xref: /openbmc/linux/drivers/net/wireless/ath/ath9k/recv.c (revision 63dc02bd)
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 #include "ar9003_mac.h"
20 
21 #define SKB_CB_ATHBUF(__skb)	(*((struct ath_buf **)__skb->cb))
22 
23 static inline bool ath_is_alt_ant_ratio_better(int alt_ratio, int maxdelta,
24 					       int mindelta, int main_rssi_avg,
25 					       int alt_rssi_avg, int pkt_count)
26 {
27 	return (((alt_ratio >= ATH_ANT_DIV_COMB_ALT_ANT_RATIO2) &&
28 		(alt_rssi_avg > main_rssi_avg + maxdelta)) ||
29 		(alt_rssi_avg > main_rssi_avg + mindelta)) && (pkt_count > 50);
30 }
31 
32 static inline bool ath_ant_div_comb_alt_check(u8 div_group, int alt_ratio,
33 					int curr_main_set, int curr_alt_set,
34 					int alt_rssi_avg, int main_rssi_avg)
35 {
36 	bool result = false;
37 	switch (div_group) {
38 	case 0:
39 		if (alt_ratio > ATH_ANT_DIV_COMB_ALT_ANT_RATIO)
40 			result = true;
41 		break;
42 	case 1:
43 	case 2:
44 		if ((((curr_main_set == ATH_ANT_DIV_COMB_LNA2) &&
45 			(curr_alt_set == ATH_ANT_DIV_COMB_LNA1) &&
46 				(alt_rssi_avg >= (main_rssi_avg - 5))) ||
47 			((curr_main_set == ATH_ANT_DIV_COMB_LNA1) &&
48 			(curr_alt_set == ATH_ANT_DIV_COMB_LNA2) &&
49 				(alt_rssi_avg >= (main_rssi_avg - 2)))) &&
50 							(alt_rssi_avg >= 4))
51 			result = true;
52 		else
53 			result = false;
54 		break;
55 	}
56 
57 	return result;
58 }
59 
60 static inline bool ath9k_check_auto_sleep(struct ath_softc *sc)
61 {
62 	return sc->ps_enabled &&
63 	       (sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_AUTOSLEEP);
64 }
65 
66 /*
67  * Setup and link descriptors.
68  *
69  * 11N: we can no longer afford to self link the last descriptor.
70  * MAC acknowledges BA status as long as it copies frames to host
71  * buffer (or rx fifo). This can incorrectly acknowledge packets
72  * to a sender if last desc is self-linked.
73  */
74 static void ath_rx_buf_link(struct ath_softc *sc, struct ath_buf *bf)
75 {
76 	struct ath_hw *ah = sc->sc_ah;
77 	struct ath_common *common = ath9k_hw_common(ah);
78 	struct ath_desc *ds;
79 	struct sk_buff *skb;
80 
81 	ATH_RXBUF_RESET(bf);
82 
83 	ds = bf->bf_desc;
84 	ds->ds_link = 0; /* link to null */
85 	ds->ds_data = bf->bf_buf_addr;
86 
87 	/* virtual addr of the beginning of the buffer. */
88 	skb = bf->bf_mpdu;
89 	BUG_ON(skb == NULL);
90 	ds->ds_vdata = skb->data;
91 
92 	/*
93 	 * setup rx descriptors. The rx_bufsize here tells the hardware
94 	 * how much data it can DMA to us and that we are prepared
95 	 * to process
96 	 */
97 	ath9k_hw_setuprxdesc(ah, ds,
98 			     common->rx_bufsize,
99 			     0);
100 
101 	if (sc->rx.rxlink == NULL)
102 		ath9k_hw_putrxbuf(ah, bf->bf_daddr);
103 	else
104 		*sc->rx.rxlink = bf->bf_daddr;
105 
106 	sc->rx.rxlink = &ds->ds_link;
107 }
108 
109 static void ath_setdefantenna(struct ath_softc *sc, u32 antenna)
110 {
111 	/* XXX block beacon interrupts */
112 	ath9k_hw_setantenna(sc->sc_ah, antenna);
113 	sc->rx.defant = antenna;
114 	sc->rx.rxotherant = 0;
115 }
116 
117 static void ath_opmode_init(struct ath_softc *sc)
118 {
119 	struct ath_hw *ah = sc->sc_ah;
120 	struct ath_common *common = ath9k_hw_common(ah);
121 
122 	u32 rfilt, mfilt[2];
123 
124 	/* configure rx filter */
125 	rfilt = ath_calcrxfilter(sc);
126 	ath9k_hw_setrxfilter(ah, rfilt);
127 
128 	/* configure bssid mask */
129 	ath_hw_setbssidmask(common);
130 
131 	/* configure operational mode */
132 	ath9k_hw_setopmode(ah);
133 
134 	/* calculate and install multicast filter */
135 	mfilt[0] = mfilt[1] = ~0;
136 	ath9k_hw_setmcastfilter(ah, mfilt[0], mfilt[1]);
137 }
138 
139 static bool ath_rx_edma_buf_link(struct ath_softc *sc,
140 				 enum ath9k_rx_qtype qtype)
141 {
142 	struct ath_hw *ah = sc->sc_ah;
143 	struct ath_rx_edma *rx_edma;
144 	struct sk_buff *skb;
145 	struct ath_buf *bf;
146 
147 	rx_edma = &sc->rx.rx_edma[qtype];
148 	if (skb_queue_len(&rx_edma->rx_fifo) >= rx_edma->rx_fifo_hwsize)
149 		return false;
150 
151 	bf = list_first_entry(&sc->rx.rxbuf, struct ath_buf, list);
152 	list_del_init(&bf->list);
153 
154 	skb = bf->bf_mpdu;
155 
156 	ATH_RXBUF_RESET(bf);
157 	memset(skb->data, 0, ah->caps.rx_status_len);
158 	dma_sync_single_for_device(sc->dev, bf->bf_buf_addr,
159 				ah->caps.rx_status_len, DMA_TO_DEVICE);
160 
161 	SKB_CB_ATHBUF(skb) = bf;
162 	ath9k_hw_addrxbuf_edma(ah, bf->bf_buf_addr, qtype);
163 	skb_queue_tail(&rx_edma->rx_fifo, skb);
164 
165 	return true;
166 }
167 
168 static void ath_rx_addbuffer_edma(struct ath_softc *sc,
169 				  enum ath9k_rx_qtype qtype, int size)
170 {
171 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
172 	struct ath_buf *bf, *tbf;
173 
174 	if (list_empty(&sc->rx.rxbuf)) {
175 		ath_dbg(common, QUEUE, "No free rx buf available\n");
176 		return;
177 	}
178 
179 	list_for_each_entry_safe(bf, tbf, &sc->rx.rxbuf, list)
180 		if (!ath_rx_edma_buf_link(sc, qtype))
181 			break;
182 
183 }
184 
185 static void ath_rx_remove_buffer(struct ath_softc *sc,
186 				 enum ath9k_rx_qtype qtype)
187 {
188 	struct ath_buf *bf;
189 	struct ath_rx_edma *rx_edma;
190 	struct sk_buff *skb;
191 
192 	rx_edma = &sc->rx.rx_edma[qtype];
193 
194 	while ((skb = skb_dequeue(&rx_edma->rx_fifo)) != NULL) {
195 		bf = SKB_CB_ATHBUF(skb);
196 		BUG_ON(!bf);
197 		list_add_tail(&bf->list, &sc->rx.rxbuf);
198 	}
199 }
200 
201 static void ath_rx_edma_cleanup(struct ath_softc *sc)
202 {
203 	struct ath_hw *ah = sc->sc_ah;
204 	struct ath_common *common = ath9k_hw_common(ah);
205 	struct ath_buf *bf;
206 
207 	ath_rx_remove_buffer(sc, ATH9K_RX_QUEUE_LP);
208 	ath_rx_remove_buffer(sc, ATH9K_RX_QUEUE_HP);
209 
210 	list_for_each_entry(bf, &sc->rx.rxbuf, list) {
211 		if (bf->bf_mpdu) {
212 			dma_unmap_single(sc->dev, bf->bf_buf_addr,
213 					common->rx_bufsize,
214 					DMA_BIDIRECTIONAL);
215 			dev_kfree_skb_any(bf->bf_mpdu);
216 			bf->bf_buf_addr = 0;
217 			bf->bf_mpdu = NULL;
218 		}
219 	}
220 
221 	INIT_LIST_HEAD(&sc->rx.rxbuf);
222 
223 	kfree(sc->rx.rx_bufptr);
224 	sc->rx.rx_bufptr = NULL;
225 }
226 
227 static void ath_rx_edma_init_queue(struct ath_rx_edma *rx_edma, int size)
228 {
229 	skb_queue_head_init(&rx_edma->rx_fifo);
230 	rx_edma->rx_fifo_hwsize = size;
231 }
232 
233 static int ath_rx_edma_init(struct ath_softc *sc, int nbufs)
234 {
235 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
236 	struct ath_hw *ah = sc->sc_ah;
237 	struct sk_buff *skb;
238 	struct ath_buf *bf;
239 	int error = 0, i;
240 	u32 size;
241 
242 	ath9k_hw_set_rx_bufsize(ah, common->rx_bufsize -
243 				    ah->caps.rx_status_len);
244 
245 	ath_rx_edma_init_queue(&sc->rx.rx_edma[ATH9K_RX_QUEUE_LP],
246 			       ah->caps.rx_lp_qdepth);
247 	ath_rx_edma_init_queue(&sc->rx.rx_edma[ATH9K_RX_QUEUE_HP],
248 			       ah->caps.rx_hp_qdepth);
249 
250 	size = sizeof(struct ath_buf) * nbufs;
251 	bf = kzalloc(size, GFP_KERNEL);
252 	if (!bf)
253 		return -ENOMEM;
254 
255 	INIT_LIST_HEAD(&sc->rx.rxbuf);
256 	sc->rx.rx_bufptr = bf;
257 
258 	for (i = 0; i < nbufs; i++, bf++) {
259 		skb = ath_rxbuf_alloc(common, common->rx_bufsize, GFP_KERNEL);
260 		if (!skb) {
261 			error = -ENOMEM;
262 			goto rx_init_fail;
263 		}
264 
265 		memset(skb->data, 0, common->rx_bufsize);
266 		bf->bf_mpdu = skb;
267 
268 		bf->bf_buf_addr = dma_map_single(sc->dev, skb->data,
269 						 common->rx_bufsize,
270 						 DMA_BIDIRECTIONAL);
271 		if (unlikely(dma_mapping_error(sc->dev,
272 						bf->bf_buf_addr))) {
273 				dev_kfree_skb_any(skb);
274 				bf->bf_mpdu = NULL;
275 				bf->bf_buf_addr = 0;
276 				ath_err(common,
277 					"dma_mapping_error() on RX init\n");
278 				error = -ENOMEM;
279 				goto rx_init_fail;
280 		}
281 
282 		list_add_tail(&bf->list, &sc->rx.rxbuf);
283 	}
284 
285 	return 0;
286 
287 rx_init_fail:
288 	ath_rx_edma_cleanup(sc);
289 	return error;
290 }
291 
292 static void ath_edma_start_recv(struct ath_softc *sc)
293 {
294 	spin_lock_bh(&sc->rx.rxbuflock);
295 
296 	ath9k_hw_rxena(sc->sc_ah);
297 
298 	ath_rx_addbuffer_edma(sc, ATH9K_RX_QUEUE_HP,
299 			      sc->rx.rx_edma[ATH9K_RX_QUEUE_HP].rx_fifo_hwsize);
300 
301 	ath_rx_addbuffer_edma(sc, ATH9K_RX_QUEUE_LP,
302 			      sc->rx.rx_edma[ATH9K_RX_QUEUE_LP].rx_fifo_hwsize);
303 
304 	ath_opmode_init(sc);
305 
306 	ath9k_hw_startpcureceive(sc->sc_ah, (sc->sc_flags & SC_OP_OFFCHANNEL));
307 
308 	spin_unlock_bh(&sc->rx.rxbuflock);
309 }
310 
311 static void ath_edma_stop_recv(struct ath_softc *sc)
