1 /*
2  * Copyright (c) 2008-2011 Atheros Communications Inc.
3  *
4  * Permission to use, copy, modify, and/or distribute this software for any
5  * purpose with or without fee is hereby granted, provided that the above
6  * copyright notice and this permission notice appear in all copies.
7  *
8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15  */
16 
17 #include <linux/dma-mapping.h>
18 #include "ath9k.h"
19 
20 #define FUDGE 2
21 
22 static void ath9k_reset_beacon_status(struct ath_softc *sc)
23 {
24 	sc->beacon.tx_processed = false;
25 	sc->beacon.tx_last = false;
26 }
27 
28 /*
29  *  This function will modify certain transmit queue properties depending on
30  *  the operating mode of the station (AP or AdHoc).  Parameters are AIFS
31  *  settings and channel width min/max
32 */
33 static void ath9k_beaconq_config(struct ath_softc *sc)
34 {
35 	struct ath_hw *ah = sc->sc_ah;
36 	struct ath_common *common = ath9k_hw_common(ah);
37 	struct ath9k_tx_queue_info qi, qi_be;
38 	struct ath_txq *txq;
39 
40 	ath9k_hw_get_txq_props(ah, sc->beacon.beaconq, &qi);
41 
42 	if (sc->sc_ah->opmode == NL80211_IFTYPE_AP ||
43 	    sc->sc_ah->opmode == NL80211_IFTYPE_MESH_POINT) {
44 		/* Always burst out beacon and CAB traffic. */
45 		qi.tqi_aifs = 1;
46 		qi.tqi_cwmin = 0;
47 		qi.tqi_cwmax = 0;
48 	} else {
49 		/* Adhoc mode; important thing is to use 2x cwmin. */
50 		txq = sc->tx.txq_map[IEEE80211_AC_BE];
51 		ath9k_hw_get_txq_props(ah, txq->axq_qnum, &qi_be);
52 		qi.tqi_aifs = qi_be.tqi_aifs;
53 		if (ah->slottime == ATH9K_SLOT_TIME_20)
54 			qi.tqi_cwmin = 2*qi_be.tqi_cwmin;
55 		else
56 			qi.tqi_cwmin = 4*qi_be.tqi_cwmin;
57 		qi.tqi_cwmax = qi_be.tqi_cwmax;
58 	}
59 
60 	if (!ath9k_hw_set_txq_props(ah, sc->beacon.beaconq, &qi)) {
61 		ath_err(common, "Unable to update h/w beacon queue parameters\n");
62 	} else {
63 		ath9k_hw_resettxqueue(ah, sc->beacon.beaconq);
64 	}
65 }
66 
67 /*
68  *  Associates the beacon frame buffer with a transmit descriptor.  Will set
69  *  up rate codes, and channel flags. Beacons are always sent out at the
70  *  lowest rate, and are not retried.
71 */
72 static void ath9k_beacon_setup(struct ath_softc *sc, struct ieee80211_vif *vif,
73 			     struct ath_buf *bf, int rateidx)
74 {
75 	struct sk_buff *skb = bf->bf_mpdu;
76 	struct ath_hw *ah = sc->sc_ah;
77 	struct ath_common *common = ath9k_hw_common(ah);
78 	struct ath_tx_info info;
79 	struct ieee80211_supported_band *sband;
80 	u8 chainmask = ah->txchainmask;
81 	u8 i, rate = 0;
82 
83 	sband = &common->sbands[sc->cur_chandef.chan->band];
84 	rate = sband->bitrates[rateidx].hw_value;
85 	if (vif->bss_conf.use_short_preamble)
86 		rate |= sband->bitrates[rateidx].hw_value_short;
