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 if (rx_stats->rs_more) {
111 * Frame spans multiple descriptors; this cannot happen yet
112 * as we don't support jumbograms. If not in monitor mode,
113 * discard the frame. Enable this if you want to see
114 * error frames in Monitor mode.
116 if (ah->opmode != NL80211_IFTYPE_MONITOR)
118 } else if (rx_stats->rs_status != 0) {
119 if (rx_stats->rs_status & ATH9K_RXERR_CRC)
120 rxs->flag |= RX_FLAG_FAILED_FCS_CRC;
121 if (rx_stats->rs_status & ATH9K_RXERR_PHY)
124 if (rx_stats->rs_status & ATH9K_RXERR_DECRYPT) {
125 *decrypt_error = true;
126 } else if (rx_stats->rs_status & ATH9K_RXERR_MIC) {
127 if (ieee80211_is_ctl(fc))
129 * Sometimes, we get invalid
130 * MIC failures on valid control frames.
131 * Remove these mic errors.
133 rx_stats->rs_status &= ~ATH9K_RXERR_MIC;
135 rxs->flag |= RX_FLAG_MMIC_ERROR;
138 * Reject error frames with the exception of
139 * decryption and MIC failures. For monitor mode,
140 * we also ignore the CRC error.
142 if (ah->opmode == NL80211_IFTYPE_MONITOR) {
143 if (rx_stats->rs_status &
144 ~(ATH9K_RXERR_DECRYPT | ATH9K_RXERR_MIC |
148 if (rx_stats->rs_status &
149 ~(ATH9K_RXERR_DECRYPT | ATH9K_RXERR_MIC)) {
157 static u8 ath9k_process_rate(struct ath_common *common,
158 struct ieee80211_hw *hw,
159 struct ath_rx_status *rx_stats,
160 struct ieee80211_rx_status *rxs,
163 struct ieee80211_supported_band *sband;
164 enum ieee80211_band band;
167 band = hw->conf.channel->band;
168 sband = hw->wiphy->bands[band];
170 if (rx_stats->rs_rate & 0x80) {
172 rxs->flag |= RX_FLAG_HT;
173 if (rx_stats->rs_flags & ATH9K_RX_2040)
174 rxs->flag |= RX_FLAG_40MHZ;
175 if (rx_stats->rs_flags & ATH9K_RX_GI)
176 rxs->flag |= RX_FLAG_SHORT_GI;
177 return rx_stats->rs_rate & 0x7f;
180 for (i = 0; i < sband->n_bitrates; i++) {
181 if (sband->bitrates[i].hw_value == rx_stats->rs_rate)
183 if (sband->bitrates[i].hw_value_short == rx_stats->rs_rate) {
184 rxs->flag |= RX_FLAG_SHORTPRE;
189 /* No valid hardware bitrate found -- we should not get here */
190 ath_print(common, ATH_DBG_XMIT, "unsupported hw bitrate detected "
191 "0x%02x using 1 Mbit\n", rx_stats->rs_rate);
192 if ((common->debug_mask & ATH_DBG_XMIT))
193 print_hex_dump_bytes("", DUMP_PREFIX_NONE, skb->data, skb->len);
199 * Theory for reporting quality:
201 * At a hardware RSSI of 45 you will be able to use MCS 7 reliably.
202 * At a hardware RSSI of 45 you will be able to use MCS 15 reliably.
203 * At a hardware RSSI of 35 you should be able use 54 Mbps reliably.
205 * MCS 7 is the highets MCS index usable by a 1-stream device.
206 * MCS 15 is the highest MCS index usable by a 2-stream device.
208 * All ath9k devices are either 1-stream or 2-stream.
210 * How many bars you see is derived from the qual reporting.
