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)) {
151 static u8 ath9k_process_rate(struct ath_common *common,
152 struct ieee80211_hw *hw,
153 struct ath_rx_status *rx_stats,
154 struct ieee80211_rx_status *rxs,
157 struct ieee80211_supported_band *sband;
158 enum ieee80211_band band;
161 band = hw->conf.channel->band;
162 sband = hw->wiphy->bands[band];
164 if (rx_stats->rs_rate & 0x80) {
166 rxs->flag |= RX_FLAG_HT;
167 if (rx_stats->rs_flags & ATH9K_RX_2040)
168 rxs->flag |= RX_FLAG_40MHZ;
169 if (rx_stats->rs_flags & ATH9K_RX_GI)
170 rxs->flag |= RX_FLAG_SHORT_GI;
171 return rx_stats->rs_rate & 0x7f;
174 for (i = 0; i < sband->n_bitrates; i++) {
175 if (sband->bitrates[i].hw_value == rx_stats->rs_rate)
177 if (sband->bitrates[i].hw_value_short == rx_stats->rs_rate) {
178 rxs->flag |= RX_FLAG_SHORTPRE;
183 /* No valid hardware bitrate found -- we should not get here */
184 ath_print(common, ATH_DBG_XMIT, "unsupported hw bitrate detected "
185 "0x%02x using 1 Mbit\n", rx_stats->rs_rate);
186 if ((common->debug_mask & ATH_DBG_XMIT))
187 print_hex_dump_bytes("", DUMP_PREFIX_NONE, skb->data, skb->len);
193 * For Decrypt or Demic errors, we only mark packet status here and always push
194 * up the frame up to let mac80211 handle the actual error case, be it no
195 * decryption key or real decryption error. This let us keep statistics there.
197 static int ath_rx_prepare(struct ath_common *common,
198 struct ieee80211_hw *hw,
199 struct sk_buff *skb, struct ath_rx_status *rx_stats,
200 struct ieee80211_rx_status *rx_status,
203 struct ath_hw *ah = common->ah;
204 struct ieee80211_hdr *hdr;
206 struct ieee80211_sta *sta;
208 int last_rssi = ATH_RSSI_DUMMY_MARKER;
210 hdr = (struct ieee80211_hdr *)skb->data;
211 fc = hdr->frame_control;
212 memset(rx_status, 0, sizeof(struct ieee80211_rx_status));
214 if (!ath9k_rx_accept(common, skb, rx_status, rx_stats, decrypt_error))
219 /* XXX: use ieee80211_find_sta! */
220 sta = ieee80211_find_sta_by_hw(hw, hdr->addr2);
222 an = (struct ath_node *) sta->drv_priv;
223 if (rx_stats->rs_rssi != ATH9K_RSSI_BAD &&
224 !rx_stats->rs_moreaggr)
225 ATH_RSSI_LPF(an->last_rssi, rx_stats->rs_rssi);
226 last_rssi = an->last_rssi;
230 if (likely(last_rssi != ATH_RSSI_DUMMY_MARKER))
231 rx_stats->rs_rssi = ATH_EP_RND(last_rssi,
232 ATH_RSSI_EP_MULTIPLIER);
233 if (rx_stats->rs_rssi < 0)
234 rx_stats->rs_rssi = 0;
235 else if (rx_stats->rs_rssi > 127)
236 rx_stats->rs_rssi = 127;
238 /* Update Beacon RSSI, this is used by ANI. */
239 if (ieee80211_is_beacon(fc))
240 ah->stats.avgbrssi = rx_stats->rs_rssi;
242 rx_status->rate_idx = ath9k_process_rate(common, hw,
243 rx_stats, rx_status, skb);
244 rx_status->mactime = ath9k_hw_extend_tsf(ah, rx_stats->rs_tstamp);
245 rx_status->band = hw->conf.channel->band;
246 rx_status->freq = hw->conf.channel->center_freq;
247 rx_status->noise = common->ani.noise_floor;
248 rx_status->signal = ATH_DEFAULT_NOISE_FLOOR + rx_stats->rs_rssi;
249 rx_status->antenna = rx_stats->rs_antenna;
252 * Theory for reporting quality:
254 * At a hardware RSSI of 45 you will be able to use MCS 7 reliably.