312 {
313 	ath_rx_remove_buffer(sc, ATH9K_RX_QUEUE_HP);
314 	ath_rx_remove_buffer(sc, ATH9K_RX_QUEUE_LP);
315 }
316 
317 int ath_rx_init(struct ath_softc *sc, int nbufs)
318 {
319 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
320 	struct sk_buff *skb;
321 	struct ath_buf *bf;
322 	int error = 0;
323 
324 	spin_lock_init(&sc->sc_pcu_lock);
325 	sc->sc_flags &= ~SC_OP_RXFLUSH;
326 	spin_lock_init(&sc->rx.rxbuflock);
327 
328 	common->rx_bufsize = IEEE80211_MAX_MPDU_LEN / 2 +
329 			     sc->sc_ah->caps.rx_status_len;
330 
331 	if (sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_EDMA) {
332 		return ath_rx_edma_init(sc, nbufs);
333 	} else {
334 		ath_dbg(common, CONFIG, "cachelsz %u rxbufsize %u\n",
335 			common->cachelsz, common->rx_bufsize);
336 
337 		/* Initialize rx descriptors */
338 
339 		error = ath_descdma_setup(sc, &sc->rx.rxdma, &sc->rx.rxbuf,
340 				"rx", nbufs, 1, 0);
341 		if (error != 0) {
342 			ath_err(common,
343 				"failed to allocate rx descriptors: %d\n",
344 				error);
345 			goto err;
346 		}
347 
348 		list_for_each_entry(bf, &sc->rx.rxbuf, list) {
349 			skb = ath_rxbuf_alloc(common, common->rx_bufsize,
350 					      GFP_KERNEL);
351 			if (skb == NULL) {
352 				error = -ENOMEM;
353 				goto err;
354 			}
355 
356 			bf->bf_mpdu = skb;
357 			bf->bf_buf_addr = dma_map_single(sc->dev, skb->data,
358 					common->rx_bufsize,
359 					DMA_FROM_DEVICE);
360 			if (unlikely(dma_mapping_error(sc->dev,
361 							bf->bf_buf_addr))) {
362 				dev_kfree_skb_any(skb);
363 				bf->bf_mpdu = NULL;
364 				bf->bf_buf_addr = 0;
365 				ath_err(common,
366 					"dma_mapping_error() on RX init\n");
367 				error = -ENOMEM;
368 				goto err;
369 			}
370 		}
371 		sc->rx.rxlink = NULL;
372 	}
373 
374 err:
375 	if (error)
376 		ath_rx_cleanup(sc);
377 
378 	return error;
379 }
380 
381 void ath_rx_cleanup(struct ath_softc *sc)
382 {
383 	struct ath_hw *ah = sc->sc_ah;
384 	struct ath_common *common = ath9k_hw_common(ah);
385 	struct sk_buff *skb;
386 	struct ath_buf *bf;
387 
388 	if (sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_EDMA) {
389 		ath_rx_edma_cleanup(sc);
390 		return;
391 	} else {
392 		list_for_each_entry(bf, &sc->rx.rxbuf, list) {
393 			skb = bf->bf_mpdu;
394 			if (skb) {
395 				dma_unmap_single(sc->dev, bf->bf_buf_addr,
396 						common->rx_bufsize,
397 						DMA_FROM_DEVICE);
398 				dev_kfree_skb(skb);
399 				bf->bf_buf_addr = 0;
400 				bf->bf_mpdu = NULL;
401 			}
402 		}
403 
404 		if (sc->rx.rxdma.dd_desc_len != 0)
405 			ath_descdma_cleanup(sc, &sc->rx.rxdma, &sc->rx.rxbuf);
406 	}
407 }
408 
409 /*
410  * Calculate the receive filter according to the
411  * operating mode and state:
412  *
413  * o always accept unicast, broadcast, and multicast traffic
414  * o maintain current state of phy error reception (the hal
415  *   may enable phy error frames for noise immunity work)
416  * o probe request frames are accepted only when operating in
417  *   hostap, adhoc, or monitor modes
418  * o enable promiscuous mode according to the interface state
419  * o accept beacons:
420  *   - when operating in adhoc mode so the 802.11 layer creates
421  *     node table entries for peers,
422  *   - when operating in station mode for collecting rssi data when
423  *     the station is otherwise quiet, or
424  *   - when operating as a repeater so we see repeater-sta beacons
425  *   - when scanning
426  */
427 
428 u32 ath_calcrxfilter(struct ath_softc *sc)
429 {
430 	u32 rfilt;
431 
432 	rfilt = ATH9K_RX_FILTER_UCAST | ATH9K_RX_FILTER_BCAST
433 		| ATH9K_RX_FILTER_MCAST;
434 
435 	if (sc->rx.rxfilter & FIF_PROBE_REQ)
436 		rfilt |= ATH9K_RX_FILTER_PROBEREQ;
437 
438 	/*
439 	 * Set promiscuous mode when FIF_PROMISC_IN_BSS is enabled for station
440 	 * mode interface or when in monitor mode. AP mode does not need this
441 	 * since it receives all in-BSS frames anyway.
442 	 */
443 	if (sc->sc_ah->is_monitoring)
444 		rfilt |= ATH9K_RX_FILTER_PROM;
445 
446 	if (sc->rx.rxfilter & FIF_CONTROL)
447 		rfilt |= ATH9K_RX_FILTER_CONTROL;
448 
449 	if ((sc->sc_ah->opmode == NL80211_IFTYPE_STATION) &&
450 	    (sc->nvifs <= 1) &&
451 	    !(sc->rx.rxfilter & FIF_BCN_PRBRESP_PROMISC))
452 		rfilt |= ATH9K_RX_FILTER_MYBEACON;
453 	else
454 		rfilt |= ATH9K_RX_FILTER_BEACON;
455 
456 	if ((sc->sc_ah->opmode == NL80211_IFTYPE_AP) ||
457 	    (sc->rx.rxfilter & FIF_PSPOLL))
458 		rfilt |= ATH9K_RX_FILTER_PSPOLL;
459 
460 	if (conf_is_ht(&sc->hw->conf))
461 		rfilt |= ATH9K_RX_FILTER_COMP_BAR;
462 
463 	if (sc->nvifs > 1 || (sc->rx.rxfilter & FIF_OTHER_BSS)) {
464 		/* The following may also be needed for other older chips */
465 		if (sc->sc_ah->hw_version.macVersion == AR_SREV_VERSION_9160)
466 			rfilt |= ATH9K_RX_FILTER_PROM;
467 		rfilt |= ATH9K_RX_FILTER_MCAST_BCAST_ALL;
468 	}
469 
470 	return rfilt;
471 
472 }
473 
474 int ath_startrecv(struct ath_softc *sc)
475 {
476 	struct ath_hw *ah = sc->sc_ah;
477 	struct ath_buf *bf, *tbf;
478 
479 	if (ah->caps.hw_caps & ATH9K_HW_CAP_EDMA) {
480 		ath_edma_start_recv(sc);
481 		return 0;
482 	}
483 
484 	spin_lock_bh(&sc->rx.rxbuflock);
485 	if (list_empty(&sc->rx.rxbuf))
486 		goto start_recv;
487 
488 	sc->rx.rxlink = NULL;
489 	list_for_each_entry_safe(bf, tbf, &sc->rx.rxbuf, list) {
490 		ath_rx_buf_link(sc, bf);
491 	}
492 
493 	/* We could have deleted elements so the list may be empty now */
494 	if (list_empty(&sc->rx.rxbuf))
495 		goto start_recv;
496 
497 	bf = list_first_entry(&sc->rx.rxbuf, struct ath_buf, list);
498 	ath9k_hw_putrxbuf(ah, bf->bf_daddr);
499 	ath9k_hw_rxena(ah);
500 
501 start_recv:
502 	ath_opmode_init(sc);
503 	ath9k_hw_startpcureceive(ah, (sc->sc_flags & SC_OP_OFFCHANNEL));
504 
505 	spin_unlock_bh(&sc->rx.rxbuflock);
506 
507 	return 0;
508 }
509 
510 bool ath_stoprecv(struct ath_softc *sc)
511 {
512 	struct ath_hw *ah = sc->sc_ah;
513 	bool stopped, reset = false;
514 
515 	spin_lock_bh(&sc->rx.rxbuflock);
516 	ath9k_hw_abortpcurecv(ah);
517 	ath9k_hw_setrxfilter(ah, 0);
518 	stopped = ath9k_hw_stopdmarecv(ah, &reset);
519 
520 	if (sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_EDMA)
521 		ath_edma_stop_recv(sc);
522 	else
523 		sc->rx.rxlink = NULL;
524 	spin_unlock_bh(&sc->rx.rxbuflock);
525 
526 	if (!(ah->ah_flags & AH_UNPLUGGED) &&
527 	    unlikely(!stopped)) {
528 		ath_err(ath9k_hw_common(sc->sc_ah),
529 			"Could not stop RX, we could be "
530 			"confusing the DMA engine when we start RX up\n");
531 		ATH_DBG_WARN_ON_ONCE(!stopped);
532 	}
533 	return stopped && !reset;
534 }
535 
536 void ath_flushrecv(struct ath_softc *sc)
537 {
538 	sc->sc_flags |= SC_OP_RXFLUSH;
539 	if (sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_EDMA)
540 		ath_rx_tasklet(sc, 1, true);
541 	ath_rx_tasklet(sc, 1, false);
542 	sc->sc_flags &= ~SC_OP_RXFLUSH;
543 }
544 
545 static bool ath_beacon_dtim_pending_cab(struct sk_buff *skb)
546 {
547 	/* Check whether the Beacon frame has DTIM indicating buffered bc/mc */
548 	struct ieee80211_mgmt *mgmt;
549 	u8 *pos, *end, id, elen;
550 	struct ieee80211_tim_ie *tim;
551 
552 	mgmt = (struct ieee80211_mgmt *)skb->data;
553 	pos = mgmt->u.beacon.variable;
554 	end = skb->data + skb->len;
555 
556 	while (pos + 2 < end) {
557 		id = *pos++;
558 		elen = *pos++;
559 		if (pos + elen > end)
560 			break;
561 
562 		if (id == WLAN_EID_TIM) {
563 			if (elen < sizeof(*tim))
564 				break;
565 			tim = (struct ieee80211_tim_ie *) pos;
566 			if (tim->dtim_count != 0)
567 				break;
568 			return tim->bitmap_ctrl & 0x01;
569 		}
570 
571 		pos += elen;
572 	}
573 
574 	return false;
575 }
576 
577 static void ath_rx_ps_beacon(struct ath_softc *sc, struct sk_buff *skb)
578 {
579 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
580 
581 	if (skb->len < 24 + 8 + 2 + 2)
582 		return;
583 
584 	sc->ps_flags &= ~PS_WAIT_FOR_BEACON;
585 
586 	if (sc->ps_flags & PS_BEACON_SYNC) {
587 		sc->ps_flags &= ~PS_BEACON_SYNC;
588 		ath_dbg(common, PS,
589 			"Reconfigure Beacon timers based on timestamp from the AP\n");
590 		ath_set_beacon(sc);
591 	}
592 
593 	if (ath_beacon_dtim_pending_cab(skb)) {
594 		/*
595 		 * Remain awake waiting for buffered broadcast/multicast
596 		 * frames. If the last broadcast/multicast frame is not
597 		 * received properly, the next beacon frame will work as
598 		 * a backup trigger for returning into NETWORK SLEEP state,
599 		 * so we are waiting for it as well.
