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_rxbuf **)__skb->cb))
22
23static inline bool ath9k_check_auto_sleep(struct ath_softc *sc)
24{
25 return sc->ps_enabled &&
26 (sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_AUTOSLEEP);
27}
28
29/*
30 * Setup and link descriptors.
31 *
32 * 11N: we can no longer afford to self link the last descriptor.
33 * MAC acknowledges BA status as long as it copies frames to host
34 * buffer (or rx fifo). This can incorrectly acknowledge packets
35 * to a sender if last desc is self-linked.
36 */
37static void ath_rx_buf_link(struct ath_softc *sc, struct ath_rxbuf *bf,
38 bool flush)
39{
40 struct ath_hw *ah = sc->sc_ah;
41 struct ath_common *common = ath9k_hw_common(ah);
42 struct ath_desc *ds;
43 struct sk_buff *skb;
44
45 ds = bf->bf_desc;
46 ds->ds_link = 0; /* link to null */
47 ds->ds_data = bf->bf_buf_addr;
48
49 /* virtual addr of the beginning of the buffer. */
50 skb = bf->bf_mpdu;
51 BUG_ON(skb == NULL);
52 ds->ds_vdata = skb->data;
53
54 /*
55 * setup rx descriptors. The rx_bufsize here tells the hardware
56 * how much data it can DMA to us and that we are prepared
57 * to process
58 */
59 ath9k_hw_setuprxdesc(ah, ds,
60 size: common->rx_bufsize,
61 flags: 0);
62
63 if (sc->rx.rxlink)
64 *sc->rx.rxlink = bf->bf_daddr;
65 else if (!flush)
66 ath9k_hw_putrxbuf(ah, rxdp: bf->bf_daddr);
67
68 sc->rx.rxlink = &ds->ds_link;
69}
70
71static void ath_rx_buf_relink(struct ath_softc *sc, struct ath_rxbuf *bf,
72 bool flush)
73{
74 if (sc->rx.buf_hold)
75 ath_rx_buf_link(sc, bf: sc->rx.buf_hold, flush);
76
77 sc->rx.buf_hold = bf;
78}
79
80static void ath_setdefantenna(struct ath_softc *sc, u32 antenna)
81{
82 /* XXX block beacon interrupts */
83 ath9k_hw_setantenna(ah: sc->sc_ah, antenna);
84 sc->rx.defant = antenna;
85 sc->rx.rxotherant = 0;
86}
87
88static void ath_opmode_init(struct ath_softc *sc)
89{
90 struct ath_hw *ah = sc->sc_ah;
91 struct ath_common *common = ath9k_hw_common(ah);
92
93 u32 rfilt, mfilt[2];
94
95 /* configure rx filter */
96 rfilt = ath_calcrxfilter(sc);
97 ath9k_hw_setrxfilter(ah, bits: rfilt);
98
99 /* configure bssid mask */
100 ath_hw_setbssidmask(common);
101
102 /* configure operational mode */
103 ath9k_hw_setopmode(ah);
104
105 /* calculate and install multicast filter */
106 mfilt[0] = mfilt[1] = ~0;
107 ath9k_hw_setmcastfilter(ah, filter0: mfilt[0], filter1: mfilt[1]);
108}
109
110static bool ath_rx_edma_buf_link(struct ath_softc *sc,
111 enum ath9k_rx_qtype qtype)
112{
113 struct ath_hw *ah = sc->sc_ah;
114 struct ath_rx_edma *rx_edma;
115 struct sk_buff *skb;
116 struct ath_rxbuf *bf;
117
118 rx_edma = &sc->rx.rx_edma[qtype];
119 if (skb_queue_len(list_: &rx_edma->rx_fifo) >= rx_edma->rx_fifo_hwsize)
120 return false;
121
122 bf = list_first_entry(&sc->rx.rxbuf, struct ath_rxbuf, list);
123 list_del_init(entry: &bf->list);
124
125 skb = bf->bf_mpdu;
126
127 memset(skb->data, 0, ah->caps.rx_status_len);
128 dma_sync_single_for_device(dev: sc->dev, addr: bf->bf_buf_addr,
129 size: ah->caps.rx_status_len, dir: DMA_TO_DEVICE);
130
131 SKB_CB_ATHBUF(skb) = bf;
132 ath9k_hw_addrxbuf_edma(ah, rxdp: bf->bf_buf_addr, qtype);
133 __skb_queue_tail(list: &rx_edma->rx_fifo, newsk: skb);
134
135 return true;
136}
137
138static void ath_rx_addbuffer_edma(struct ath_softc *sc,
139 enum ath9k_rx_qtype qtype)
140{
141 struct ath_common *common = ath9k_hw_common(ah: sc->sc_ah);
142 struct ath_rxbuf *bf, *tbf;
143
144 if (list_empty(head: &sc->rx.rxbuf)) {
145 ath_dbg(common, QUEUE, "No free rx buf available\n");
146 return;
147 }
148
149 list_for_each_entry_safe(bf, tbf, &sc->rx.rxbuf, list)
150 if (!ath_rx_edma_buf_link(sc, qtype))
151 break;
152
153}
154
155static void ath_rx_remove_buffer(struct ath_softc *sc,
156 enum ath9k_rx_qtype qtype)
157{
158 struct ath_rxbuf *bf;
159 struct ath_rx_edma *rx_edma;
160 struct sk_buff *skb;
161
162 rx_edma = &sc->rx.rx_edma[qtype];
163
164 while ((skb = __skb_dequeue(list: &rx_edma->rx_fifo)) != NULL) {
165 bf = SKB_CB_ATHBUF(skb);
166 BUG_ON(!bf);
167 list_add_tail(new: &bf->list, head: &sc->rx.rxbuf);
168 }
169}
170
171static void ath_rx_edma_cleanup(struct ath_softc *sc)
172{