255 * At a hardware RSSI of 45 you will be able to use MCS 15 reliably.
256 * At a hardware RSSI of 35 you should be able use 54 Mbps reliably.
258 * MCS 7 is the highets MCS index usable by a 1-stream device.
259 * MCS 15 is the highest MCS index usable by a 2-stream device.
261 * All ath9k devices are either 1-stream or 2-stream.
263 * How many bars you see is derived from the qual reporting.
265 * A more elaborate scheme can be used here but it requires tables
266 * of SNR/throughput for each possible mode used. For the MCS table
267 * you can refer to the wireless wiki:
269 * http://wireless.kernel.org/en/developers/Documentation/ieee80211/802.11n
272 if (conf_is_ht(&hw->conf))
273 rx_status->qual = rx_stats->rs_rssi * 100 / 45;
275 rx_status->qual = rx_stats->rs_rssi * 100 / 35;
277 /* rssi can be more than 45 though, anything above that
278 * should be considered at 100% */
279 if (rx_status->qual > 100)
280 rx_status->qual = 100;
282 rx_status->flag |= RX_FLAG_TSFT;
289 static void ath_opmode_init(struct ath_softc *sc)
291 struct ath_hw *ah = sc->sc_ah;
292 struct ath_common *common = ath9k_hw_common(ah);
296 /* configure rx filter */
297 rfilt = ath_calcrxfilter(sc);
298 ath9k_hw_setrxfilter(ah, rfilt);
300 /* configure bssid mask */
301 if (ah->caps.hw_caps & ATH9K_HW_CAP_BSSIDMASK)
302 ath_hw_setbssidmask(common);
304 /* configure operational mode */
305 ath9k_hw_setopmode(ah);
307 /* Handle any link-level address change. */
308 ath9k_hw_setmac(ah, common->macaddr);
310 /* calculate and install multicast filter */
311 mfilt[0] = mfilt[1] = ~0;
312 ath9k_hw_setmcastfilter(ah, mfilt[0], mfilt[1]);
315 int ath_rx_init(struct ath_softc *sc, int nbufs)
317 struct ath_common *common = ath9k_hw_common(sc->sc_ah);
322 spin_lock_init(&sc->rx.rxflushlock);
323 sc->sc_flags &= ~SC_OP_RXFLUSH;
324 spin_lock_init(&sc->rx.rxbuflock);
326 sc->rx.bufsize = roundup(IEEE80211_MAX_MPDU_LEN,
327 min(common->cachelsz, (u16)64));
329 ath_print(common, ATH_DBG_CONFIG, "cachelsz %u rxbufsize %u\n",
330 common->cachelsz, sc->rx.bufsize);
332 /* Initialize rx descriptors */
334 error = ath_descdma_setup(sc, &sc->rx.rxdma, &sc->rx.rxbuf,
337 ath_print(common, ATH_DBG_FATAL,
338 "failed to allocate rx descriptors: %d\n", error);
342 list_for_each_entry(bf, &sc->rx.rxbuf, list) {
343 skb = ath_rxbuf_alloc(common, sc->rx.bufsize, GFP_KERNEL);
350 bf->bf_buf_addr = dma_map_single(sc->dev, skb->data,
353 if (unlikely(dma_mapping_error(sc->dev,
355 dev_kfree_skb_any(skb);
357 ath_print(common, ATH_DBG_FATAL,
358 "dma_mapping_error() on RX init\n");
362 bf->bf_dmacontext = bf->bf_buf_addr;
364 sc->rx.rxlink = NULL;