600 		 */
601 		ath_dbg(common, PS,
602 			"Received DTIM beacon indicating buffered broadcast/multicast frame(s)\n");
603 		sc->ps_flags |= PS_WAIT_FOR_CAB | PS_WAIT_FOR_BEACON;
604 		return;
605 	}
606 
607 	if (sc->ps_flags & PS_WAIT_FOR_CAB) {
608 		/*
609 		 * This can happen if a broadcast frame is dropped or the AP
610 		 * fails to send a frame indicating that all CAB frames have
611 		 * been delivered.
612 		 */
613 		sc->ps_flags &= ~PS_WAIT_FOR_CAB;
614 		ath_dbg(common, PS, "PS wait for CAB frames timed out\n");
615 	}
616 }
617 
618 static void ath_rx_ps(struct ath_softc *sc, struct sk_buff *skb, bool mybeacon)
619 {
620 	struct ieee80211_hdr *hdr;
621 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
622 
623 	hdr = (struct ieee80211_hdr *)skb->data;
624 
625 	/* Process Beacon and CAB receive in PS state */
626 	if (((sc->ps_flags & PS_WAIT_FOR_BEACON) || ath9k_check_auto_sleep(sc))
627 	    && mybeacon)
628 		ath_rx_ps_beacon(sc, skb);
629 	else if ((sc->ps_flags & PS_WAIT_FOR_CAB) &&
630 		 (ieee80211_is_data(hdr->frame_control) ||
631 		  ieee80211_is_action(hdr->frame_control)) &&
632 		 is_multicast_ether_addr(hdr->addr1) &&
633 		 !ieee80211_has_moredata(hdr->frame_control)) {
634 		/*
635 		 * No more broadcast/multicast frames to be received at this
636 		 * point.
637 		 */
638 		sc->ps_flags &= ~(PS_WAIT_FOR_CAB | PS_WAIT_FOR_BEACON);
639 		ath_dbg(common, PS,
640 			"All PS CAB frames received, back to sleep\n");
641 	} else if ((sc->ps_flags & PS_WAIT_FOR_PSPOLL_DATA) &&
642 		   !is_multicast_ether_addr(hdr->addr1) &&
643 		   !ieee80211_has_morefrags(hdr->frame_control)) {
644 		sc->ps_flags &= ~PS_WAIT_FOR_PSPOLL_DATA;
645 		ath_dbg(common, PS,
646 			"Going back to sleep after having received PS-Poll data (0x%lx)\n",
647 			sc->ps_flags & (PS_WAIT_FOR_BEACON |
648 					PS_WAIT_FOR_CAB |
649 					PS_WAIT_FOR_PSPOLL_DATA |
650 					PS_WAIT_FOR_TX_ACK));
651 	}
652 }
653 
654 static bool ath_edma_get_buffers(struct ath_softc *sc,
655 				 enum ath9k_rx_qtype qtype,
656 				 struct ath_rx_status *rs,
657 				 struct ath_buf **dest)
658 {
659 	struct ath_rx_edma *rx_edma = &sc->rx.rx_edma[qtype];
660 	struct ath_hw *ah = sc->sc_ah;
661 	struct ath_common *common = ath9k_hw_common(ah);
662 	struct sk_buff *skb;
663 	struct ath_buf *bf;
664 	int ret;
665 
666 	skb = skb_peek(&rx_edma->rx_fifo);
667 	if (!skb)
668 		return false;
669 
670 	bf = SKB_CB_ATHBUF(skb);
671 	BUG_ON(!bf);
672 
673 	dma_sync_single_for_cpu(sc->dev, bf->bf_buf_addr,
674 				common->rx_bufsize, DMA_FROM_DEVICE);
675 
676 	ret = ath9k_hw_process_rxdesc_edma(ah, rs, skb->data);
677 	if (ret == -EINPROGRESS) {
678 		/*let device gain the buffer again*/
679 		dma_sync_single_for_device(sc->dev, bf->bf_buf_addr,
680 				common->rx_bufsize, DMA_FROM_DEVICE);
681 		return false;
682 	}
683 
684 	__skb_unlink(skb, &rx_edma->rx_fifo);
685 	if (ret == -EINVAL) {
686 		/* corrupt descriptor, skip this one and the following one */
687 		list_add_tail(&bf->list, &sc->rx.rxbuf);
688 		ath_rx_edma_buf_link(sc, qtype);
689 
690 		skb = skb_peek(&rx_edma->rx_fifo);
691 		if (skb) {
692 			bf = SKB_CB_ATHBUF(skb);
693 			BUG_ON(!bf);
694 
695 			__skb_unlink(skb, &rx_edma->rx_fifo);
696 			list_add_tail(&bf->list, &sc->rx.rxbuf);
697 			ath_rx_edma_buf_link(sc, qtype);
698 		} else {
699 			bf = NULL;
700 		}
701 	}
702 
703 	*dest = bf;
704 	return true;
705 }
706 
707 static struct ath_buf *ath_edma_get_next_rx_buf(struct ath_softc *sc,
708 						struct ath_rx_status *rs,
709 						enum ath9k_rx_qtype qtype)
710 {
711 	struct ath_buf *bf = NULL;
712 
713 	while (ath_edma_get_buffers(sc, qtype, rs, &bf)) {
714 		if (!bf)
715 			continue;
716 
717 		return bf;
718 	}
719 	return NULL;
720 }
721 
722 static struct ath_buf *ath_get_next_rx_buf(struct ath_softc *sc,
723 					   struct ath_rx_status *rs)
724 {
725 	struct ath_hw *ah = sc->sc_ah;
726 	struct ath_common *common = ath9k_hw_common(ah);
727 	struct ath_desc *ds;
728 	struct ath_buf *bf;
729 	int ret;
730 
731 	if (list_empty(&sc->rx.rxbuf)) {
732 		sc->rx.rxlink = NULL;
733 		return NULL;
734 	}
735 
736 	bf = list_first_entry(&sc->rx.rxbuf, struct ath_buf, list);
737 	ds = bf->bf_desc;
738 
739 	/*
740 	 * Must provide the virtual address of the current
741 	 * descriptor, the physical address, and the virtual
742 	 * address of the next descriptor in the h/w chain.
743 	 * This allows the HAL to look ahead to see if the
744 	 * hardware is done with a descriptor by checking the
745 	 * done bit in the following descriptor and the address
746 	 * of the current descriptor the DMA engine is working
747 	 * on.  All this is necessary because of our use of
748 	 * a self-linked list to avoid rx overruns.
749 	 */
750 	ret = ath9k_hw_rxprocdesc(ah, ds, rs);
751 	if (ret == -EINPROGRESS) {
752 		struct ath_rx_status trs;
753 		struct ath_buf *tbf;
754 		struct ath_desc *tds;
755 
756 		memset(&trs, 0, sizeof(trs));
757 		if (list_is_last(&bf->list, &sc->rx.rxbuf)) {
758 			sc->rx.rxlink = NULL;
759 			return NULL;
760 		}
761 
762 		tbf = list_entry(bf->list.next, struct ath_buf, list);
763 
764 		/*
765 		 * On some hardware the descriptor status words could
766 		 * get corrupted, including the done bit. Because of
767 		 * this, check if the next descriptor's done bit is
768 		 * set or not.
769 		 *
770 		 * If the next descriptor's done bit is set, the current
771 		 * descriptor has been corrupted. Force s/w to discard
772 		 * this descriptor and continue...
773 		 */
774 
775 		tds = tbf->bf_desc;
776 		ret = ath9k_hw_rxprocdesc(ah, tds, &trs);
777 		if (ret == -EINPROGRESS)
778 			return NULL;
779 	}
780 
781 	if (!bf->bf_mpdu)
782 		return bf;
783 
784 	/*
785 	 * Synchronize the DMA transfer with CPU before
786 	 * 1. accessing the frame
787 	 * 2. requeueing the same buffer to h/w
788 	 */
789 	dma_sync_single_for_cpu(sc->dev, bf->bf_buf_addr,
790 			common->rx_bufsize,
791 			DMA_FROM_DEVICE);
792 
793 	return bf;
794 }
795 
796 /* Assumes you've already done the endian to CPU conversion */
797 static bool ath9k_rx_accept(struct ath_common *common,
798 			    struct ieee80211_hdr *hdr,
799 			    struct ieee80211_rx_status *rxs,
800 			    struct ath_rx_status *rx_stats,
801 			    bool *decrypt_error)
802 {
803 	struct ath_softc *sc = (struct ath_softc *) common->priv;
804 	bool is_mc, is_valid_tkip, strip_mic, mic_error;
805 	struct ath_hw *ah = common->ah;
806 	__le16 fc;
807 	u8 rx_status_len = ah->caps.rx_status_len;
808 
809 	fc = hdr->frame_control;
810 
811 	is_mc = !!is_multicast_ether_addr(hdr->addr1);
812 	is_valid_tkip = rx_stats->rs_keyix != ATH9K_RXKEYIX_INVALID &&
813 		test_bit(rx_stats->rs_keyix, common->tkip_keymap);
814 	strip_mic = is_valid_tkip && ieee80211_is_data(fc) &&
815 		!(rx_stats->rs_status &
816 		(ATH9K_RXERR_DECRYPT | ATH9K_RXERR_CRC | ATH9K_RXERR_MIC |
817 		 ATH9K_RXERR_KEYMISS));
818 
819 	/*
820 	 * Key miss events are only relevant for pairwise keys where the
821 	 * descriptor does contain a valid key index. This has been observed
822 	 * mostly with CCMP encryption.
823 	 */
824 	if (rx_stats->rs_keyix == ATH9K_RXKEYIX_INVALID)
825 		rx_stats->rs_status &= ~ATH9K_RXERR_KEYMISS;
826 
827 	if (!rx_stats->rs_datalen)
828 		return false;
829         /*
830          * rs_status follows rs_datalen so if rs_datalen is too large
831          * we can take a hint that hardware corrupted it, so ignore
832          * those frames.
