xref: /openbmc/linux/drivers/net/wireless/ath/ath9k/recv.c (revision 69dbdd819599e2f3b77c172e83af512845bca5ad)
1 /*
2  * Copyright (c) 2008-2009 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 "ath9k.h"
18 #include "ar9003_mac.h"
19 
20 #define SKB_CB_ATHBUF(__skb)	(*((struct ath_buf **)__skb->cb))
21 
22 static inline bool ath_is_alt_ant_ratio_better(int alt_ratio, int maxdelta,
23 					       int mindelta, int main_rssi_avg,
24 					       int alt_rssi_avg, int pkt_count)
25 {
26 	return (((alt_ratio >= ATH_ANT_DIV_COMB_ALT_ANT_RATIO2) &&
27 		(alt_rssi_avg > main_rssi_avg + maxdelta)) ||
28 		(alt_rssi_avg > main_rssi_avg + mindelta)) && (pkt_count > 50);
29 }
30 
31 static inline bool ath9k_check_auto_sleep(struct ath_softc *sc)
32 {
33 	return sc->ps_enabled &&
34 	       (sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_AUTOSLEEP);
35 }
36 
37 static struct ieee80211_hw * ath_get_virt_hw(struct ath_softc *sc,
38 					     struct ieee80211_hdr *hdr)
39 {
40 	struct ieee80211_hw *hw = sc->pri_wiphy->hw;
41 	int i;
42 
43 	spin_lock_bh(&sc->wiphy_lock);
44 	for (i = 0; i < sc->num_sec_wiphy; i++) {
45 		struct ath_wiphy *aphy = sc->sec_wiphy[i];
46 		if (aphy == NULL)
47 			continue;
48 		if (compare_ether_addr(hdr->addr1, aphy->hw->wiphy->perm_addr)
49 		    == 0) {
50 			hw = aphy->hw;
51 			break;
52 		}
53 	}
54 	spin_unlock_bh(&sc->wiphy_lock);
55 	return hw;
56 }
57 
58 /*
59  * Setup and link descriptors.
60  *
61  * 11N: we can no longer afford to self link the last descriptor.
62  * MAC acknowledges BA status as long as it copies frames to host
63  * buffer (or rx fifo). This can incorrectly acknowledge packets
64  * to a sender if last desc is self-linked.
65  */
66 static void ath_rx_buf_link(struct ath_softc *sc, struct ath_buf *bf)
67 {
68 	struct ath_hw *ah = sc->sc_ah;
69 	struct ath_common *common = ath9k_hw_common(ah);
70 	struct ath_desc *ds;
71 	struct sk_buff *skb;
72 
73 	ATH_RXBUF_RESET(bf);
74 
75 	ds = bf->bf_desc;
76 	ds->ds_link = 0; /* link to null */
77 	ds->ds_data = bf->bf_buf_addr;
78 
79 	/* virtual addr of the beginning of the buffer. */
80 	skb = bf->bf_mpdu;
81 	BUG_ON(skb == NULL);
82 	ds->ds_vdata = skb->data;
83 
84 	/*
85 	 * setup rx descriptors. The rx_bufsize here tells the hardware
86 	 * how much data it can DMA to us and that we are prepared
87 	 * to process
88 	 */
89 	ath9k_hw_setuprxdesc(ah, ds,
90 			     common->rx_bufsize,
91 			     0);
92 
93 	if (sc->rx.rxlink == NULL)
94 		ath9k_hw_putrxbuf(ah, bf->bf_daddr);
95 	else
96 		*sc->rx.rxlink = bf->bf_daddr;
97 
98 	sc->rx.rxlink = &ds->ds_link;
99 	ath9k_hw_rxena(ah);
100 }
101 
102 static void ath_setdefantenna(struct ath_softc *sc, u32 antenna)
103 {
104 	/* XXX block beacon interrupts */
105 	ath9k_hw_setantenna(sc->sc_ah, antenna);
106 	sc->rx.defant = antenna;
107 	sc->rx.rxotherant = 0;
108 }
109 
110 static void ath_opmode_init(struct ath_softc *sc)
111 {
112 	struct ath_hw *ah = sc->sc_ah;
113 	struct ath_common *common = ath9k_hw_common(ah);
114 
115 	u32 rfilt, mfilt[2];
116 
117 	/* configure rx filter */
118 	rfilt = ath_calcrxfilter(sc);
119 	ath9k_hw_setrxfilter(ah, rfilt);
120 
121 	/* configure bssid mask */
122 	ath_hw_setbssidmask(common);
123 
124 	/* configure operational mode */
125 	ath9k_hw_setopmode(ah);
126 
127 	/* calculate and install multicast filter */
128 	mfilt[0] = mfilt[1] = ~0;
129 	ath9k_hw_setmcastfilter(ah, mfilt[0], mfilt[1]);
130 }
131 
132 static bool ath_rx_edma_buf_link(struct ath_softc *sc,
133 				 enum ath9k_rx_qtype qtype)
134 {
135 	struct ath_hw *ah = sc->sc_ah;
136 	struct ath_rx_edma *rx_edma;
137 	struct sk_buff *skb;
138 	struct ath_buf *bf;
139 
140 	rx_edma = &sc->rx.rx_edma[qtype];
141 	if (skb_queue_len(&rx_edma->rx_fifo) >= rx_edma->rx_fifo_hwsize)
142 		return false;
143 
144 	bf = list_first_entry(&sc->rx.rxbuf, struct ath_buf, list);
145 	list_del_init(&bf->list);
146 
147 	skb = bf->bf_mpdu;
148 
149 	ATH_RXBUF_RESET(bf);
150 	memset(skb->data, 0, ah->caps.rx_status_len);
151 	dma_sync_single_for_device(sc->dev, bf->bf_buf_addr,
152 				ah->caps.rx_status_len, DMA_TO_DEVICE);
153 
154 	SKB_CB_ATHBUF(skb) = bf;
155 	ath9k_hw_addrxbuf_edma(ah, bf->bf_buf_addr, qtype);
156 	skb_queue_tail(&rx_edma->rx_fifo, skb);
157 
158 	return true;
159 }
160 
161 static void ath_rx_addbuffer_edma(struct ath_softc *sc,
162 				  enum ath9k_rx_qtype qtype, int size)
163 {
164 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
165 	u32 nbuf = 0;
166 
167 	if (list_empty(&sc->rx.rxbuf)) {
168 		ath_print(common, ATH_DBG_QUEUE, "No free rx buf available\n");
169 		return;
170 	}
171 
172 	while (!list_empty(&sc->rx.rxbuf)) {
173 		nbuf++;
174 
175 		if (!ath_rx_edma_buf_link(sc, qtype))
176 			break;
177 
178 		if (nbuf >= size)
179 			break;
180 	}
181 }
182 
183 static void ath_rx_remove_buffer(struct ath_softc *sc,
184 				 enum ath9k_rx_qtype qtype)
185 {
186 	struct ath_buf *bf;
187 	struct ath_rx_edma *rx_edma;
188 	struct sk_buff *skb;
189 
190 	rx_edma = &sc->rx.rx_edma[qtype];
191 
192 	while ((skb = skb_dequeue(&rx_edma->rx_fifo)) != NULL) {
193 		bf = SKB_CB_ATHBUF(skb);
194 		BUG_ON(!bf);
195 		list_add_tail(&bf->list, &sc->rx.rxbuf);
196 	}
197 }
198 
199 static void ath_rx_edma_cleanup(struct ath_softc *sc)
200 {
201 	struct ath_buf *bf;
202 
203 	ath_rx_remove_buffer(sc, ATH9K_RX_QUEUE_LP);
204 	ath_rx_remove_buffer(sc, ATH9K_RX_QUEUE_HP);
205 
206 	list_for_each_entry(bf, &sc->rx.rxbuf, list) {
207 		if (bf->bf_mpdu)
208 			dev_kfree_skb_any(bf->bf_mpdu);
209 	}
210 
211 	INIT_LIST_HEAD(&sc->rx.rxbuf);
212 
213 	kfree(sc->rx.rx_bufptr);
214 	sc->rx.rx_bufptr = NULL;
215 }
216 
217 static void ath_rx_edma_init_queue(struct ath_rx_edma *rx_edma, int size)
218 {
219 	skb_queue_head_init(&rx_edma->rx_fifo);
220 	skb_queue_head_init(&rx_edma->rx_buffers);
221 	rx_edma->rx_fifo_hwsize = size;
222 }
223 
224 static int ath_rx_edma_init(struct ath_softc *sc, int nbufs)
225 {
226 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
227 	struct ath_hw *ah = sc->sc_ah;
228 	struct sk_buff *skb;
229 	struct ath_buf *bf;
230 	int error = 0, i;
231 	u32 size;
232 
233 
234 	common->rx_bufsize = roundup(IEEE80211_MAX_MPDU_LEN +
