2 * Copyright (c) 2008-2009 Atheros Communications Inc.
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.
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.
19 static struct ieee80211_hw * ath_get_virt_hw(struct ath_softc *sc,
20 struct ieee80211_hdr *hdr)
22 struct ieee80211_hw *hw = sc->pri_wiphy->hw;
25 spin_lock_bh(&sc->wiphy_lock);
26 for (i = 0; i < sc->num_sec_wiphy; i++) {
27 struct ath_wiphy *aphy = sc->sec_wiphy[i];
30 if (compare_ether_addr(hdr->addr1, aphy->hw->wiphy->perm_addr)
36 spin_unlock_bh(&sc->wiphy_lock);
41 * Setup and link descriptors.
43 * 11N: we can no longer afford to self link the last descriptor.
44 * MAC acknowledges BA status as long as it copies frames to host
45 * buffer (or rx fifo). This can incorrectly acknowledge packets
46 * to a sender if last desc is self-linked.
48 static void ath_rx_buf_link(struct ath_softc *sc, struct ath_buf *bf)
50 struct ath_hw *ah = sc->sc_ah;
51 struct ath_common *common = ath9k_hw_common(ah);
58 ds->ds_link = 0; /* link to null */
59 ds->ds_data = bf->bf_buf_addr;
61 /* virtual addr of the beginning of the buffer. */
64 ds->ds_vdata = skb->data;
67 * setup rx descriptors. The rx_bufsize here tells the hardware
68 * how much data it can DMA to us and that we are prepared
71 ath9k_hw_setuprxdesc(ah, ds,
75 if (sc->rx.rxlink == NULL)
76 ath9k_hw_putrxbuf(ah, bf->bf_daddr);
78 *sc->rx.rxlink = bf->bf_daddr;
80 sc->rx.rxlink = &ds->ds_link;
84 static void ath_setdefantenna(struct ath_softc *sc, u32 antenna)
86 /* XXX block beacon interrupts */
87 ath9k_hw_setantenna(sc->sc_ah, antenna);
88 sc->rx.defant = antenna;
89 sc->rx.rxotherant = 0;
92 /* Assumes you've already done the endian to CPU conversion */
93 static bool ath9k_rx_accept(struct ath_common *common,
95 struct ieee80211_rx_status *rxs,
96 struct ath_rx_status *rx_stats,
99 struct ath_hw *ah = common->ah;
100 struct ieee80211_hdr *hdr;
103 hdr = (struct ieee80211_hdr *) skb->data;
104 fc = hdr->frame_control;
106 if (!rx_stats->rs_datalen)
109 * rs_status follows rs_datalen so if rs_datalen is too large
110 * we can take a hint that hardware corrupted it, so ignore
113 if (rx_stats->rs_datalen > common->rx_bufsize)
116 if (rx_stats->rs_more) {
118 * Frame spans multiple descriptors; this cannot happen yet
119 * as we don't support jumbograms. If not in monitor mode,
120 * discard the frame. Enable this if you want to see
121 * error frames in Monitor mode.
123 if (ah->opmode != NL80211_IFTYPE_MONITOR)
125 } else if (rx_stats->rs_status != 0) {
126 if (rx_stats->rs_status & ATH9K_RXERR_CRC)
127 rxs->flag |= RX_FLAG_FAILED_FCS_CRC;
128 if (rx_stats->rs_status & ATH9K_RXERR_PHY)
131 if (rx_stats->rs_status & ATH9K_RXERR_DECRYPT) {
132 *decrypt_error = true;
133 } else if (rx_stats->rs_status & ATH9K_RXERR_MIC) {
134 if (ieee80211_is_ctl(fc))
136 * Sometimes, we get invalid
137 * MIC failures on valid control frames.
138 * Remove these mic errors.
140 rx_stats->rs_status &= ~ATH9K_RXERR_MIC;
142 rxs->flag |= RX_FLAG_MMIC_ERROR;
145 * Reject error frames with the exception of
146 * decryption and MIC failures. For monitor mode,
147 * we also ignore the CRC error.