373 void ath_rx_cleanup(struct ath_softc *sc)
378 list_for_each_entry(bf, &sc->rx.rxbuf, list) {
381 dma_unmap_single(sc->dev, bf->bf_buf_addr,
382 sc->rx.bufsize, DMA_FROM_DEVICE);
387 if (sc->rx.rxdma.dd_desc_len != 0)
388 ath_descdma_cleanup(sc, &sc->rx.rxdma, &sc->rx.rxbuf);
392 * Calculate the receive filter according to the
393 * operating mode and state:
395 * o always accept unicast, broadcast, and multicast traffic
396 * o maintain current state of phy error reception (the hal
397 * may enable phy error frames for noise immunity work)
398 * o probe request frames are accepted only when operating in
399 * hostap, adhoc, or monitor modes
400 * o enable promiscuous mode according to the interface state
402 * - when operating in adhoc mode so the 802.11 layer creates
403 * node table entries for peers,
404 * - when operating in station mode for collecting rssi data when
405 * the station is otherwise quiet, or
406 * - when operating as a repeater so we see repeater-sta beacons
410 u32 ath_calcrxfilter(struct ath_softc *sc)
412 #define RX_FILTER_PRESERVE (ATH9K_RX_FILTER_PHYERR | ATH9K_RX_FILTER_PHYRADAR)
416 rfilt = (ath9k_hw_getrxfilter(sc->sc_ah) & RX_FILTER_PRESERVE)
417 | ATH9K_RX_FILTER_UCAST | ATH9K_RX_FILTER_BCAST
418 | ATH9K_RX_FILTER_MCAST;
420 /* If not a STA, enable processing of Probe Requests */
421 if (sc->sc_ah->opmode != NL80211_IFTYPE_STATION)
422 rfilt |= ATH9K_RX_FILTER_PROBEREQ;
425 * Set promiscuous mode when FIF_PROMISC_IN_BSS is enabled for station
426 * mode interface or when in monitor mode. AP mode does not need this
427 * since it receives all in-BSS frames anyway.
429 if (((sc->sc_ah->opmode != NL80211_IFTYPE_AP) &&
430 (sc->rx.rxfilter & FIF_PROMISC_IN_BSS)) ||
431 (sc->sc_ah->opmode == NL80211_IFTYPE_MONITOR))
432 rfilt |= ATH9K_RX_FILTER_PROM;
434 if (sc->rx.rxfilter & FIF_CONTROL)
435 rfilt |= ATH9K_RX_FILTER_CONTROL;
437 if ((sc->sc_ah->opmode == NL80211_IFTYPE_STATION) &&
438 !(sc->rx.rxfilter & FIF_BCN_PRBRESP_PROMISC))
439 rfilt |= ATH9K_RX_FILTER_MYBEACON;
441 rfilt |= ATH9K_RX_FILTER_BEACON;
443 if ((AR_SREV_9280_10_OR_LATER(sc->sc_ah) ||
444 AR_SREV_9285_10_OR_LATER(sc->sc_ah)) &&
445 (sc->sc_ah->opmode == NL80211_IFTYPE_AP) &&
446 (sc->rx.rxfilter & FIF_PSPOLL))
447 rfilt |= ATH9K_RX_FILTER_PSPOLL;
449 if (conf_is_ht(&sc->hw->conf))
450 rfilt |= ATH9K_RX_FILTER_COMP_BAR;
452 if (sc->sec_wiphy || (sc->rx.rxfilter & FIF_OTHER_BSS)) {
453 /* TODO: only needed if more than one BSSID is in use in
454 * station/adhoc mode */
455 /* The following may also be needed for other older chips */
456 if (sc->sc_ah->hw_version.macVersion == AR_SREV_VERSION_9160)