833          */
834 	if (rx_stats->rs_datalen > (common->rx_bufsize - rx_status_len))
835 		return false;
836 
837 	/* Only use error bits from the last fragment */
838 	if (rx_stats->rs_more)
839 		return true;
840 
841 	mic_error = is_valid_tkip && !ieee80211_is_ctl(fc) &&
842 		!ieee80211_has_morefrags(fc) &&
843 		!(le16_to_cpu(hdr->seq_ctrl) & IEEE80211_SCTL_FRAG) &&
844 		(rx_stats->rs_status & ATH9K_RXERR_MIC);
845 
846 	/*
847 	 * The rx_stats->rs_status will not be set until the end of the
848 	 * chained descriptors so it can be ignored if rs_more is set. The
849 	 * rs_more will be false at the last element of the chained
850 	 * descriptors.
851 	 */
852 	if (rx_stats->rs_status != 0) {
853 		u8 status_mask;
854 
855 		if (rx_stats->rs_status & ATH9K_RXERR_CRC) {
856 			rxs->flag |= RX_FLAG_FAILED_FCS_CRC;
857 			mic_error = false;
858 		}
859 		if (rx_stats->rs_status & ATH9K_RXERR_PHY)
860 			return false;
861 
862 		if ((rx_stats->rs_status & ATH9K_RXERR_DECRYPT) ||
863 		    (!is_mc && (rx_stats->rs_status & ATH9K_RXERR_KEYMISS))) {
864 			*decrypt_error = true;
865 			mic_error = false;
866 		}
867 
868 		/*
869 		 * Reject error frames with the exception of
870 		 * decryption and MIC failures. For monitor mode,
871 		 * we also ignore the CRC error.
872 		 */
873 		status_mask = ATH9K_RXERR_DECRYPT | ATH9K_RXERR_MIC |
874 			      ATH9K_RXERR_KEYMISS;
875 
876 		if (ah->is_monitoring && (sc->rx.rxfilter & FIF_FCSFAIL))
877 			status_mask |= ATH9K_RXERR_CRC;
878 
879 		if (rx_stats->rs_status & ~status_mask)
880 			return false;
881 	}
882 
883 	/*
884 	 * For unicast frames the MIC error bit can have false positives,
885 	 * so all MIC error reports need to be validated in software.
886 	 * False negatives are not common, so skip software verification
887 	 * if the hardware considers the MIC valid.
888 	 */
889 	if (strip_mic)
890 		rxs->flag |= RX_FLAG_MMIC_STRIPPED;
891 	else if (is_mc && mic_error)
892 		rxs->flag |= RX_FLAG_MMIC_ERROR;
893 
894 	return true;
895 }
896 
897 static int ath9k_process_rate(struct ath_common *common,
898 			      struct ieee80211_hw *hw,
899 			      struct ath_rx_status *rx_stats,
900 			      struct ieee80211_rx_status *rxs)
901 {
902 	struct ieee80211_supported_band *sband;
903 	enum ieee80211_band band;
904 	unsigned int i = 0;
905 
906 	band = hw->conf.channel->band;
907 	sband = hw->wiphy->bands[band];
908 
909 	if (rx_stats->rs_rate & 0x80) {
910 		/* HT rate */
911 		rxs->flag |= RX_FLAG_HT;
912 		if (rx_stats->rs_flags & ATH9K_RX_2040)
913 			rxs->flag |= RX_FLAG_40MHZ;
914 		if (rx_stats->rs_flags & ATH9K_RX_GI)
915 			rxs->flag |= RX_FLAG_SHORT_GI;
916 		rxs->rate_idx = rx_stats->rs_rate & 0x7f;
917 		return 0;
918 	}
919 
920 	for (i = 0; i < sband->n_bitrates; i++) {
921 		if (sband->bitrates[i].hw_value == rx_stats->rs_rate) {
922 			rxs->rate_idx = i;
923 			return 0;
924 		}
925 		if (sband->bitrates[i].hw_value_short == rx_stats->rs_rate) {
926 			rxs->flag |= RX_FLAG_SHORTPRE;
927 			rxs->rate_idx = i;
928 			return 0;
929 		}
930 	}
931 
932 	/*
933 	 * No valid hardware bitrate found -- we should not get here
934 	 * because hardware has already validated this frame as OK.
935 	 */
936 	ath_dbg(common, ANY,
937 		"unsupported hw bitrate detected 0x%02x using 1 Mbit\n",
938 		rx_stats->rs_rate);
939 
940 	return -EINVAL;
941 }
942 
943 static void ath9k_process_rssi(struct ath_common *common,
944 			       struct ieee80211_hw *hw,
945 			       struct ieee80211_hdr *hdr,
946 			       struct ath_rx_status *rx_stats)
947 {
948 	struct ath_softc *sc = hw->priv;
949 	struct ath_hw *ah = common->ah;
950 	int last_rssi;
951 	int rssi = rx_stats->rs_rssi;
952 
953 	if (!rx_stats->is_mybeacon ||
954 	    ((ah->opmode != NL80211_IFTYPE_STATION) &&
955 	     (ah->opmode != NL80211_IFTYPE_ADHOC)))
956 		return;
957 
958 	if (rx_stats->rs_rssi != ATH9K_RSSI_BAD && !rx_stats->rs_moreaggr)
959 		ATH_RSSI_LPF(sc->last_rssi, rx_stats->rs_rssi);
960 
961 	last_rssi = sc->last_rssi;
962 	if (likely(last_rssi != ATH_RSSI_DUMMY_MARKER))
963 		rssi = ATH_EP_RND(last_rssi, ATH_RSSI_EP_MULTIPLIER);
964 	if (rssi < 0)
965 		rssi = 0;
966 
967 	/* Update Beacon RSSI, this is used by ANI. */
968 	ah->stats.avgbrssi = rssi;
969 }
970 
971 /*
972  * For Decrypt or Demic errors, we only mark packet status here and always push
973  * up the frame up to let mac80211 handle the actual error case, be it no
974  * decryption key or real decryption error. This let us keep statistics there.
975  */
976 static int ath9k_rx_skb_preprocess(struct ath_common *common,
977 				   struct ieee80211_hw *hw,
978 				   struct ieee80211_hdr *hdr,
979 				   struct ath_rx_status *rx_stats,
980 				   struct ieee80211_rx_status *rx_status,
981 				   bool *decrypt_error)
982 {
983 	struct ath_hw *ah = common->ah;
984 
985 	/*
986 	 * everything but the rate is checked here, the rate check is done
987 	 * separately to avoid doing two lookups for a rate for each frame.
988 	 */
989 	if (!ath9k_rx_accept(common, hdr, rx_status, rx_stats, decrypt_error))
990 		return -EINVAL;
991 
992 	/* Only use status info from the last fragment */
993 	if (rx_stats->rs_more)
994 		return 0;
995 
996 	ath9k_process_rssi(common, hw, hdr, rx_stats);
997 
998 	if (ath9k_process_rate(common, hw, rx_stats, rx_status))
999 		return -EINVAL;
1000 
1001 	rx_status->band = hw->conf.channel->band;
1002 	rx_status->freq = hw->conf.channel->center_freq;
1003 	rx_status->signal = ah->noise + rx_stats->rs_rssi;
1004 	rx_status->antenna = rx_stats->rs_antenna;
1005 	rx_status->flag |= RX_FLAG_MACTIME_MPDU;
1006 	if (rx_stats->rs_moreaggr)
1007 		rx_status->flag |= RX_FLAG_NO_SIGNAL_VAL;
1008 
1009 	return 0;
1010 }
1011 
1012 static void ath9k_rx_skb_postprocess(struct ath_common *common,
1013 				     struct sk_buff *skb,
1014 				     struct ath_rx_status *rx_stats,
1015 				     struct ieee80211_rx_status *rxs,
1016 				     bool decrypt_error)
1017 {
1018 	struct ath_hw *ah = common->ah;
1019 	struct ieee80211_hdr *hdr;
1020 	int hdrlen, padpos, padsize;
1021 	u8 keyix;
1022 	__le16 fc;
1023 
1024 	/* see if any padding is done by the hw and remove it */
1025 	hdr = (struct ieee80211_hdr *) skb->data;
1026 	hdrlen = ieee80211_get_hdrlen_from_skb(skb);
1027 	fc = hdr->frame_control;
1028 	padpos = ath9k_cmn_padpos(hdr->frame_control);
1029 
1030 	/* The MAC header is padded to have 32-bit boundary if the
1031 	 * packet payload is non-zero. The general calculation for
1032 	 * padsize would take into account odd header lengths:
1033 	 * padsize = (4 - padpos % 4) % 4; However, since only
1034 	 * even-length headers are used, padding can only be 0 or 2
1035 	 * bytes and we can optimize this a bit. In addition, we must
1036 	 * not try to remove padding from short control frames that do
1037 	 * not have payload. */
1038 	padsize = padpos & 3;
1039 	if (padsize && skb->len>=padpos+padsize+FCS_LEN) {
1040 		memmove(skb->data + padsize, skb->data, padpos);
1041 		skb_pull(skb, padsize);
1042 	}
1043 
1044 	keyix = rx_stats->rs_keyix;
1045 
1046 	if (!(keyix == ATH9K_RXKEYIX_INVALID) && !decrypt_error &&
1047 	    ieee80211_has_protected(fc)) {
1048 		rxs->flag |= RX_FLAG_DECRYPTED;
1049 	} else if (ieee80211_has_protected(fc)
1050 		   && !decrypt_error && skb->len >= hdrlen + 4) {
1051 		keyix = skb->data[hdrlen + 3] >> 6;
1052 
1053 		if (test_bit(keyix, common->keymap))
1054 			rxs->flag |= RX_FLAG_DECRYPTED;
1055 	}
1056 	if (ah->sw_mgmt_crypto &&
1057 	    (rxs->flag & RX_FLAG_DECRYPTED) &&
1058 	    ieee80211_is_mgmt(fc))
1059 		/* Use software decrypt for management frames. */
1060 		rxs->flag &= ~RX_FLAG_DECRYPTED;
1061 }
1062 
1063 static void ath_lnaconf_alt_good_scan(struct ath_ant_comb *antcomb,