173 struct ath_hw *ah = sc->sc_ah;
174 struct ath_common *common = ath9k_hw_common(ah);
175 struct ath_rxbuf *bf;
176
177 ath_rx_remove_buffer(sc, qtype: ATH9K_RX_QUEUE_LP);
178 ath_rx_remove_buffer(sc, qtype: ATH9K_RX_QUEUE_HP);
179
180 list_for_each_entry(bf, &sc->rx.rxbuf, list) {
181 if (bf->bf_mpdu) {
182 dma_unmap_single(sc->dev, bf->bf_buf_addr,
183 common->rx_bufsize,
184 DMA_BIDIRECTIONAL);
185 dev_kfree_skb_any(skb: bf->bf_mpdu);
186 bf->bf_buf_addr = 0;
187 bf->bf_mpdu = NULL;
188 }
189 }
190}
191
192static void ath_rx_edma_init_queue(struct ath_rx_edma *rx_edma, int size)
193{
194 __skb_queue_head_init(list: &rx_edma->rx_fifo);
195 rx_edma->rx_fifo_hwsize = size;
196}
197
198static int ath_rx_edma_init(struct ath_softc *sc, int nbufs)
199{
200 struct ath_common *common = ath9k_hw_common(ah: sc->sc_ah);
201 struct ath_hw *ah = sc->sc_ah;
202 struct sk_buff *skb;
203 struct ath_rxbuf *bf;
204 int error = 0, i;
205 u32 size;
206
207 ath9k_hw_set_rx_bufsize(ah, buf_size: common->rx_bufsize -
208 ah->caps.rx_status_len);
209
210 ath_rx_edma_init_queue(rx_edma: &sc->rx.rx_edma[ATH9K_RX_QUEUE_LP],
211 size: ah->caps.rx_lp_qdepth);
212 ath_rx_edma_init_queue(rx_edma: &sc->rx.rx_edma[ATH9K_RX_QUEUE_HP],
213 size: ah->caps.rx_hp_qdepth);
214
215 size = sizeof(struct ath_rxbuf) * nbufs;
216 bf = devm_kzalloc(dev: sc->dev, size, GFP_KERNEL);
217 if (!bf)
218 return -ENOMEM;
219
220 INIT_LIST_HEAD(list: &sc->rx.rxbuf);
221
222 for (i = 0; i < nbufs; i++, bf++) {
223 skb = ath_rxbuf_alloc(common, len: common->rx_bufsize, GFP_KERNEL);
224 if (!skb) {
225 error = -ENOMEM;
226 goto rx_init_fail;
227 }
228
229 memset(skb->data, 0, common->rx_bufsize);
230 bf->bf_mpdu = skb;
231
232 bf->bf_buf_addr = dma_map_single(sc->dev, skb->data,
233 common->rx_bufsize,
234 DMA_BIDIRECTIONAL);
235 if (unlikely(dma_mapping_error(sc->dev,
236 bf->bf_buf_addr))) {
237 dev_kfree_skb_any(skb);
238 bf->bf_mpdu = NULL;
239 bf->bf_buf_addr = 0;
240 ath_err(common,
241 "dma_mapping_error() on RX init\n");
242 error = -ENOMEM;
243 goto rx_init_fail;
244 }
245
246 list_add_tail(new: &bf->list, head: &sc->rx.rxbuf);
247 }
248
249 return 0;
250
251rx_init_fail:
252 ath_rx_edma_cleanup(sc);
253 return error;
254}
255
256static void ath_edma_start_recv(struct ath_softc *sc)
257{
258 ath9k_hw_rxena(ah: sc->sc_ah);
259 ath_rx_addbuffer_edma(sc, qtype: ATH9K_RX_QUEUE_HP);
260 ath_rx_addbuffer_edma(sc, qtype: ATH9K_RX_QUEUE_LP);
261 ath_opmode_init(sc);
262 ath9k_hw_startpcureceive(ah: sc->sc_ah, is_scanning: sc->cur_chan->offchannel);
263}
264
265static void ath_edma_stop_recv(struct ath_softc *sc)
266{
267 ath_rx_remove_buffer(sc, qtype: ATH9K_RX_QUEUE_HP);
268 ath_rx_remove_buffer(sc, qtype: ATH9K_RX_QUEUE_LP);
269}
270
271int ath_rx_init(struct ath_softc *sc, int nbufs)
272{
273 struct ath_common *common = ath9k_hw_common(ah: sc->sc_ah);
274 struct sk_buff *skb;
275 struct ath_rxbuf *bf;
276 int error = 0;
277
278 spin_lock_init(&sc->sc_pcu_lock);
279
280 common->rx_bufsize = IEEE80211_MAX_MPDU_LEN / 2 +
281 sc->sc_ah->caps.rx_status_len;
282
283 if (sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_EDMA)
284 return ath_rx_edma_init(sc, nbufs);
285
286 ath_dbg(common, CONFIG, "cachelsz %u rxbufsize %u\n",
287 common->cachelsz, common->rx_bufsize);
288
289 /* Initialize rx descriptors */
290
291 error = ath_descdma_setup(sc, dd: &sc->rx.rxdma, head: &sc->rx.rxbuf,
292 name: "rx", nbuf: nbufs, ndesc: 1, is_tx: 0);
293 if (error != 0) {
294 ath_err(common,
295 "failed to allocate rx descriptors: %d\n",
296 error);
297 goto err;
298 }
299
300 list_for_each_entry(bf, &sc->rx.rxbuf, list) {
301 skb = ath_rxbuf_alloc(common, len: common->rx_bufsize,
302 GFP_KERNEL);
303 if (skb == NULL) {
304 error = -ENOMEM;
305 goto err;
306 }
307
308 bf->bf_mpdu = skb;
309 bf->bf_buf_addr = dma_map_single(sc->dev, skb->data,
310 common->rx_bufsize,
311 DMA_FROM_DEVICE);
312 if (unlikely(dma_mapping_error(sc->dev,
313 bf->bf_buf_addr))) {
314 dev_kfree_skb_any(skb);
315 bf->bf_mpdu = NULL;
316 bf->bf_buf_addr = 0;
317 ath_err(common,
318 "dma_mapping_error() on RX init\n");
319 error = -ENOMEM;
320 goto err;
321 }
322 }
323 sc->rx.rxlink = NULL;