212 * A more elaborate scheme can be used here but it requires tables
213 * of SNR/throughput for each possible mode used. For the MCS table
214 * you can refer to the wireless wiki:
216 * http://wireless.kernel.org/en/developers/Documentation/ieee80211/802.11n
219 static int ath9k_compute_qual(struct ieee80211_hw *hw,
220 struct ath_rx_status *rx_stats)
224 if (conf_is_ht(&hw->conf))
225 qual = rx_stats->rs_rssi * 100 / 45;
227 qual = rx_stats->rs_rssi * 100 / 35;
230 * rssi can be more than 45 though, anything above that
231 * should be considered at 100%
239 static void ath9k_process_rssi(struct ath_common *common,
240 struct ieee80211_hw *hw,
242 struct ath_rx_status *rx_stats)
244 struct ath_hw *ah = common->ah;
245 struct ieee80211_sta *sta;
246 struct ieee80211_hdr *hdr;
248 int last_rssi = ATH_RSSI_DUMMY_MARKER;
251 hdr = (struct ieee80211_hdr *)skb->data;
252 fc = hdr->frame_control;
255 /* XXX: use ieee80211_find_sta! */
256 sta = ieee80211_find_sta_by_hw(hw, hdr->addr2);
258 an = (struct ath_node *) sta->drv_priv;
259 if (rx_stats->rs_rssi != ATH9K_RSSI_BAD &&
260 !rx_stats->rs_moreaggr)
261 ATH_RSSI_LPF(an->last_rssi, rx_stats->rs_rssi);
262 last_rssi = an->last_rssi;
266 if (likely(last_rssi != ATH_RSSI_DUMMY_MARKER))
267 rx_stats->rs_rssi = ATH_EP_RND(last_rssi,
268 ATH_RSSI_EP_MULTIPLIER);
269 if (rx_stats->rs_rssi < 0)
270 rx_stats->rs_rssi = 0;
271 else if (rx_stats->rs_rssi > 127)
272 rx_stats->rs_rssi = 127;
274 /* Update Beacon RSSI, this is used by ANI. */
275 if (ieee80211_is_beacon(fc))
276 ah->stats.avgbrssi = rx_stats->rs_rssi;
280 * For Decrypt or Demic errors, we only mark packet status here and always push
281 * up the frame up to let mac80211 handle the actual error case, be it no
282 * decryption key or real decryption error. This let us keep statistics there.
284 static int ath_rx_prepare(struct ath_common *common,
285 struct ieee80211_hw *hw,
286 struct sk_buff *skb, struct ath_rx_status *rx_stats,
287 struct ieee80211_rx_status *rx_status,
290 struct ath_hw *ah = common->ah;
292 if (!ath9k_rx_accept(common, skb, rx_status, rx_stats, decrypt_error))
295 ath9k_process_rssi(common, hw, skb, rx_stats);
297 rx_status->rate_idx = ath9k_process_rate(common, hw,
298 rx_stats, rx_status, skb);
299 rx_status->mactime = ath9k_hw_extend_tsf(ah, rx_stats->rs_tstamp);
300 rx_status->band = hw->conf.channel->band;
301 rx_status->freq = hw->conf.channel->center_freq;
302 rx_status->noise = common->ani.noise_floor;
303 rx_status->signal = ATH_DEFAULT_NOISE_FLOOR + rx_stats->rs_rssi;
304 rx_status->antenna = rx_stats->rs_antenna;
305 rx_status->qual = ath9k_compute_qual(hw, rx_stats);
306 rx_status->flag |= RX_FLAG_TSFT;
313 static void ath_opmode_init(struct ath_softc *sc)
315 struct ath_hw *ah = sc->sc_ah;
316 struct ath_common *common = ath9k_hw_common(ah);
320 /* configure rx filter */
321 rfilt = ath_calcrxfilter(sc);
322 ath9k_hw_setrxfilter(ah, rfilt);
324 /* configure bssid mask */
325 if (ah->caps.hw_caps & ATH9K_HW_CAP_BSSIDMASK)
326 ath_hw_setbssidmask(common);
