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;
57 ds->ds_link = 0; /* link to null */
58 ds->ds_data = bf->bf_buf_addr;
60 /* virtual addr of the beginning of the buffer. */
63 ds->ds_vdata = skb->data;
65 /* setup rx descriptors. The rx.bufsize here tells the harware
66 * how much data it can DMA to us and that we are prepared
68 ath9k_hw_setuprxdesc(ah, ds,
72 if (sc->rx.rxlink == NULL)
73 ath9k_hw_putrxbuf(ah, bf->bf_daddr);
75 *sc->rx.rxlink = bf->bf_daddr;
77 sc->rx.rxlink = &ds->ds_link;
81 static void ath_setdefantenna(struct ath_softc *sc, u32 antenna)
83 /* XXX block beacon interrupts */
84 ath9k_hw_setantenna(sc->sc_ah, antenna);
85 sc->rx.defant = antenna;
86 sc->rx.rxotherant = 0;
89 /* Assumes you've already done the endian to CPU conversion */
90 static bool ath9k_rx_accept(struct ath_common *common,
92 struct ieee80211_rx_status *rxs,
93 struct ath_rx_status *rx_stats,
96 struct ath_hw *ah = common->ah;
97 struct ieee80211_hdr *hdr;
100 hdr = (struct ieee80211_hdr *) skb->data;
101 fc = hdr->frame_control;
103 if (rx_stats->rs_more) {
105 * Frame spans multiple descriptors; this cannot happen yet
106 * as we don't support jumbograms. If not in monitor mode,
107 * discard the frame. Enable this if you want to see
108 * error frames in Monitor mode.
110 if (ah->opmode != NL80211_IFTYPE_MONITOR)
112 } else if (rx_stats->rs_status != 0) {
113 if (rx_stats->rs_status & ATH9K_RXERR_CRC)
114 rxs->flag |= RX_FLAG_FAILED_FCS_CRC;
115 if (rx_stats->rs_status & ATH9K_RXERR_PHY)
118 if (rx_stats->rs_status & ATH9K_RXERR_DECRYPT) {
119 *decrypt_error = true;
120 } else if (rx_stats->rs_status & ATH9K_RXERR_MIC) {
121 if (ieee80211_is_ctl(fc))
123 * Sometimes, we get invalid
124 * MIC failures on valid control frames.
125 * Remove these mic errors.
127 rx_stats->rs_status &= ~ATH9K_RXERR_MIC;
129 rxs->flag |= RX_FLAG_MMIC_ERROR;
132 * Reject error frames with the exception of
133 * decryption and MIC failures. For monitor mode,
134 * we also ignore the CRC error.
136 if (ah->opmode == NL80211_IFTYPE_MONITOR) {
137 if (rx_stats->rs_status &
138 ~(ATH9K_RXERR_DECRYPT | ATH9K_RXERR_MIC |
142 if (rx_stats->rs_status &
143 ~(ATH9K_RXERR_DECRYPT | ATH9K_RXERR_MIC)) {
152 * For Decrypt or Demic errors, we only mark packet status here and always push
153 * up the frame up to let mac80211 handle the actual error case, be it no
154 * decryption key or real decryption error. This let us keep statistics there.