1064 				      struct ath_hw_antcomb_conf ant_conf,
1065 				      int main_rssi_avg)
1066 {
1067 	antcomb->quick_scan_cnt = 0;
1068 
1069 	if (ant_conf.main_lna_conf == ATH_ANT_DIV_COMB_LNA2)
1070 		antcomb->rssi_lna2 = main_rssi_avg;
1071 	else if (ant_conf.main_lna_conf == ATH_ANT_DIV_COMB_LNA1)
1072 		antcomb->rssi_lna1 = main_rssi_avg;
1073 
1074 	switch ((ant_conf.main_lna_conf << 4) | ant_conf.alt_lna_conf) {
1075 	case 0x10: /* LNA2 A-B */
1076 		antcomb->main_conf = ATH_ANT_DIV_COMB_LNA1_MINUS_LNA2;
1077 		antcomb->first_quick_scan_conf =
1078 			ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2;
1079 		antcomb->second_quick_scan_conf = ATH_ANT_DIV_COMB_LNA1;
1080 		break;
1081 	case 0x20: /* LNA1 A-B */
1082 		antcomb->main_conf = ATH_ANT_DIV_COMB_LNA1_MINUS_LNA2;
1083 		antcomb->first_quick_scan_conf =
1084 			ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2;
1085 		antcomb->second_quick_scan_conf = ATH_ANT_DIV_COMB_LNA2;
1086 		break;
1087 	case 0x21: /* LNA1 LNA2 */
1088 		antcomb->main_conf = ATH_ANT_DIV_COMB_LNA2;
1089 		antcomb->first_quick_scan_conf =
1090 			ATH_ANT_DIV_COMB_LNA1_MINUS_LNA2;
1091 		antcomb->second_quick_scan_conf =
1092 			ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2;
1093 		break;
1094 	case 0x12: /* LNA2 LNA1 */
1095 		antcomb->main_conf = ATH_ANT_DIV_COMB_LNA1;
1096 		antcomb->first_quick_scan_conf =
1097 			ATH_ANT_DIV_COMB_LNA1_MINUS_LNA2;
1098 		antcomb->second_quick_scan_conf =
1099 			ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2;
1100 		break;
1101 	case 0x13: /* LNA2 A+B */
1102 		antcomb->main_conf = ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2;
1103 		antcomb->first_quick_scan_conf =
1104 			ATH_ANT_DIV_COMB_LNA1_MINUS_LNA2;
1105 		antcomb->second_quick_scan_conf = ATH_ANT_DIV_COMB_LNA1;
1106 		break;
1107 	case 0x23: /* LNA1 A+B */
1108 		antcomb->main_conf = ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2;
1109 		antcomb->first_quick_scan_conf =
1110 			ATH_ANT_DIV_COMB_LNA1_MINUS_LNA2;
1111 		antcomb->second_quick_scan_conf = ATH_ANT_DIV_COMB_LNA2;
1112 		break;
1113 	default:
1114 		break;
1115 	}
1116 }
1117 
1118 static void ath_select_ant_div_from_quick_scan(struct ath_ant_comb *antcomb,
1119 				struct ath_hw_antcomb_conf *div_ant_conf,
1120 				int main_rssi_avg, int alt_rssi_avg,
1121 				int alt_ratio)
1122 {
1123 	/* alt_good */
1124 	switch (antcomb->quick_scan_cnt) {
1125 	case 0:
1126 		/* set alt to main, and alt to first conf */
1127 		div_ant_conf->main_lna_conf = antcomb->main_conf;
1128 		div_ant_conf->alt_lna_conf = antcomb->first_quick_scan_conf;
1129 		break;
1130 	case 1:
1131 		/* set alt to main, and alt to first conf */
1132 		div_ant_conf->main_lna_conf = antcomb->main_conf;
1133 		div_ant_conf->alt_lna_conf = antcomb->second_quick_scan_conf;
1134 		antcomb->rssi_first = main_rssi_avg;
1135 		antcomb->rssi_second = alt_rssi_avg;
1136 
1137 		if (antcomb->main_conf == ATH_ANT_DIV_COMB_LNA1) {
1138 			/* main is LNA1 */
1139 			if (ath_is_alt_ant_ratio_better(alt_ratio,
1140 						ATH_ANT_DIV_COMB_LNA1_DELTA_HI,
1141 						ATH_ANT_DIV_COMB_LNA1_DELTA_LOW,
1142 						main_rssi_avg, alt_rssi_avg,
1143 						antcomb->total_pkt_count))
1144 				antcomb->first_ratio = true;
1145 			else
1146 				antcomb->first_ratio = false;
1147 		} else if (antcomb->main_conf == ATH_ANT_DIV_COMB_LNA2) {
1148 			if (ath_is_alt_ant_ratio_better(alt_ratio,
1149 						ATH_ANT_DIV_COMB_LNA1_DELTA_MID,
1150 						ATH_ANT_DIV_COMB_LNA1_DELTA_LOW,
1151 						main_rssi_avg, alt_rssi_avg,
1152 						antcomb->total_pkt_count))
1153 				antcomb->first_ratio = true;
1154 			else
1155 				antcomb->first_ratio = false;
1156 		} else {
1157 			if ((((alt_ratio >= ATH_ANT_DIV_COMB_ALT_ANT_RATIO2) &&
1158 			    (alt_rssi_avg > main_rssi_avg +
1159 			    ATH_ANT_DIV_COMB_LNA1_DELTA_HI)) ||
1160 			    (alt_rssi_avg > main_rssi_avg)) &&
1161 			    (antcomb->total_pkt_count > 50))
1162 				antcomb->first_ratio = true;
1163 			else
1164 				antcomb->first_ratio = false;
1165 		}
1166 		break;
1167 	case 2:
1168 		antcomb->alt_good = false;
1169 		antcomb->scan_not_start = false;
1170 		antcomb->scan = false;
1171 		antcomb->rssi_first = main_rssi_avg;
1172 		antcomb->rssi_third = alt_rssi_avg;
1173 
1174 		if (antcomb->second_quick_scan_conf == ATH_ANT_DIV_COMB_LNA1)
1175 			antcomb->rssi_lna1 = alt_rssi_avg;
1176 		else if (antcomb->second_quick_scan_conf ==
1177 			 ATH_ANT_DIV_COMB_LNA2)
1178 			antcomb->rssi_lna2 = alt_rssi_avg;
1179 		else if (antcomb->second_quick_scan_conf ==
1180 			 ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2) {
1181 			if (antcomb->main_conf == ATH_ANT_DIV_COMB_LNA2)
1182 				antcomb->rssi_lna2 = main_rssi_avg;
1183 			else if (antcomb->main_conf == ATH_ANT_DIV_COMB_LNA1)
1184 				antcomb->rssi_lna1 = main_rssi_avg;
1185 		}
1186 
1187 		if (antcomb->rssi_lna2 > antcomb->rssi_lna1 +
1188 		    ATH_ANT_DIV_COMB_LNA1_LNA2_SWITCH_DELTA)
1189 			div_ant_conf->main_lna_conf = ATH_ANT_DIV_COMB_LNA2;
1190 		else
1191 			div_ant_conf->main_lna_conf = ATH_ANT_DIV_COMB_LNA1;
1192 
1193 		if (antcomb->main_conf == ATH_ANT_DIV_COMB_LNA1) {
1194 			if (ath_is_alt_ant_ratio_better(alt_ratio,
1195 						ATH_ANT_DIV_COMB_LNA1_DELTA_HI,
1196 						ATH_ANT_DIV_COMB_LNA1_DELTA_LOW,
1197 						main_rssi_avg, alt_rssi_avg,
1198 						antcomb->total_pkt_count))
1199 				antcomb->second_ratio = true;
1200 			else
1201 				antcomb->second_ratio = false;
1202 		} else if (antcomb->main_conf == ATH_ANT_DIV_COMB_LNA2) {
1203 			if (ath_is_alt_ant_ratio_better(alt_ratio,
1204 						ATH_ANT_DIV_COMB_LNA1_DELTA_MID,
1205 						ATH_ANT_DIV_COMB_LNA1_DELTA_LOW,
1206 						main_rssi_avg, alt_rssi_avg,
1207 						antcomb->total_pkt_count))
1208 				antcomb->second_ratio = true;
1209 			else
1210 				antcomb->second_ratio = false;
1211 		} else {
1212 			if ((((alt_ratio >= ATH_ANT_DIV_COMB_ALT_ANT_RATIO2) &&
1213 			    (alt_rssi_avg > main_rssi_avg +
1214 			    ATH_ANT_DIV_COMB_LNA1_DELTA_HI)) ||
1215 			    (alt_rssi_avg > main_rssi_avg)) &&
1216 			    (antcomb->total_pkt_count > 50))
1217 				antcomb->second_ratio = true;
1218 			else
1219 				antcomb->second_ratio = false;
1220 		}
1221 
1222 		/* set alt to the conf with maximun ratio */
1223 		if (antcomb->first_ratio && antcomb->second_ratio) {
1224 			if (antcomb->rssi_second > antcomb->rssi_third) {
1225 				/* first alt*/
1226 				if ((antcomb->first_quick_scan_conf ==
1227 				    ATH_ANT_DIV_COMB_LNA1) ||
1228 				    (antcomb->first_quick_scan_conf ==
1229 				    ATH_ANT_DIV_COMB_LNA2))
1230 					/* Set alt LNA1 or LNA2*/
1231 					if (div_ant_conf->main_lna_conf ==
1232 					    ATH_ANT_DIV_COMB_LNA2)
1233 						div_ant_conf->alt_lna_conf =
1234 							ATH_ANT_DIV_COMB_LNA1;
1235 					else
1236 						div_ant_conf->alt_lna_conf =
1237 							ATH_ANT_DIV_COMB_LNA2;
1238 				else
1239 					/* Set alt to A+B or A-B */
1240 					div_ant_conf->alt_lna_conf =
1241 						antcomb->first_quick_scan_conf;
1242 			} else if ((antcomb->second_quick_scan_conf ==
1243 				   ATH_ANT_DIV_COMB_LNA1) ||
1244 				   (antcomb->second_quick_scan_conf ==
1245 				   ATH_ANT_DIV_COMB_LNA2)) {
1246 				/* Set alt LNA1 or LNA2 */
1247 				if (div_ant_conf->main_lna_conf ==
1248 				    ATH_ANT_DIV_COMB_LNA2)
1249 					div_ant_conf->alt_lna_conf =
1250 						ATH_ANT_DIV_COMB_LNA1;
1251 				else
1252 					div_ant_conf->alt_lna_conf =
1253 						ATH_ANT_DIV_COMB_LNA2;
1254 			} else {
1255 				/* Set alt to A+B or A-B */
1256 				div_ant_conf->alt_lna_conf =
1257 					antcomb->second_quick_scan_conf;
1258 			}
1259 		} else if (antcomb->first_ratio) {
1260 			/* first alt */
1261 			if ((antcomb->first_quick_scan_conf ==
1262 			    ATH_ANT_DIV_COMB_LNA1) ||
1263 			    (antcomb->first_quick_scan_conf ==