324err:
325 if (error)
326 ath_rx_cleanup(sc);
327
328 return error;
329}
330
331void ath_rx_cleanup(struct ath_softc *sc)
332{
333 struct ath_hw *ah = sc->sc_ah;
334 struct ath_common *common = ath9k_hw_common(ah);
335 struct sk_buff *skb;
336 struct ath_rxbuf *bf;
337
338 if (sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_EDMA) {
339 ath_rx_edma_cleanup(sc);
340 return;
341 }
342
343 list_for_each_entry(bf, &sc->rx.rxbuf, list) {
344 skb = bf->bf_mpdu;
345 if (skb) {
346 dma_unmap_single(sc->dev, bf->bf_buf_addr,
347 common->rx_bufsize,
348 DMA_FROM_DEVICE);
349 dev_kfree_skb(skb);
350 bf->bf_buf_addr = 0;
351 bf->bf_mpdu = NULL;
352 }
353 }
354}
355
356/*
357 * Calculate the receive filter according to the
358 * operating mode and state:
359 *
360 * o always accept unicast, broadcast, and multicast traffic
361 * o maintain current state of phy error reception (the hal
362 * may enable phy error frames for noise immunity work)
363 * o probe request frames are accepted only when operating in
364 * hostap, adhoc, or monitor modes
365 * o enable promiscuous mode according to the interface state
366 * o accept beacons:
367 * - when operating in adhoc mode so the 802.11 layer creates
368 * node table entries for peers,
369 * - when operating in station mode for collecting rssi data when
370 * the station is otherwise quiet, or
371 * - when operating as a repeater so we see repeater-sta beacons
372 * - when scanning
373 */
374
375u32 ath_calcrxfilter(struct ath_softc *sc)
376{
377 struct ath_common *common = ath9k_hw_common(ah: sc->sc_ah);
378 u32 rfilt;
379
380 if (IS_ENABLED(CONFIG_ATH9K_TX99))
381 return 0;
382
383 rfilt = ATH9K_RX_FILTER_UCAST | ATH9K_RX_FILTER_BCAST
384 | ATH9K_RX_FILTER_MCAST;
385
386 /* if operating on a DFS channel, enable radar pulse detection */
387 if (sc->hw->conf.radar_enabled)
388 rfilt |= ATH9K_RX_FILTER_PHYRADAR | ATH9K_RX_FILTER_PHYERR;
389
390 spin_lock_bh(lock: &sc->chan_lock);
391
392 if (sc->cur_chan->rxfilter & FIF_PROBE_REQ)
393 rfilt |= ATH9K_RX_FILTER_PROBEREQ;
394
395 if (sc->sc_ah->is_monitoring)
396 rfilt |= ATH9K_RX_FILTER_PROM;
397
398 if ((sc->cur_chan->rxfilter & FIF_CONTROL) ||
399 sc->sc_ah->dynack.enabled)
400 rfilt |= ATH9K_RX_FILTER_CONTROL;
401
402 if ((sc->sc_ah->opmode == NL80211_IFTYPE_STATION) &&
403 (sc->cur_chan->nvifs <= 1) &&
404 !(sc->cur_chan->rxfilter & FIF_BCN_PRBRESP_PROMISC))
405 rfilt |= ATH9K_RX_FILTER_MYBEACON;
406 else if (sc->sc_ah->opmode != NL80211_IFTYPE_OCB)
407 rfilt |= ATH9K_RX_FILTER_BEACON;
408
409 if ((sc->sc_ah->opmode == NL80211_IFTYPE_AP) ||
410 (sc->cur_chan->rxfilter & FIF_PSPOLL))
411 rfilt |= ATH9K_RX_FILTER_PSPOLL;
412
413 if (sc->cur_chandef.width != NL80211_CHAN_WIDTH_20_NOHT)
414 rfilt |= ATH9K_RX_FILTER_COMP_BAR;
415
416 if (sc->cur_chan->nvifs > 1 ||
417 (sc->cur_chan->rxfilter & (FIF_OTHER_BSS | FIF_MCAST_ACTION))) {
418 /* This is needed for older chips */
419 if (sc->sc_ah->hw_version.macVersion <= AR_SREV_VERSION_9160)
420 rfilt |= ATH9K_RX_FILTER_PROM;
421 rfilt |= ATH9K_RX_FILTER_MCAST_BCAST_ALL;
422 }
423
424 if (AR_SREV_9550(sc->sc_ah) || AR_SREV_9531(sc->sc_ah) ||
425 AR_SREV_9561(sc->sc_ah))
426 rfilt |= ATH9K_RX_FILTER_4ADDRESS;
427
428 if (AR_SREV_9462(sc->sc_ah) || AR_SREV_9565(sc->sc_ah))
429 rfilt |= ATH9K_RX_FILTER_CONTROL_WRAPPER;
430
431 if (ath9k_is_chanctx_enabled() &&
432 test_bit(ATH_OP_SCANNING, &common->op_flags))
433 rfilt |= ATH9K_RX_FILTER_BEACON;
434
435 spin_unlock_bh(lock: &sc->chan_lock);
436
437 return rfilt;
438
439}
440
441void ath_startrecv(struct ath_softc *sc)
442{
443 struct ath_hw *ah = sc->sc_ah;
444 struct ath_rxbuf *bf, *tbf;
445
446 if (ah->caps.hw_caps & ATH9K_HW_CAP_EDMA) {
447 ath_edma_start_recv(sc);
448 return;
449 }
450
451 if (list_empty(head: &sc->rx.rxbuf))
452 goto start_recv;
453
454 sc->rx.buf_hold = NULL;
455 sc->rx.rxlink = NULL;
456 list_for_each_entry_safe(bf, tbf, &sc->rx.rxbuf, list) {
457 ath_rx_buf_link(sc, bf, flush: false);
458 }
459
460 /* We could have deleted elements so the list may be empty now */
461 if (list_empty(head: &sc->rx.rxbuf))
462 goto start_recv;
463
464 bf = list_first_entry(&sc->rx.rxbuf, struct ath_rxbuf, list);