235 				     ah->caps.rx_status_len,
236 				     min(common->cachelsz, (u16)64));
237 
238 	ath9k_hw_set_rx_bufsize(ah, common->rx_bufsize -
239 				    ah->caps.rx_status_len);
240 
241 	ath_rx_edma_init_queue(&sc->rx.rx_edma[ATH9K_RX_QUEUE_LP],
242 			       ah->caps.rx_lp_qdepth);
243 	ath_rx_edma_init_queue(&sc->rx.rx_edma[ATH9K_RX_QUEUE_HP],
244 			       ah->caps.rx_hp_qdepth);
245 
246 	size = sizeof(struct ath_buf) * nbufs;
247 	bf = kzalloc(size, GFP_KERNEL);
248 	if (!bf)
249 		return -ENOMEM;
250 
251 	INIT_LIST_HEAD(&sc->rx.rxbuf);
252 	sc->rx.rx_bufptr = bf;
253 
254 	for (i = 0; i < nbufs; i++, bf++) {
255 		skb = ath_rxbuf_alloc(common, common->rx_bufsize, GFP_KERNEL);
256 		if (!skb) {
257 			error = -ENOMEM;
258 			goto rx_init_fail;
259 		}
260 
261 		memset(skb->data, 0, common->rx_bufsize);
262 		bf->bf_mpdu = skb;
263 
264 		bf->bf_buf_addr = dma_map_single(sc->dev, skb->data,
265 						 common->rx_bufsize,
266 						 DMA_BIDIRECTIONAL);
267 		if (unlikely(dma_mapping_error(sc->dev,
268 						bf->bf_buf_addr))) {
269 				dev_kfree_skb_any(skb);
270 				bf->bf_mpdu = NULL;
271 				bf->bf_buf_addr = 0;
272 				ath_print(common, ATH_DBG_FATAL,
273 					"dma_mapping_error() on RX init\n");
274 				error = -ENOMEM;
275 				goto rx_init_fail;
276 		}
277 
278 		list_add_tail(&bf->list, &sc->rx.rxbuf);
279 	}
280 
281 	return 0;
282 
283 rx_init_fail:
284 	ath_rx_edma_cleanup(sc);
285 	return error;
286 }
287 
288 static void ath_edma_start_recv(struct ath_softc *sc)
289 {
290 	spin_lock_bh(&sc->rx.rxbuflock);
291 
292 	ath9k_hw_rxena(sc->sc_ah);
293 
294 	ath_rx_addbuffer_edma(sc, ATH9K_RX_QUEUE_HP,
295 			      sc->rx.rx_edma[ATH9K_RX_QUEUE_HP].rx_fifo_hwsize);
296 
297 	ath_rx_addbuffer_edma(sc, ATH9K_RX_QUEUE_LP,
298 			      sc->rx.rx_edma[ATH9K_RX_QUEUE_LP].rx_fifo_hwsize);
299 
300 	ath_opmode_init(sc);
301 
302 	ath9k_hw_startpcureceive(sc->sc_ah, (sc->sc_flags & SC_OP_OFFCHANNEL));
303 
304 	spin_unlock_bh(&sc->rx.rxbuflock);
305 }
306 
307 static void ath_edma_stop_recv(struct ath_softc *sc)
308 {
309 	ath_rx_remove_buffer(sc, ATH9K_RX_QUEUE_HP);
310 	ath_rx_remove_buffer(sc, ATH9K_RX_QUEUE_LP);
311 }
312 
313 int ath_rx_init(struct ath_softc *sc, int nbufs)
314 {
315 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
316 	struct sk_buff *skb;
317 	struct ath_buf *bf;
318 	int error = 0;
319 
320 	spin_lock_init(&sc->rx.pcu_lock);
321 	sc->sc_flags &= ~SC_OP_RXFLUSH;
322 	spin_lock_init(&sc->rx.rxbuflock);
323 
324 	if (sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_EDMA) {
325 		return ath_rx_edma_init(sc, nbufs);
326 	} else {
327 		common->rx_bufsize = roundup(IEEE80211_MAX_MPDU_LEN,
328 				min(common->cachelsz, (u16)64));
329 
330 		ath_print(common, ATH_DBG_CONFIG, "cachelsz %u rxbufsize %u\n",
331 				common->cachelsz, common->rx_bufsize);
332 
333 		/* Initialize rx descriptors */
334 
335 		error = ath_descdma_setup(sc, &sc->rx.rxdma, &sc->rx.rxbuf,
336 				"rx", nbufs, 1, 0);
337 		if (error != 0) {
338 			ath_print(common, ATH_DBG_FATAL,
339 				  "failed to allocate rx descriptors: %d\n",
340 				  error);
341 			goto err;
342 		}
343 
344 		list_for_each_entry(bf, &sc->rx.rxbuf, list) {
345 			skb = ath_rxbuf_alloc(common, common->rx_bufsize,
346 					      GFP_KERNEL);
347 			if (skb == NULL) {
348 				error = -ENOMEM;
349 				goto err;
350 			}
351 
352 			bf->bf_mpdu = skb;
353 			bf->bf_buf_addr = dma_map_single(sc->dev, skb->data,
354 					common->rx_bufsize,
355 					DMA_FROM_DEVICE);
356 			if (unlikely(dma_mapping_error(sc->dev,
357 							bf->bf_buf_addr))) {
358 				dev_kfree_skb_any(skb);
359 				bf->bf_mpdu = NULL;
360 				bf->bf_buf_addr = 0;
361 				ath_print(common, ATH_DBG_FATAL,
362 					  "dma_mapping_error() on RX init\n");
363 				error = -ENOMEM;
364 				goto err;
365 			}
366 		}
367 		sc->rx.rxlink = NULL;
368 	}
369 
370 err:
371 	if (error)
372 		ath_rx_cleanup(sc);
373 
374 	return error;
375 }
376 
377 void ath_rx_cleanup(struct ath_softc *sc)
378 {
379 	struct ath_hw *ah = sc->sc_ah;
380 	struct ath_common *common = ath9k_hw_common(ah);
381 	struct sk_buff *skb;
382 	struct ath_buf *bf;
383 
384 	if (sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_EDMA) {
385 		ath_rx_edma_cleanup(sc);
386 		return;
387 	} else {
388 		list_for_each_entry(bf, &sc->rx.rxbuf, list) {
389 			skb = bf->bf_mpdu;
390 			if (skb) {
391 				dma_unmap_single(sc->dev, bf->bf_buf_addr,
392 						common->rx_bufsize,
393 						DMA_FROM_DEVICE);
394 				dev_kfree_skb(skb);
395 				bf->bf_buf_addr = 0;
396 				bf->bf_mpdu = NULL;
397 			}
398 		}
399 
400 		if (sc->rx.rxdma.dd_desc_len != 0)
401 			ath_descdma_cleanup(sc, &sc->rx.rxdma, &sc->rx.rxbuf);
402 	}
403 }
404 
405 /*
406  * Calculate the receive filter according to the
407  * operating mode and state:
408  *
409  * o always accept unicast, broadcast, and multicast traffic
410  * o maintain current state of phy error reception (the hal
411  *   may enable phy error frames for noise immunity work)
412  * o probe request frames are accepted only when operating in
413  *   hostap, adhoc, or monitor modes
414  * o enable promiscuous mode according to the interface state
415  * o accept beacons:
416  *   - when operating in adhoc mode so the 802.11 layer creates
417  *     node table entries for peers,
418  *   - when operating in station mode for collecting rssi data when
419  *     the station is otherwise quiet, or
420  *   - when operating as a repeater so we see repeater-sta beacons
421  *   - when scanning
422  */
423 
424 u32 ath_calcrxfilter(struct ath_softc *sc)
425 {
426 #define	RX_FILTER_PRESERVE (ATH9K_RX_FILTER_PHYERR | ATH9K_RX_FILTER_PHYRADAR)
427 
428 	u32 rfilt;
429 
430 	rfilt = (ath9k_hw_getrxfilter(sc->sc_ah) & RX_FILTER_PRESERVE)
431 		| ATH9K_RX_FILTER_UCAST | ATH9K_RX_FILTER_BCAST
432 		| ATH9K_RX_FILTER_MCAST;
433 
434 	if (sc->rx.rxfilter & FIF_PROBE_REQ)
435 		rfilt |= ATH9K_RX_FILTER_PROBEREQ;
436 
437 	/*
438 	 * Set promiscuous mode when FIF_PROMISC_IN_BSS is enabled for station
439 	 * mode interface or when in monitor mode. AP mode does not need this
440 	 * since it receives all in-BSS frames anyway.