87 
88 	memset(&info, 0, sizeof(info));
89 	info.pkt_len = skb->len + FCS_LEN;
90 	info.type = ATH9K_PKT_TYPE_BEACON;
91 	for (i = 0; i < 4; i++)
92 		info.txpower[i] = MAX_RATE_POWER;
93 	info.keyix = ATH9K_TXKEYIX_INVALID;
94 	info.keytype = ATH9K_KEY_TYPE_CLEAR;
95 	info.flags = ATH9K_TXDESC_NOACK | ATH9K_TXDESC_CLRDMASK;
96 
97 	info.buf_addr[0] = bf->bf_buf_addr;
98 	info.buf_len[0] = roundup(skb->len, 4);
99 
100 	info.is_first = true;
101 	info.is_last = true;
102 
103 	info.qcu = sc->beacon.beaconq;
104 
105 	info.rates[0].Tries = 1;
106 	info.rates[0].Rate = rate;
107 	info.rates[0].ChSel = ath_txchainmask_reduction(sc, chainmask, rate);
108 
109 	ath9k_hw_set_txdesc(ah, bf->bf_desc, &info);
110 }
111 
112 static struct ath_buf *ath9k_beacon_generate(struct ieee80211_hw *hw,
113 					     struct ieee80211_vif *vif)
114 {
115 	struct ath_softc *sc = hw->priv;
116 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
117 	struct ath_buf *bf;
118 	struct ath_vif *avp = (void *)vif->drv_priv;
119 	struct sk_buff *skb;
120 	struct ath_txq *cabq = sc->beacon.cabq;
121 	struct ieee80211_tx_info *info;
122 	struct ieee80211_mgmt *mgmt_hdr;
123 	int cabq_depth;
124 
125 	if (avp->av_bcbuf == NULL)
126 		return NULL;
127 
128 	bf = avp->av_bcbuf;
129 	skb = bf->bf_mpdu;
130 	if (skb) {
131 		dma_unmap_single(sc->dev, bf->bf_buf_addr,
132 				 skb->len, DMA_TO_DEVICE);
133 		dev_kfree_skb_any(skb);
134 		bf->bf_buf_addr = 0;
135 		bf->bf_mpdu = NULL;
136 	}
137 
138 	skb = ieee80211_beacon_get(hw, vif);
139 	if (skb == NULL)
140 		return NULL;
141 
142 	bf->bf_mpdu = skb;
143 
144 	mgmt_hdr = (struct ieee80211_mgmt *)skb->data;
145 	mgmt_hdr->u.beacon.timestamp = avp->tsf_adjust;
146 
147 	info = IEEE80211_SKB_CB(skb);
148 
149 	ath_assign_seq(common, skb);
150 
151 	/* Always assign NOA attr when MCC enabled */
152 	if (ath9k_is_chanctx_enabled())
153 		ath9k_beacon_add_noa(sc, avp, skb);
154 
155 	bf->bf_buf_addr = dma_map_single(sc->dev, skb->data,
156 					 skb->len, DMA_TO_DEVICE);
157 	if (unlikely(dma_mapping_error(sc->dev, bf->bf_buf_addr))) {
158 		dev_kfree_skb_any(skb);
159 		bf->bf_mpdu = NULL;
160 		bf->bf_buf_addr = 0;
161 		ath_err(common, "dma_mapping_error on beaconing\n");
162 		return NULL;
163 	}
164 
165 	skb = ieee80211_get_buffered_bc(hw, vif);
166 
167 	/*
168 	 * if the CABQ traffic from previous DTIM is pending and the current
169 	 *  beacon is also a DTIM.
170 	 *  1) if there is only one vif let the cab traffic continue.
171 	 *  2) if there are more than one vif and we are using staggered
172 	 *     beacons, then drain the cabq by dropping all the frames in
173 	 *     the cabq so that the current vifs cab traffic can be scheduled.