465 ath9k_hw_putrxbuf(ah, rxdp: bf->bf_daddr);
466 ath9k_hw_rxena(ah);
467
468start_recv:
469 ath_opmode_init(sc);
470 ath9k_hw_startpcureceive(ah, is_scanning: sc->cur_chan->offchannel);
471}
472
473static void ath_flushrecv(struct ath_softc *sc)
474{
475 if (sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_EDMA)
476 ath_rx_tasklet(sc, flush: 1, hp: true);
477 ath_rx_tasklet(sc, flush: 1, hp: false);
478}
479
480bool ath_stoprecv(struct ath_softc *sc)
481{
482 struct ath_hw *ah = sc->sc_ah;
483 bool stopped, reset = false;
484
485 ath9k_hw_abortpcurecv(ah);
486 ath9k_hw_setrxfilter(ah, bits: 0);
487 stopped = ath9k_hw_stopdmarecv(ah, reset: &reset);
488
489 ath_flushrecv(sc);
490
491 if (sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_EDMA)
492 ath_edma_stop_recv(sc);
493 else
494 sc->rx.rxlink = NULL;
495
496 if (!(ah->ah_flags & AH_UNPLUGGED) &&
497 unlikely(!stopped)) {
498 ath_dbg(ath9k_hw_common(sc->sc_ah), RESET,
499 "Failed to stop Rx DMA\n");
500 RESET_STAT_INC(sc, RESET_RX_DMA_ERROR);
501 }
502 return stopped && !reset;
503}
504
505static bool ath_beacon_dtim_pending_cab(struct sk_buff *skb)
506{
507 /* Check whether the Beacon frame has DTIM indicating buffered bc/mc */
508 struct ieee80211_mgmt *mgmt;
509 u8 *pos, *end, id, elen;
510 struct ieee80211_tim_ie *tim;
511
512 mgmt = (struct ieee80211_mgmt *)skb->data;
513 pos = mgmt->u.beacon.variable;
514 end = skb->data + skb->len;
515
516 while (pos + 2 < end) {
517 id = *pos++;
518 elen = *pos++;
519 if (pos + elen > end)
520 break;
521
522 if (id == WLAN_EID_TIM) {
523 if (elen < sizeof(*tim))
524 break;
525 tim = (struct ieee80211_tim_ie *) pos;
526 if (tim->dtim_count != 0)
527 break;
528 return tim->bitmap_ctrl & 0x01;
529 }
530
531 pos += elen;
532 }
533
534 return false;
535}
536
537static void ath_rx_ps_beacon(struct ath_softc *sc, struct sk_buff *skb)
538{
539 struct ath_common *common = ath9k_hw_common(ah: sc->sc_ah);
540 bool skip_beacon = false;
541
542 if (skb->len < 24 + 8 + 2 + 2)
543 return;
544
545 sc->ps_flags &= ~PS_WAIT_FOR_BEACON;
546
547 if (sc->ps_flags & PS_BEACON_SYNC) {
548 sc->ps_flags &= ~PS_BEACON_SYNC;
549 ath_dbg(common, PS,
550 "Reconfigure beacon timers based on synchronized timestamp\n");
551
552#ifdef CONFIG_ATH9K_CHANNEL_CONTEXT
553 if (ath9k_is_chanctx_enabled()) {
554 if (sc->cur_chan == &sc->offchannel.chan)
555 skip_beacon = true;
556 }
557#endif
558
559 if (!skip_beacon &&
560 !(WARN_ON_ONCE(sc->cur_chan->beacon.beacon_interval == 0)))
561 ath9k_set_beacon(sc);
562
563 ath9k_p2p_beacon_sync(sc);
564 }
565
566 if (ath_beacon_dtim_pending_cab(skb)) {
567 /*
568 * Remain awake waiting for buffered broadcast/multicast
569 * frames. If the last broadcast/multicast frame is not
570 * received properly, the next beacon frame will work as
571 * a backup trigger for returning into NETWORK SLEEP state,
572 * so we are waiting for it as well.
573 */
574 ath_dbg(common, PS,
575 "Received DTIM beacon indicating buffered broadcast/multicast frame(s)\n");
576 sc->ps_flags |= PS_WAIT_FOR_CAB | PS_WAIT_FOR_BEACON;
577 return;
578 }
579
580 if (sc->ps_flags & PS_WAIT_FOR_CAB) {
581 /*
582 * This can happen if a broadcast frame is dropped or the AP
583 * fails to send a frame indicating that all CAB frames have
584 * been delivered.
585 */
586 sc->ps_flags &= ~PS_WAIT_FOR_CAB;
587 ath_dbg(common, PS, "PS wait for CAB frames timed out\n");
588 }
589}
590
591static void ath_rx_ps(struct ath_softc *sc, struct sk_buff *skb, bool mybeacon)
592{
593 struct ieee80211_hdr *hdr;
594 struct ath_common *common = ath9k_hw_common(ah: sc->sc_ah);
595
596 hdr = (struct ieee80211_hdr *)skb->data;
597
598 /* Process Beacon and CAB receive in PS state */
599 if (((sc->ps_flags & PS_WAIT_FOR_BEACON) || ath9k_check_auto_sleep(sc))
600 && mybeacon) {
601 ath_rx_ps_beacon(sc, skb);
602 } else if ((sc->ps_flags & PS_WAIT_FOR_CAB) &&
603 (ieee80211_is_data(fc: hdr->frame_control) ||
604 ieee80211_is_action(fc: hdr->frame_control)) &&
605 is_multicast_ether_addr(addr: hdr->addr1) &&
606 !ieee80211_has_moredata(fc: hdr->frame_control)) {
607 /*
608 * No more broadcast/multicast frames to be received at this
609 * point.