156 static int ath_rx_prepare(struct ath_common *common,
157 struct ieee80211_hw *hw,
158 struct sk_buff *skb, struct ath_rx_status *rx_stats,
159 struct ieee80211_rx_status *rx_status,
162 struct ath_hw *ah = common->ah;
163 struct ieee80211_hdr *hdr;
166 struct ieee80211_sta *sta;
168 int last_rssi = ATH_RSSI_DUMMY_MARKER;
170 hdr = (struct ieee80211_hdr *)skb->data;
171 fc = hdr->frame_control;
172 memset(rx_status, 0, sizeof(struct ieee80211_rx_status));
174 if (!ath9k_rx_accept(common, skb, rx_status, rx_stats, decrypt_error))
177 ratecode = rx_stats->rs_rate;
179 if (ratecode & 0x80) {
181 rx_status->flag |= RX_FLAG_HT;
182 if (rx_stats->rs_flags & ATH9K_RX_2040)
183 rx_status->flag |= RX_FLAG_40MHZ;
184 if (rx_stats->rs_flags & ATH9K_RX_GI)
185 rx_status->flag |= RX_FLAG_SHORT_GI;
186 rx_status->rate_idx = ratecode & 0x7f;
188 struct ieee80211_supported_band *sband;
190 enum ieee80211_band band;
192 band = hw->conf.channel->band;
193 sband = hw->wiphy->bands[band];
195 for (i = 0; i < sband->n_bitrates; i++) {
196 if (sband->bitrates[i].hw_value == rx_stats->rs_rate) {
197 rx_status->rate_idx = i;
200 if (sband->bitrates[i].hw_value_short ==
202 rx_status->rate_idx = i;
203 rx_status->flag |= RX_FLAG_SHORTPRE;
210 /* XXX: use ieee80211_find_sta! */
211 sta = ieee80211_find_sta_by_hw(hw, hdr->addr2);
213 an = (struct ath_node *) sta->drv_priv;
214 if (rx_stats->rs_rssi != ATH9K_RSSI_BAD &&
215 !rx_stats->rs_moreaggr)
216 ATH_RSSI_LPF(an->last_rssi, rx_stats->rs_rssi);
217 last_rssi = an->last_rssi;
221 if (likely(last_rssi != ATH_RSSI_DUMMY_MARKER))
222 rx_stats->rs_rssi = ATH_EP_RND(last_rssi,
223 ATH_RSSI_EP_MULTIPLIER);
224 if (rx_stats->rs_rssi < 0)
225 rx_stats->rs_rssi = 0;
226 else if (rx_stats->rs_rssi > 127)
227 rx_stats->rs_rssi = 127;
229 /* Update Beacon RSSI, this is used by ANI. */
230 if (ieee80211_is_beacon(fc))
231 ah->stats.avgbrssi = rx_stats->rs_rssi;
233 rx_status->mactime = ath9k_hw_extend_tsf(ah, rx_stats->rs_tstamp);
234 rx_status->band = hw->conf.channel->band;
235 rx_status->freq = hw->conf.channel->center_freq;
236 rx_status->noise = common->ani.noise_floor;
237 rx_status->signal = ATH_DEFAULT_NOISE_FLOOR + rx_stats->rs_rssi;
238 rx_status->antenna = rx_stats->rs_antenna;
241 * Theory for reporting quality:
243 * At a hardware RSSI of 45 you will be able to use MCS 7 reliably.
244 * At a hardware RSSI of 45 you will be able to use MCS 15 reliably.
245 * At a hardware RSSI of 35 you should be able use 54 Mbps reliably.
247 * MCS 7 is the highets MCS index usable by a 1-stream device.
248 * MCS 15 is the highest MCS index usable by a 2-stream device.
250 * All ath9k devices are either 1-stream or 2-stream.
252 * How many bars you see is derived from the qual reporting.