457 rfilt |= ATH9K_RX_FILTER_PROM;
458 rfilt |= ATH9K_RX_FILTER_MCAST_BCAST_ALL;
463 #undef RX_FILTER_PRESERVE
466 int ath_startrecv(struct ath_softc *sc)
468 struct ath_hw *ah = sc->sc_ah;
469 struct ath_buf *bf, *tbf;
471 spin_lock_bh(&sc->rx.rxbuflock);
472 if (list_empty(&sc->rx.rxbuf))
475 sc->rx.rxlink = NULL;
476 list_for_each_entry_safe(bf, tbf, &sc->rx.rxbuf, list) {
477 ath_rx_buf_link(sc, bf);
480 /* We could have deleted elements so the list may be empty now */
481 if (list_empty(&sc->rx.rxbuf))
484 bf = list_first_entry(&sc->rx.rxbuf, struct ath_buf, list);
485 ath9k_hw_putrxbuf(ah, bf->bf_daddr);
489 spin_unlock_bh(&sc->rx.rxbuflock);
491 ath9k_hw_startpcureceive(ah);
496 bool ath_stoprecv(struct ath_softc *sc)
498 struct ath_hw *ah = sc->sc_ah;
501 ath9k_hw_stoppcurecv(ah);
502 ath9k_hw_setrxfilter(ah, 0);
503 stopped = ath9k_hw_stopdmarecv(ah);
504 sc->rx.rxlink = NULL;
509 void ath_flushrecv(struct ath_softc *sc)
511 spin_lock_bh(&sc->rx.rxflushlock);
512 sc->sc_flags |= SC_OP_RXFLUSH;
513 ath_rx_tasklet(sc, 1);
514 sc->sc_flags &= ~SC_OP_RXFLUSH;
515 spin_unlock_bh(&sc->rx.rxflushlock);
518 static bool ath_beacon_dtim_pending_cab(struct sk_buff *skb)
520 /* Check whether the Beacon frame has DTIM indicating buffered bc/mc */
521 struct ieee80211_mgmt *mgmt;
522 u8 *pos, *end, id, elen;
523 struct ieee80211_tim_ie *tim;
525 mgmt = (struct ieee80211_mgmt *)skb->data;
526 pos = mgmt->u.beacon.variable;
527 end = skb->data + skb->len;
529 while (pos + 2 < end) {
532 if (pos + elen > end)
535 if (id == WLAN_EID_TIM) {
536 if (elen < sizeof(*tim))
538 tim = (struct ieee80211_tim_ie *) pos;
539 if (tim->dtim_count != 0)
541 return tim->bitmap_ctrl & 0x01;
550 static void ath_rx_ps_beacon(struct ath_softc *sc, struct sk_buff *skb)
552 struct ieee80211_mgmt *mgmt;
553 struct ath_common *common = ath9k_hw_common(sc->sc_ah);
555 if (skb->len < 24 + 8 + 2 + 2)
558 mgmt = (struct ieee80211_mgmt *)skb->data;
559 if (memcmp(common->curbssid, mgmt->bssid, ETH_ALEN) != 0)
560 return; /* not from our current AP */
562 sc->sc_flags &= ~SC_OP_WAIT_FOR_BEACON;
564 if (sc->sc_flags & SC_OP_BEACON_SYNC) {
565 sc->sc_flags &= ~SC_OP_BEACON_SYNC;
566 ath_print(common, ATH_DBG_PS,
567 "Reconfigure Beacon timers based on "
568 "timestamp from the AP\n");
569 ath_beacon_config(sc, NULL);
572 if (ath_beacon_dtim_pending_cab(skb)) {
574 * Remain awake waiting for buffered broadcast/multicast
575 * frames. If the last broadcast/multicast frame is not
576 * received properly, the next beacon frame will work as
577 * a backup trigger for returning into NETWORK SLEEP state,
578 * so we are waiting for it as well.