610 */
611 sc->ps_flags &= ~(PS_WAIT_FOR_CAB | PS_WAIT_FOR_BEACON);
612 ath_dbg(common, PS,
613 "All PS CAB frames received, back to sleep\n");
614 } else if ((sc->ps_flags & PS_WAIT_FOR_PSPOLL_DATA) &&
615 !is_multicast_ether_addr(addr: hdr->addr1) &&
616 !ieee80211_has_morefrags(fc: hdr->frame_control)) {
617 sc->ps_flags &= ~PS_WAIT_FOR_PSPOLL_DATA;
618 ath_dbg(common, PS,
619 "Going back to sleep after having received PS-Poll data (0x%lx)\n",
620 sc->ps_flags & (PS_WAIT_FOR_BEACON |
621 PS_WAIT_FOR_CAB |
622 PS_WAIT_FOR_PSPOLL_DATA |
623 PS_WAIT_FOR_TX_ACK));
624 }
625}
626
627static bool ath_edma_get_buffers(struct ath_softc *sc,
628 enum ath9k_rx_qtype qtype,
629 struct ath_rx_status *rs,
630 struct ath_rxbuf **dest)
631{
632 struct ath_rx_edma *rx_edma = &sc->rx.rx_edma[qtype];
633 struct ath_hw *ah = sc->sc_ah;
634 struct ath_common *common = ath9k_hw_common(ah);
635 struct sk_buff *skb;
636 struct ath_rxbuf *bf;
637 int ret;
638
639 skb = skb_peek(list_: &rx_edma->rx_fifo);
640 if (!skb)
641 return false;
642
643 bf = SKB_CB_ATHBUF(skb);
644 BUG_ON(!bf);
645
646 dma_sync_single_for_cpu(dev: sc->dev, addr: bf->bf_buf_addr,
647 size: common->rx_bufsize, dir: DMA_FROM_DEVICE);
648
649 ret = ath9k_hw_process_rxdesc_edma(ah, rxs: rs, buf_addr: skb->data);
650 if (ret == -EINPROGRESS) {
651 /*let device gain the buffer again*/
652 dma_sync_single_for_device(dev: sc->dev, addr: bf->bf_buf_addr,
653 size: common->rx_bufsize, dir: DMA_FROM_DEVICE);
654 return false;
655 }
656
657 __skb_unlink(skb, list: &rx_edma->rx_fifo);
658 if (ret == -EINVAL) {
659 /* corrupt descriptor, skip this one and the following one */
660 list_add_tail(new: &bf->list, head: &sc->rx.rxbuf);
661 ath_rx_edma_buf_link(sc, qtype);
662
663 skb = skb_peek(list_: &rx_edma->rx_fifo);
664 if (skb) {
665 bf = SKB_CB_ATHBUF(skb);
666 BUG_ON(!bf);
667
668 __skb_unlink(skb, list: &rx_edma->rx_fifo);
669 list_add_tail(new: &bf->list, head: &sc->rx.rxbuf);
670 ath_rx_edma_buf_link(sc, qtype);
671 }
672
673 bf = NULL;
674 }
675
676 *dest = bf;
677 return true;
678}
679
680static struct ath_rxbuf *ath_edma_get_next_rx_buf(struct ath_softc *sc,
681 struct ath_rx_status *rs,
682 enum ath9k_rx_qtype qtype)
683{
684 struct ath_rxbuf *bf = NULL;
685
686 while (ath_edma_get_buffers(sc, qtype, rs, dest: &bf)) {
687 if (!bf)
688 continue;
689
690 return bf;
691 }
692 return NULL;
693}
694
695static struct ath_rxbuf *ath_get_next_rx_buf(struct ath_softc *sc,
696 struct ath_rx_status *rs)
697{
698 struct ath_hw *ah = sc->sc_ah;
699 struct ath_common *common = ath9k_hw_common(ah);
700 struct ath_desc *ds;
701 struct ath_rxbuf *bf;
702 int ret;
703
704 if (list_empty(head: &sc->rx.rxbuf)) {
705 sc->rx.rxlink = NULL;
706 return NULL;
707 }
708
709 bf = list_first_entry(&sc->rx.rxbuf, struct ath_rxbuf, list);
710 if (bf == sc->rx.buf_hold)
711 return NULL;
712
713 ds = bf->bf_desc;
714
715 /*
716 * Must provide the virtual address of the current
717 * descriptor, the physical address, and the virtual
718 * address of the next descriptor in the h/w chain.
719 * This allows the HAL to look ahead to see if the
720 * hardware is done with a descriptor by checking the
721 * done bit in the following descriptor and the address
722 * of the current descriptor the DMA engine is working
723 * on. All this is necessary because of our use of
724 * a self-linked list to avoid rx overruns.
725 */
726 ret = ath9k_hw_rxprocdesc(ah, ds, rs);
727 if (ret == -EINPROGRESS) {
728 struct ath_rx_status trs;
729 struct ath_rxbuf *tbf;
730 struct ath_desc *tds;
731
732 memset(&trs, 0, sizeof(trs));
733 if (list_is_last(list: &bf->list, head: &sc->rx.rxbuf)) {
734 sc->rx.rxlink = NULL;
735 return NULL;
736 }
737
738 tbf = list_entry(bf->list.next, struct ath_rxbuf, list);
739
740 /*
741 * On some hardware the descriptor status words could
742 * get corrupted, including the done bit. Because of
743 * this, check if the next descriptor's done bit is
744 * set or not.
745 *
746 * If the next descriptor's done bit is set, the current
747 * descriptor has been corrupted. Force s/w to discard
748 * this descriptor and continue...
749 */
750
751 tds = tbf->bf_desc;
752 ret = ath9k_hw_rxprocdesc(ah, ds: tds, rs: &trs);
753 if (ret == -EINPROGRESS)
754 return NULL;
755
756 /*
757 * Re-check previous descriptor, in case it has been filled
758 * in the mean time.
759 */
760 ret = ath9k_hw_rxprocdesc(ah, ds, rs);
761 if (ret == -EINPROGRESS) {
762 /*
763 * mark descriptor as zero-length and set the 'more'
764 * flag to ensure that both buffers get discarded
765 */
766 rs->rs_datalen = 0;
767 rs->rs_more = true;
768 }
769 }
770
771 list_del(entry: &bf->list);
772 if (!bf->bf_mpdu)
773 return bf;
774
775 /*
776 * Synchronize the DMA transfer with CPU before
777 * 1. accessing the frame
778 * 2. requeueing the same buffer to h/w
779 */
780 dma_sync_single_for_cpu(dev: sc->dev, addr: bf->bf_buf_addr,
781 size: common->rx_bufsize,
782 dir: DMA_FROM_DEVICE);
783
784 return bf;
785}
786
787static void ath9k_process_tsf(struct ath_rx_status *rs,
788 struct ieee80211_rx_status *rxs,
789 u64 tsf)
790{
791 u32 tsf_lower = tsf & 0xffffffff;
792
793 rxs->mactime = (tsf & ~0xffffffffULL) | rs->rs_tstamp;
794 if (rs->rs_tstamp > tsf_lower &&
795 unlikely(rs->rs_tstamp - tsf_lower > 0x10000000))
796 rxs->mactime -= 0x100000000ULL;
797
798 if (rs->rs_tstamp < tsf_lower &&
799 unlikely(tsf_lower - rs->rs_tstamp > 0x10000000))
800 rxs->mactime += 0x100000000ULL;
801}
802
803/*
804 * For Decrypt or Demic errors, we only mark packet status here and always push
805 * up the frame up to let mac80211 handle the actual error case, be it no
806 * decryption key or real decryption error. This let us keep statistics there.