1264 			    ATH_ANT_DIV_COMB_LNA2))
1265 					/* Set alt LNA1 or LNA2 */
1266 				if (div_ant_conf->main_lna_conf ==
1267 				    ATH_ANT_DIV_COMB_LNA2)
1268 					div_ant_conf->alt_lna_conf =
1269 							ATH_ANT_DIV_COMB_LNA1;
1270 				else
1271 					div_ant_conf->alt_lna_conf =
1272 							ATH_ANT_DIV_COMB_LNA2;
1273 			else
1274 				/* Set alt to A+B or A-B */
1275 				div_ant_conf->alt_lna_conf =
1276 						antcomb->first_quick_scan_conf;
1277 		} else if (antcomb->second_ratio) {
1278 				/* second alt */
1279 			if ((antcomb->second_quick_scan_conf ==
1280 			    ATH_ANT_DIV_COMB_LNA1) ||
1281 			    (antcomb->second_quick_scan_conf ==
1282 			    ATH_ANT_DIV_COMB_LNA2))
1283 				/* Set alt LNA1 or LNA2 */
1284 				if (div_ant_conf->main_lna_conf ==
1285 				    ATH_ANT_DIV_COMB_LNA2)
1286 					div_ant_conf->alt_lna_conf =
1287 						ATH_ANT_DIV_COMB_LNA1;
1288 				else
1289 					div_ant_conf->alt_lna_conf =
1290 						ATH_ANT_DIV_COMB_LNA2;
1291 			else
1292 				/* Set alt to A+B or A-B */
1293 				div_ant_conf->alt_lna_conf =
1294 						antcomb->second_quick_scan_conf;
1295 		} else {
1296 			/* main is largest */
1297 			if ((antcomb->main_conf == ATH_ANT_DIV_COMB_LNA1) ||
1298 			    (antcomb->main_conf == ATH_ANT_DIV_COMB_LNA2))
1299 				/* Set alt LNA1 or LNA2 */
1300 				if (div_ant_conf->main_lna_conf ==
1301 				    ATH_ANT_DIV_COMB_LNA2)
1302 					div_ant_conf->alt_lna_conf =
1303 							ATH_ANT_DIV_COMB_LNA1;
1304 				else
1305 					div_ant_conf->alt_lna_conf =
1306 							ATH_ANT_DIV_COMB_LNA2;
1307 			else
1308 				/* Set alt to A+B or A-B */
1309 				div_ant_conf->alt_lna_conf = antcomb->main_conf;
1310 		}
1311 		break;
1312 	default:
1313 		break;
1314 	}
1315 }
1316 
1317 static void ath_ant_div_conf_fast_divbias(struct ath_hw_antcomb_conf *ant_conf,
1318 		struct ath_ant_comb *antcomb, int alt_ratio)
1319 {
1320 	if (ant_conf->div_group == 0) {
1321 		/* Adjust the fast_div_bias based on main and alt lna conf */
1322 		switch ((ant_conf->main_lna_conf << 4) |
1323 				ant_conf->alt_lna_conf) {
1324 		case 0x01: /* A-B LNA2 */
1325 			ant_conf->fast_div_bias = 0x3b;
1326 			break;
1327 		case 0x02: /* A-B LNA1 */
1328 			ant_conf->fast_div_bias = 0x3d;
1329 			break;
1330 		case 0x03: /* A-B A+B */
1331 			ant_conf->fast_div_bias = 0x1;
1332 			break;
1333 		case 0x10: /* LNA2 A-B */
1334 			ant_conf->fast_div_bias = 0x7;
1335 			break;
1336 		case 0x12: /* LNA2 LNA1 */
1337 			ant_conf->fast_div_bias = 0x2;
1338 			break;
1339 		case 0x13: /* LNA2 A+B */
1340 			ant_conf->fast_div_bias = 0x7;
1341 			break;
1342 		case 0x20: /* LNA1 A-B */
1343 			ant_conf->fast_div_bias = 0x6;
1344 			break;
1345 		case 0x21: /* LNA1 LNA2 */
1346 			ant_conf->fast_div_bias = 0x0;
1347 			break;
1348 		case 0x23: /* LNA1 A+B */
1349 			ant_conf->fast_div_bias = 0x6;
1350 			break;
1351 		case 0x30: /* A+B A-B */
1352 			ant_conf->fast_div_bias = 0x1;
1353 			break;
1354 		case 0x31: /* A+B LNA2 */
1355 			ant_conf->fast_div_bias = 0x3b;
1356 			break;
1357 		case 0x32: /* A+B LNA1 */
1358 			ant_conf->fast_div_bias = 0x3d;
1359 			break;
1360 		default:
1361 			break;
1362 		}
1363 	} else if (ant_conf->div_group == 1) {
1364 		/* Adjust the fast_div_bias based on main and alt_lna_conf */
1365 		switch ((ant_conf->main_lna_conf << 4) |
1366 			ant_conf->alt_lna_conf) {
1367 		case 0x01: /* A-B LNA2 */
1368 			ant_conf->fast_div_bias = 0x1;
1369 			ant_conf->main_gaintb = 0;
1370 			ant_conf->alt_gaintb = 0;
1371 			break;
1372 		case 0x02: /* A-B LNA1 */
1373 			ant_conf->fast_div_bias = 0x1;
1374 			ant_conf->main_gaintb = 0;
1375 			ant_conf->alt_gaintb = 0;
1376 			break;
1377 		case 0x03: /* A-B A+B */
1378 			ant_conf->fast_div_bias = 0x1;
1379 			ant_conf->main_gaintb = 0;
1380 			ant_conf->alt_gaintb = 0;
1381 			break;
1382 		case 0x10: /* LNA2 A-B */
1383 			if (!(antcomb->scan) &&
1384 			    (alt_ratio > ATH_ANT_DIV_COMB_ALT_ANT_RATIO))
1385 				ant_conf->fast_div_bias = 0x3f;
1386 			else
1387 				ant_conf->fast_div_bias = 0x1;
1388 			ant_conf->main_gaintb = 0;
1389 			ant_conf->alt_gaintb = 0;
1390 			break;
1391 		case 0x12: /* LNA2 LNA1 */
1392 			ant_conf->fast_div_bias = 0x1;
1393 			ant_conf->main_gaintb = 0;
1394 			ant_conf->alt_gaintb = 0;
1395 			break;
1396 		case 0x13: /* LNA2 A+B */
1397 			if (!(antcomb->scan) &&
1398 			    (alt_ratio > ATH_ANT_DIV_COMB_ALT_ANT_RATIO))
1399 				ant_conf->fast_div_bias = 0x3f;
1400 			else
1401 				ant_conf->fast_div_bias = 0x1;
1402 			ant_conf->main_gaintb = 0;
1403 			ant_conf->alt_gaintb = 0;
1404 			break;
1405 		case 0x20: /* LNA1 A-B */
1406 			if (!(antcomb->scan) &&
1407 			    (alt_ratio > ATH_ANT_DIV_COMB_ALT_ANT_RATIO))
1408 				ant_conf->fast_div_bias = 0x3f;
1409 			else
1410 				ant_conf->fast_div_bias = 0x1;
1411 			ant_conf->main_gaintb = 0;
1412 			ant_conf->alt_gaintb = 0;
1413 			break;
1414 		case 0x21: /* LNA1 LNA2 */
1415 			ant_conf->fast_div_bias = 0x1;
1416 			ant_conf->main_gaintb = 0;
1417 			ant_conf->alt_gaintb = 0;
1418 			break;
1419 		case 0x23: /* LNA1 A+B */
1420 			if (!(antcomb->scan) &&
1421 			    (alt_ratio > ATH_ANT_DIV_COMB_ALT_ANT_RATIO))
1422 				ant_conf->fast_div_bias = 0x3f;
1423 			else
1424 				ant_conf->fast_div_bias = 0x1;
1425 			ant_conf->main_gaintb = 0;
1426 			ant_conf->alt_gaintb = 0;
1427 			break;
1428 		case 0x30: /* A+B A-B */
1429 			ant_conf->fast_div_bias = 0x1;
1430 			ant_conf->main_gaintb = 0;
1431 			ant_conf->alt_gaintb = 0;
1432 			break;
1433 		case 0x31: /* A+B LNA2 */
1434 			ant_conf->fast_div_bias = 0x1;
1435 			ant_conf->main_gaintb = 0;
1436 			ant_conf->alt_gaintb = 0;
1437 			break;
1438 		case 0x32: /* A+B LNA1 */
1439 			ant_conf->fast_div_bias = 0x1;
1440 			ant_conf->main_gaintb = 0;
1441 			ant_conf->alt_gaintb = 0;
1442 			break;
1443 		default:
1444 			break;
1445 		}
1446 	} else if (ant_conf->div_group == 2) {
1447 		/* Adjust the fast_div_bias based on main and alt_lna_conf */
1448 		switch ((ant_conf->main_lna_conf << 4) |
1449 				ant_conf->alt_lna_conf) {
1450 		case 0x01: /* A-B LNA2 */
1451 			ant_conf->fast_div_bias = 0x1;
1452 			ant_conf->main_gaintb = 0;
1453 			ant_conf->alt_gaintb = 0;
1454 			break;
1455 		case 0x02: /* A-B LNA1 */
1456 			ant_conf->fast_div_bias = 0x1;
1457 			ant_conf->main_gaintb = 0;
1458 			ant_conf->alt_gaintb = 0;
1459 			break;
1460 		case 0x03: /* A-B A+B */
1461 			ant_conf->fast_div_bias = 0x1;
1462 			ant_conf->main_gaintb = 0;
1463 			ant_conf->alt_gaintb = 0;
1464 			break;
1465 		case 0x10: /* LNA2 A-B */
1466 			if (!(antcomb->scan) &&
1467 				(alt_ratio > ATH_ANT_DIV_COMB_ALT_ANT_RATIO))
1468 				ant_conf->fast_div_bias = 0x1;
1469 			else
1470 				ant_conf->fast_div_bias = 0x2;
1471 			ant_conf->main_gaintb = 0;
1472 			ant_conf->alt_gaintb = 0;
1473 			break;
1474 		case 0x12: /* LNA2 LNA1 */
1475 			ant_conf->fast_div_bias = 0x1;
1476 			ant_conf->main_gaintb = 0;
1477 			ant_conf->alt_gaintb = 0;
1478 			break;
1479 		case 0x13: /* LNA2 A+B */
1480 			if (!(antcomb->scan) &&
1481 				(alt_ratio > ATH_ANT_DIV_COMB_ALT_ANT_RATIO))
1482 				ant_conf->fast_div_bias = 0x1;
1483 			else
1484 				ant_conf->fast_div_bias = 0x2;
1485 			ant_conf->main_gaintb = 0;
1486 			ant_conf->alt_gaintb = 0;
1487 			break;
1488 		case 0x20: /* LNA1 A-B */
1489 			if (!(antcomb->scan) &&
1490 				(alt_ratio > ATH_ANT_DIV_COMB_ALT_ANT_RATIO))
1491 				ant_conf->fast_div_bias = 0x1;
1492 			else
1493 				ant_conf->fast_div_bias = 0x2;
1494 			ant_conf->main_gaintb = 0;
1495 			ant_conf->alt_gaintb = 0;
1496 			break;
1497 		case 0x21: /* LNA1 LNA2 */
1498 			ant_conf->fast_div_bias = 0x1;
1499 			ant_conf->main_gaintb = 0;
1500 			ant_conf->alt_gaintb = 0;
1501 			break;
1502 		case 0x23: /* LNA1 A+B */
1503 			if (!(antcomb->scan) &&