328 /* configure operational mode */
329 ath9k_hw_setopmode(ah);
331 /* Handle any link-level address change. */
332 ath9k_hw_setmac(ah, common->macaddr);
334 /* calculate and install multicast filter */
335 mfilt[0] = mfilt[1] = ~0;
336 ath9k_hw_setmcastfilter(ah, mfilt[0], mfilt[1]);
339 int ath_rx_init(struct ath_softc *sc, int nbufs)
341 struct ath_common *common = ath9k_hw_common(sc->sc_ah);
346 spin_lock_init(&sc->rx.rxflushlock);
347 sc->sc_flags &= ~SC_OP_RXFLUSH;
348 spin_lock_init(&sc->rx.rxbuflock);
350 common->rx_bufsize = roundup(IEEE80211_MAX_MPDU_LEN,
351 min(common->cachelsz, (u16)64));
353 ath_print(common, ATH_DBG_CONFIG, "cachelsz %u rxbufsize %u\n",
354 common->cachelsz, common->rx_bufsize);
356 /* Initialize rx descriptors */
358 error = ath_descdma_setup(sc, &sc->rx.rxdma, &sc->rx.rxbuf,
361 ath_print(common, ATH_DBG_FATAL,
362 "failed to allocate rx descriptors: %d\n", error);
366 list_for_each_entry(bf, &sc->rx.rxbuf, list) {
367 skb = ath_rxbuf_alloc(common, common->rx_bufsize, GFP_KERNEL);
374 bf->bf_buf_addr = dma_map_single(sc->dev, skb->data,
377 if (unlikely(dma_mapping_error(sc->dev,
379 dev_kfree_skb_any(skb);
381 ath_print(common, ATH_DBG_FATAL,
382 "dma_mapping_error() on RX init\n");
386 bf->bf_dmacontext = bf->bf_buf_addr;
388 sc->rx.rxlink = NULL;
397 void ath_rx_cleanup(struct ath_softc *sc)
399 struct ath_hw *ah = sc->sc_ah;
400 struct ath_common *common = ath9k_hw_common(ah);
404 list_for_each_entry(bf, &sc->rx.rxbuf, list) {
407 dma_unmap_single(sc->dev, bf->bf_buf_addr,
408 common->rx_bufsize, DMA_FROM_DEVICE);
413 if (sc->rx.rxdma.dd_desc_len != 0)
414 ath_descdma_cleanup(sc, &sc->rx.rxdma, &sc->rx.rxbuf);
418 * Calculate the receive filter according to the
419 * operating mode and state:
421 * o always accept unicast, broadcast, and multicast traffic
422 * o maintain current state of phy error reception (the hal
423 * may enable phy error frames for noise immunity work)
424 * o probe request frames are accepted only when operating in
425 * hostap, adhoc, or monitor modes
426 * o enable promiscuous mode according to the interface state
428 * - when operating in adhoc mode so the 802.11 layer creates
429 * node table entries for peers,
430 * - when operating in station mode for collecting rssi data when
431 * the station is otherwise quiet, or
432 * - when operating as a repeater so we see repeater-sta beacons
436 u32 ath_calcrxfilter(struct ath_softc *sc)
438 #define RX_FILTER_PRESERVE (ATH9K_RX_FILTER_PHYERR | ATH9K_RX_FILTER_PHYRADAR)
442 rfilt = (ath9k_hw_getrxfilter(sc->sc_ah) & RX_FILTER_PRESERVE)
443 | ATH9K_RX_FILTER_UCAST | ATH9K_RX_FILTER_BCAST
444 | ATH9K_RX_FILTER_MCAST;
446 /* If not a STA, enable processing of Probe Requests */
447 if (sc->sc_ah->opmode != NL80211_IFTYPE_STATION)
448 rfilt |= ATH9K_RX_FILTER_PROBEREQ;
451 * Set promiscuous mode when FIF_PROMISC_IN_BSS is enabled for station
452 * mode interface or when in monitor mode. AP mode does not need this
453 * since it receives all in-BSS frames anyway.