807 */
808static int ath9k_rx_skb_preprocess(struct ath_softc *sc,
809 struct sk_buff *skb,
810 struct ath_rx_status *rx_stats,
811 struct ieee80211_rx_status *rx_status,
812 bool *decrypt_error, u64 tsf)
813{
814 struct ieee80211_hw *hw = sc->hw;
815 struct ath_hw *ah = sc->sc_ah;
816 struct ath_common *common = ath9k_hw_common(ah);
817 struct ieee80211_hdr *hdr;
818 bool discard_current = sc->rx.discard_next;
819 bool is_phyerr;
820
821 /*
822 * Discard corrupt descriptors which are marked in
823 * ath_get_next_rx_buf().
824 */
825 if (discard_current)
826 goto corrupt;
827
828 sc->rx.discard_next = false;
829
830 /*
831 * Discard zero-length packets and packets smaller than an ACK
832 * which are not PHY_ERROR (short radar pulses have a length of 3)
833 */
834 is_phyerr = rx_stats->rs_status & ATH9K_RXERR_PHY;
835 if (!rx_stats->rs_datalen ||
836 (rx_stats->rs_datalen < 10 && !is_phyerr)) {
837 RX_STAT_INC(sc, rx_len_err);
838 goto corrupt;
839 }
840
841 /*
842 * rs_status follows rs_datalen so if rs_datalen is too large
843 * we can take a hint that hardware corrupted it, so ignore
844 * those frames.
845 */
846 if (rx_stats->rs_datalen > (common->rx_bufsize - ah->caps.rx_status_len)) {
847 RX_STAT_INC(sc, rx_len_err);
848 goto corrupt;
849 }
850
851 /* Only use status info from the last fragment */
852 if (rx_stats->rs_more)
853 return 0;
854
855 /*
856 * Return immediately if the RX descriptor has been marked
857 * as corrupt based on the various error bits.
858 *
859 * This is different from the other corrupt descriptor
860 * condition handled above.
861 */
862 if (rx_stats->rs_status & ATH9K_RXERR_CORRUPT_DESC)
863 goto corrupt;
864
865 hdr = (struct ieee80211_hdr *) (skb->data + ah->caps.rx_status_len);
866
867 ath9k_process_tsf(rs: rx_stats, rxs: rx_status, tsf);
868 ath_debug_stat_rx(sc, rs: rx_stats);
869
870 /*
871 * Process PHY errors and return so that the packet
872 * can be dropped.
873 */
874 if (rx_stats->rs_status & ATH9K_RXERR_PHY) {
875 /*
876 * DFS and spectral are mutually exclusive
877 *
878 * Since some chips use PHYERR_RADAR as indication for both, we
879 * need to double check which feature is enabled to prevent
880 * feeding spectral or dfs-detector with wrong frames.
881 */
882 if (hw->conf.radar_enabled) {
883 ath9k_dfs_process_phyerr(sc, data: hdr, rs: rx_stats,
884 mactime: rx_status->mactime);
885 } else if (sc->spec_priv.spectral_mode != SPECTRAL_DISABLED &&
886 ath_cmn_process_fft(spec_priv: &sc->spec_priv, hdr, rs: rx_stats,
887 tsf: rx_status->mactime)) {
888 RX_STAT_INC(sc, rx_spectral);
889 }
890 return -EINVAL;
891 }
892
893 /*
894 * everything but the rate is checked here, the rate check is done
895 * separately to avoid doing two lookups for a rate for each frame.
896 */
897 spin_lock_bh(lock: &sc->chan_lock);
898 if (!ath9k_cmn_rx_accept(common, hdr, rxs: rx_status, rx_stats, decrypt_error,
899 rxfilter: sc->cur_chan->rxfilter)) {
900 spin_unlock_bh(lock: &sc->chan_lock);
901 return -EINVAL;
902 }
903 spin_unlock_bh(lock: &sc->chan_lock);
904
905 if (ath_is_mybeacon(common, hdr)) {
906 RX_STAT_INC(sc, rx_beacons);
907 rx_stats->is_mybeacon = true;
908 }
909
910 /*
911 * This shouldn't happen, but have a safety check anyway.
912 */
913 if (WARN_ON(!ah->curchan))
914 return -EINVAL;
915
916 if (ath9k_cmn_process_rate(common, hw, rx_stats, rxs: rx_status)) {
917 /*
918 * No valid hardware bitrate found -- we should not get here
919 * because hardware has already validated this frame as OK.
920 */
921 ath_dbg(common, ANY, "unsupported hw bitrate detected 0x%02x using 1 Mbit\n",
922 rx_stats->rs_rate);
923 RX_STAT_INC(sc, rx_rate_err);
924 return -EINVAL;
925 }
926
927 if (ath9k_is_chanctx_enabled()) {
928 if (rx_stats->is_mybeacon)
929 ath_chanctx_beacon_recv_ev(sc,
930 ev: ATH_CHANCTX_EVENT_BEACON_RECEIVED);
931 }
932
933 ath9k_cmn_process_rssi(common, hw, rx_stats, rxs: rx_status);
934
935 rx_status->band = ah->curchan->chan->band;
936 rx_status->freq = ah->curchan->chan->center_freq;
937 rx_status->antenna = rx_stats->rs_antenna;
938 rx_status->flag |= RX_FLAG_MACTIME_END;
939
940#ifdef CONFIG_ATH9K_BTCOEX_SUPPORT
941 if (ieee80211_is_data_present(fc: hdr->frame_control) &&
942 !ieee80211_is_qos_nullfunc(fc: hdr->frame_control))
943 sc->rx.num_pkts++;
944#endif
945
946 return 0;
947
948corrupt:
949 sc->rx.discard_next = rx_stats->rs_more;
950 return -EINVAL;
951}
952
953/*
954 * Run the LNA combining algorithm only in these cases:
955 *
956 * Standalone WLAN cards with both LNA/Antenna diversity
957 * enabled in the EEPROM.