254 * A more elaborate scheme can be used here but it requires tables
255 * of SNR/throughput for each possible mode used. For the MCS table
256 * you can refer to the wireless wiki:
258 * http://wireless.kernel.org/en/developers/Documentation/ieee80211/802.11n
261 if (conf_is_ht(&hw->conf))
262 rx_status->qual = rx_stats->rs_rssi * 100 / 45;
264 rx_status->qual = rx_stats->rs_rssi * 100 / 35;
266 /* rssi can be more than 45 though, anything above that
267 * should be considered at 100% */
268 if (rx_status->qual > 100)
269 rx_status->qual = 100;
271 rx_status->flag |= RX_FLAG_TSFT;
278 static void ath_opmode_init(struct ath_softc *sc)
280 struct ath_hw *ah = sc->sc_ah;
281 struct ath_common *common = ath9k_hw_common(ah);
285 /* configure rx filter */
286 rfilt = ath_calcrxfilter(sc);
287 ath9k_hw_setrxfilter(ah, rfilt);
289 /* configure bssid mask */
290 if (ah->caps.hw_caps & ATH9K_HW_CAP_BSSIDMASK)
291 ath_hw_setbssidmask(common);
293 /* configure operational mode */
294 ath9k_hw_setopmode(ah);
296 /* Handle any link-level address change. */
297 ath9k_hw_setmac(ah, common->macaddr);
299 /* calculate and install multicast filter */
300 mfilt[0] = mfilt[1] = ~0;
301 ath9k_hw_setmcastfilter(ah, mfilt[0], mfilt[1]);
304 int ath_rx_init(struct ath_softc *sc, int nbufs)
306 struct ath_common *common = ath9k_hw_common(sc->sc_ah);
311 spin_lock_init(&sc->rx.rxflushlock);
312 sc->sc_flags &= ~SC_OP_RXFLUSH;
313 spin_lock_init(&sc->rx.rxbuflock);
315 sc->rx.bufsize = roundup(IEEE80211_MAX_MPDU_LEN,
316 min(common->cachelsz, (u16)64));
318 ath_print(common, ATH_DBG_CONFIG, "cachelsz %u rxbufsize %u\n",
319 common->cachelsz, sc->rx.bufsize);
321 /* Initialize rx descriptors */
323 error = ath_descdma_setup(sc, &sc->rx.rxdma, &sc->rx.rxbuf,
326 ath_print(common, ATH_DBG_FATAL,
327 "failed to allocate rx descriptors: %d\n", error);
331 list_for_each_entry(bf, &sc->rx.rxbuf, list) {
332 skb = ath_rxbuf_alloc(common, sc->rx.bufsize, GFP_KERNEL);
339 bf->bf_buf_addr = dma_map_single(sc->dev, skb->data,
342 if (unlikely(dma_mapping_error(sc->dev,
344 dev_kfree_skb_any(skb);
346 ath_print(common, ATH_DBG_FATAL,
347 "dma_mapping_error() on RX init\n");
351 bf->bf_dmacontext = bf->bf_buf_addr;
353 sc->rx.rxlink = NULL;
362 void ath_rx_cleanup(struct ath_softc *sc)
367 list_for_each_entry(bf, &sc->rx.rxbuf, list) {
370 dma_unmap_single(sc->dev, bf->bf_buf_addr,
371 sc->rx.bufsize, DMA_FROM_DEVICE);
376 if (sc->rx.rxdma.dd_desc_len != 0)
377 ath_descdma_cleanup(sc, &sc->rx.rxdma, &sc->rx.rxbuf);
381 * Calculate the receive filter according to the
382 * operating mode and state:
384 * o always accept unicast, broadcast, and multicast traffic
385 * o maintain current state of phy error reception (the hal
386 * may enable phy error frames for noise immunity work)
387 * o probe request frames are accepted only when operating in
388 * hostap, adhoc, or monitor modes
389 * o enable promiscuous mode according to the interface state
391 * - when operating in adhoc mode so the 802.11 layer creates
392 * node table entries for peers,
393 * - when operating in station mode for collecting rssi data when
394 * the station is otherwise quiet, or
395 * - when operating as a repeater so we see repeater-sta beacons
399 u32 ath_calcrxfilter(struct ath_softc *sc)
401 #define RX_FILTER_PRESERVE (ATH9K_RX_FILTER_PHYERR | ATH9K_RX_FILTER_PHYRADAR)
405 rfilt = (ath9k_hw_getrxfilter(sc->sc_ah) & RX_FILTER_PRESERVE)
406 | ATH9K_RX_FILTER_UCAST | ATH9K_RX_FILTER_BCAST
407 | ATH9K_RX_FILTER_MCAST;
409 /* If not a STA, enable processing of Probe Requests */
410 if (sc->sc_ah->opmode != NL80211_IFTYPE_STATION)
411 rfilt |= ATH9K_RX_FILTER_PROBEREQ;
414 * Set promiscuous mode when FIF_PROMISC_IN_BSS is enabled for station
415 * mode interface or when in monitor mode. AP mode does not need this
416 * since it receives all in-BSS frames anyway.