149 if (ah->opmode == NL80211_IFTYPE_MONITOR) {
150 if (rx_stats->rs_status &
151 ~(ATH9K_RXERR_DECRYPT | ATH9K_RXERR_MIC |
155 if (rx_stats->rs_status &
156 ~(ATH9K_RXERR_DECRYPT | ATH9K_RXERR_MIC)) {
164 static u8 ath9k_process_rate(struct ath_common *common,
165 struct ieee80211_hw *hw,
166 struct ath_rx_status *rx_stats,
167 struct ieee80211_rx_status *rxs,
170 struct ieee80211_supported_band *sband;
171 enum ieee80211_band band;
174 band = hw->conf.channel->band;
175 sband = hw->wiphy->bands[band];
177 if (rx_stats->rs_rate & 0x80) {
179 rxs->flag |= RX_FLAG_HT;
180 if (rx_stats->rs_flags & ATH9K_RX_2040)
181 rxs->flag |= RX_FLAG_40MHZ;
182 if (rx_stats->rs_flags & ATH9K_RX_GI)
183 rxs->flag |= RX_FLAG_SHORT_GI;
184 return rx_stats->rs_rate & 0x7f;
187 for (i = 0; i < sband->n_bitrates; i++) {
188 if (sband->bitrates[i].hw_value == rx_stats->rs_rate)
190 if (sband->bitrates[i].hw_value_short == rx_stats->rs_rate) {
191 rxs->flag |= RX_FLAG_SHORTPRE;
196 /* No valid hardware bitrate found -- we should not get here */
197 ath_print(common, ATH_DBG_XMIT, "unsupported hw bitrate detected "
198 "0x%02x using 1 Mbit\n", rx_stats->rs_rate);
199 if ((common->debug_mask & ATH_DBG_XMIT))
200 print_hex_dump_bytes("", DUMP_PREFIX_NONE, skb->data, skb->len);
206 * Theory for reporting quality:
208 * At a hardware RSSI of 45 you will be able to use MCS 7 reliably.
209 * At a hardware RSSI of 45 you will be able to use MCS 15 reliably.
210 * At a hardware RSSI of 35 you should be able use 54 Mbps reliably.
212 * MCS 7 is the highets MCS index usable by a 1-stream device.
213 * MCS 15 is the highest MCS index usable by a 2-stream device.
215 * All ath9k devices are either 1-stream or 2-stream.
217 * How many bars you see is derived from the qual reporting.
219 * A more elaborate scheme can be used here but it requires tables
220 * of SNR/throughput for each possible mode used. For the MCS table
221 * you can refer to the wireless wiki:
223 * http://wireless.kernel.org/en/developers/Documentation/ieee80211/802.11n
226 static int ath9k_compute_qual(struct ieee80211_hw *hw,
227 struct ath_rx_status *rx_stats)
231 if (conf_is_ht(&hw->conf))
232 qual = rx_stats->rs_rssi * 100 / 45;
234 qual = rx_stats->rs_rssi * 100 / 35;
237 * rssi can be more than 45 though, anything above that
238 * should be considered at 100%
246 static void ath9k_process_rssi(struct ath_common *common,
247 struct ieee80211_hw *hw,
249 struct ath_rx_status *rx_stats)
251 struct ath_hw *ah = common->ah;
252 struct ieee80211_sta *sta;
253 struct ieee80211_hdr *hdr;
255 int last_rssi = ATH_RSSI_DUMMY_MARKER;
258 hdr = (struct ieee80211_hdr *)skb->data;
259 fc = hdr->frame_control;
262 /* XXX: use ieee80211_find_sta! */
263 sta = ieee80211_find_sta_by_hw(hw, hdr->addr2);
265 an = (struct ath_node *) sta->drv_priv;
266 if (rx_stats->rs_rssi != ATH9K_RSSI_BAD &&
267 !rx_stats->rs_moreaggr)
268 ATH_RSSI_LPF(an->last_rssi, rx_stats->rs_rssi);
269 last_rssi = an->last_rssi;
273 if (likely(last_rssi != ATH_RSSI_DUMMY_MARKER))
274 rx_stats->rs_rssi = ATH_EP_RND(last_rssi,
275 ATH_RSSI_EP_MULTIPLIER);
276 if (rx_stats->rs_rssi < 0)
277 rx_stats->rs_rssi = 0;
278 else if (rx_stats->rs_rssi > 127)
279 rx_stats->rs_rssi = 127;
281 /* Update Beacon RSSI, this is used by ANI. */
282 if (ieee80211_is_beacon(fc))
283 ah->stats.avgbrssi = rx_stats->rs_rssi;
287 * For Decrypt or Demic errors, we only mark packet status here and always push
288 * up the frame up to let mac80211 handle the actual error case, be it no
289 * decryption key or real decryption error. This let us keep statistics there.