958 *
959 * WLAN+BT cards which are in the supported card list
960 * in ath_pci_id_table and the user has loaded the
961 * driver with "bt_ant_diversity" set to true.
962 */
963static void ath9k_antenna_check(struct ath_softc *sc,
964 struct ath_rx_status *rs)
965{
966 struct ath_hw *ah = sc->sc_ah;
967 struct ath9k_hw_capabilities *pCap = &ah->caps;
968 struct ath_common *common = ath9k_hw_common(ah);
969
970 if (!(ah->caps.hw_caps & ATH9K_HW_CAP_ANT_DIV_COMB))
971 return;
972
973 /*
974 * Change the default rx antenna if rx diversity
975 * chooses the other antenna 3 times in a row.
976 */
977 if (sc->rx.defant != rs->rs_antenna) {
978 if (++sc->rx.rxotherant >= 3)
979 ath_setdefantenna(sc, antenna: rs->rs_antenna);
980 } else {
981 sc->rx.rxotherant = 0;
982 }
983
984 if (pCap->hw_caps & ATH9K_HW_CAP_BT_ANT_DIV) {
985 if (common->bt_ant_diversity)
986 ath_ant_comb_scan(sc, rs);
987 } else {
988 ath_ant_comb_scan(sc, rs);
989 }
990}
991
992static void ath9k_apply_ampdu_details(struct ath_softc *sc,
993 struct ath_rx_status *rs, struct ieee80211_rx_status *rxs)
994{
995 if (rs->rs_isaggr) {
996 rxs->flag |= RX_FLAG_AMPDU_DETAILS | RX_FLAG_AMPDU_LAST_KNOWN;
997
998 rxs->ampdu_reference = sc->rx.ampdu_ref;
999
1000 if (!rs->rs_moreaggr) {
1001 rxs->flag |= RX_FLAG_AMPDU_IS_LAST;
1002 sc->rx.ampdu_ref++;
1003 }
1004
1005 if (rs->rs_flags & ATH9K_RX_DELIM_CRC_PRE)
1006 rxs->flag |= RX_FLAG_AMPDU_DELIM_CRC_ERROR;
1007 }
1008}
1009
1010static void ath_rx_count_airtime(struct ath_softc *sc,
1011 struct ath_rx_status *rs,
1012 struct sk_buff *skb)
1013{
1014 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
1015 struct ath_hw *ah = sc->sc_ah;
1016 struct ath_common *common = ath9k_hw_common(ah);
1017 struct ieee80211_sta *sta;
1018 struct ieee80211_rx_status *rxs;
1019 const struct ieee80211_rate *rate;
1020 bool is_sgi, is_40, is_sp;
1021 int phy;
1022 u16 len = rs->rs_datalen;
1023 u32 airtime = 0;
1024 u8 tidno;
1025
1026 if (!ieee80211_is_data(fc: hdr->frame_control))
1027 return;
1028
1029 rcu_read_lock();
1030
1031 sta = ieee80211_find_sta_by_ifaddr(hw: sc->hw, addr: hdr->addr2, NULL);
1032 if (!sta)
1033 goto exit;
1034 tidno = skb->priority & IEEE80211_QOS_CTL_TID_MASK;
1035
1036 rxs = IEEE80211_SKB_RXCB(skb);
1037
1038 is_sgi = !!(rxs->enc_flags & RX_ENC_FLAG_SHORT_GI);
1039 is_40 = !!(rxs->bw == RATE_INFO_BW_40);
1040 is_sp = !!(rxs->enc_flags & RX_ENC_FLAG_SHORTPRE);
1041
1042 if (!!(rxs->encoding == RX_ENC_HT)) {
1043 /* MCS rates */
1044
1045 airtime += ath_pkt_duration(sc, rix: rxs->rate_idx, pktlen: len,
1046 width: is_40, half_gi: is_sgi, shortPreamble: is_sp);
1047 } else {
1048
1049 phy = IS_CCK_RATE(rs->rs_rate) ? WLAN_RC_PHY_CCK : WLAN_RC_PHY_OFDM;
1050 rate = &common->sbands[rxs->band].bitrates[rxs->rate_idx];
1051 airtime += ath9k_hw_computetxtime(ah, phy, kbps: rate->bitrate * 100,
1052 frameLen: len, rateix: rxs->rate_idx, shortPreamble: is_sp);
1053 }
1054
1055 ieee80211_sta_register_airtime(pubsta: sta, tid: tidno, tx_airtime: 0, rx_airtime: airtime);
1056exit:
1057 rcu_read_unlock();
1058}
1059
1060int ath_rx_tasklet(struct ath_softc *sc, int flush, bool hp)
1061{
1062 struct ath_rxbuf *bf;
1063 struct sk_buff *skb = NULL, *requeue_skb, *hdr_skb;
1064 struct ieee80211_rx_status *rxs;
1065 struct ath_hw *ah = sc->sc_ah;
1066 struct ath_common *common = ath9k_hw_common(ah);
1067 struct ieee80211_hw *hw = sc->hw;
1068 int retval;
1069 struct ath_rx_status rs;
1070 enum ath9k_rx_qtype qtype;
1071 bool edma = !!(ah->caps.hw_caps & ATH9K_HW_CAP_EDMA);
1072 int dma_type;
1073 u64 tsf = 0;
1074 unsigned long flags;
1075 dma_addr_t new_buf_addr;
1076 unsigned int budget = 512;
1077 struct ieee80211_hdr *hdr;
1078
1079 if (edma)
1080 dma_type = DMA_BIDIRECTIONAL;
1081 else
1082 dma_type = DMA_FROM_DEVICE;
1083
1084 qtype = hp ? ATH9K_RX_QUEUE_HP : ATH9K_RX_QUEUE_LP;
1085
1086 tsf = ath9k_hw_gettsf64(ah);
1087
1088 do {
1089 bool decrypt_error = false;
1090
1091 memset(&rs, 0, sizeof(rs));
1092 if (edma)
1093 bf = ath_edma_get_next_rx_buf(sc, rs: &rs, qtype);
1094 else
1095 bf = ath_get_next_rx_buf(sc, rs: &rs);
1096
1097 if (!bf)
1098 break;
1099
1100 skb = bf->bf_mpdu;
1101 if (!skb)
1102 continue;
1103
1104 /*
1105 * Take frame header from the first fragment and RX status from
1106 * the last one.