418 if (((sc->sc_ah->opmode != NL80211_IFTYPE_AP) &&
419 (sc->rx.rxfilter & FIF_PROMISC_IN_BSS)) ||
420 (sc->sc_ah->opmode == NL80211_IFTYPE_MONITOR))
421 rfilt |= ATH9K_RX_FILTER_PROM;
423 if (sc->rx.rxfilter & FIF_CONTROL)
424 rfilt |= ATH9K_RX_FILTER_CONTROL;
426 if ((sc->sc_ah->opmode == NL80211_IFTYPE_STATION) &&
427 !(sc->rx.rxfilter & FIF_BCN_PRBRESP_PROMISC))
428 rfilt |= ATH9K_RX_FILTER_MYBEACON;
430 rfilt |= ATH9K_RX_FILTER_BEACON;
432 if ((AR_SREV_9280_10_OR_LATER(sc->sc_ah) ||
433 AR_SREV_9285_10_OR_LATER(sc->sc_ah)) &&
434 (sc->sc_ah->opmode == NL80211_IFTYPE_AP) &&
435 (sc->rx.rxfilter & FIF_PSPOLL))
436 rfilt |= ATH9K_RX_FILTER_PSPOLL;
438 if (conf_is_ht(&sc->hw->conf))
439 rfilt |= ATH9K_RX_FILTER_COMP_BAR;
441 if (sc->sec_wiphy || (sc->rx.rxfilter & FIF_OTHER_BSS)) {
442 /* TODO: only needed if more than one BSSID is in use in
443 * station/adhoc mode */
444 /* The following may also be needed for other older chips */
445 if (sc->sc_ah->hw_version.macVersion == AR_SREV_VERSION_9160)
446 rfilt |= ATH9K_RX_FILTER_PROM;
447 rfilt |= ATH9K_RX_FILTER_MCAST_BCAST_ALL;
452 #undef RX_FILTER_PRESERVE
455 int ath_startrecv(struct ath_softc *sc)
457 struct ath_hw *ah = sc->sc_ah;
458 struct ath_buf *bf, *tbf;
460 spin_lock_bh(&sc->rx.rxbuflock);
461 if (list_empty(&sc->rx.rxbuf))
464 sc->rx.rxlink = NULL;
465 list_for_each_entry_safe(bf, tbf, &sc->rx.rxbuf, list) {
466 ath_rx_buf_link(sc, bf);
469 /* We could have deleted elements so the list may be empty now */
470 if (list_empty(&sc->rx.rxbuf))
473 bf = list_first_entry(&sc->rx.rxbuf, struct ath_buf, list);
474 ath9k_hw_putrxbuf(ah, bf->bf_daddr);
478 spin_unlock_bh(&sc->rx.rxbuflock);
480 ath9k_hw_startpcureceive(ah);
485 bool ath_stoprecv(struct ath_softc *sc)
487 struct ath_hw *ah = sc->sc_ah;
490 ath9k_hw_stoppcurecv(ah);
491 ath9k_hw_setrxfilter(ah, 0);
492 stopped = ath9k_hw_stopdmarecv(ah);
493 sc->rx.rxlink = NULL;
498 void ath_flushrecv(struct ath_softc *sc)
500 spin_lock_bh(&sc->rx.rxflushlock);
501 sc->sc_flags |= SC_OP_RXFLUSH;
502 ath_rx_tasklet(sc, 1);
503 sc->sc_flags &= ~SC_OP_RXFLUSH;
504 spin_unlock_bh(&sc->rx.rxflushlock);
507 static bool ath_beacon_dtim_pending_cab(struct sk_buff *skb)
509 /* Check whether the Beacon frame has DTIM indicating buffered bc/mc */
510 struct ieee80211_mgmt *mgmt;
511 u8 *pos, *end, id, elen;
512 struct ieee80211_tim_ie *tim;
514 mgmt = (struct ieee80211_mgmt *)skb->data;
515 pos = mgmt->u.beacon.variable;
516 end = skb->data + skb->len;
518 while (pos + 2 < end) {
521 if (pos + elen > end)
524 if (id == WLAN_EID_TIM) {
525 if (elen < sizeof(*tim))
527 tim = (struct ieee80211_tim_ie *) pos;
528 if (tim->dtim_count != 0)
530 return tim->bitmap_ctrl & 0x01;
539 static void ath_rx_ps_beacon(struct ath_softc *sc, struct sk_buff *skb)
541 struct ieee80211_mgmt *mgmt;
542 struct ath_common *common = ath9k_hw_common(sc->sc_ah);
544 if (skb->len < 24 + 8 + 2 + 2)
547 mgmt = (struct ieee80211_mgmt *)skb->data;