174 	 */
175 	spin_lock_bh(&cabq->axq_lock);
176 	cabq_depth = cabq->axq_depth;
177 	spin_unlock_bh(&cabq->axq_lock);
178 
179 	if (skb && cabq_depth) {
180 		if (sc->cur_chan->nvifs > 1) {
181 			ath_dbg(common, BEACON,
182 				"Flushing previous cabq traffic\n");
183 			ath_draintxq(sc, cabq);
184 		}
185 	}
186 
187 	ath9k_beacon_setup(sc, vif, bf, info->control.rates[0].idx);
188 
189 	if (skb)
190 		ath_tx_cabq(hw, vif, skb);
191 
192 	return bf;
193 }
194 
195 void ath9k_beacon_assign_slot(struct ath_softc *sc, struct ieee80211_vif *vif)
196 {
197 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
198 	struct ath_vif *avp = (void *)vif->drv_priv;
199 	int slot;
200 
201 	avp->av_bcbuf = list_first_entry(&sc->beacon.bbuf, struct ath_buf, list);
202 	list_del(&avp->av_bcbuf->list);
203 
204 	for (slot = 0; slot < ATH_BCBUF; slot++) {
205 		if (sc->beacon.bslot[slot] == NULL) {
206 			avp->av_bslot = slot;
207 			break;
208 		}
209 	}
210 
211 	sc->beacon.bslot[avp->av_bslot] = vif;
212 	sc->nbcnvifs++;
213 
214 	ath_dbg(common, CONFIG, "Added interface at beacon slot: %d\n",
215 		avp->av_bslot);
216 }
217 
218 void ath9k_beacon_remove_slot(struct ath_softc *sc, struct ieee80211_vif *vif)
219 {
220 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
221 	struct ath_vif *avp = (void *)vif->drv_priv;
222 	struct ath_buf *bf = avp->av_bcbuf;
223 	struct ath_beacon_config *cur_conf = &sc->cur_chan->beacon;
224 
225 	ath_dbg(common, CONFIG, "Removing interface at beacon slot: %d\n",
226 		avp->av_bslot);
227 
228 	tasklet_disable(&sc->bcon_tasklet);
229 
230 	cur_conf->enable_beacon &= ~BIT(avp->av_bslot);
231 
232 	if (bf && bf->bf_mpdu) {
233 		struct sk_buff *skb = bf->bf_mpdu;
234 		dma_unmap_single(sc->dev, bf->bf_buf_addr,
235 				 skb->len, DMA_TO_DEVICE);
236 		dev_kfree_skb_any(skb);
237 		bf->bf_mpdu = NULL;
238 		bf->bf_buf_addr = 0;
239 	}
240 
241 	avp->av_bcbuf = NULL;
242 	sc->beacon.bslot[avp->av_bslot] = NULL;
243 	sc->nbcnvifs--;
244 	list_add_tail(&bf->list, &sc->beacon.bbuf);
245 
246 	tasklet_enable(&sc->bcon_tasklet);
247 }
248 
249 static int ath9k_beacon_choose_slot(struct ath_softc *sc)
250 {
251 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
252 	struct ath_beacon_config *cur_conf = &sc->cur_chan->beacon;
253 	u16 intval;
254 	u32 tsftu;
255 	u64 tsf;
256 	int slot;
257 
258 	if (sc->sc_ah->opmode != NL80211_IFTYPE_AP &&
259 	    sc->sc_ah->opmode != NL80211_IFTYPE_MESH_POINT) {
260 		ath_dbg(common, BEACON, "slot 0, tsf: %llu\n",
261 			ath9k_hw_gettsf64(sc->sc_ah));
262 		return 0;
263 	}
264 
265 	intval = cur_conf->beacon_interval ? : ATH_DEFAULT_BINTVAL;
266 	tsf = ath9k_hw_gettsf64(sc->sc_ah);
267 	tsf += TU_TO_USEC(sc->sc_ah->config.sw_beacon_response_time);
268 	tsftu = TSF_TO_TU((tsf * ATH_BCBUF) >>32, tsf * ATH_BCBUF);
269 	slot = (tsftu % (intval * ATH_BCBUF)) / intval;
270 
271 	ath_dbg(common, BEACON, "slot: %d tsf: %llu tsftu: %u\n",
272 		slot, tsf, tsftu / ATH_BCBUF);
273 
274 	return slot;
275 }
276 
277 static void ath9k_set_tsfadjust(struct ath_softc *sc, struct ieee80211_vif *vif)
278 {
279 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
280 	struct ath_vif *avp = (void *)vif->drv_priv;
281 	struct ath_beacon_config *cur_conf = &avp->chanctx->beacon;
282 	u32 tsfadjust;
283 
284 	if (avp->av_bslot == 0)
285 		return;
286 
287 	tsfadjust = cur_conf->beacon_interval * avp->av_bslot;
288 	tsfadjust = TU_TO_USEC(tsfadjust) / ATH_BCBUF;
289 	avp->tsf_adjust = cpu_to_le64(tsfadjust);
290 
291 	ath_dbg(common, CONFIG, "tsfadjust is: %llu for bslot: %d\n",