1107 */
1108 if (sc->rx.frag)
1109 hdr_skb = sc->rx.frag;
1110 else
1111 hdr_skb = skb;
1112
1113 rxs = IEEE80211_SKB_RXCB(skb: hdr_skb);
1114 memset(rxs, 0, sizeof(struct ieee80211_rx_status));
1115
1116 retval = ath9k_rx_skb_preprocess(sc, skb: hdr_skb, rx_stats: &rs, rx_status: rxs,
1117 decrypt_error: &decrypt_error, tsf);
1118 if (retval)
1119 goto requeue_drop_frag;
1120
1121 /* Ensure we always have an skb to requeue once we are done
1122 * processing the current buffer's skb */
1123 requeue_skb = ath_rxbuf_alloc(common, len: common->rx_bufsize, GFP_ATOMIC);
1124
1125 /* If there is no memory we ignore the current RX'd frame,
1126 * tell hardware it can give us a new frame using the old
1127 * skb and put it at the tail of the sc->rx.rxbuf list for
1128 * processing. */
1129 if (!requeue_skb) {
1130 RX_STAT_INC(sc, rx_oom_err);
1131 goto requeue_drop_frag;
1132 }
1133
1134 /* We will now give hardware our shiny new allocated skb */
1135 new_buf_addr = dma_map_single(sc->dev, requeue_skb->data,
1136 common->rx_bufsize, dma_type);
1137 if (unlikely(dma_mapping_error(sc->dev, new_buf_addr))) {
1138 dev_kfree_skb_any(skb: requeue_skb);
1139 goto requeue_drop_frag;
1140 }
1141
1142 /* Unmap the frame */
1143 dma_unmap_single(sc->dev, bf->bf_buf_addr,
1144 common->rx_bufsize, dma_type);
1145
1146 bf->bf_mpdu = requeue_skb;
1147 bf->bf_buf_addr = new_buf_addr;
1148
1149 skb_put(skb, len: rs.rs_datalen + ah->caps.rx_status_len);
1150 if (ah->caps.rx_status_len)
1151 skb_pull(skb, len: ah->caps.rx_status_len);
1152
1153 if (!rs.rs_more)
1154 ath9k_cmn_rx_skb_postprocess(common, skb: hdr_skb, rx_stats: &rs,
1155 rxs, decrypt_error);
1156
1157 if (rs.rs_more) {
1158 RX_STAT_INC(sc, rx_frags);
1159 /*
1160 * rs_more indicates chained descriptors which can be
1161 * used to link buffers together for a sort of
1162 * scatter-gather operation.
1163 */
1164 if (sc->rx.frag) {
1165 /* too many fragments - cannot handle frame */
1166 dev_kfree_skb_any(skb: sc->rx.frag);
1167 dev_kfree_skb_any(skb);
1168 RX_STAT_INC(sc, rx_too_many_frags_err);
1169 skb = NULL;
1170 }
1171 sc->rx.frag = skb;
1172 goto requeue;
1173 }
1174
1175 if (sc->rx.frag) {
1176 int space = skb->len - skb_tailroom(skb: hdr_skb);
1177
1178 if (pskb_expand_head(skb: hdr_skb, nhead: 0, ntail: space, GFP_ATOMIC) < 0) {
1179 dev_kfree_skb(skb);
1180 RX_STAT_INC(sc, rx_oom_err);
1181 goto requeue_drop_frag;
1182 }
1183
1184 sc->rx.frag = NULL;
1185
1186 skb_copy_from_linear_data(skb, to: skb_put(skb: hdr_skb, len: skb->len),
1187 len: skb->len);
1188 dev_kfree_skb_any(skb);
1189 skb = hdr_skb;
1190 }
1191
1192 if (rxs->flag & RX_FLAG_MMIC_STRIPPED)
1193 skb_trim(skb, len: skb->len - 8);
1194
1195 spin_lock_irqsave(&sc->sc_pm_lock, flags);
1196 if ((sc->ps_flags & (PS_WAIT_FOR_BEACON |
1197 PS_WAIT_FOR_CAB |
1198 PS_WAIT_FOR_PSPOLL_DATA)) ||
1199 ath9k_check_auto_sleep(sc))
1200 ath_rx_ps(sc, skb, mybeacon: rs.is_mybeacon);
1201 spin_unlock_irqrestore(lock: &sc->sc_pm_lock, flags);
1202
1203 ath9k_antenna_check(sc, rs: &rs);
1204 ath9k_apply_ampdu_details(sc, rs: &rs, rxs);
1205 ath_debug_rate_stats(sc, rs: &rs, skb);
1206 ath_rx_count_airtime(sc, rs: &rs, skb);
1207
1208 hdr = (struct ieee80211_hdr *)skb->data;
1209 if (ieee80211_is_ack(fc: hdr->frame_control))
1210 ath_dynack_sample_ack_ts(ah: sc->sc_ah, skb, ts: rs.rs_tstamp);
1211
1212 ieee80211_rx(hw, skb);
1213
1214requeue_drop_frag:
1215 if (sc->rx.frag) {
1216 dev_kfree_skb_any(skb: sc->rx.frag);
1217 sc->rx.frag = NULL;
1218 }
1219requeue:
1220 list_add_tail(new: &bf->list, head: &sc->rx.rxbuf);
1221
1222 if (!edma) {
1223 ath_rx_buf_relink(sc, bf, flush);
1224 if (!flush)
1225 ath9k_hw_rxena(ah);
1226 } else if (!flush) {
1227 ath_rx_edma_buf_link(sc, qtype);
1228 }
1229
1230 if (!budget--)
1231 break;
1232 } while (1);
1233
1234 if (!(ah->imask & ATH9K_INT_RXEOL)) {
1235 ah->imask |= (ATH9K_INT_RXEOL | ATH9K_INT_RXORN);
1236 ath9k_hw_set_interrupts(ah);
1237 }
1238
1239 return 0;
1240}
1241

source code of linux/drivers/net/wireless/ath/ath9k/recv.c