441 	 */
442 	if (((sc->sc_ah->opmode != NL80211_IFTYPE_AP) &&
443 	     (sc->rx.rxfilter & FIF_PROMISC_IN_BSS)) ||
444 	    (sc->sc_ah->opmode == NL80211_IFTYPE_MONITOR))
445 		rfilt |= ATH9K_RX_FILTER_PROM;
446 
447 	if (sc->rx.rxfilter & FIF_CONTROL)
448 		rfilt |= ATH9K_RX_FILTER_CONTROL;
449 
450 	if ((sc->sc_ah->opmode == NL80211_IFTYPE_STATION) &&
451 	    (sc->nvifs <= 1) &&
452 	    !(sc->rx.rxfilter & FIF_BCN_PRBRESP_PROMISC))
453 		rfilt |= ATH9K_RX_FILTER_MYBEACON;
454 	else
455 		rfilt |= ATH9K_RX_FILTER_BEACON;
456 
457 	if ((AR_SREV_9280_20_OR_LATER(sc->sc_ah) ||
458 	    AR_SREV_9285_12_OR_LATER(sc->sc_ah)) &&
459 	    (sc->sc_ah->opmode == NL80211_IFTYPE_AP) &&
460 	    (sc->rx.rxfilter & FIF_PSPOLL))
461 		rfilt |= ATH9K_RX_FILTER_PSPOLL;
462 
463 	if (conf_is_ht(&sc->hw->conf))
464 		rfilt |= ATH9K_RX_FILTER_COMP_BAR;
465 
466 	if (sc->sec_wiphy || (sc->nvifs > 1) ||
467 	    (sc->rx.rxfilter & FIF_OTHER_BSS)) {
468 		/* The following may also be needed for other older chips */
469 		if (sc->sc_ah->hw_version.macVersion == AR_SREV_VERSION_9160)
470 			rfilt |= ATH9K_RX_FILTER_PROM;
471 		rfilt |= ATH9K_RX_FILTER_MCAST_BCAST_ALL;
472 	}
473 
474 	return rfilt;
475 
476 #undef RX_FILTER_PRESERVE
477 }
478 
479 int ath_startrecv(struct ath_softc *sc)
480 {
481 	struct ath_hw *ah = sc->sc_ah;
482 	struct ath_buf *bf, *tbf;
483 
484 	if (ah->caps.hw_caps & ATH9K_HW_CAP_EDMA) {
485 		ath_edma_start_recv(sc);
486 		return 0;
487 	}
488 
489 	spin_lock_bh(&sc->rx.rxbuflock);
490 	if (list_empty(&sc->rx.rxbuf))
491 		goto start_recv;
492 
493 	sc->rx.rxlink = NULL;
494 	list_for_each_entry_safe(bf, tbf, &sc->rx.rxbuf, list) {
495 		ath_rx_buf_link(sc, bf);
496 	}
497 
498 	/* We could have deleted elements so the list may be empty now */
499 	if (list_empty(&sc->rx.rxbuf))
500 		goto start_recv;
501 
502 	bf = list_first_entry(&sc->rx.rxbuf, struct ath_buf, list);
503 	ath9k_hw_putrxbuf(ah, bf->bf_daddr);
504 	ath9k_hw_rxena(ah);
505 
506 start_recv:
507 	ath_opmode_init(sc);
508 	ath9k_hw_startpcureceive(ah, (sc->sc_flags & SC_OP_OFFCHANNEL));
509 
510 	spin_unlock_bh(&sc->rx.rxbuflock);
511 
512 	return 0;
513 }
514 
515 bool ath_stoprecv(struct ath_softc *sc)
516 {
517 	struct ath_hw *ah = sc->sc_ah;
518 	bool stopped;
519 
520 	spin_lock_bh(&sc->rx.rxbuflock);
521 	ath9k_hw_stoppcurecv(ah);
522 	ath9k_hw_setrxfilter(ah, 0);
523 	stopped = ath9k_hw_stopdmarecv(ah);
524 
525 	if (sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_EDMA)
526 		ath_edma_stop_recv(sc);
527 	else
528 		sc->rx.rxlink = NULL;
529 	spin_unlock_bh(&sc->rx.rxbuflock);
530 
531 	return stopped;
532 }
533 
534 void ath_flushrecv(struct ath_softc *sc)
535 {
536 	sc->sc_flags |= SC_OP_RXFLUSH;
537 	if (sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_EDMA)
538 		ath_rx_tasklet(sc, 1, true);
539 	ath_rx_tasklet(sc, 1, false);
540 	sc->sc_flags &= ~SC_OP_RXFLUSH;
541 }
542 
543 static bool ath_beacon_dtim_pending_cab(struct sk_buff *skb)
544 {
545 	/* Check whether the Beacon frame has DTIM indicating buffered bc/mc */
546 	struct ieee80211_mgmt *mgmt;
547 	u8 *pos, *end, id, elen;
548 	struct ieee80211_tim_ie *tim;
549 
550 	mgmt = (struct ieee80211_mgmt *)skb->data;
551 	pos = mgmt->u.beacon.variable;
552 	end = skb->data + skb->len;
553 
554 	while (pos + 2 < end) {
555 		id = *pos++;
556 		elen = *pos++;
557 		if (pos + elen > end)
558 			break;
559 
560 		if (id == WLAN_EID_TIM) {
561 			if (elen < sizeof(*tim))
562 				break;
563 			tim = (struct ieee80211_tim_ie *) pos;
564 			if (tim->dtim_count != 0)
565 				break;
566 			return tim->bitmap_ctrl & 0x01;
567 		}
568 
569 		pos += elen;
570 	}
571 
572 	return false;
573 }
574 
575 static void ath_rx_ps_beacon(struct ath_softc *sc, struct sk_buff *skb)
576 {
577 	struct ieee80211_mgmt *mgmt;
578 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
579 
580 	if (skb->len < 24 + 8 + 2 + 2)
581 		return;
582 
583 	mgmt = (struct ieee80211_mgmt *)skb->data;
584 	if (memcmp(common->curbssid, mgmt->bssid, ETH_ALEN) != 0)
585 		return; /* not from our current AP */
586 
587 	sc->ps_flags &= ~PS_WAIT_FOR_BEACON;
588 
589 	if (sc->ps_flags & PS_BEACON_SYNC) {
590 		sc->ps_flags &= ~PS_BEACON_SYNC;
591 		ath_print(common, ATH_DBG_PS,
592 			  "Reconfigure Beacon timers based on "
593 			  "timestamp from the AP\n");
594 		ath_beacon_config(sc, NULL);
595 	}
596 
597 	if (ath_beacon_dtim_pending_cab(skb)) {
598 		/*
599 		 * Remain awake waiting for buffered broadcast/multicast
600 		 * frames. If the last broadcast/multicast frame is not
601 		 * received properly, the next beacon frame will work as
602 		 * a backup trigger for returning into NETWORK SLEEP state,
603 		 * so we are waiting for it as well.
604 		 */
605 		ath_print(common, ATH_DBG_PS, "Received DTIM beacon indicating "
606 			  "buffered broadcast/multicast frame(s)\n");
607 		sc->ps_flags |= PS_WAIT_FOR_CAB | PS_WAIT_FOR_BEACON;
608 		return;
609 	}
610 
611 	if (sc->ps_flags & PS_WAIT_FOR_CAB) {
612 		/*
613 		 * This can happen if a broadcast frame is dropped or the AP
614 		 * fails to send a frame indicating that all CAB frames have
615 		 * been delivered.
616 		 */
617 		sc->ps_flags &= ~PS_WAIT_FOR_CAB;
618 		ath_print(common, ATH_DBG_PS,
619 			  "PS wait for CAB frames timed out\n");
620 	}
621 }
622 
623 static void ath_rx_ps(struct ath_softc *sc, struct sk_buff *skb)
624 {
625 	struct ieee80211_hdr *hdr;
626 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
627 
628 	hdr = (struct ieee80211_hdr *)skb->data;
629 
630 	/* Process Beacon and CAB receive in PS state */
631 	if (((sc->ps_flags & PS_WAIT_FOR_BEACON) || ath9k_check_auto_sleep(sc))
632 	    && ieee80211_is_beacon(hdr->frame_control))
633 		ath_rx_ps_beacon(sc, skb);
634 	else if ((sc->ps_flags & PS_WAIT_FOR_CAB) &&
635 		 (ieee80211_is_data(hdr->frame_control) ||
636 		  ieee80211_is_action(hdr->frame_control)) &&
637 		 is_multicast_ether_addr(hdr->addr1) &&
638 		 !ieee80211_has_moredata(hdr->frame_control)) {
639 		/*
640 		 * No more broadcast/multicast frames to be received at this
641 		 * point.
642 		 */
643 		sc->ps_flags &= ~(PS_WAIT_FOR_CAB | PS_WAIT_FOR_BEACON);
644 		ath_print(common, ATH_DBG_PS,
645 			  "All PS CAB frames received, back to sleep\n");
646 	} else if ((sc->ps_flags & PS_WAIT_FOR_PSPOLL_DATA) &&
647 		   !is_multicast_ether_addr(hdr->addr1) &&
648 		   !ieee80211_has_morefrags(hdr->frame_control)) {
649 		sc->ps_flags &= ~PS_WAIT_FOR_PSPOLL_DATA;
650 		ath_print(common, ATH_DBG_PS,
651 			  "Going back to sleep after having received "
652 			  "PS-Poll data (0x%lx)\n",
653 			sc->ps_flags & (PS_WAIT_FOR_BEACON |
654 					PS_WAIT_FOR_CAB |
655 					PS_WAIT_FOR_PSPOLL_DATA |
656 					PS_WAIT_FOR_TX_ACK));
657 	}
658 }
659 
660 static void ath_rx_send_to_mac80211(struct ieee80211_hw *hw,
661 				    struct ath_softc *sc, struct sk_buff *skb,
662 				    struct ieee80211_rx_status *rxs)
663 {
664 	struct ieee80211_hdr *hdr;
665 
666 	hdr = (struct ieee80211_hdr *)skb->data;
667 
668 	/* Send the frame to mac80211 */
669 	if (is_multicast_ether_addr(hdr->addr1)) {
670 		int i;
671 		/*
672 		 * Deliver broadcast/multicast frames to all suitable
673 		 * virtual wiphys.
674 		 */
675 		/* TODO: filter based on channel configuration */
676 		for (i = 0; i < sc->num_sec_wiphy; i++) {
677 			struct ath_wiphy *aphy = sc->sec_wiphy[i];
678 			struct sk_buff *nskb;
679 			if (aphy == NULL)
680 				continue;
681 			nskb = skb_copy(skb, GFP_ATOMIC);
682 			if (!nskb)
683 				continue;
684 			ieee80211_rx(aphy->hw, nskb);
685 		}
686 		ieee80211_rx(sc->hw, skb);
687 	} else
688 		/* Deliver unicast frames based on receiver address */
689 		ieee80211_rx(hw, skb);
690 }
691 
692 static bool ath_edma_get_buffers(struct ath_softc *sc,
693 				 enum ath9k_rx_qtype qtype)
694 {
695 	struct ath_rx_edma *rx_edma = &sc->rx.rx_edma[qtype];
696 	struct ath_hw *ah = sc->sc_ah;
697 	struct ath_common *common = ath9k_hw_common(ah);
698 	struct sk_buff *skb;
699 	struct ath_buf *bf;
700 	int ret;
701 
702 	skb = skb_peek(&rx_edma->rx_fifo);
703 	if (!skb)
704 		return false;
705 
706 	bf = SKB_CB_ATHBUF(skb);
707 	BUG_ON(!bf);
708 
709 	dma_sync_single_for_cpu(sc->dev, bf->bf_buf_addr,
710 				common->rx_bufsize, DMA_FROM_DEVICE);
711 
712 	ret = ath9k_hw_process_rxdesc_edma(ah, NULL, skb->data);
713 	if (ret == -EINPROGRESS) {
714 		/*let device gain the buffer again*/
715 		dma_sync_single_for_device(sc->dev, bf->bf_buf_addr,
716 				common->rx_bufsize, DMA_FROM_DEVICE);
717 		return false;
718 	}
719 
720 	__skb_unlink(skb, &rx_edma->rx_fifo);
721 	if (ret == -EINVAL) {
722 		/* corrupt descriptor, skip this one and the following one */
723 		list_add_tail(&bf->list, &sc->rx.rxbuf);
724 		ath_rx_edma_buf_link(sc, qtype);
725 		skb = skb_peek(&rx_edma->rx_fifo);
726 		if (!skb)
727 			return true;
728 
729 		bf = SKB_CB_ATHBUF(skb);
730 		BUG_ON(!bf);
731 
732 		__skb_unlink(skb, &rx_edma->rx_fifo);
733 		list_add_tail(&bf->list, &sc->rx.rxbuf);
734 		ath_rx_edma_buf_link(sc, qtype);
735 		return true;
736 	}
737 	skb_queue_tail(&rx_edma->rx_buffers, skb);
738 
739 	return true;
740 }
741 
742 static struct ath_buf *ath_edma_get_next_rx_buf(struct ath_softc *sc,
743 						struct ath_rx_status *rs,
744 						enum ath9k_rx_qtype qtype)
745 {
746 	struct ath_rx_edma *rx_edma = &sc->rx.rx_edma[qtype];
747 	struct sk_buff *skb;
748 	struct ath_buf *bf;
749 
750 	while (ath_edma_get_buffers(sc, qtype));
751 	skb = __skb_dequeue(&rx_edma->rx_buffers);
752 	if (!skb)
753 		return NULL;
754 
755 	bf = SKB_CB_ATHBUF(skb);
756 	ath9k_hw_process_rxdesc_edma(sc->sc_ah, rs, skb->data);
757 	return bf;
758 }
759 
760 static struct ath_buf *ath_get_next_rx_buf(struct ath_softc *sc,
761 					   struct ath_rx_status *rs)
762 {
763 	struct ath_hw *ah = sc->sc_ah;
764 	struct ath_common *common = ath9k_hw_common(ah);
765 	struct ath_desc *ds;
766 	struct ath_buf *bf;
767 	int ret;
768 
769 	if (list_empty(&sc->rx.rxbuf)) {
770 		sc->rx.rxlink = NULL;
771 		return NULL;
772 	}
773 
774 	bf = list_first_entry(&sc->rx.rxbuf, struct ath_buf, list);
775 	ds = bf->bf_desc;
776 
777 	/*
778 	 * Must provide the virtual address of the current
779 	 * descriptor, the physical address, and the virtual
780 	 * address of the next descriptor in the h/w chain.