455 if (((sc->sc_ah->opmode != NL80211_IFTYPE_AP) &&
456 (sc->rx.rxfilter & FIF_PROMISC_IN_BSS)) ||
457 (sc->sc_ah->opmode == NL80211_IFTYPE_MONITOR))
458 rfilt |= ATH9K_RX_FILTER_PROM;
460 if (sc->rx.rxfilter & FIF_CONTROL)
461 rfilt |= ATH9K_RX_FILTER_CONTROL;
463 if ((sc->sc_ah->opmode == NL80211_IFTYPE_STATION) &&
464 !(sc->rx.rxfilter & FIF_BCN_PRBRESP_PROMISC))
465 rfilt |= ATH9K_RX_FILTER_MYBEACON;
467 rfilt |= ATH9K_RX_FILTER_BEACON;
469 if ((AR_SREV_9280_10_OR_LATER(sc->sc_ah) ||
470 AR_SREV_9285_10_OR_LATER(sc->sc_ah)) &&
471 (sc->sc_ah->opmode == NL80211_IFTYPE_AP) &&
472 (sc->rx.rxfilter & FIF_PSPOLL))
473 rfilt |= ATH9K_RX_FILTER_PSPOLL;
475 if (conf_is_ht(&sc->hw->conf))
476 rfilt |= ATH9K_RX_FILTER_COMP_BAR;
478 if (sc->sec_wiphy || (sc->rx.rxfilter & FIF_OTHER_BSS)) {
479 /* TODO: only needed if more than one BSSID is in use in
480 * station/adhoc mode */
481 /* The following may also be needed for other older chips */
482 if (sc->sc_ah->hw_version.macVersion == AR_SREV_VERSION_9160)
483 rfilt |= ATH9K_RX_FILTER_PROM;
484 rfilt |= ATH9K_RX_FILTER_MCAST_BCAST_ALL;
489 #undef RX_FILTER_PRESERVE
492 int ath_startrecv(struct ath_softc *sc)
494 struct ath_hw *ah = sc->sc_ah;
495 struct ath_buf *bf, *tbf;
497 spin_lock_bh(&sc->rx.rxbuflock);
498 if (list_empty(&sc->rx.rxbuf))
501 sc->rx.rxlink = NULL;
502 list_for_each_entry_safe(bf, tbf, &sc->rx.rxbuf, list) {
503 ath_rx_buf_link(sc, bf);
506 /* We could have deleted elements so the list may be empty now */
507 if (list_empty(&sc->rx.rxbuf))
510 bf = list_first_entry(&sc->rx.rxbuf, struct ath_buf, list);
511 ath9k_hw_putrxbuf(ah, bf->bf_daddr);
515 spin_unlock_bh(&sc->rx.rxbuflock);
517 ath9k_hw_startpcureceive(ah);
522 bool ath_stoprecv(struct ath_softc *sc)
524 struct ath_hw *ah = sc->sc_ah;
527 ath9k_hw_stoppcurecv(ah);
528 ath9k_hw_setrxfilter(ah, 0);
529 stopped = ath9k_hw_stopdmarecv(ah);
530 sc->rx.rxlink = NULL;
535 void ath_flushrecv(struct ath_softc *sc)
537 spin_lock_bh(&sc->rx.rxflushlock);
538 sc->sc_flags |= SC_OP_RXFLUSH;
539 ath_rx_tasklet(sc, 1);
540 sc->sc_flags &= ~SC_OP_RXFLUSH;
541 spin_unlock_bh(&sc->rx.rxflushlock);
544 static bool ath_beacon_dtim_pending_cab(struct sk_buff *skb)
546 /* Check whether the Beacon frame has DTIM indicating buffered bc/mc */
547 struct ieee80211_mgmt *mgmt;
548 u8 *pos, *end, id, elen;
549 struct ieee80211_tim_ie *tim;
551 mgmt = (struct ieee80211_mgmt *)skb->data;
552 pos = mgmt->u.beacon.variable;
553 end = skb->data + skb->len;
555 while (pos + 2 < end) {
558 if (pos + elen > end)
561 if (id == WLAN_EID_TIM) {
562 if (elen < sizeof(*tim))
564 tim = (struct ieee80211_tim_ie *) pos;
565 if (tim->dtim_count != 0)
567 return tim->bitmap_ctrl & 0x01;
576 static void ath_rx_ps_beacon(struct ath_softc *sc, struct sk_buff *skb)
578 struct ieee80211_mgmt *mgmt;
579 struct ath_common *common = ath9k_hw_common(sc->sc_ah);
581 if (skb->len < 24 + 8 + 2 + 2)