548 if (memcmp(common->curbssid, mgmt->bssid, ETH_ALEN) != 0)
549 return; /* not from our current AP */
551 sc->sc_flags &= ~SC_OP_WAIT_FOR_BEACON;
553 if (sc->sc_flags & SC_OP_BEACON_SYNC) {
554 sc->sc_flags &= ~SC_OP_BEACON_SYNC;
555 ath_print(common, ATH_DBG_PS,
556 "Reconfigure Beacon timers based on "
557 "timestamp from the AP\n");
558 ath_beacon_config(sc, NULL);
561 if (ath_beacon_dtim_pending_cab(skb)) {
563 * Remain awake waiting for buffered broadcast/multicast
564 * frames. If the last broadcast/multicast frame is not
565 * received properly, the next beacon frame will work as
566 * a backup trigger for returning into NETWORK SLEEP state,
567 * so we are waiting for it as well.
569 ath_print(common, ATH_DBG_PS, "Received DTIM beacon indicating "
570 "buffered broadcast/multicast frame(s)\n");
571 sc->sc_flags |= SC_OP_WAIT_FOR_CAB | SC_OP_WAIT_FOR_BEACON;
575 if (sc->sc_flags & SC_OP_WAIT_FOR_CAB) {
577 * This can happen if a broadcast frame is dropped or the AP
578 * fails to send a frame indicating that all CAB frames have
581 sc->sc_flags &= ~SC_OP_WAIT_FOR_CAB;
582 ath_print(common, ATH_DBG_PS,
583 "PS wait for CAB frames timed out\n");
587 static void ath_rx_ps(struct ath_softc *sc, struct sk_buff *skb)
589 struct ieee80211_hdr *hdr;
590 struct ath_common *common = ath9k_hw_common(sc->sc_ah);
592 hdr = (struct ieee80211_hdr *)skb->data;
594 /* Process Beacon and CAB receive in PS state */
595 if ((sc->sc_flags & SC_OP_WAIT_FOR_BEACON) &&
596 ieee80211_is_beacon(hdr->frame_control))
597 ath_rx_ps_beacon(sc, skb);
598 else if ((sc->sc_flags & SC_OP_WAIT_FOR_CAB) &&
599 (ieee80211_is_data(hdr->frame_control) ||
600 ieee80211_is_action(hdr->frame_control)) &&
601 is_multicast_ether_addr(hdr->addr1) &&
602 !ieee80211_has_moredata(hdr->frame_control)) {
604 * No more broadcast/multicast frames to be received at this
607 sc->sc_flags &= ~SC_OP_WAIT_FOR_CAB;
608 ath_print(common, ATH_DBG_PS,
609 "All PS CAB frames received, back to sleep\n");
610 } else if ((sc->sc_flags & SC_OP_WAIT_FOR_PSPOLL_DATA) &&
611 !is_multicast_ether_addr(hdr->addr1) &&
612 !ieee80211_has_morefrags(hdr->frame_control)) {
613 sc->sc_flags &= ~SC_OP_WAIT_FOR_PSPOLL_DATA;
614 ath_print(common, ATH_DBG_PS,
615 "Going back to sleep after having received "
616 "PS-Poll data (0x%x)\n",
617 sc->sc_flags & (SC_OP_WAIT_FOR_BEACON |
619 SC_OP_WAIT_FOR_PSPOLL_DATA |
620 SC_OP_WAIT_FOR_TX_ACK));
624 static void ath_rx_send_to_mac80211(struct ieee80211_hw *hw,
625 struct ath_softc *sc, struct sk_buff *skb,
626 struct ieee80211_rx_status *rx_status)
628 struct ieee80211_hdr *hdr;
630 hdr = (struct ieee80211_hdr *)skb->data;
632 /* Send the frame to mac80211 */
633 if (is_multicast_ether_addr(hdr->addr1)) {
636 * Deliver broadcast/multicast frames to all suitable
639 /* TODO: filter based on channel configuration */
640 for (i = 0; i < sc->num_sec_wiphy; i++) {
641 struct ath_wiphy *aphy = sc->sec_wiphy[i];
642 struct sk_buff *nskb;
645 nskb = skb_copy(skb, GFP_ATOMIC);