781 	 * This allows the HAL to look ahead to see if the
782 	 * hardware is done with a descriptor by checking the
783 	 * done bit in the following descriptor and the address
784 	 * of the current descriptor the DMA engine is working
785 	 * on.  All this is necessary because of our use of
786 	 * a self-linked list to avoid rx overruns.
787 	 */
788 	ret = ath9k_hw_rxprocdesc(ah, ds, rs, 0);
789 	if (ret == -EINPROGRESS) {
790 		struct ath_rx_status trs;
791 		struct ath_buf *tbf;
792 		struct ath_desc *tds;
793 
794 		memset(&trs, 0, sizeof(trs));
795 		if (list_is_last(&bf->list, &sc->rx.rxbuf)) {
796 			sc->rx.rxlink = NULL;
797 			return NULL;
798 		}
799 
800 		tbf = list_entry(bf->list.next, struct ath_buf, list);
801 
802 		/*
803 		 * On some hardware the descriptor status words could
804 		 * get corrupted, including the done bit. Because of
805 		 * this, check if the next descriptor's done bit is
806 		 * set or not.
807 		 *
808 		 * If the next descriptor's done bit is set, the current
809 		 * descriptor has been corrupted. Force s/w to discard
810 		 * this descriptor and continue...
811 		 */
812 
813 		tds = tbf->bf_desc;
814 		ret = ath9k_hw_rxprocdesc(ah, tds, &trs, 0);
815 		if (ret == -EINPROGRESS)
816 			return NULL;
817 	}
818 
819 	if (!bf->bf_mpdu)
820 		return bf;
821 
822 	/*
823 	 * Synchronize the DMA transfer with CPU before
824 	 * 1. accessing the frame
825 	 * 2. requeueing the same buffer to h/w
826 	 */
827 	dma_sync_single_for_cpu(sc->dev, bf->bf_buf_addr,
828 			common->rx_bufsize,
829 			DMA_FROM_DEVICE);
830 
831 	return bf;
832 }
833 
834 /* Assumes you've already done the endian to CPU conversion */
835 static bool ath9k_rx_accept(struct ath_common *common,
836 			    struct ieee80211_hdr *hdr,
837 			    struct ieee80211_rx_status *rxs,
838 			    struct ath_rx_status *rx_stats,
839 			    bool *decrypt_error)
840 {
841 	struct ath_hw *ah = common->ah;
842 	__le16 fc;
843 	u8 rx_status_len = ah->caps.rx_status_len;
844 
845 	fc = hdr->frame_control;
846 
847 	if (!rx_stats->rs_datalen)
848 		return false;
849         /*
850          * rs_status follows rs_datalen so if rs_datalen is too large
851          * we can take a hint that hardware corrupted it, so ignore
852          * those frames.
853          */
854 	if (rx_stats->rs_datalen > (common->rx_bufsize - rx_status_len))
855 		return false;
856 
857 	/*
858 	 * rs_more indicates chained descriptors which can be used
859 	 * to link buffers together for a sort of scatter-gather
860 	 * operation.
861 	 * reject the frame, we don't support scatter-gather yet and
862 	 * the frame is probably corrupt anyway
863 	 */
864 	if (rx_stats->rs_more)
865 		return false;
866 
867 	/*
868 	 * The rx_stats->rs_status will not be set until the end of the
869 	 * chained descriptors so it can be ignored if rs_more is set. The
870 	 * rs_more will be false at the last element of the chained
871 	 * descriptors.
872 	 */
873 	if (rx_stats->rs_status != 0) {
874 		if (rx_stats->rs_status & ATH9K_RXERR_CRC)
875 			rxs->flag |= RX_FLAG_FAILED_FCS_CRC;
876 		if (rx_stats->rs_status & ATH9K_RXERR_PHY)
877 			return false;
878 
879 		if (rx_stats->rs_status & ATH9K_RXERR_DECRYPT) {
880 			*decrypt_error = true;
881 		} else if (rx_stats->rs_status & ATH9K_RXERR_MIC) {
882 			/*
883 			 * The MIC error bit is only valid if the frame
884 			 * is not a control frame or fragment, and it was
885 			 * decrypted using a valid TKIP key.
886 			 */
887 			if (!ieee80211_is_ctl(fc) &&
888 			    !ieee80211_has_morefrags(fc) &&
889 			    !(le16_to_cpu(hdr->seq_ctrl) & IEEE80211_SCTL_FRAG) &&
890 			    test_bit(rx_stats->rs_keyix, common->tkip_keymap))
891 				rxs->flag |= RX_FLAG_MMIC_ERROR;
892 			else
893 				rx_stats->rs_status &= ~ATH9K_RXERR_MIC;
894 		}
895 		/*
896 		 * Reject error frames with the exception of
897 		 * decryption and MIC failures. For monitor mode,
898 		 * we also ignore the CRC error.
899 		 */
900 		if (ah->opmode == NL80211_IFTYPE_MONITOR) {
901 			if (rx_stats->rs_status &
902 			    ~(ATH9K_RXERR_DECRYPT | ATH9K_RXERR_MIC |
903 			      ATH9K_RXERR_CRC))
904 				return false;
905 		} else {
906 			if (rx_stats->rs_status &
907 			    ~(ATH9K_RXERR_DECRYPT | ATH9K_RXERR_MIC)) {
908 				return false;
909 			}
910 		}
911 	}
912 	return true;
913 }
914 
915 static int ath9k_process_rate(struct ath_common *common,
916 			      struct ieee80211_hw *hw,
917 			      struct ath_rx_status *rx_stats,
918 			      struct ieee80211_rx_status *rxs)
919 {
920 	struct ieee80211_supported_band *sband;
921 	enum ieee80211_band band;
922 	unsigned int i = 0;
923 
924 	band = hw->conf.channel->band;
925 	sband = hw->wiphy->bands[band];
926 
927 	if (rx_stats->rs_rate & 0x80) {
928 		/* HT rate */
929 		rxs->flag |= RX_FLAG_HT;
930 		if (rx_stats->rs_flags & ATH9K_RX_2040)
931 			rxs->flag |= RX_FLAG_40MHZ;
932 		if (rx_stats->rs_flags & ATH9K_RX_GI)
933 			rxs->flag |= RX_FLAG_SHORT_GI;
934 		rxs->rate_idx = rx_stats->rs_rate & 0x7f;
935 		return 0;
936 	}
937 
938 	for (i = 0; i < sband->n_bitrates; i++) {
939 		if (sband->bitrates[i].hw_value == rx_stats->rs_rate) {
940 			rxs->rate_idx = i;
941 			return 0;
942 		}
943 		if (sband->bitrates[i].hw_value_short == rx_stats->rs_rate) {
944 			rxs->flag |= RX_FLAG_SHORTPRE;
945 			rxs->rate_idx = i;
946 			return 0;
947 		}
948 	}
949 
950 	/*
951 	 * No valid hardware bitrate found -- we should not get here
952 	 * because hardware has already validated this frame as OK.
953 	 */
954 	ath_print(common, ATH_DBG_XMIT, "unsupported hw bitrate detected "
955 		  "0x%02x using 1 Mbit\n", rx_stats->rs_rate);
956 
957 	return -EINVAL;
958 }
959 
960 static void ath9k_process_rssi(struct ath_common *common,
961 			       struct ieee80211_hw *hw,
962 			       struct ieee80211_hdr *hdr,
963 			       struct ath_rx_status *rx_stats)
964 {
965 	struct ath_hw *ah = common->ah;
966 	struct ieee80211_sta *sta;
967 	struct ath_node *an;
968 	int last_rssi = ATH_RSSI_DUMMY_MARKER;
969 	__le16 fc;
970 
971 	fc = hdr->frame_control;
972 
973 	rcu_read_lock();
974 	/*
975 	 * XXX: use ieee80211_find_sta! This requires quite a bit of work
976 	 * under the current ath9k virtual wiphy implementation as we have
977 	 * no way of tying a vif to wiphy. Typically vifs are attached to
978 	 * at least one sdata of a wiphy on mac80211 but with ath9k virtual
979 	 * wiphy you'd have to iterate over every wiphy and each sdata.