584 mgmt = (struct ieee80211_mgmt *)skb->data;
585 if (memcmp(common->curbssid, mgmt->bssid, ETH_ALEN) != 0)
586 return; /* not from our current AP */
588 sc->sc_flags &= ~SC_OP_WAIT_FOR_BEACON;
590 if (sc->sc_flags & SC_OP_BEACON_SYNC) {
591 sc->sc_flags &= ~SC_OP_BEACON_SYNC;
592 ath_print(common, ATH_DBG_PS,
593 "Reconfigure Beacon timers based on "
594 "timestamp from the AP\n");
595 ath_beacon_config(sc, NULL);
598 if (ath_beacon_dtim_pending_cab(skb)) {
600 * Remain awake waiting for buffered broadcast/multicast
601 * frames. If the last broadcast/multicast frame is not
602 * received properly, the next beacon frame will work as
603 * a backup trigger for returning into NETWORK SLEEP state,
604 * so we are waiting for it as well.
606 ath_print(common, ATH_DBG_PS, "Received DTIM beacon indicating "
607 "buffered broadcast/multicast frame(s)\n");
608 sc->sc_flags |= SC_OP_WAIT_FOR_CAB | SC_OP_WAIT_FOR_BEACON;
612 if (sc->sc_flags & SC_OP_WAIT_FOR_CAB) {
614 * This can happen if a broadcast frame is dropped or the AP
615 * fails to send a frame indicating that all CAB frames have
618 sc->sc_flags &= ~SC_OP_WAIT_FOR_CAB;
619 ath_print(common, ATH_DBG_PS,
620 "PS wait for CAB frames timed out\n");
624 static void ath_rx_ps(struct ath_softc *sc, struct sk_buff *skb)
626 struct ieee80211_hdr *hdr;
627 struct ath_common *common = ath9k_hw_common(sc->sc_ah);
629 hdr = (struct ieee80211_hdr *)skb->data;
631 /* Process Beacon and CAB receive in PS state */
632 if ((sc->sc_flags & SC_OP_WAIT_FOR_BEACON) &&
633 ieee80211_is_beacon(hdr->frame_control))
634 ath_rx_ps_beacon(sc, skb);
635 else if ((sc->sc_flags & SC_OP_WAIT_FOR_CAB) &&
636 (ieee80211_is_data(hdr->frame_control) ||
637 ieee80211_is_action(hdr->frame_control)) &&
638 is_multicast_ether_addr(hdr->addr1) &&
639 !ieee80211_has_moredata(hdr->frame_control)) {
641 * No more broadcast/multicast frames to be received at this
644 sc->sc_flags &= ~SC_OP_WAIT_FOR_CAB;
645 ath_print(common, ATH_DBG_PS,
646 "All PS CAB frames received, back to sleep\n");
647 } else if ((sc->sc_flags & SC_OP_WAIT_FOR_PSPOLL_DATA) &&
648 !is_multicast_ether_addr(hdr->addr1) &&
649 !ieee80211_has_morefrags(hdr->frame_control)) {
650 sc->sc_flags &= ~SC_OP_WAIT_FOR_PSPOLL_DATA;
651 ath_print(common, ATH_DBG_PS,
652 "Going back to sleep after having received "
653 "PS-Poll data (0x%x)\n",
654 sc->sc_flags & (SC_OP_WAIT_FOR_BEACON |
656 SC_OP_WAIT_FOR_PSPOLL_DATA |
657 SC_OP_WAIT_FOR_TX_ACK));
661 static void ath_rx_send_to_mac80211(struct ieee80211_hw *hw,
662 struct ath_softc *sc, struct sk_buff *skb,
663 struct ieee80211_rx_status *rxs)
665 struct ieee80211_hdr *hdr;
667 hdr = (struct ieee80211_hdr *)skb->data;
669 /* Send the frame to mac80211 */
670 if (is_multicast_ether_addr(hdr->addr1)) {
673 * Deliver broadcast/multicast frames to all suitable
676 /* TODO: filter based on channel configuration */
677 for (i = 0; i < sc->num_sec_wiphy; i++) {