291 static int ath9k_rx_skb_preprocess(struct ath_common *common,
292 struct ieee80211_hw *hw,
294 struct ath_rx_status *rx_stats,
295 struct ieee80211_rx_status *rx_status,
298 struct ath_hw *ah = common->ah;
300 if (!ath9k_rx_accept(common, skb, rx_status, rx_stats, decrypt_error))
303 ath9k_process_rssi(common, hw, skb, rx_stats);
305 rx_status->rate_idx = ath9k_process_rate(common, hw,
306 rx_stats, rx_status, skb);
307 rx_status->mactime = ath9k_hw_extend_tsf(ah, rx_stats->rs_tstamp);
308 rx_status->band = hw->conf.channel->band;
309 rx_status->freq = hw->conf.channel->center_freq;
310 rx_status->noise = common->ani.noise_floor;
311 rx_status->signal = ATH_DEFAULT_NOISE_FLOOR + rx_stats->rs_rssi;
312 rx_status->antenna = rx_stats->rs_antenna;
313 rx_status->qual = ath9k_compute_qual(hw, rx_stats);
314 rx_status->flag |= RX_FLAG_TSFT;
319 static void ath_opmode_init(struct ath_softc *sc)
321 struct ath_hw *ah = sc->sc_ah;
322 struct ath_common *common = ath9k_hw_common(ah);
326 /* configure rx filter */
327 rfilt = ath_calcrxfilter(sc);
328 ath9k_hw_setrxfilter(ah, rfilt);
330 /* configure bssid mask */
331 if (ah->caps.hw_caps & ATH9K_HW_CAP_BSSIDMASK)
332 ath_hw_setbssidmask(common);
334 /* configure operational mode */
335 ath9k_hw_setopmode(ah);
337 /* Handle any link-level address change. */
338 ath9k_hw_setmac(ah, common->macaddr);
340 /* calculate and install multicast filter */
341 mfilt[0] = mfilt[1] = ~0;
342 ath9k_hw_setmcastfilter(ah, mfilt[0], mfilt[1]);
345 int ath_rx_init(struct ath_softc *sc, int nbufs)
347 struct ath_common *common = ath9k_hw_common(sc->sc_ah);
352 spin_lock_init(&sc->rx.rxflushlock);
353 sc->sc_flags &= ~SC_OP_RXFLUSH;
354 spin_lock_init(&sc->rx.rxbuflock);
356 common->rx_bufsize = roundup(IEEE80211_MAX_MPDU_LEN,
357 min(common->cachelsz, (u16)64));
359 ath_print(common, ATH_DBG_CONFIG, "cachelsz %u rxbufsize %u\n",
360 common->cachelsz, common->rx_bufsize);
362 /* Initialize rx descriptors */
364 error = ath_descdma_setup(sc, &sc->rx.rxdma, &sc->rx.rxbuf,
367 ath_print(common, ATH_DBG_FATAL,
368 "failed to allocate rx descriptors: %d\n", error);
372 list_for_each_entry(bf, &sc->rx.rxbuf, list) {
373 skb = ath_rxbuf_alloc(common, common->rx_bufsize, GFP_KERNEL);
380 bf->bf_buf_addr = dma_map_single(sc->dev, skb->data,
383 if (unlikely(dma_mapping_error(sc->dev,
385 dev_kfree_skb_any(skb);
387 ath_print(common, ATH_DBG_FATAL,
388 "dma_mapping_error() on RX init\n");
392 bf->bf_dmacontext = bf->bf_buf_addr;
394 sc->rx.rxlink = NULL;
403 void ath_rx_cleanup(struct ath_softc *sc)
405 struct ath_hw *ah = sc->sc_ah;
406 struct ath_common *common = ath9k_hw_common(ah);
410 list_for_each_entry(bf, &sc->rx.rxbuf, list) {
413 dma_unmap_single(sc->dev, bf->bf_buf_addr,
414 common->rx_bufsize, DMA_FROM_DEVICE);
419 if (sc->rx.rxdma.dd_desc_len != 0)
420 ath_descdma_cleanup(sc, &sc->rx.rxdma, &sc->rx.rxbuf);
424 * Calculate the receive filter according to the
425 * operating mode and state:
427 * o always accept unicast, broadcast, and multicast traffic
428 * o maintain current state of phy error reception (the hal