292 		(unsigned long long)tsfadjust, avp->av_bslot);
293 }
294 
295 bool ath9k_csa_is_finished(struct ath_softc *sc, struct ieee80211_vif *vif)
296 {
297 	if (!vif || !vif->csa_active)
298 		return false;
299 
300 	if (!ieee80211_csa_is_complete(vif))
301 		return false;
302 
303 	ieee80211_csa_finish(vif);
304 	return true;
305 }
306 
307 static void ath9k_csa_update_vif(void *data, u8 *mac, struct ieee80211_vif *vif)
308 {
309 	struct ath_softc *sc = data;
310 	ath9k_csa_is_finished(sc, vif);
311 }
312 
313 void ath9k_csa_update(struct ath_softc *sc)
314 {
315 	ieee80211_iterate_active_interfaces_atomic(sc->hw,
316 						   IEEE80211_IFACE_ITER_NORMAL,
317 						   ath9k_csa_update_vif, sc);
318 }
319 
320 void ath9k_beacon_tasklet(unsigned long data)
321 {
322 	struct ath_softc *sc = (struct ath_softc *)data;
323 	struct ath_hw *ah = sc->sc_ah;
324 	struct ath_common *common = ath9k_hw_common(ah);
325 	struct ath_buf *bf = NULL;
326 	struct ieee80211_vif *vif;
327 	bool edma = !!(ah->caps.hw_caps & ATH9K_HW_CAP_EDMA);
328 	int slot;
329 
330 	if (test_bit(ATH_OP_HW_RESET, &common->op_flags)) {
331 		ath_dbg(common, RESET,
332 			"reset work is pending, skip beaconing now\n");
333 		return;
334 	}
335 
336 	/*
337 	 * Check if the previous beacon has gone out.  If
338 	 * not don't try to post another, skip this period
339 	 * and wait for the next.  Missed beacons indicate
340 	 * a problem and should not occur.  If we miss too
341 	 * many consecutive beacons reset the device.
342 	 */
343 	if (ath9k_hw_numtxpending(ah, sc->beacon.beaconq) != 0) {
344 		sc->beacon.bmisscnt++;
345 
346 		ath9k_hw_check_nav(ah);
347 
348 		/*
349 		 * If the previous beacon has not been transmitted
350 		 * and a MAC/BB hang has been identified, return
351 		 * here because a chip reset would have been
352 		 * initiated.
353 		 */
354 		if (!ath_hw_check(sc))
355 			return;
356 
357 		if (sc->beacon.bmisscnt < BSTUCK_THRESH * sc->nbcnvifs) {
358 			ath_dbg(common, BSTUCK,
359 				"missed %u consecutive beacons\n",
360 				sc->beacon.bmisscnt);
361 			ath9k_hw_stop_dma_queue(ah, sc->beacon.beaconq);
362 			if (sc->beacon.bmisscnt > 3)
363 				ath9k_hw_bstuck_nfcal(ah);
364 		} else if (sc->beacon.bmisscnt >= BSTUCK_THRESH) {
365 			ath_dbg(common, BSTUCK, "beacon is officially stuck\n");
366 			sc->beacon.bmisscnt = 0;
367 			ath9k_queue_reset(sc, RESET_TYPE_BEACON_STUCK);
368 		}
369 
370 		return;
371 	}
372 
373 	slot = ath9k_beacon_choose_slot(sc);
374 	vif = sc->beacon.bslot[slot];
375 
376 	/* EDMA devices check that in the tx completion function. */
377 	if (!edma) {
378 		if (ath9k_is_chanctx_enabled()) {
379 			ath_chanctx_beacon_sent_ev(sc,
380 					  ATH_CHANCTX_EVENT_BEACON_SENT);
381 		}
382 
383 		if (ath9k_csa_is_finished(sc, vif))
384 			return;
385 	}
386 
387 	if (!vif || !vif->bss_conf.enable_beacon)
388 		return;
389 
390 	if (ath9k_is_chanctx_enabled()) {
391 		ath_chanctx_event(sc, vif, ATH_CHANCTX_EVENT_BEACON_PREPARE);
392 	}
393 
394 	bf = ath9k_beacon_generate(sc->hw, vif);
395 
396 	if (sc->beacon.bmisscnt != 0) {
397 		ath_dbg(common, BSTUCK, "resume beacon xmit after %u misses\n",
398 			sc->beacon.bmisscnt);
399 		sc->beacon.bmisscnt = 0;
400 	}
401 
402 	/*
403 	 * Handle slot time change when a non-ERP station joins/leaves
404 	 * an 11g network.  The 802.11 layer notifies us via callback,
405 	 * we mark updateslot, then wait one beacon before effecting
406 	 * the change.  This gives associated stations at least one
407 	 * beacon interval to note the state change.