678 struct ath_wiphy *aphy = sc->sec_wiphy[i];
679 struct sk_buff *nskb;
682 nskb = skb_copy(skb, GFP_ATOMIC);
685 ieee80211_rx(aphy->hw, nskb);
687 ieee80211_rx(sc->hw, skb);
689 /* Deliver unicast frames based on receiver address */
690 ieee80211_rx(hw, skb);
693 int ath_rx_tasklet(struct ath_softc *sc, int flush)
695 #define PA2DESC(_sc, _pa) \
696 ((struct ath_desc *)((caddr_t)(_sc)->rx.rxdma.dd_desc + \
697 ((_pa) - (_sc)->rx.rxdma.dd_desc_paddr)))
701 struct ath_rx_status *rx_stats;
702 struct sk_buff *skb = NULL, *requeue_skb;
703 struct ieee80211_rx_status *rxs;
704 struct ath_hw *ah = sc->sc_ah;
705 struct ath_common *common = ath9k_hw_common(ah);
707 * The hw can techncically differ from common->hw when using ath9k
708 * virtual wiphy so to account for that we iterate over the active
709 * wiphys and find the appropriate wiphy and therefore hw.
711 struct ieee80211_hw *hw = NULL;
712 struct ieee80211_hdr *hdr;
713 int hdrlen, padsize, retval;
714 bool decrypt_error = false;
718 spin_lock_bh(&sc->rx.rxbuflock);
721 /* If handling rx interrupt and flush is in progress => exit */
722 if ((sc->sc_flags & SC_OP_RXFLUSH) && (flush == 0))
725 if (list_empty(&sc->rx.rxbuf)) {
726 sc->rx.rxlink = NULL;
730 bf = list_first_entry(&sc->rx.rxbuf, struct ath_buf, list);
734 * Must provide the virtual address of the current
735 * descriptor, the physical address, and the virtual
736 * address of the next descriptor in the h/w chain.
737 * This allows the HAL to look ahead to see if the
738 * hardware is done with a descriptor by checking the
739 * done bit in the following descriptor and the address
740 * of the current descriptor the DMA engine is working
741 * on. All this is necessary because of our use of
742 * a self-linked list to avoid rx overruns.
744 retval = ath9k_hw_rxprocdesc(ah, ds,
746 PA2DESC(sc, ds->ds_link),
748 if (retval == -EINPROGRESS) {
750 struct ath_desc *tds;
752 if (list_is_last(&bf->list, &sc->rx.rxbuf)) {
753 sc->rx.rxlink = NULL;
757 tbf = list_entry(bf->list.next, struct ath_buf, list);
760 * On some hardware the descriptor status words could
761 * get corrupted, including the done bit. Because of
762 * this, check if the next descriptor's done bit is
765 * If the next descriptor's done bit is set, the current
766 * descriptor has been corrupted. Force s/w to discard
767 * this descriptor and continue...
771 retval = ath9k_hw_rxprocdesc(ah, tds, tbf->bf_daddr,
772 PA2DESC(sc, tds->ds_link), 0);
773 if (retval == -EINPROGRESS) {
783 * Synchronize the DMA transfer with CPU before
784 * 1. accessing the frame
785 * 2. requeueing the same buffer to h/w
787 dma_sync_single_for_cpu(sc->dev, bf->bf_buf_addr,
791 hdr = (struct ieee80211_hdr *) skb->data;
792 rxs = IEEE80211_SKB_RXCB(skb);
794 hw = ath_get_virt_hw(sc, hdr);
795 rx_stats = &ds->ds_rxstat;
798 * If we're asked to flush receive queue, directly
799 * chain it back at the queue without processing it.