980 	 */
981 	if (is_multicast_ether_addr(hdr->addr1))
982 		sta = ieee80211_find_sta_by_ifaddr(hw, hdr->addr2, NULL);
983 	else
984 		sta = ieee80211_find_sta_by_ifaddr(hw, hdr->addr2, hdr->addr1);
985 
986 	if (sta) {
987 		an = (struct ath_node *) sta->drv_priv;
988 		if (rx_stats->rs_rssi != ATH9K_RSSI_BAD &&
989 		   !rx_stats->rs_moreaggr)
990 			ATH_RSSI_LPF(an->last_rssi, rx_stats->rs_rssi);
991 		last_rssi = an->last_rssi;
992 	}
993 	rcu_read_unlock();
994 
995 	if (likely(last_rssi != ATH_RSSI_DUMMY_MARKER))
996 		rx_stats->rs_rssi = ATH_EP_RND(last_rssi,
997 					      ATH_RSSI_EP_MULTIPLIER);
998 	if (rx_stats->rs_rssi < 0)
999 		rx_stats->rs_rssi = 0;
1000 
1001 	/* Update Beacon RSSI, this is used by ANI. */
1002 	if (ieee80211_is_beacon(fc))
1003 		ah->stats.avgbrssi = rx_stats->rs_rssi;
1004 }
1005 
1006 /*
1007  * For Decrypt or Demic errors, we only mark packet status here and always push
1008  * up the frame up to let mac80211 handle the actual error case, be it no
1009  * decryption key or real decryption error. This let us keep statistics there.
1010  */
1011 static int ath9k_rx_skb_preprocess(struct ath_common *common,
1012 				   struct ieee80211_hw *hw,
1013 				   struct ieee80211_hdr *hdr,
1014 				   struct ath_rx_status *rx_stats,
1015 				   struct ieee80211_rx_status *rx_status,
1016 				   bool *decrypt_error)
1017 {
1018 	memset(rx_status, 0, sizeof(struct ieee80211_rx_status));
1019 
1020 	/*
1021 	 * everything but the rate is checked here, the rate check is done
1022 	 * separately to avoid doing two lookups for a rate for each frame.
1023 	 */
1024 	if (!ath9k_rx_accept(common, hdr, rx_status, rx_stats, decrypt_error))
1025 		return -EINVAL;
1026 
1027 	ath9k_process_rssi(common, hw, hdr, rx_stats);
1028 
1029 	if (ath9k_process_rate(common, hw, rx_stats, rx_status))
1030 		return -EINVAL;
1031 
1032 	rx_status->band = hw->conf.channel->band;
1033 	rx_status->freq = hw->conf.channel->center_freq;
1034 	rx_status->signal = ATH_DEFAULT_NOISE_FLOOR + rx_stats->rs_rssi;
1035 	rx_status->antenna = rx_stats->rs_antenna;
1036 	rx_status->flag |= RX_FLAG_TSFT;
1037 
1038 	return 0;
1039 }
1040 
1041 static void ath9k_rx_skb_postprocess(struct ath_common *common,
1042 				     struct sk_buff *skb,
1043 				     struct ath_rx_status *rx_stats,
1044 				     struct ieee80211_rx_status *rxs,
1045 				     bool decrypt_error)
1046 {
1047 	struct ath_hw *ah = common->ah;
1048 	struct ieee80211_hdr *hdr;
1049 	int hdrlen, padpos, padsize;
1050 	u8 keyix;
1051 	__le16 fc;
1052 
1053 	/* see if any padding is done by the hw and remove it */
1054 	hdr = (struct ieee80211_hdr *) skb->data;
1055 	hdrlen = ieee80211_get_hdrlen_from_skb(skb);
1056 	fc = hdr->frame_control;
1057 	padpos = ath9k_cmn_padpos(hdr->frame_control);
1058 
1059 	/* The MAC header is padded to have 32-bit boundary if the
1060 	 * packet payload is non-zero. The general calculation for
1061 	 * padsize would take into account odd header lengths:
1062 	 * padsize = (4 - padpos % 4) % 4; However, since only
1063 	 * even-length headers are used, padding can only be 0 or 2
1064 	 * bytes and we can optimize this a bit. In addition, we must
1065 	 * not try to remove padding from short control frames that do
1066 	 * not have payload. */
1067 	padsize = padpos & 3;
1068 	if (padsize && skb->len>=padpos+padsize+FCS_LEN) {
1069 		memmove(skb->data + padsize, skb->data, padpos);
1070 		skb_pull(skb, padsize);
1071 	}
1072 
1073 	keyix = rx_stats->rs_keyix;
1074 
1075 	if (!(keyix == ATH9K_RXKEYIX_INVALID) && !decrypt_error &&
1076 	    ieee80211_has_protected(fc)) {
1077 		rxs->flag |= RX_FLAG_DECRYPTED;
1078 	} else if (ieee80211_has_protected(fc)
1079 		   && !decrypt_error && skb->len >= hdrlen + 4) {
1080 		keyix = skb->data[hdrlen + 3] >> 6;
1081 
1082 		if (test_bit(keyix, common->keymap))
1083 			rxs->flag |= RX_FLAG_DECRYPTED;
1084 	}
1085 	if (ah->sw_mgmt_crypto &&
1086 	    (rxs->flag & RX_FLAG_DECRYPTED) &&
1087 	    ieee80211_is_mgmt(fc))
1088 		/* Use software decrypt for management frames. */
1089 		rxs->flag &= ~RX_FLAG_DECRYPTED;
1090 }
1091 
1092 static void ath_lnaconf_alt_good_scan(struct ath_ant_comb *antcomb,
1093 				      struct ath_hw_antcomb_conf ant_conf,
1094 				      int main_rssi_avg)
1095 {
1096 	antcomb->quick_scan_cnt = 0;
1097 
1098 	if (ant_conf.main_lna_conf == ATH_ANT_DIV_COMB_LNA2)
1099 		antcomb->rssi_lna2 = main_rssi_avg;
1100 	else if (ant_conf.main_lna_conf == ATH_ANT_DIV_COMB_LNA1)
1101 		antcomb->rssi_lna1 = main_rssi_avg;
1102 
1103 	switch ((ant_conf.main_lna_conf << 4) | ant_conf.alt_lna_conf) {
1104 	case (0x10): /* LNA2 A-B */
1105 		antcomb->main_conf = ATH_ANT_DIV_COMB_LNA1_MINUS_LNA2;
1106 		antcomb->first_quick_scan_conf =
1107 			ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2;
1108 		antcomb->second_quick_scan_conf = ATH_ANT_DIV_COMB_LNA1;
1109 		break;
1110 	case (0x20): /* LNA1 A-B */
1111 		antcomb->main_conf = ATH_ANT_DIV_COMB_LNA1_MINUS_LNA2;
1112 		antcomb->first_quick_scan_conf =
1113 			ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2;
1114 		antcomb->second_quick_scan_conf = ATH_ANT_DIV_COMB_LNA2;
1115 		break;
1116 	case (0x21): /* LNA1 LNA2 */
1117 		antcomb->main_conf = ATH_ANT_DIV_COMB_LNA2;
1118 		antcomb->first_quick_scan_conf =
1119 			ATH_ANT_DIV_COMB_LNA1_MINUS_LNA2;
1120 		antcomb->second_quick_scan_conf =
1121 			ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2;
1122 		break;
1123 	case (0x12): /* LNA2 LNA1 */
1124 		antcomb->main_conf = ATH_ANT_DIV_COMB_LNA1;
1125 		antcomb->first_quick_scan_conf =
1126 			ATH_ANT_DIV_COMB_LNA1_MINUS_LNA2;
1127 		antcomb->second_quick_scan_conf =
1128 			ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2;
1129 		break;
1130 	case (0x13): /* LNA2 A+B */
1131 		antcomb->main_conf = ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2;
1132 		antcomb->first_quick_scan_conf =
1133 			ATH_ANT_DIV_COMB_LNA1_MINUS_LNA2;
1134 		antcomb->second_quick_scan_conf = ATH_ANT_DIV_COMB_LNA1;
1135 		break;
1136 	case (0x23): /* LNA1 A+B */
1137 		antcomb->main_conf = ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2;
1138 		antcomb->first_quick_scan_conf =
1139 			ATH_ANT_DIV_COMB_LNA1_MINUS_LNA2;
1140 		antcomb->second_quick_scan_conf = ATH_ANT_DIV_COMB_LNA2;
1141 		break;
1142 	default:
1143 		break;
1144 	}
1145 }
1146 
1147 static void ath_select_ant_div_from_quick_scan(struct ath_ant_comb *antcomb,
1148 				struct ath_hw_antcomb_conf *div_ant_conf,
1149 				int main_rssi_avg, int alt_rssi_avg,
1150 				int alt_ratio)
1151 {
1152 	/* alt_good */
1153 	switch (antcomb->quick_scan_cnt) {
1154 	case 0:
1155 		/* set alt to main, and alt to first conf */
1156 		div_ant_conf->main_lna_conf = antcomb->main_conf;
1157 		div_ant_conf->alt_lna_conf = antcomb->first_quick_scan_conf;
1158 		break;
1159 	case 1:
1160 		/* set alt to main, and alt to first conf */
1161 		div_ant_conf->main_lna_conf = antcomb->main_conf;
1162 		div_ant_conf->alt_lna_conf = antcomb->second_quick_scan_conf;