429 * may enable phy error frames for noise immunity work)
430 * o probe request frames are accepted only when operating in
431 * hostap, adhoc, or monitor modes
432 * o enable promiscuous mode according to the interface state
434 * - when operating in adhoc mode so the 802.11 layer creates
435 * node table entries for peers,
436 * - when operating in station mode for collecting rssi data when
437 * the station is otherwise quiet, or
438 * - when operating as a repeater so we see repeater-sta beacons
442 u32 ath_calcrxfilter(struct ath_softc *sc)
444 #define RX_FILTER_PRESERVE (ATH9K_RX_FILTER_PHYERR | ATH9K_RX_FILTER_PHYRADAR)
448 rfilt = (ath9k_hw_getrxfilter(sc->sc_ah) & RX_FILTER_PRESERVE)
449 | ATH9K_RX_FILTER_UCAST | ATH9K_RX_FILTER_BCAST
450 | ATH9K_RX_FILTER_MCAST;
452 /* If not a STA, enable processing of Probe Requests */
453 if (sc->sc_ah->opmode != NL80211_IFTYPE_STATION)
454 rfilt |= ATH9K_RX_FILTER_PROBEREQ;
457 * Set promiscuous mode when FIF_PROMISC_IN_BSS is enabled for station
458 * mode interface or when in monitor mode. AP mode does not need this
459 * since it receives all in-BSS frames anyway.
461 if (((sc->sc_ah->opmode != NL80211_IFTYPE_AP) &&
462 (sc->rx.rxfilter & FIF_PROMISC_IN_BSS)) ||
463 (sc->sc_ah->opmode == NL80211_IFTYPE_MONITOR))
464 rfilt |= ATH9K_RX_FILTER_PROM;
466 if (sc->rx.rxfilter & FIF_CONTROL)
467 rfilt |= ATH9K_RX_FILTER_CONTROL;
469 if ((sc->sc_ah->opmode == NL80211_IFTYPE_STATION) &&
470 !(sc->rx.rxfilter & FIF_BCN_PRBRESP_PROMISC))
471 rfilt |= ATH9K_RX_FILTER_MYBEACON;
473 rfilt |= ATH9K_RX_FILTER_BEACON;
475 if ((AR_SREV_9280_10_OR_LATER(sc->sc_ah) ||
476 AR_SREV_9285_10_OR_LATER(sc->sc_ah)) &&
477 (sc->sc_ah->opmode == NL80211_IFTYPE_AP) &&
478 (sc->rx.rxfilter & FIF_PSPOLL))
479 rfilt |= ATH9K_RX_FILTER_PSPOLL;
481 if (conf_is_ht(&sc->hw->conf))
482 rfilt |= ATH9K_RX_FILTER_COMP_BAR;
484 if (sc->sec_wiphy || (sc->rx.rxfilter & FIF_OTHER_BSS)) {
485 /* TODO: only needed if more than one BSSID is in use in
486 * station/adhoc mode */
487 /* The following may also be needed for other older chips */
488 if (sc->sc_ah->hw_version.macVersion == AR_SREV_VERSION_9160)
489 rfilt |= ATH9K_RX_FILTER_PROM;
490 rfilt |= ATH9K_RX_FILTER_MCAST_BCAST_ALL;
495 #undef RX_FILTER_PRESERVE
498 int ath_startrecv(struct ath_softc *sc)
500 struct ath_hw *ah = sc->sc_ah;
501 struct ath_buf *bf, *tbf;
503 spin_lock_bh(&sc->rx.rxbuflock);
504 if (list_empty(&sc->rx.rxbuf))
507 sc->rx.rxlink = NULL;
508 list_for_each_entry_safe(bf, tbf, &sc->rx.rxbuf, list) {
509 ath_rx_buf_link(sc, bf);
512 /* We could have deleted elements so the list may be empty now */
513 if (list_empty(&sc->rx.rxbuf))
516 bf = list_first_entry(&sc->rx.rxbuf, struct ath_buf, list);
517 ath9k_hw_putrxbuf(ah, bf->bf_daddr);
521 spin_unlock_bh(&sc->rx.rxbuflock);
523 ath9k_hw_startpcureceive(ah);
528 bool ath_stoprecv(struct ath_softc *sc)
530 struct ath_hw *ah = sc->sc_ah;
533 ath9k_hw_stoppcurecv(ah);
534 ath9k_hw_setrxfilter(ah, 0);
535 stopped = ath9k_hw_stopdmarecv(ah);
536 sc->rx.rxlink = NULL;
541 void ath_flushrecv(struct ath_softc *sc)
543 spin_lock_bh(&sc->rx.rxflushlock);
