSG_POWER,
650               "%s: time delta=%d msec\n", __func__,
651               (int) ticks_to_msecs(ticks - ic->ic_lastdata));
652 
653 out:
654           return;
655 }
656