1163 		antcomb->rssi_first = main_rssi_avg;
1164 		antcomb->rssi_second = alt_rssi_avg;
1165 
1166 		if (antcomb->main_conf == ATH_ANT_DIV_COMB_LNA1) {
1167 			/* main is LNA1 */
1168 			if (ath_is_alt_ant_ratio_better(alt_ratio,
1169 						ATH_ANT_DIV_COMB_LNA1_DELTA_HI,
1170 						ATH_ANT_DIV_COMB_LNA1_DELTA_LOW,
1171 						main_rssi_avg, alt_rssi_avg,
1172 						antcomb->total_pkt_count))
1173 				antcomb->first_ratio = true;
1174 			else
1175 				antcomb->first_ratio = false;
1176 		} else if (antcomb->main_conf == ATH_ANT_DIV_COMB_LNA2) {
1177 			if (ath_is_alt_ant_ratio_better(alt_ratio,
1178 						ATH_ANT_DIV_COMB_LNA1_DELTA_MID,
1179 						ATH_ANT_DIV_COMB_LNA1_DELTA_LOW,
1180 						main_rssi_avg, alt_rssi_avg,
1181 						antcomb->total_pkt_count))
1182 				antcomb->first_ratio = true;
1183 			else
1184 				antcomb->first_ratio = false;
1185 		} else {
1186 			if ((((alt_ratio >= ATH_ANT_DIV_COMB_ALT_ANT_RATIO2) &&
1187 			    (alt_rssi_avg > main_rssi_avg +
1188 			    ATH_ANT_DIV_COMB_LNA1_DELTA_HI)) ||
1189 			    (alt_rssi_avg > main_rssi_avg)) &&
1190 			    (antcomb->total_pkt_count > 50))
1191 				antcomb->first_ratio = true;
1192 			else
1193 				antcomb->first_ratio = false;
1194 		}
1195 		break;
1196 	case 2:
1197 		antcomb->alt_good = false;
1198 		antcomb->scan_not_start = false;
1199 		antcomb->scan = false;
1200 		antcomb->rssi_first = main_rssi_avg;
1201 		antcomb->rssi_third = alt_rssi_avg;
1202 
1203 		if (antcomb->second_quick_scan_conf == ATH_ANT_DIV_COMB_LNA1)
1204 			antcomb->rssi_lna1 = alt_rssi_avg;
1205 		else if (antcomb->second_quick_scan_conf ==
1206 			 ATH_ANT_DIV_COMB_LNA2)
1207 			antcomb->rssi_lna2 = alt_rssi_avg;
1208 		else if (antcomb->second_quick_scan_conf ==
1209 			 ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2) {
1210 			if (antcomb->main_conf == ATH_ANT_DIV_COMB_LNA2)
1211 				antcomb->rssi_lna2 = main_rssi_avg;
1212 			else if (antcomb->main_conf == ATH_ANT_DIV_COMB_LNA1)
1213 				antcomb->rssi_lna1 = main_rssi_avg;
1214 		}
1215 
1216 		if (antcomb->rssi_lna2 > antcomb->rssi_lna1 +
1217 		    ATH_ANT_DIV_COMB_LNA1_LNA2_SWITCH_DELTA)
1218 			div_ant_conf->main_lna_conf = ATH_ANT_DIV_COMB_LNA2;
1219 		else
1220 			div_ant_conf->main_lna_conf = ATH_ANT_DIV_COMB_LNA1;
1221 
1222 		if (antcomb->main_conf == ATH_ANT_DIV_COMB_LNA1) {
1223 			if (ath_is_alt_ant_ratio_better(alt_ratio,
1224 						ATH_ANT_DIV_COMB_LNA1_DELTA_HI,
1225 						ATH_ANT_DIV_COMB_LNA1_DELTA_LOW,
1226 						main_rssi_avg, alt_rssi_avg,
1227 						antcomb->total_pkt_count))
1228 				antcomb->second_ratio = true;
1229 			else
1230 				antcomb->second_ratio = false;
1231 		} else if (antcomb->main_conf == ATH_ANT_DIV_COMB_LNA2) {
1232 			if (ath_is_alt_ant_ratio_better(alt_ratio,
1233 						ATH_ANT_DIV_COMB_LNA1_DELTA_MID,
1234 						ATH_ANT_DIV_COMB_LNA1_DELTA_LOW,
1235 						main_rssi_avg, alt_rssi_avg,
1236 						antcomb->total_pkt_count))
1237 				antcomb->second_ratio = true;
1238 			else
1239 				antcomb->second_ratio = false;
1240 		} else {
1241 			if ((((alt_ratio >= ATH_ANT_DIV_COMB_ALT_ANT_RATIO2) &&
1242 			    (alt_rssi_avg > main_rssi_avg +
1243 			    ATH_ANT_DIV_COMB_LNA1_DELTA_HI)) ||
1244 			    (alt_rssi_avg > main_rssi_avg)) &&
1245 			    (antcomb->total_pkt_count > 50))
1246 				antcomb->second_ratio = true;
1247 			else
1248 				antcomb->second_ratio = false;
1249 		}
1250 
1251 		/* set alt to the conf with maximun ratio */
1252 		if (antcomb->first_ratio && antcomb->second_ratio) {
1253 			if (antcomb->rssi_second > antcomb->rssi_third) {
1254 				/* first alt*/
1255 				if ((antcomb->first_quick_scan_conf ==
1256 				    ATH_ANT_DIV_COMB_LNA1) ||
1257 				    (antcomb->first_quick_scan_conf ==
1258 				    ATH_ANT_DIV_COMB_LNA2))
1259 					/* Set alt LNA1 or LNA2*/
1260 					if (div_ant_conf->main_lna_conf ==
1261 					    ATH_ANT_DIV_COMB_LNA2)
1262 						div_ant_conf->alt_lna_conf =
1263 							ATH_ANT_DIV_COMB_LNA1;
1264 					else
1265 						div_ant_conf->alt_lna_conf =
1266 							ATH_ANT_DIV_COMB_LNA2;
1267 				else
1268 					/* Set alt to A+B or A-B */
1269 					div_ant_conf->alt_lna_conf =
1270 						antcomb->first_quick_scan_conf;
1271 			} else if ((antcomb->second_quick_scan_conf ==
1272 				   ATH_ANT_DIV_COMB_LNA1) ||
1273 				   (antcomb->second_quick_scan_conf ==
1274 				   ATH_ANT_DIV_COMB_LNA2)) {
1275 				/* Set alt LNA1 or LNA2 */
1276 				if (div_ant_conf->main_lna_conf ==
1277 				    ATH_ANT_DIV_COMB_LNA2)
1278 					div_ant_conf->alt_lna_conf =
1279 						ATH_ANT_DIV_COMB_LNA1;
1280 				else
1281 					div_ant_conf->alt_lna_conf =
1282 						ATH_ANT_DIV_COMB_LNA2;
1283 			} else {
1284 				/* Set alt to A+B or A-B */
1285 				div_ant_conf->alt_lna_conf =
1286 					antcomb->second_quick_scan_conf;
1287 			}
1288 		} else if (antcomb->first_ratio) {
1289 			/* first alt */
1290 			if ((antcomb->first_quick_scan_conf ==
1291 			    ATH_ANT_DIV_COMB_LNA1) ||
1292 			    (antcomb->first_quick_scan_conf ==
1293 			    ATH_ANT_DIV_COMB_LNA2))
1294 					/* Set alt LNA1 or LNA2 */
1295 				if (div_ant_conf->main_lna_conf ==
1296 				    ATH_ANT_DIV_COMB_LNA2)
1297 					div_ant_conf->alt_lna_conf =
1298 							ATH_ANT_DIV_COMB_LNA1;
1299 				else
1300 					div_ant_conf->alt_lna_conf =
1301 							ATH_ANT_DIV_COMB_LNA2;
1302 			else
1303 				/* Set alt to A+B or A-B */
1304 				div_ant_conf->alt_lna_conf =
1305 						antcomb->first_quick_scan_conf;
1306 		} else if (antcomb->second_ratio) {
1307 				/* second alt */
1308 			if ((antcomb->second_quick_scan_conf ==
1309 			    ATH_ANT_DIV_COMB_LNA1) ||
1310 			    (antcomb->second_quick_scan_conf ==
1311 			    ATH_ANT_DIV_COMB_LNA2))
1312 				/* Set alt LNA1 or LNA2 */
1313 				if (div_ant_conf->main_lna_conf ==
1314 				    ATH_ANT_DIV_COMB_LNA2)
1315 					div_ant_conf->alt_lna_conf =
1316 						ATH_ANT_DIV_COMB_LNA1;
1317 				else
1318 					div_ant_conf->alt_lna_conf =
1319 						ATH_ANT_DIV_COMB_LNA2;
1320 			else
1321 				/* Set alt to A+B or A-B */
1322 				div_ant_conf->alt_lna_conf =
1323 						antcomb->second_quick_scan_conf;
1324 		} else {
1325 			/* main is largest */
1326 			if ((antcomb->main_conf == ATH_ANT_DIV_COMB_LNA1) ||
1327 			    (antcomb->main_conf == ATH_ANT_DIV_COMB_LNA2))
1328 				/* Set alt LNA1 or LNA2 */
1329 				if (div_ant_conf->main_lna_conf ==
1330 				    ATH_ANT_DIV_COMB_LNA2)
1331 					div_ant_conf->alt_lna_conf =
1332 							ATH_ANT_DIV_COMB_LNA1;
1333 				else
1334 					div_ant_conf->alt_lna_conf =
1335 							ATH_ANT_DIV_COMB_LNA2;
1336 			else
1337 				/* Set alt to A+B or A-B */
1338 				div_ant_conf->alt_lna_conf = antcomb->main_conf;
1339 		}
1340 		break;
1341 	default:
1342 		break;
1343 	}
1344 }
1345 
1346 static void ath_ant_div_conf_fast_divbias(struct ath_hw_antcomb_conf *ant_conf)
1347 {
1348 	/* Adjust the fast_div_bias based on main and alt lna conf */
1349 	switch ((ant_conf->main_lna_conf << 4) | ant_conf->alt_lna_conf) {
1350 	case (0x01): /* A-B LNA2 */
1351 		ant_conf->fast_div_bias = 0x3b;
1352 		break;