544 sc->sc_flags |= SC_OP_RXFLUSH;
545 ath_rx_tasklet(sc, 1);
546 sc->sc_flags &= ~SC_OP_RXFLUSH;
547 spin_unlock_bh(&sc->rx.rxflushlock);
550 static bool ath_beacon_dtim_pending_cab(struct sk_buff *skb)
552 /* Check whether the Beacon frame has DTIM indicating buffered bc/mc */
553 struct ieee80211_mgmt *mgmt;
554 u8 *pos, *end, id, elen;
555 struct ieee80211_tim_ie *tim;
557 mgmt = (struct ieee80211_mgmt *)skb->data;
558 pos = mgmt->u.beacon.variable;
559 end = skb->data + skb->len;
561 while (pos + 2 < end) {
564 if (pos + elen > end)
567 if (id == WLAN_EID_TIM) {
568 if (elen < sizeof(*tim))
570 tim = (struct ieee80211_tim_ie *) pos;
571 if (tim->dtim_count != 0)
573 return tim->bitmap_ctrl & 0x01;
582 static void ath_rx_ps_beacon(struct ath_softc *sc, struct sk_buff *skb)
584 struct ieee80211_mgmt *mgmt;
585 struct ath_common *common = ath9k_hw_common(sc->sc_ah);
587 if (skb->len < 24 + 8 + 2 + 2)
590 mgmt = (struct ieee80211_mgmt *)skb->data;
591 if (memcmp(common->curbssid, mgmt->bssid, ETH_ALEN) != 0)
592 return; /* not from our current AP */
594 sc->sc_flags &= ~SC_OP_WAIT_FOR_BEACON;
596 if (sc->sc_flags & SC_OP_BEACON_SYNC) {
597 sc->sc_flags &= ~SC_OP_BEACON_SYNC;
598 ath_print(common, ATH_DBG_PS,
599 "Reconfigure Beacon timers based on "
600 "timestamp from the AP\n");
601 ath_beacon_config(sc, NULL);
604 if (ath_beacon_dtim_pending_cab(skb)) {
606 * Remain awake waiting for buffered broadcast/multicast
607 * frames. If the last broadcast/multicast frame is not
608 * received properly, the next beacon frame will work as
609 * a backup trigger for returning into NETWORK SLEEP state,
610 * so we are waiting for it as well.
612 ath_print(common, ATH_DBG_PS, "Received DTIM beacon indicating "
613 "buffered broadcast/multicast frame(s)\n");
614 sc->sc_flags |= SC_OP_WAIT_FOR_CAB | SC_OP_WAIT_FOR_BEACON;
618 if (sc->sc_flags & SC_OP_WAIT_FOR_CAB) {
620 * This can happen if a broadcast frame is dropped or the AP
621 * fails to send a frame indicating that all CAB frames have
624 sc->sc_flags &= ~SC_OP_WAIT_FOR_CAB;
625 ath_print(common, ATH_DBG_PS,
626 "PS wait for CAB frames timed out\n");
630 static void ath_rx_ps(struct ath_softc *sc, struct sk_buff *skb)
632 struct ieee80211_hdr *hdr;
633 struct ath_common *common = ath9k_hw_common(sc->sc_ah);
635 hdr = (struct ieee80211_hdr *)skb->data;
637 /* Process Beacon and CAB receive in PS state */
638 if ((sc->sc_flags & SC_OP_WAIT_FOR_BEACON) &&
639 ieee80211_is_beacon(hdr->frame_control))
640 ath_rx_ps_beacon(sc, skb);
641 else if ((sc->sc_flags & SC_OP_WAIT_FOR_CAB) &&
642 (ieee80211_is_data(hdr->frame_control) ||
643 ieee80211_is_action(hdr->frame_control)) &&
644 is_multicast_ether_addr(hdr->addr1) &&
645 !ieee80211_has_moredata(hdr->frame_control)) {
647 * No more broadcast/multicast frames to be received at this
650 sc->sc_flags &= ~SC_OP_WAIT_FOR_CAB;
651 ath_print(common, ATH_DBG_PS,
652 "All PS CAB frames received, back to sleep\n");
653 } else if ((sc->sc_flags & SC_OP_WAIT_FOR_PSPOLL_DATA) &&
654 !is_multicast_ether_addr(hdr->addr1) &&
655 !ieee80211_has_morefrags(hdr->frame_control)) {