1504 				(alt_ratio > ATH_ANT_DIV_COMB_ALT_ANT_RATIO))
1505 				ant_conf->fast_div_bias = 0x1;
1506 			else
1507 				ant_conf->fast_div_bias = 0x2;
1508 			ant_conf->main_gaintb = 0;
1509 			ant_conf->alt_gaintb = 0;
1510 			break;
1511 		case 0x30: /* A+B A-B */
1512 			ant_conf->fast_div_bias = 0x1;
1513 			ant_conf->main_gaintb = 0;
1514 			ant_conf->alt_gaintb = 0;
1515 			break;
1516 		case 0x31: /* A+B LNA2 */
1517 			ant_conf->fast_div_bias = 0x1;
1518 			ant_conf->main_gaintb = 0;
1519 			ant_conf->alt_gaintb = 0;
1520 			break;
1521 		case 0x32: /* A+B LNA1 */
1522 			ant_conf->fast_div_bias = 0x1;
1523 			ant_conf->main_gaintb = 0;
1524 			ant_conf->alt_gaintb = 0;
1525 			break;
1526 		default:
1527 			break;
1528 		}
1529 	}
1530 }
1531 
1532 /* Antenna diversity and combining */
1533 static void ath_ant_comb_scan(struct ath_softc *sc, struct ath_rx_status *rs)
1534 {
1535 	struct ath_hw_antcomb_conf div_ant_conf;
1536 	struct ath_ant_comb *antcomb = &sc->ant_comb;
1537 	int alt_ratio = 0, alt_rssi_avg = 0, main_rssi_avg = 0, curr_alt_set;
1538 	int curr_main_set;
1539 	int main_rssi = rs->rs_rssi_ctl0;
1540 	int alt_rssi = rs->rs_rssi_ctl1;
1541 	int rx_ant_conf,  main_ant_conf;
1542 	bool short_scan = false;
1543 
1544 	rx_ant_conf = (rs->rs_rssi_ctl2 >> ATH_ANT_RX_CURRENT_SHIFT) &
1545 		       ATH_ANT_RX_MASK;
1546 	main_ant_conf = (rs->rs_rssi_ctl2 >> ATH_ANT_RX_MAIN_SHIFT) &
1547 			 ATH_ANT_RX_MASK;
1548 
1549 	/* Record packet only when both main_rssi and  alt_rssi is positive */
1550 	if (main_rssi > 0 && alt_rssi > 0) {
1551 		antcomb->total_pkt_count++;
1552 		antcomb->main_total_rssi += main_rssi;
1553 		antcomb->alt_total_rssi  += alt_rssi;
1554 		if (main_ant_conf == rx_ant_conf)
1555 			antcomb->main_recv_cnt++;
1556 		else
1557 			antcomb->alt_recv_cnt++;
1558 	}
1559 
1560 	/* Short scan check */
1561 	if (antcomb->scan && antcomb->alt_good) {
1562 		if (time_after(jiffies, antcomb->scan_start_time +
1563 		    msecs_to_jiffies(ATH_ANT_DIV_COMB_SHORT_SCAN_INTR)))
1564 			short_scan = true;
1565 		else
1566 			if (antcomb->total_pkt_count ==
1567 			    ATH_ANT_DIV_COMB_SHORT_SCAN_PKTCOUNT) {
1568 				alt_ratio = ((antcomb->alt_recv_cnt * 100) /
1569 					    antcomb->total_pkt_count);
1570 				if (alt_ratio < ATH_ANT_DIV_COMB_ALT_ANT_RATIO)
1571 					short_scan = true;
1572 			}
1573 	}
1574 
1575 	if (((antcomb->total_pkt_count < ATH_ANT_DIV_COMB_MAX_PKTCOUNT) ||
1576 	    rs->rs_moreaggr) && !short_scan)
1577 		return;
1578 
1579 	if (antcomb->total_pkt_count) {
1580 		alt_ratio = ((antcomb->alt_recv_cnt * 100) /
1581 			     antcomb->total_pkt_count);
1582 		main_rssi_avg = (antcomb->main_total_rssi /
1583 				 antcomb->total_pkt_count);
1584 		alt_rssi_avg = (antcomb->alt_total_rssi /
1585 				 antcomb->total_pkt_count);
1586 	}
1587 
1588 
1589 	ath9k_hw_antdiv_comb_conf_get(sc->sc_ah, &div_ant_conf);
1590 	curr_alt_set = div_ant_conf.alt_lna_conf;
1591 	curr_main_set = div_ant_conf.main_lna_conf;
1592 
1593 	antcomb->count++;
1594 
1595 	if (antcomb->count == ATH_ANT_DIV_COMB_MAX_COUNT) {
1596 		if (alt_ratio > ATH_ANT_DIV_COMB_ALT_ANT_RATIO) {
1597 			ath_lnaconf_alt_good_scan(antcomb, div_ant_conf,
1598 						  main_rssi_avg);
1599 			antcomb->alt_good = true;
1600 		} else {
1601 			antcomb->alt_good = false;
1602 		}
1603 
1604 		antcomb->count = 0;
1605 		antcomb->scan = true;
1606 		antcomb->scan_not_start = true;
1607 	}
1608 
1609 	if (!antcomb->scan) {
1610 		if (ath_ant_div_comb_alt_check(div_ant_conf.div_group,
1611 					alt_ratio, curr_main_set, curr_alt_set,
1612 					alt_rssi_avg, main_rssi_avg)) {
1613 			if (curr_alt_set == ATH_ANT_DIV_COMB_LNA2) {
1614 				/* Switch main and alt LNA */
1615 				div_ant_conf.main_lna_conf =
1616 						ATH_ANT_DIV_COMB_LNA2;
1617 				div_ant_conf.alt_lna_conf  =
1618 						ATH_ANT_DIV_COMB_LNA1;
1619 			} else if (curr_alt_set == ATH_ANT_DIV_COMB_LNA1) {
1620 				div_ant_conf.main_lna_conf =
1621 						ATH_ANT_DIV_COMB_LNA1;
1622 				div_ant_conf.alt_lna_conf  =
1623 						ATH_ANT_DIV_COMB_LNA2;
1624 			}
1625 
1626 			goto div_comb_done;
1627 		} else if ((curr_alt_set != ATH_ANT_DIV_COMB_LNA1) &&
1628 			   (curr_alt_set != ATH_ANT_DIV_COMB_LNA2)) {
1629 			/* Set alt to another LNA */
1630 			if (curr_main_set == ATH_ANT_DIV_COMB_LNA2)
1631 				div_ant_conf.alt_lna_conf =
1632 						ATH_ANT_DIV_COMB_LNA1;
1633 			else if (curr_main_set == ATH_ANT_DIV_COMB_LNA1)
1634 				div_ant_conf.alt_lna_conf =
1635 						ATH_ANT_DIV_COMB_LNA2;
1636 
1637 			goto div_comb_done;
1638 		}
1639 
1640 		if ((alt_rssi_avg < (main_rssi_avg +
1641 						div_ant_conf.lna1_lna2_delta)))
1642 			goto div_comb_done;
1643 	}
1644 
1645 	if (!antcomb->scan_not_start) {
1646 		switch (curr_alt_set) {
1647 		case ATH_ANT_DIV_COMB_LNA2:
1648 			antcomb->rssi_lna2 = alt_rssi_avg;
1649 			antcomb->rssi_lna1 = main_rssi_avg;
1650 			antcomb->scan = true;
1651 			/* set to A+B */
1652 			div_ant_conf.main_lna_conf =
1653 				ATH_ANT_DIV_COMB_LNA1;
1654 			div_ant_conf.alt_lna_conf  =
1655 				ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2;
1656 			break;
1657 		case ATH_ANT_DIV_COMB_LNA1:
1658 			antcomb->rssi_lna1 = alt_rssi_avg;
1659 			antcomb->rssi_lna2 = main_rssi_avg;
1660 			antcomb->scan = true;
1661 			/* set to A+B */
1662 			div_ant_conf.main_lna_conf = ATH_ANT_DIV_COMB_LNA2;
1663 			div_ant_conf.alt_lna_conf  =
1664 				ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2;
1665 			break;
1666 		case ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2:
1667 			antcomb->rssi_add = alt_rssi_avg;
1668 			antcomb->scan = true;
1669 			/* set to A-B */
1670 			div_ant_conf.alt_lna_conf =
1671 				ATH_ANT_DIV_COMB_LNA1_MINUS_LNA2;
1672 			break;
1673 		case ATH_ANT_DIV_COMB_LNA1_MINUS_LNA2:
1674 			antcomb->rssi_sub = alt_rssi_avg;
1675 			antcomb->scan = false;
1676 			if (antcomb->rssi_lna2 >
1677 			    (antcomb->rssi_lna1 +
1678 			    ATH_ANT_DIV_COMB_LNA1_LNA2_SWITCH_DELTA)) {
1679 				/* use LNA2 as main LNA */
1680 				if ((antcomb->rssi_add > antcomb->rssi_lna1) &&
1681 				    (antcomb->rssi_add > antcomb->rssi_sub)) {
1682 					/* set to A+B */
1683 					div_ant_conf.main_lna_conf =
1684 						ATH_ANT_DIV_COMB_LNA2;
1685 					div_ant_conf.alt_lna_conf  =
1686 						ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2;
1687 				} else if (antcomb->rssi_sub >
1688 					   antcomb->rssi_lna1) {
1689 					/* set to A-B */
1690 					div_ant_conf.main_lna_conf =
1691 						ATH_ANT_DIV_COMB_LNA2;
1692 					div_ant_conf.alt_lna_conf =
1693 						ATH_ANT_DIV_COMB_LNA1_MINUS_LNA2;
1694 				} else {
1695 					/* set to LNA1 */
1696 					div_ant_conf.main_lna_conf =
1697 						ATH_ANT_DIV_COMB_LNA2;
1698 					div_ant_conf.alt_lna_conf =
1699 						ATH_ANT_DIV_COMB_LNA1;
1700 				}
1701 			} else {
1702 				/* use LNA1 as main LNA */
1703 				if ((antcomb->rssi_add > antcomb->rssi_lna2) &&
1704 				    (antcomb->rssi_add > antcomb->rssi_sub)) {
1705 					/* set to A+B */
1706 					div_ant_conf.main_lna_conf =
1707 						ATH_ANT_DIV_COMB_LNA1;
1708 					div_ant_conf.alt_lna_conf  =
1709 						ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2;
1710 				} else if (antcomb->rssi_sub >
1711 					   antcomb->rssi_lna1) {
1712 					/* set to A-B */
1713 					div_ant_conf.main_lna_conf =
1714 						ATH_ANT_DIV_COMB_LNA1;
1715 					div_ant_conf.alt_lna_conf =
1716 						ATH_ANT_DIV_COMB_LNA1_MINUS_LNA2;
1717 				} else {
1718 					/* set to LNA2 */
1719 					div_ant_conf.main_lna_conf =
1720 						ATH_ANT_DIV_COMB_LNA1;
1721 					div_ant_conf.alt_lna_conf =
1722 						ATH_ANT_DIV_COMB_LNA2;
1723 				}
1724 			}
1725 			break;
1726 		default:
1727 			break;
1728 		}
1729 	} else {
1730 		if (!antcomb->alt_good) {
1731 			antcomb->scan_not_start = false;
1732 			/* Set alt to another LNA */