1353 	case (0x02): /* A-B LNA1 */
1354 		ant_conf->fast_div_bias = 0x3d;
1355 		break;
1356 	case (0x03): /* A-B A+B */
1357 		ant_conf->fast_div_bias = 0x1;
1358 		break;
1359 	case (0x10): /* LNA2 A-B */
1360 		ant_conf->fast_div_bias = 0x7;
1361 		break;
1362 	case (0x12): /* LNA2 LNA1 */
1363 		ant_conf->fast_div_bias = 0x2;
1364 		break;
1365 	case (0x13): /* LNA2 A+B */
1366 		ant_conf->fast_div_bias = 0x7;
1367 		break;
1368 	case (0x20): /* LNA1 A-B */
1369 		ant_conf->fast_div_bias = 0x6;
1370 		break;
1371 	case (0x21): /* LNA1 LNA2 */
1372 		ant_conf->fast_div_bias = 0x0;
1373 		break;
1374 	case (0x23): /* LNA1 A+B */
1375 		ant_conf->fast_div_bias = 0x6;
1376 		break;
1377 	case (0x30): /* A+B A-B */
1378 		ant_conf->fast_div_bias = 0x1;
1379 		break;
1380 	case (0x31): /* A+B LNA2 */
1381 		ant_conf->fast_div_bias = 0x3b;
1382 		break;
1383 	case (0x32): /* A+B LNA1 */
1384 		ant_conf->fast_div_bias = 0x3d;
1385 		break;
1386 	default:
1387 		break;
1388 	}
1389 }
1390 
1391 /* Antenna diversity and combining */
1392 static void ath_ant_comb_scan(struct ath_softc *sc, struct ath_rx_status *rs)
1393 {
1394 	struct ath_hw_antcomb_conf div_ant_conf;
1395 	struct ath_ant_comb *antcomb = &sc->ant_comb;
1396 	int alt_ratio = 0, alt_rssi_avg = 0, main_rssi_avg = 0, curr_alt_set;
1397 	int curr_main_set, curr_bias;
1398 	int main_rssi = rs->rs_rssi_ctl0;
1399 	int alt_rssi = rs->rs_rssi_ctl1;
1400 	int rx_ant_conf,  main_ant_conf;
1401 	bool short_scan = false;
1402 
1403 	rx_ant_conf = (rs->rs_rssi_ctl2 >> ATH_ANT_RX_CURRENT_SHIFT) &
1404 		       ATH_ANT_RX_MASK;
1405 	main_ant_conf = (rs->rs_rssi_ctl2 >> ATH_ANT_RX_MAIN_SHIFT) &
1406 			 ATH_ANT_RX_MASK;
1407 
1408 	/* Record packet only when alt_rssi is positive */
1409 	if (alt_rssi > 0) {
1410 		antcomb->total_pkt_count++;
1411 		antcomb->main_total_rssi += main_rssi;
1412 		antcomb->alt_total_rssi  += alt_rssi;
1413 		if (main_ant_conf == rx_ant_conf)
1414 			antcomb->main_recv_cnt++;
1415 		else
1416 			antcomb->alt_recv_cnt++;
1417 	}
1418 
1419 	/* Short scan check */
1420 	if (antcomb->scan && antcomb->alt_good) {
1421 		if (time_after(jiffies, antcomb->scan_start_time +
1422 		    msecs_to_jiffies(ATH_ANT_DIV_COMB_SHORT_SCAN_INTR)))
1423 			short_scan = true;
1424 		else
1425 			if (antcomb->total_pkt_count ==
1426 			    ATH_ANT_DIV_COMB_SHORT_SCAN_PKTCOUNT) {
1427 				alt_ratio = ((antcomb->alt_recv_cnt * 100) /
1428 					    antcomb->total_pkt_count);
1429 				if (alt_ratio < ATH_ANT_DIV_COMB_ALT_ANT_RATIO)
1430 					short_scan = true;
1431 			}
1432 	}
1433 
1434 	if (((antcomb->total_pkt_count < ATH_ANT_DIV_COMB_MAX_PKTCOUNT) ||
1435 	    rs->rs_moreaggr) && !short_scan)
1436 		return;
1437 
1438 	if (antcomb->total_pkt_count) {
1439 		alt_ratio = ((antcomb->alt_recv_cnt * 100) /
1440 			     antcomb->total_pkt_count);
1441 		main_rssi_avg = (antcomb->main_total_rssi /
1442 				 antcomb->total_pkt_count);
1443 		alt_rssi_avg = (antcomb->alt_total_rssi /
1444 				 antcomb->total_pkt_count);
1445 	}
1446 
1447 
1448 	ath9k_hw_antdiv_comb_conf_get(sc->sc_ah, &div_ant_conf);
1449 	curr_alt_set = div_ant_conf.alt_lna_conf;
1450 	curr_main_set = div_ant_conf.main_lna_conf;
1451 	curr_bias = div_ant_conf.fast_div_bias;
1452 
1453 	antcomb->count++;
1454 
1455 	if (antcomb->count == ATH_ANT_DIV_COMB_MAX_COUNT) {
1456 		if (alt_ratio > ATH_ANT_DIV_COMB_ALT_ANT_RATIO) {
1457 			ath_lnaconf_alt_good_scan(antcomb, div_ant_conf,
1458 						  main_rssi_avg);
1459 			antcomb->alt_good = true;
1460 		} else {
1461 			antcomb->alt_good = false;
1462 		}
1463 
1464 		antcomb->count = 0;
1465 		antcomb->scan = true;
1466 		antcomb->scan_not_start = true;
1467 	}
1468 
1469 	if (!antcomb->scan) {
1470 		if (alt_ratio > ATH_ANT_DIV_COMB_ALT_ANT_RATIO) {
1471 			if (curr_alt_set == ATH_ANT_DIV_COMB_LNA2) {
1472 				/* Switch main and alt LNA */
1473 				div_ant_conf.main_lna_conf =
1474 						ATH_ANT_DIV_COMB_LNA2;
1475 				div_ant_conf.alt_lna_conf  =
1476 						ATH_ANT_DIV_COMB_LNA1;
1477 			} else if (curr_alt_set == ATH_ANT_DIV_COMB_LNA1) {
1478 				div_ant_conf.main_lna_conf =
1479 						ATH_ANT_DIV_COMB_LNA1;
1480 				div_ant_conf.alt_lna_conf  =
1481 						ATH_ANT_DIV_COMB_LNA2;
1482 			}
1483 
1484 			goto div_comb_done;
1485 		} else if ((curr_alt_set != ATH_ANT_DIV_COMB_LNA1) &&
1486 			   (curr_alt_set != ATH_ANT_DIV_COMB_LNA2)) {
1487 			/* Set alt to another LNA */
1488 			if (curr_main_set == ATH_ANT_DIV_COMB_LNA2)
1489 				div_ant_conf.alt_lna_conf =
1490 						ATH_ANT_DIV_COMB_LNA1;
1491 			else if (curr_main_set == ATH_ANT_DIV_COMB_LNA1)
1492 				div_ant_conf.alt_lna_conf =
1493 						ATH_ANT_DIV_COMB_LNA2;
1494 
1495 			goto div_comb_done;
1496 		}
1497 
1498 		if ((alt_rssi_avg < (main_rssi_avg +
1499 		    ATH_ANT_DIV_COMB_LNA1_LNA2_DELTA)))
1500 			goto div_comb_done;
1501 	}
1502 
1503 	if (!antcomb->scan_not_start) {
1504 		switch (curr_alt_set) {
1505 		case ATH_ANT_DIV_COMB_LNA2:
1506 			antcomb->rssi_lna2 = alt_rssi_avg;
1507 			antcomb->rssi_lna1 = main_rssi_avg;
1508 			antcomb->scan = true;
1509 			/* set to A+B */
1510 			div_ant_conf.main_lna_conf =
1511 				ATH_ANT_DIV_COMB_LNA1;
1512 			div_ant_conf.alt_lna_conf  =
1513 				ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2;
1514 			break;
1515 		case ATH_ANT_DIV_COMB_LNA1:
1516 			antcomb->rssi_lna1 = alt_rssi_avg;
1517 			antcomb->rssi_lna2 = main_rssi_avg;
1518 			antcomb->scan = true;
1519 			/* set to A+B */
1520 			div_ant_conf.main_lna_conf = ATH_ANT_DIV_COMB_LNA2;
1521 			div_ant_conf.alt_lna_conf  =
1522 				ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2;
1523 			break;
1524 		case ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2:
1525 			antcomb->rssi_add = alt_rssi_avg;
1526 			antcomb->scan = true;
1527 			/* set to A-B */
1528 			div_ant_conf.alt_lna_conf =
1529 				ATH_ANT_DIV_COMB_LNA1_MINUS_LNA2;
1530 			break;
1531 		case ATH_ANT_DIV_COMB_LNA1_MINUS_LNA2:
1532 			antcomb->rssi_sub = alt_rssi_avg;
1533 			antcomb->scan = false;
1534 			if (antcomb->rssi_lna2 >
1535 			    (antcomb->rssi_lna1 +
1536 			    ATH_ANT_DIV_COMB_LNA1_LNA2_SWITCH_DELTA)) {
1537 				/* use LNA2 as main LNA */
1538 				if ((antcomb->rssi_add > antcomb->rssi_lna1) &&
1539 				    (antcomb->rssi_add > antcomb->rssi_sub)) {
1540 					/* set to A+B */
1541 					div_ant_conf.main_lna_conf =
1542 						ATH_ANT_DIV_COMB_LNA2;
1543 					div_ant_conf.alt_lna_conf  =
1544 						ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2;
1545 				} else if (antcomb->rssi_sub >
1546 					   antcomb->rssi_lna1) {
1547 					/* set to A-B */
1548 					div_ant_conf.main_lna_conf =
1549 						ATH_ANT_DIV_COMB_LNA2;
1550 					div_ant_conf.alt_lna_conf =
1551 						ATH_ANT_DIV_COMB_LNA1_MINUS_LNA2;
1552 				} else {
1553 					/* set to LNA1 */
1554 					div_ant_conf.main_lna_conf =
1555 						ATH_ANT_DIV_COMB_LNA2;
1556 					div_ant_conf.alt_lna_conf =
1557 						ATH_ANT_DIV_COMB_LNA1;
1558 				}
1559 			} else {
1560 				/* use LNA1 as main LNA */