656 sc->sc_flags &= ~SC_OP_WAIT_FOR_PSPOLL_DATA;
657 ath_print(common, ATH_DBG_PS,
658 "Going back to sleep after having received "
659 "PS-Poll data (0x%x)\n",
660 sc->sc_flags & (SC_OP_WAIT_FOR_BEACON |
662 SC_OP_WAIT_FOR_PSPOLL_DATA |
663 SC_OP_WAIT_FOR_TX_ACK));
667 static void ath_rx_send_to_mac80211(struct ieee80211_hw *hw,
668 struct ath_softc *sc, struct sk_buff *skb,
669 struct ieee80211_rx_status *rxs)
671 struct ieee80211_hdr *hdr;
673 hdr = (struct ieee80211_hdr *)skb->data;
675 /* Send the frame to mac80211 */
676 if (is_multicast_ether_addr(hdr->addr1)) {
679 * Deliver broadcast/multicast frames to all suitable
682 /* TODO: filter based on channel configuration */
683 for (i = 0; i < sc->num_sec_wiphy; i++) {
684 struct ath_wiphy *aphy = sc->sec_wiphy[i];
685 struct sk_buff *nskb;
688 nskb = skb_copy(skb, GFP_ATOMIC);
691 ieee80211_rx(aphy->hw, nskb);
693 ieee80211_rx(sc->hw, skb);
695 /* Deliver unicast frames based on receiver address */
696 ieee80211_rx(hw, skb);
699 int ath_rx_tasklet(struct ath_softc *sc, int flush)
701 #define PA2DESC(_sc, _pa) \
702 ((struct ath_desc *)((caddr_t)(_sc)->rx.rxdma.dd_desc + \
703 ((_pa) - (_sc)->rx.rxdma.dd_desc_paddr)))
707 struct ath_rx_status *rx_stats;
708 struct sk_buff *skb = NULL, *requeue_skb;
709 struct ieee80211_rx_status *rxs;
710 struct ath_hw *ah = sc->sc_ah;
711 struct ath_common *common = ath9k_hw_common(ah);
713 * The hw can techncically differ from common->hw when using ath9k
714 * virtual wiphy so to account for that we iterate over the active
715 * wiphys and find the appropriate wiphy and therefore hw.
717 struct ieee80211_hw *hw = NULL;
718 struct ieee80211_hdr *hdr;
719 int hdrlen, padsize, retval;
720 bool decrypt_error = false;
724 spin_lock_bh(&sc->rx.rxbuflock);
727 /* If handling rx interrupt and flush is in progress => exit */
728 if ((sc->sc_flags & SC_OP_RXFLUSH) && (flush == 0))
731 if (list_empty(&sc->rx.rxbuf)) {
732 sc->rx.rxlink = NULL;
736 bf = list_first_entry(&sc->rx.rxbuf, struct ath_buf, list);
740 * Must provide the virtual address of the current
741 * descriptor, the physical address, and the virtual
742 * address of the next descriptor in the h/w chain.
743 * This allows the HAL to look ahead to see if the
744 * hardware is done with a descriptor by checking the
745 * done bit in the following descriptor and the address
746 * of the current descriptor the DMA engine is working
747 * on. All this is necessary because of our use of
748 * a self-linked list to avoid rx overruns.
750 retval = ath9k_hw_rxprocdesc(ah, ds,
752 PA2DESC(sc, ds->ds_link),
754 if (retval == -EINPROGRESS) {
756 struct ath_desc *tds;
758 if (list_is_last(&bf->list, &sc->rx.rxbuf)) {
759 sc->rx.rxlink = NULL;
763 tbf = list_entry(bf->list.next, struct ath_buf, list);
766 * On some hardware the descriptor status words could
767 * get corrupted, including the done bit. Because of
768 * this, check if the next descriptor's done bit is
771 * If the next descriptor's done bit is set, the current
772 * descriptor has been corrupted. Force s/w to discard
773 * this descriptor and continue...