804 /* The status portion of the descriptor could get corrupted. */
805 if (common->rx_bufsize < rx_stats->rs_datalen)
808 if (!ath_rx_prepare(common, hw, skb, rx_stats,
809 rxs, &decrypt_error))
812 /* Ensure we always have an skb to requeue once we are done
813 * processing the current buffer's skb */
814 requeue_skb = ath_rxbuf_alloc(common, common->rx_bufsize, GFP_ATOMIC);
816 /* If there is no memory we ignore the current RX'd frame,
817 * tell hardware it can give us a new frame using the old
818 * skb and put it at the tail of the sc->rx.rxbuf list for
823 /* Unmap the frame */
824 dma_unmap_single(sc->dev, bf->bf_buf_addr,
828 skb_put(skb, rx_stats->rs_datalen);
830 /* see if any padding is done by the hw and remove it */
831 hdrlen = ieee80211_get_hdrlen_from_skb(skb);
832 fc = hdr->frame_control;
834 /* The MAC header is padded to have 32-bit boundary if the
835 * packet payload is non-zero. The general calculation for
836 * padsize would take into account odd header lengths:
837 * padsize = (4 - hdrlen % 4) % 4; However, since only
838 * even-length headers are used, padding can only be 0 or 2
839 * bytes and we can optimize this a bit. In addition, we must
840 * not try to remove padding from short control frames that do
841 * not have payload. */
842 padsize = hdrlen & 3;
843 if (padsize && hdrlen >= 24) {
844 memmove(skb->data + padsize, skb->data, hdrlen);
845 skb_pull(skb, padsize);
848 keyix = rx_stats->rs_keyix;
850 if (!(keyix == ATH9K_RXKEYIX_INVALID) && !decrypt_error) {
851 rxs->flag |= RX_FLAG_DECRYPTED;
852 } else if (ieee80211_has_protected(fc)
853 && !decrypt_error && skb->len >= hdrlen + 4) {
854 keyix = skb->data[hdrlen + 3] >> 6;
856 if (test_bit(keyix, sc->keymap))
857 rxs->flag |= RX_FLAG_DECRYPTED;
859 if (ah->sw_mgmt_crypto &&
860 (rxs->flag & RX_FLAG_DECRYPTED) &&
861 ieee80211_is_mgmt(fc))
862 /* Use software decrypt for management frames. */
863 rxs->flag &= ~RX_FLAG_DECRYPTED;
865 /* We will now give hardware our shiny new allocated skb */
866 bf->bf_mpdu = requeue_skb;
867 bf->bf_buf_addr = dma_map_single(sc->dev, requeue_skb->data,
870 if (unlikely(dma_mapping_error(sc->dev,
872 dev_kfree_skb_any(requeue_skb);
874 ath_print(common, ATH_DBG_FATAL,
875 "dma_mapping_error() on RX\n");
876 ath_rx_send_to_mac80211(hw, sc, skb, rxs);
879 bf->bf_dmacontext = bf->bf_buf_addr;
882 * change the default rx antenna if rx diversity chooses the
883 * other antenna 3 times in a row.
885 if (sc->rx.defant != ds->ds_rxstat.rs_antenna) {
886 if (++sc->rx.rxotherant >= 3)
887 ath_setdefantenna(sc, rx_stats->rs_antenna);
889 sc->rx.rxotherant = 0;
892 if (unlikely(sc->sc_flags & (SC_OP_WAIT_FOR_BEACON |
894 SC_OP_WAIT_FOR_PSPOLL_DATA)))
897 ath_rx_send_to_mac80211(hw, sc, skb, rxs);
900 list_move_tail(&bf->list, &sc->rx.rxbuf);
901 ath_rx_buf_link(sc, bf);
904 spin_unlock_bh(&sc->rx.rxbuflock);