647 memcpy(IEEE80211_SKB_RXCB(nskb), rx_status,
649 ieee80211_rx(aphy->hw, nskb);
652 memcpy(IEEE80211_SKB_RXCB(skb), rx_status, sizeof(*rx_status));
653 ieee80211_rx(sc->hw, skb);
655 /* Deliver unicast frames based on receiver address */
656 memcpy(IEEE80211_SKB_RXCB(skb), rx_status, sizeof(*rx_status));
657 ieee80211_rx(hw, skb);
661 int ath_rx_tasklet(struct ath_softc *sc, int flush)
663 #define PA2DESC(_sc, _pa) \
664 ((struct ath_desc *)((caddr_t)(_sc)->rx.rxdma.dd_desc + \
665 ((_pa) - (_sc)->rx.rxdma.dd_desc_paddr)))
669 struct ath_rx_status *rx_stats;
670 struct sk_buff *skb = NULL, *requeue_skb;
671 struct ieee80211_rx_status rx_status;
672 struct ath_hw *ah = sc->sc_ah;
673 struct ath_common *common = ath9k_hw_common(ah);
675 * The hw can techncically differ from common->hw when using ath9k
676 * virtual wiphy so to account for that we iterate over the active
677 * wiphys and find the appropriate wiphy and therefore hw.
679 struct ieee80211_hw *hw = NULL;
680 struct ieee80211_hdr *hdr;
681 int hdrlen, padsize, retval;
682 bool decrypt_error = false;
686 spin_lock_bh(&sc->rx.rxbuflock);
689 /* If handling rx interrupt and flush is in progress => exit */
690 if ((sc->sc_flags & SC_OP_RXFLUSH) && (flush == 0))
693 if (list_empty(&sc->rx.rxbuf)) {
694 sc->rx.rxlink = NULL;
698 bf = list_first_entry(&sc->rx.rxbuf, struct ath_buf, list);
702 * Must provide the virtual address of the current
703 * descriptor, the physical address, and the virtual
704 * address of the next descriptor in the h/w chain.
705 * This allows the HAL to look ahead to see if the
706 * hardware is done with a descriptor by checking the
707 * done bit in the following descriptor and the address
708 * of the current descriptor the DMA engine is working
709 * on. All this is necessary because of our use of
710 * a self-linked list to avoid rx overruns.
712 retval = ath9k_hw_rxprocdesc(ah, ds,
714 PA2DESC(sc, ds->ds_link),
716 if (retval == -EINPROGRESS) {
718 struct ath_desc *tds;
720 if (list_is_last(&bf->list, &sc->rx.rxbuf)) {
721 sc->rx.rxlink = NULL;
725 tbf = list_entry(bf->list.next, struct ath_buf, list);
728 * On some hardware the descriptor status words could
729 * get corrupted, including the done bit. Because of
730 * this, check if the next descriptor's done bit is
733 * If the next descriptor's done bit is set, the current
734 * descriptor has been corrupted. Force s/w to discard
735 * this descriptor and continue...
739 retval = ath9k_hw_rxprocdesc(ah, tds, tbf->bf_daddr,
740 PA2DESC(sc, tds->ds_link), 0);
741 if (retval == -EINPROGRESS) {
751 * Synchronize the DMA transfer with CPU before
752 * 1. accessing the frame
753 * 2. requeueing the same buffer to h/w
755 dma_sync_single_for_cpu(sc->dev, bf->bf_buf_addr,
759 hdr = (struct ieee80211_hdr *) skb->data;
760 hw = ath_get_virt_hw(sc, hdr);
761 rx_stats = &ds->ds_rxstat;
764 * If we're asked to flush receive queue, directly
765 * chain it back at the queue without processing it.