777 retval = ath9k_hw_rxprocdesc(ah, tds, tbf->bf_daddr,
778 PA2DESC(sc, tds->ds_link), 0);
779 if (retval == -EINPROGRESS) {
789 * Synchronize the DMA transfer with CPU before
790 * 1. accessing the frame
791 * 2. requeueing the same buffer to h/w
793 dma_sync_single_for_cpu(sc->dev, bf->bf_buf_addr,
797 hdr = (struct ieee80211_hdr *) skb->data;
798 rxs = IEEE80211_SKB_RXCB(skb);
800 hw = ath_get_virt_hw(sc, hdr);
801 rx_stats = &ds->ds_rxstat;
804 * If we're asked to flush receive queue, directly
805 * chain it back at the queue without processing it.
810 retval = ath9k_rx_skb_preprocess(common, hw, skb, rx_stats,
811 rxs, &decrypt_error);
815 /* Ensure we always have an skb to requeue once we are done
816 * processing the current buffer's skb */
817 requeue_skb = ath_rxbuf_alloc(common, common->rx_bufsize, GFP_ATOMIC);
819 /* If there is no memory we ignore the current RX'd frame,
820 * tell hardware it can give us a new frame using the old
821 * skb and put it at the tail of the sc->rx.rxbuf list for
826 /* Unmap the frame */
827 dma_unmap_single(sc->dev, bf->bf_buf_addr,
831 skb_put(skb, rx_stats->rs_datalen);
833 /* see if any padding is done by the hw and remove it */
834 hdrlen = ieee80211_get_hdrlen_from_skb(skb);
835 fc = hdr->frame_control;
837 /* The MAC header is padded to have 32-bit boundary if the
838 * packet payload is non-zero. The general calculation for
839 * padsize would take into account odd header lengths:
840 * padsize = (4 - hdrlen % 4) % 4; However, since only
841 * even-length headers are used, padding can only be 0 or 2
842 * bytes and we can optimize this a bit. In addition, we must
843 * not try to remove padding from short control frames that do
844 * not have payload. */
845 padsize = hdrlen & 3;
846 if (padsize && hdrlen >= 24) {
847 memmove(skb->data + padsize, skb->data, hdrlen);
848 skb_pull(skb, padsize);
851 keyix = rx_stats->rs_keyix;
853 if (!(keyix == ATH9K_RXKEYIX_INVALID) && !decrypt_error) {
854 rxs->flag |= RX_FLAG_DECRYPTED;
855 } else if (ieee80211_has_protected(fc)
856 && !decrypt_error && skb->len >= hdrlen + 4) {
857 keyix = skb->data[hdrlen + 3] >> 6;
859 if (test_bit(keyix, common->keymap))
860 rxs->flag |= RX_FLAG_DECRYPTED;
862 if (ah->sw_mgmt_crypto &&
863 (rxs->flag & RX_FLAG_DECRYPTED) &&
864 ieee80211_is_mgmt(fc))
865 /* Use software decrypt for management frames. */
866 rxs->flag &= ~RX_FLAG_DECRYPTED;
868 /* We will now give hardware our shiny new allocated skb */
869 bf->bf_mpdu = requeue_skb;
870 bf->bf_buf_addr = dma_map_single(sc->dev, requeue_skb->data,
873 if (unlikely(dma_mapping_error(sc->dev,
875 dev_kfree_skb_any(requeue_skb);
877 ath_print(common, ATH_DBG_FATAL,
878 "dma_mapping_error() on RX\n");
879 ath_rx_send_to_mac80211(hw, sc, skb, rxs);
882 bf->bf_dmacontext = bf->bf_buf_addr;
885 * change the default rx antenna if rx diversity chooses the
886 * other antenna 3 times in a row.
888 if (sc->rx.defant != ds->ds_rxstat.rs_antenna) {
889 if (++sc->rx.rxotherant >= 3)
890 ath_setdefantenna(sc, rx_stats->rs_antenna);
892 sc->rx.rxotherant = 0;
895 if (unlikely(sc->sc_flags & (SC_OP_WAIT_FOR_BEACON |
897 SC_OP_WAIT_FOR_PSPOLL_DATA)))
900 ath_rx_send_to_mac80211(hw, sc, skb, rxs);
903 list_move_tail(&bf->list, &sc->rx.rxbuf);
904 ath_rx_buf_link(sc, bf);
907 spin_unlock_bh(&sc->rx.rxbuflock);