1561 				if ((antcomb->rssi_add > antcomb->rssi_lna2) &&
1562 				    (antcomb->rssi_add > antcomb->rssi_sub)) {
1563 					/* set to A+B */
1564 					div_ant_conf.main_lna_conf =
1565 						ATH_ANT_DIV_COMB_LNA1;
1566 					div_ant_conf.alt_lna_conf  =
1567 						ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2;
1568 				} else if (antcomb->rssi_sub >
1569 					   antcomb->rssi_lna1) {
1570 					/* set to A-B */
1571 					div_ant_conf.main_lna_conf =
1572 						ATH_ANT_DIV_COMB_LNA1;
1573 					div_ant_conf.alt_lna_conf =
1574 						ATH_ANT_DIV_COMB_LNA1_MINUS_LNA2;
1575 				} else {
1576 					/* set to LNA2 */
1577 					div_ant_conf.main_lna_conf =
1578 						ATH_ANT_DIV_COMB_LNA1;
1579 					div_ant_conf.alt_lna_conf =
1580 						ATH_ANT_DIV_COMB_LNA2;
1581 				}
1582 			}
1583 			break;
1584 		default:
1585 			break;
1586 		}
1587 	} else {
1588 		if (!antcomb->alt_good) {
1589 			antcomb->scan_not_start = false;
1590 			/* Set alt to another LNA */
1591 			if (curr_main_set == ATH_ANT_DIV_COMB_LNA2) {
1592 				div_ant_conf.main_lna_conf =
1593 						ATH_ANT_DIV_COMB_LNA2;
1594 				div_ant_conf.alt_lna_conf =
1595 						ATH_ANT_DIV_COMB_LNA1;
1596 			} else if (curr_main_set == ATH_ANT_DIV_COMB_LNA1) {
1597 				div_ant_conf.main_lna_conf =
1598 						ATH_ANT_DIV_COMB_LNA1;
1599 				div_ant_conf.alt_lna_conf =
1600 						ATH_ANT_DIV_COMB_LNA2;
1601 			}
1602 			goto div_comb_done;
1603 		}
1604 	}
1605 
1606 	ath_select_ant_div_from_quick_scan(antcomb, &div_ant_conf,
1607 					   main_rssi_avg, alt_rssi_avg,
1608 					   alt_ratio);
1609 
1610 	antcomb->quick_scan_cnt++;
1611 
1612 div_comb_done:
1613 	ath_ant_div_conf_fast_divbias(&div_ant_conf);
1614 
1615 	ath9k_hw_antdiv_comb_conf_set(sc->sc_ah, &div_ant_conf);
1616 
1617 	antcomb->scan_start_time = jiffies;
1618 	antcomb->total_pkt_count = 0;
1619 	antcomb->main_total_rssi = 0;
1620 	antcomb->alt_total_rssi = 0;
1621 	antcomb->main_recv_cnt = 0;
1622 	antcomb->alt_recv_cnt = 0;
1623 }
1624 
1625 int ath_rx_tasklet(struct ath_softc *sc, int flush, bool hp)
1626 {
1627 	struct ath_buf *bf;
1628 	struct sk_buff *skb = NULL, *requeue_skb;
1629 	struct ieee80211_rx_status *rxs;
1630 	struct ath_hw *ah = sc->sc_ah;
1631 	struct ath_common *common = ath9k_hw_common(ah);
1632 	/*
1633 	 * The hw can techncically differ from common->hw when using ath9k
1634 	 * virtual wiphy so to account for that we iterate over the active
1635 	 * wiphys and find the appropriate wiphy and therefore hw.
1636 	 */
1637 	struct ieee80211_hw *hw = NULL;
1638 	struct ieee80211_hdr *hdr;
1639 	int retval;
1640 	bool decrypt_error = false;
1641 	struct ath_rx_status rs;
1642 	enum ath9k_rx_qtype qtype;
1643 	bool edma = !!(ah->caps.hw_caps & ATH9K_HW_CAP_EDMA);
1644 	int dma_type;
1645 	u8 rx_status_len = ah->caps.rx_status_len;
1646 	u64 tsf = 0;
1647 	u32 tsf_lower = 0;
1648 	unsigned long flags;
1649 
1650 	if (edma)
1651 		dma_type = DMA_BIDIRECTIONAL;
1652 	else
1653 		dma_type = DMA_FROM_DEVICE;
1654 
1655 	qtype = hp ? ATH9K_RX_QUEUE_HP : ATH9K_RX_QUEUE_LP;
1656 	spin_lock_bh(&sc->rx.rxbuflock);
1657 
1658 	tsf = ath9k_hw_gettsf64(ah);
1659 	tsf_lower = tsf & 0xffffffff;
1660 
1661 	do {
1662 		/* If handling rx interrupt and flush is in progress => exit */
1663 		if ((sc->sc_flags & SC_OP_RXFLUSH) && (flush == 0))
1664 			break;
1665 
1666 		memset(&rs, 0, sizeof(rs));
1667 		if (edma)
1668 			bf = ath_edma_get_next_rx_buf(sc, &rs, qtype);
1669 		else
1670 			bf = ath_get_next_rx_buf(sc, &rs);
1671 
1672 		if (!bf)
1673 			break;
1674 
1675 		skb = bf->bf_mpdu;
1676 		if (!skb)
1677 			continue;
1678 
1679 		hdr = (struct ieee80211_hdr *) (skb->data + rx_status_len);
1680 		rxs =  IEEE80211_SKB_RXCB(skb);
1681 
1682 		hw = ath_get_virt_hw(sc, hdr);
1683 
1684 		ath_debug_stat_rx(sc, &rs);
1685 
1686 		/*
1687 		 * If we're asked to flush receive queue, directly
1688 		 * chain it back at the queue without processing it.
1689 		 */
1690 		if (flush)
1691 			goto requeue;
1692 
1693 		retval = ath9k_rx_skb_preprocess(common, hw, hdr, &rs,
1694 						 rxs, &decrypt_error);
1695 		if (retval)
1696 			goto requeue;
1697 
1698 		rxs->mactime = (tsf & ~0xffffffffULL) | rs.rs_tstamp;
1699 		if (rs.rs_tstamp > tsf_lower &&
1700 		    unlikely(rs.rs_tstamp - tsf_lower > 0x10000000))
1701 			rxs->mactime -= 0x100000000ULL;
1702 
1703 		if (rs.rs_tstamp < tsf_lower &&
1704 		    unlikely(tsf_lower - rs.rs_tstamp > 0x10000000))
1705 			rxs->mactime += 0x100000000ULL;
1706 
1707 		/* Ensure we always have an skb to requeue once we are done
1708 		 * processing the current buffer's skb */
1709 		requeue_skb = ath_rxbuf_alloc(common, common->rx_bufsize, GFP_ATOMIC);
1710 
1711 		/* If there is no memory we ignore the current RX'd frame,
1712 		 * tell hardware it can give us a new frame using the old
1713 		 * skb and put it at the tail of the sc->rx.rxbuf list for
1714 		 * processing. */
1715 		if (!requeue_skb)
1716 			goto requeue;
1717 
1718 		/* Unmap the frame */
1719 		dma_unmap_single(sc->dev, bf->bf_buf_addr,
1720 				 common->rx_bufsize,
1721 				 dma_type);
1722 
1723 		skb_put(skb, rs.rs_datalen + ah->caps.rx_status_len);
1724 		if (ah->caps.rx_status_len)
1725 			skb_pull(skb, ah->caps.rx_status_len);
1726 
1727 		ath9k_rx_skb_postprocess(common, skb, &rs,
1728 					 rxs, decrypt_error);
1729 
1730 		/* We will now give hardware our shiny new allocated skb */
1731 		bf->bf_mpdu = requeue_skb;
1732 		bf->bf_buf_addr = dma_map_single(sc->dev, requeue_skb->data,
1733 						 common->rx_bufsize,
1734 						 dma_type);
1735 		if (unlikely(dma_mapping_error(sc->dev,
1736 			  bf->bf_buf_addr))) {
1737 			dev_kfree_skb_any(requeue_skb);
1738 			bf->bf_mpdu = NULL;
1739 			bf->bf_buf_addr = 0;
1740 			ath_print(common, ATH_DBG_FATAL,
1741 				  "dma_mapping_error() on RX\n");
1742 			ath_rx_send_to_mac80211(hw, sc, skb, rxs);
1743 			break;
1744 		}
1745 
1746 		/*
1747 		 * change the default rx antenna if rx diversity chooses the
1748 		 * other antenna 3 times in a row.
1749 		 */
1750 		if (sc->rx.defant != rs.rs_antenna) {
1751 			if (++sc->rx.rxotherant >= 3)
1752 				ath_setdefantenna(sc, rs.rs_antenna);
1753 		} else {
1754 			sc->rx.rxotherant = 0;
1755 		}
1756 
1757 		spin_lock_irqsave(&sc->sc_pm_lock, flags);
1758 		if (unlikely(ath9k_check_auto_sleep(sc) ||
1759 			     (sc->ps_flags & (PS_WAIT_FOR_BEACON |
1760 					      PS_WAIT_FOR_CAB |
1761 					      PS_WAIT_FOR_PSPOLL_DATA))))
1762 			ath_rx_ps(sc, skb);
1763 		spin_unlock_irqrestore(&sc->sc_pm_lock, flags);
1764 
1765 		if (ah->caps.hw_caps & ATH9K_HW_CAP_ANT_DIV_COMB)
1766 			ath_ant_comb_scan(sc, &rs);
1767 
1768 		ath_rx_send_to_mac80211(hw, sc, skb, rxs);
1769 
1770 requeue:
1771 		if (edma) {
1772 			list_add_tail(&bf->list, &sc->rx.rxbuf);
1773 			ath_rx_edma_buf_link(sc, qtype);
1774 		} else {
1775 			list_move_tail(&bf->list, &sc->rx.rxbuf);
1776 			ath_rx_buf_link(sc, bf);
1777 		}
1778 	} while (1);
1779 
1780 	spin_unlock_bh(&sc->rx.rxbuflock);
1781 
1782 	return 0;
1783 }
1784