408 	 *
409 	 * NB: The slot time change state machine is clocked according
410 	 *     to whether we are bursting or staggering beacons.  We
411 	 *     recognize the request to update and record the current
412 	 *     slot then don't transition until that slot is reached
413 	 *     again.  If we miss a beacon for that slot then we'll be
414 	 *     slow to transition but we'll be sure at least one beacon
415 	 *     interval has passed.  When bursting slot is always left
416 	 *     set to ATH_BCBUF so this check is a noop.
417 	 */
418 	if (sc->beacon.updateslot == UPDATE) {
419 		sc->beacon.updateslot = COMMIT;
420 		sc->beacon.slotupdate = slot;
421 	} else if (sc->beacon.updateslot == COMMIT &&
422 		   sc->beacon.slotupdate == slot) {
423 		ah->slottime = sc->beacon.slottime;
424 		ath9k_hw_init_global_settings(ah);
425 		sc->beacon.updateslot = OK;
426 	}
427 
428 	if (bf) {
429 		ath9k_reset_beacon_status(sc);
430 
431 		ath_dbg(common, BEACON,
432 			"Transmitting beacon for slot: %d\n", slot);
433 
434 		/* NB: cabq traffic should already be queued and primed */
435 		ath9k_hw_puttxbuf(ah, sc->beacon.beaconq, bf->bf_daddr);
436 
437 		if (!edma)
438 			ath9k_hw_txstart(ah, sc->beacon.beaconq);
439 	}
440 }
441 
442 /*
443  * Both nexttbtt and intval have to be in usecs.
444  */
445 static void ath9k_beacon_init(struct ath_softc *sc, u32 nexttbtt,
446 			      u32 intval, bool reset_tsf)
447 {
448 	struct ath_hw *ah = sc->sc_ah;
449 
450 	ath9k_hw_disable_interrupts(ah);
451 	if (reset_tsf)
452 		ath9k_hw_reset_tsf(ah);
453 	ath9k_beaconq_config(sc);
454 	ath9k_hw_beaconinit(ah, nexttbtt, intval);
455 	sc->beacon.bmisscnt = 0;
456 	ath9k_hw_set_interrupts(ah);
457 	ath9k_hw_enable_interrupts(ah);
458 }
459 
460 /*
461  * For multi-bss ap support beacons are either staggered evenly over N slots or
462  * burst together.  For the former arrange for the SWBA to be delivered for each
463  * slot. Slots that are not occupied will generate nothing.