1733 			if (curr_main_set == ATH_ANT_DIV_COMB_LNA2) {
1734 				div_ant_conf.main_lna_conf =
1735 						ATH_ANT_DIV_COMB_LNA2;
1736 				div_ant_conf.alt_lna_conf =
1737 						ATH_ANT_DIV_COMB_LNA1;
1738 			} else if (curr_main_set == ATH_ANT_DIV_COMB_LNA1) {
1739 				div_ant_conf.main_lna_conf =
1740 						ATH_ANT_DIV_COMB_LNA1;
1741 				div_ant_conf.alt_lna_conf =
1742 						ATH_ANT_DIV_COMB_LNA2;
1743 			}
1744 			goto div_comb_done;
1745 		}
1746 	}
1747 
1748 	ath_select_ant_div_from_quick_scan(antcomb, &div_ant_conf,
1749 					   main_rssi_avg, alt_rssi_avg,
1750 					   alt_ratio);
1751 
1752 	antcomb->quick_scan_cnt++;
1753 
1754 div_comb_done:
1755 	ath_ant_div_conf_fast_divbias(&div_ant_conf, antcomb, alt_ratio);
1756 	ath9k_hw_antdiv_comb_conf_set(sc->sc_ah, &div_ant_conf);
1757 
1758 	antcomb->scan_start_time = jiffies;
1759 	antcomb->total_pkt_count = 0;
1760 	antcomb->main_total_rssi = 0;
1761 	antcomb->alt_total_rssi = 0;
1762 	antcomb->main_recv_cnt = 0;
1763 	antcomb->alt_recv_cnt = 0;
1764 }
1765 
1766 int ath_rx_tasklet(struct ath_softc *sc, int flush, bool hp)
1767 {
1768 	struct ath_buf *bf;
1769 	struct sk_buff *skb = NULL, *requeue_skb, *hdr_skb;
1770 	struct ieee80211_rx_status *rxs;
1771 	struct ath_hw *ah = sc->sc_ah;
1772 	struct ath_common *common = ath9k_hw_common(ah);
1773 	struct ieee80211_hw *hw = sc->hw;
1774 	struct ieee80211_hdr *hdr;
1775 	int retval;
1776 	bool decrypt_error = false;
1777 	struct ath_rx_status rs;
1778 	enum ath9k_rx_qtype qtype;
1779 	bool edma = !!(ah->caps.hw_caps & ATH9K_HW_CAP_EDMA);
1780 	int dma_type;
1781 	u8 rx_status_len = ah->caps.rx_status_len;
1782 	u64 tsf = 0;
1783 	u32 tsf_lower = 0;
1784 	unsigned long flags;
1785 
1786 	if (edma)
1787 		dma_type = DMA_BIDIRECTIONAL;
1788 	else
1789 		dma_type = DMA_FROM_DEVICE;
1790 
1791 	qtype = hp ? ATH9K_RX_QUEUE_HP : ATH9K_RX_QUEUE_LP;
1792 	spin_lock_bh(&sc->rx.rxbuflock);
1793 
1794 	tsf = ath9k_hw_gettsf64(ah);
1795 	tsf_lower = tsf & 0xffffffff;
1796 
1797 	do {
1798 		/* If handling rx interrupt and flush is in progress => exit */
1799 		if ((sc->sc_flags & SC_OP_RXFLUSH) && (flush == 0))
1800 			break;
1801 
1802 		memset(&rs, 0, sizeof(rs));
1803 		if (edma)
1804 			bf = ath_edma_get_next_rx_buf(sc, &rs, qtype);
1805 		else
1806 			bf = ath_get_next_rx_buf(sc, &rs);
1807 
1808 		if (!bf)
1809 			break;
1810 
1811 		skb = bf->bf_mpdu;
1812 		if (!skb)
1813 			continue;
1814 
1815 		/*
1816 		 * Take frame header from the first fragment and RX status from
1817 		 * the last one.
1818 		 */
1819 		if (sc->rx.frag)
1820 			hdr_skb = sc->rx.frag;
1821 		else
1822 			hdr_skb = skb;
1823 
1824 		hdr = (struct ieee80211_hdr *) (hdr_skb->data + rx_status_len);
1825 		rxs = IEEE80211_SKB_RXCB(hdr_skb);
1826 		if (ieee80211_is_beacon(hdr->frame_control) &&
1827 		    !is_zero_ether_addr(common->curbssid) &&
1828 		    !compare_ether_addr(hdr->addr3, common->curbssid))
1829 			rs.is_mybeacon = true;
1830 		else
1831 			rs.is_mybeacon = false;
1832 
1833 		ath_debug_stat_rx(sc, &rs);
1834 
1835 		/*
1836 		 * If we're asked to flush receive queue, directly
1837 		 * chain it back at the queue without processing it.
1838 		 */
1839 		if (sc->sc_flags & SC_OP_RXFLUSH)
1840 			goto requeue_drop_frag;
1841 
1842 		memset(rxs, 0, sizeof(struct ieee80211_rx_status));
1843 
1844 		rxs->mactime = (tsf & ~0xffffffffULL) | rs.rs_tstamp;
1845 		if (rs.rs_tstamp > tsf_lower &&
1846 		    unlikely(rs.rs_tstamp - tsf_lower > 0x10000000))
1847 			rxs->mactime -= 0x100000000ULL;
1848 
1849 		if (rs.rs_tstamp < tsf_lower &&
1850 		    unlikely(tsf_lower - rs.rs_tstamp > 0x10000000))
1851 			rxs->mactime += 0x100000000ULL;
1852 
1853 		retval = ath9k_rx_skb_preprocess(common, hw, hdr, &rs,
1854 						 rxs, &decrypt_error);
1855 		if (retval)
1856 			goto requeue_drop_frag;
1857 
1858 		/* Ensure we always have an skb to requeue once we are done
1859 		 * processing the current buffer's skb */
1860 		requeue_skb = ath_rxbuf_alloc(common, common->rx_bufsize, GFP_ATOMIC);
1861 
1862 		/* If there is no memory we ignore the current RX'd frame,
1863 		 * tell hardware it can give us a new frame using the old
1864 		 * skb and put it at the tail of the sc->rx.rxbuf list for
1865 		 * processing. */
1866 		if (!requeue_skb)
1867 			goto requeue_drop_frag;
1868 
1869 		/* Unmap the frame */
1870 		dma_unmap_single(sc->dev, bf->bf_buf_addr,
1871 				 common->rx_bufsize,
1872 				 dma_type);
1873 
1874 		skb_put(skb, rs.rs_datalen + ah->caps.rx_status_len);
1875 		if (ah->caps.rx_status_len)
1876 			skb_pull(skb, ah->caps.rx_status_len);
1877 
1878 		if (!rs.rs_more)
1879 			ath9k_rx_skb_postprocess(common, hdr_skb, &rs,
1880 						 rxs, decrypt_error);
1881 
1882 		/* We will now give hardware our shiny new allocated skb */
1883 		bf->bf_mpdu = requeue_skb;
1884 		bf->bf_buf_addr = dma_map_single(sc->dev, requeue_skb->data,
1885 						 common->rx_bufsize,
1886 						 dma_type);
1887 		if (unlikely(dma_mapping_error(sc->dev,
1888 			  bf->bf_buf_addr))) {
1889 			dev_kfree_skb_any(requeue_skb);
1890 			bf->bf_mpdu = NULL;
1891 			bf->bf_buf_addr = 0;
1892 			ath_err(common, "dma_mapping_error() on RX\n");
1893 			ieee80211_rx(hw, skb);
1894 			break;
1895 		}
1896 
1897 		if (rs.rs_more) {
1898 			/*
1899 			 * rs_more indicates chained descriptors which can be
1900 			 * used to link buffers together for a sort of
1901 			 * scatter-gather operation.
1902 			 */
1903 			if (sc->rx.frag) {
1904 				/* too many fragments - cannot handle frame */
1905 				dev_kfree_skb_any(sc->rx.frag);
1906 				dev_kfree_skb_any(skb);
1907 				skb = NULL;
1908 			}
1909 			sc->rx.frag = skb;
1910 			goto requeue;
1911 		}
1912 
1913 		if (sc->rx.frag) {
1914 			int space = skb->len - skb_tailroom(hdr_skb);
1915 
1916 			if (pskb_expand_head(hdr_skb, 0, space, GFP_ATOMIC) < 0) {
1917 				dev_kfree_skb(skb);
1918 				goto requeue_drop_frag;
1919 			}
1920 
1921 			sc->rx.frag = NULL;
1922 
1923 			skb_copy_from_linear_data(skb, skb_put(hdr_skb, skb->len),
1924 						  skb->len);
1925 			dev_kfree_skb_any(skb);
1926 			skb = hdr_skb;
1927 		}
1928 
1929 
1930 		if (ah->caps.hw_caps & ATH9K_HW_CAP_ANT_DIV_COMB) {
1931 
1932 			/*
1933 			 * change the default rx antenna if rx diversity
1934 			 * chooses the other antenna 3 times in a row.
1935 			 */
1936 			if (sc->rx.defant != rs.rs_antenna) {
1937 				if (++sc->rx.rxotherant >= 3)
1938 					ath_setdefantenna(sc, rs.rs_antenna);
1939 			} else {
1940 				sc->rx.rxotherant = 0;
1941 			}
1942 
1943 		}
1944 
1945 		if (rxs->flag & RX_FLAG_MMIC_STRIPPED)
1946 			skb_trim(skb, skb->len - 8);
1947 
1948 		spin_lock_irqsave(&sc->sc_pm_lock, flags);
1949 
1950 		if ((sc->ps_flags & (PS_WAIT_FOR_BEACON |
1951 				     PS_WAIT_FOR_CAB |
1952 				     PS_WAIT_FOR_PSPOLL_DATA)) ||
1953 		    ath9k_check_auto_sleep(sc))
1954 			ath_rx_ps(sc, skb, rs.is_mybeacon);
1955 		spin_unlock_irqrestore(&sc->sc_pm_lock, flags);
1956 
1957 		if ((ah->caps.hw_caps & ATH9K_HW_CAP_ANT_DIV_COMB) && sc->ant_rx == 3)
1958 			ath_ant_comb_scan(sc, &rs);
1959 
1960 		ieee80211_rx(hw, skb);
1961 
1962 requeue_drop_frag:
1963 		if (sc->rx.frag) {
1964 			dev_kfree_skb_any(sc->rx.frag);
1965 			sc->rx.frag = NULL;
1966 		}
1967 requeue:
1968 		if (edma) {
1969 			list_add_tail(&bf->list, &sc->rx.rxbuf);
1970 			ath_rx_edma_buf_link(sc, qtype);
1971 		} else {
1972 			list_move_tail(&bf->list, &sc->rx.rxbuf);
1973 			ath_rx_buf_link(sc, bf);
1974 			if (!flush)
1975 				ath9k_hw_rxena(ah);
1976 		}
1977 	} while (1);
1978 
1979 	spin_unlock_bh(&sc->rx.rxbuflock);
1980 
1981 	if (!(ah->imask & ATH9K_INT_RXEOL)) {
1982 		ah->imask |= (ATH9K_INT_RXEOL | ATH9K_INT_RXORN);
1983 		ath9k_hw_set_interrupts(ah);
1984 	}
1985 
1986 	return 0;
1987 }
1988