770 if (!rx_stats->rs_datalen)
773 /* The status portion of the descriptor could get corrupted. */
774 if (sc->rx.bufsize < rx_stats->rs_datalen)
777 if (!ath_rx_prepare(common, hw, skb, rx_stats,
778 &rx_status, &decrypt_error))
781 /* Ensure we always have an skb to requeue once we are done
782 * processing the current buffer's skb */
783 requeue_skb = ath_rxbuf_alloc(common, sc->rx.bufsize, GFP_ATOMIC);
785 /* If there is no memory we ignore the current RX'd frame,
786 * tell hardware it can give us a new frame using the old
787 * skb and put it at the tail of the sc->rx.rxbuf list for
792 /* Unmap the frame */
793 dma_unmap_single(sc->dev, bf->bf_buf_addr,
797 skb_put(skb, rx_stats->rs_datalen);
799 /* see if any padding is done by the hw and remove it */
800 hdrlen = ieee80211_get_hdrlen_from_skb(skb);
801 fc = hdr->frame_control;
803 /* The MAC header is padded to have 32-bit boundary if the
804 * packet payload is non-zero. The general calculation for
805 * padsize would take into account odd header lengths:
806 * padsize = (4 - hdrlen % 4) % 4; However, since only
807 * even-length headers are used, padding can only be 0 or 2
808 * bytes and we can optimize this a bit. In addition, we must
809 * not try to remove padding from short control frames that do
810 * not have payload. */
811 padsize = hdrlen & 3;
812 if (padsize && hdrlen >= 24) {
813 memmove(skb->data + padsize, skb->data, hdrlen);
814 skb_pull(skb, padsize);
817 keyix = rx_stats->rs_keyix;
819 if (!(keyix == ATH9K_RXKEYIX_INVALID) && !decrypt_error) {
820 rx_status.flag |= RX_FLAG_DECRYPTED;
821 } else if (ieee80211_has_protected(fc)
822 && !decrypt_error && skb->len >= hdrlen + 4) {
823 keyix = skb->data[hdrlen + 3] >> 6;
825 if (test_bit(keyix, sc->keymap))
826 rx_status.flag |= RX_FLAG_DECRYPTED;
828 if (ah->sw_mgmt_crypto &&
829 (rx_status.flag & RX_FLAG_DECRYPTED) &&
830 ieee80211_is_mgmt(fc)) {
831 /* Use software decrypt for management frames. */
832 rx_status.flag &= ~RX_FLAG_DECRYPTED;
835 /* We will now give hardware our shiny new allocated skb */
836 bf->bf_mpdu = requeue_skb;
837 bf->bf_buf_addr = dma_map_single(sc->dev, requeue_skb->data,
840 if (unlikely(dma_mapping_error(sc->dev,
842 dev_kfree_skb_any(requeue_skb);
844 ath_print(common, ATH_DBG_FATAL,
845 "dma_mapping_error() on RX\n");
846 ath_rx_send_to_mac80211(hw, sc, skb, &rx_status);
849 bf->bf_dmacontext = bf->bf_buf_addr;
852 * change the default rx antenna if rx diversity chooses the
853 * other antenna 3 times in a row.
855 if (sc->rx.defant != ds->ds_rxstat.rs_antenna) {
856 if (++sc->rx.rxotherant >= 3)
857 ath_setdefantenna(sc, rx_stats->rs_antenna);
859 sc->rx.rxotherant = 0;
862 if (unlikely(sc->sc_flags & (SC_OP_WAIT_FOR_BEACON |
864 SC_OP_WAIT_FOR_PSPOLL_DATA)))
867 ath_rx_send_to_mac80211(hw, sc, skb, &rx_status);
870 list_move_tail(&bf->list, &sc->rx.rxbuf);
871 ath_rx_buf_link(sc, bf);
874 spin_unlock_bh(&sc->rx.rxbuflock);