464  */
465 static void ath9k_beacon_config_ap(struct ath_softc *sc,
466 				   struct ath_beacon_config *conf)
467 {
468 	struct ath_hw *ah = sc->sc_ah;
469 
470 	ath9k_cmn_beacon_config_ap(ah, conf, ATH_BCBUF);
471 	ath9k_beacon_init(sc, conf->nexttbtt, conf->intval, false);
472 }
473 
474 static void ath9k_beacon_config_sta(struct ath_hw *ah,
475 				    struct ath_beacon_config *conf)
476 {
477 	struct ath9k_beacon_state bs;
478 
479 	if (ath9k_cmn_beacon_config_sta(ah, conf, &bs) == -EPERM)
480 		return;
481 
482 	ath9k_hw_disable_interrupts(ah);
483 	ath9k_hw_set_sta_beacon_timers(ah, &bs);
484 	ah->imask |= ATH9K_INT_BMISS;
485 
486 	ath9k_hw_set_interrupts(ah);
487 	ath9k_hw_enable_interrupts(ah);
488 }
489 
490 static void ath9k_beacon_config_adhoc(struct ath_softc *sc,
491 				      struct ath_beacon_config *conf)
492 {
493 	struct ath_hw *ah = sc->sc_ah;
494 	struct ath_common *common = ath9k_hw_common(ah);
495 
496 	ath9k_reset_beacon_status(sc);
497 
498 	ath9k_cmn_beacon_config_adhoc(ah, conf);
499 
500 	ath9k_beacon_init(sc, conf->nexttbtt, conf->intval, conf->ibss_creator);
501 
502 	/*
503 	 * Set the global 'beacon has been configured' flag for the
504 	 * joiner case in IBSS mode.
505 	 */
506 	if (!conf->ibss_creator && conf->enable_beacon)
507 		set_bit(ATH_OP_BEACONS, &common->op_flags);
508 }
509 
510 static bool ath9k_allow_beacon_config(struct ath_softc *sc,
511 				      struct ieee80211_vif *vif)
512 {
513 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
514 	struct ath_vif *avp = (void *)vif->drv_priv;
515 
516 	if (ath9k_is_chanctx_enabled()) {
517 		/*
518 		 * If the VIF is not present in the current channel context,
519 		 * then we can't do the usual opmode checks. Allow the
520 		 * beacon config for the VIF to be updated in this case and
521 		 * return immediately.
522 		 */
523 		if (sc->cur_chan != avp->chanctx)
524 			return true;
525 	}
526 
527 	if (sc->sc_ah->opmode == NL80211_IFTYPE_AP) {
528 		if (vif->type != NL80211_IFTYPE_AP) {
529 			ath_dbg(common, CONFIG,
530 				"An AP interface is already present !\n");
531 			return false;
532 		}
533 	}
534 
535 	if (sc->sc_ah->opmode == NL80211_IFTYPE_STATION) {
536 		if ((vif->type == NL80211_IFTYPE_STATION) &&
537 		    test_bit(ATH_OP_BEACONS, &common->op_flags) &&
538 		    vif != sc->cur_chan->primary_sta) {
539 			ath_dbg(common, CONFIG,
540 				"Beacon already configured for a station interface\n");
541 			return false;
542 		}
543 	}
544 
545 	return true;
546 }
547 
548 static void ath9k_cache_beacon_config(struct ath_softc *sc,
549 				      struct ath_chanctx *ctx,
550 				      struct ieee80211_bss_conf *bss_conf)
551 {
552 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
553 	struct ath_beacon_config *cur_conf = &ctx->beacon;
554 
555 	ath_dbg(common, BEACON,
556 		"Caching beacon data for BSS: %pM\n", bss_conf->bssid);
557 
558 	cur_conf->beacon_interval = bss_conf->beacon_int;
559 	cur_conf->dtim_period = bss_conf->dtim_period;
560 	cur_conf->dtim_count = 1;
561 	cur_conf->ibss_creator = bss_conf->ibss_creator;
562 
563 	/*
564 	 * It looks like mac80211 may end up using beacon interval of zero in
565 	 * some cases (at least for mesh point). Avoid getting into an
566 	 * infinite loop by using a bit safer value instead. To be safe,
567 	 * do sanity check on beacon interval for all operating modes.
568 	 */
569 	if (cur_conf->beacon_interval == 0)
570 		cur_conf->beacon_interval = 100;
571 
572 	cur_conf->bmiss_timeout =
573 		ATH_DEFAULT_BMISS_LIMIT * cur_conf->beacon_interval;
574 
575 	/*
576 	 * We don't parse dtim period from mac80211 during the driver
577 	 * initialization as it breaks association with hidden-ssid
578 	 * AP and it causes latency in roaming
579 	 */
580 	if (cur_conf->dtim_period == 0)
581 		cur_conf->dtim_period = 1;
582 
583 }
584 
585 void ath9k_beacon_config(struct ath_softc *sc, struct ieee80211_vif *vif,
586 			 u32 changed)
587 {
588 	struct ieee80211_bss_conf *bss_conf = &vif->bss_conf;
589         struct ath_hw *ah = sc->sc_ah;
590         struct ath_common *common = ath9k_hw_common(ah);
591 	struct ath_vif *avp = (void *)vif->drv_priv;
592 	struct ath_chanctx *ctx = avp->chanctx;
593 	struct ath_beacon_config *cur_conf;
594 	unsigned long flags;
595 	bool skip_beacon = false;
596 
597 	if (!ctx)
598 		return;
599 
600 	cur_conf = &avp->chanctx->beacon;
601 	if (vif->type == NL80211_IFTYPE_AP)
602 		ath9k_set_tsfadjust(sc, vif);
603 
604 	if (!ath9k_allow_beacon_config(sc, vif))
605 		return;
606 
607 	if (vif->type == NL80211_IFTYPE_STATION) {
608 		ath9k_cache_beacon_config(sc, ctx, bss_conf);
609 		if (ctx != sc->cur_chan)
610 			return;
611 
612 		ath9k_set_beacon(sc);
613 		set_bit(ATH_OP_BEACONS, &common->op_flags);
614 		return;
615 	}
616 
617 	/*
618 	 * Take care of multiple interfaces when
619 	 * enabling/disabling SWBA.
620 	 */
621 	if (changed & BSS_CHANGED_BEACON_ENABLED) {
622 		bool enabled = cur_conf->enable_beacon;
623 
624 		if (!bss_conf->enable_beacon) {
625 			cur_conf->enable_beacon &= ~BIT(avp->av_bslot);
626 		} else {
627 			cur_conf->enable_beacon |= BIT(avp->av_bslot);
628 			if (!enabled)
629 				ath9k_cache_beacon_config(sc, ctx, bss_conf);
630 		}
631 	}
632 
633 	if (ctx != sc->cur_chan)
634 		return;
635 
636 	/*
637 	 * Configure the HW beacon registers only when we have a valid
638 	 * beacon interval.
639 	 */
640 	if (cur_conf->beacon_interval) {
641 		/*
642 		 * If we are joining an existing IBSS network, start beaconing
643 		 * only after a TSF-sync has taken place. Ensure that this
644 		 * happens by setting the appropriate flags.
645 		 */
646 		if ((changed & BSS_CHANGED_IBSS) && !bss_conf->ibss_creator &&
647 		    bss_conf->enable_beacon) {
648 			spin_lock_irqsave(&sc->sc_pm_lock, flags);
649 			sc->ps_flags |= PS_BEACON_SYNC | PS_WAIT_FOR_BEACON;
650 			spin_unlock_irqrestore(&sc->sc_pm_lock, flags);
651 			skip_beacon = true;
652 		} else {
653 			ath9k_set_beacon(sc);
654 		}
655 
656 		/*
657 		 * Do not set the ATH_OP_BEACONS flag for IBSS joiner mode
658 		 * here, it is done in ath9k_beacon_config_adhoc().
659 		 */
660 		if (cur_conf->enable_beacon && !skip_beacon)
661 			set_bit(ATH_OP_BEACONS, &common->op_flags);
662 		else
663 			clear_bit(ATH_OP_BEACONS, &common->op_flags);
664 	}
665 }
666 
667 void ath9k_set_beacon(struct ath_softc *sc)
668 {
669 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
670 	struct ath_beacon_config *cur_conf = &sc->cur_chan->beacon;
671 
672 	switch (sc->sc_ah->opmode) {
673 	case NL80211_IFTYPE_AP:
674 	case NL80211_IFTYPE_MESH_POINT:
675 		ath9k_beacon_config_ap(sc, cur_conf);
676 		break;
677 	case NL80211_IFTYPE_ADHOC:
678 		ath9k_beacon_config_adhoc(sc, cur_conf);
679 		break;
680 	case NL80211_IFTYPE_STATION:
681 		ath9k_beacon_config_sta(sc->sc_ah, cur_conf);
682 		break;
683 	default:
684 		ath_dbg(common, CONFIG, "Unsupported beaconing mode\n");
685 		return;
686 	}
687 }
688