580 ath_print(common, ATH_DBG_PS, "Received DTIM beacon indicating "
581 "buffered broadcast/multicast frame(s)\n");
582 sc->sc_flags |= SC_OP_WAIT_FOR_CAB | SC_OP_WAIT_FOR_BEACON;
586 if (sc->sc_flags & SC_OP_WAIT_FOR_CAB) {
588 * This can happen if a broadcast frame is dropped or the AP
589 * fails to send a frame indicating that all CAB frames have
592 sc->sc_flags &= ~SC_OP_WAIT_FOR_CAB;
593 ath_print(common, ATH_DBG_PS,
594 "PS wait for CAB frames timed out\n");
598 static void ath_rx_ps(struct ath_softc *sc, struct sk_buff *skb)
600 struct ieee80211_hdr *hdr;
601 struct ath_common *common = ath9k_hw_common(sc->sc_ah);
603 hdr = (struct ieee80211_hdr *)skb->data;
605 /* Process Beacon and CAB receive in PS state */
606 if ((sc->sc_flags & SC_OP_WAIT_FOR_BEACON) &&
607 ieee80211_is_beacon(hdr->frame_control))
608 ath_rx_ps_beacon(sc, skb);
609 else if ((sc->sc_flags & SC_OP_WAIT_FOR_CAB) &&
610 (ieee80211_is_data(hdr->frame_control) ||
611 ieee80211_is_action(hdr->frame_control)) &&
612 is_multicast_ether_addr(hdr->addr1) &&
613 !ieee80211_has_moredata(hdr->frame_control)) {
615 * No more broadcast/multicast frames to be received at this
618 sc->sc_flags &= ~SC_OP_WAIT_FOR_CAB;
619 ath_print(common, ATH_DBG_PS,
620 "All PS CAB frames received, back to sleep\n");
621 } else if ((sc->sc_flags & SC_OP_WAIT_FOR_PSPOLL_DATA) &&
622 !is_multicast_ether_addr(hdr->addr1) &&
623 !ieee80211_has_morefrags(hdr->frame_control)) {
624 sc->sc_flags &= ~SC_OP_WAIT_FOR_PSPOLL_DATA;
625 ath_print(common, ATH_DBG_PS,
626 "Going back to sleep after having received "
627 "PS-Poll data (0x%x)\n",
628 sc->sc_flags & (SC_OP_WAIT_FOR_BEACON |
630 SC_OP_WAIT_FOR_PSPOLL_DATA |
631 SC_OP_WAIT_FOR_TX_ACK));
635 static void ath_rx_send_to_mac80211(struct ieee80211_hw *hw,
636 struct ath_softc *sc, struct sk_buff *skb,
637 struct ieee80211_rx_status *rx_status)
639 struct ieee80211_hdr *hdr;
641 hdr = (struct ieee80211_hdr *)skb->data;
643 /* Send the frame to mac80211 */
644 if (is_multicast_ether_addr(hdr->addr1)) {
647 * Deliver broadcast/multicast frames to all suitable
650 /* TODO: filter based on channel configuration */
651 for (i = 0; i < sc->num_sec_wiphy; i++) {
652 struct ath_wiphy *aphy = sc->sec_wiphy[i];
653 struct sk_buff *nskb;
656 nskb = skb_copy(skb, GFP_ATOMIC);
658 memcpy(IEEE80211_SKB_RXCB(nskb), rx_status,
660 ieee80211_rx(aphy->hw, nskb);
663 memcpy(IEEE80211_SKB_RXCB(skb), rx_status, sizeof(*rx_status));
664 ieee80211_rx(sc->hw, skb);
666 /* Deliver unicast frames based on receiver address */
667 memcpy(IEEE80211_SKB_RXCB(skb), rx_status, sizeof(*rx_status));
668 ieee80211_rx(hw, skb);
672 int ath_rx_tasklet(struct ath_softc *sc, int flush)
674 #define PA2DESC(_sc, _pa) \
675 ((struct ath_desc *)((caddr_t)(_sc)->rx.rxdma.dd_desc + \
676 ((_pa) - (_sc)->rx.rxdma.dd_desc_paddr)))
680 struct ath_rx_status *rx_stats;
681 struct sk_buff *skb = NULL, *requeue_skb;
682 struct ieee80211_rx_status rx_status;
683 struct ath_hw *ah = sc->sc_ah;
684 struct ath_common *common = ath9k_hw_common(ah);
686 * The hw can techncically differ from common->hw when using ath9k
687 * virtual wiphy so to account for that we iterate over the active
688 * wiphys and find the appropriate wiphy and therefore hw.
690 struct ieee80211_hw *hw = NULL;
691 struct ieee80211_hdr *hdr;
692 int hdrlen, padsize, retval;
693 bool decrypt_error = false;
697 spin_lock_bh(&sc->rx.rxbuflock);
700 /* If handling rx interrupt and flush is in progress => exit */
701 if ((sc->sc_flags & SC_OP_RXFLUSH) && (flush == 0))
704 if (list_empty(&sc->rx.rxbuf)) {
705 sc->rx.rxlink = NULL;
709 bf = list_first_entry(&sc->rx.rxbuf, struct ath_buf, list);
713 * Must provide the virtual address of the current
714 * descriptor, the physical address, and the virtual
715 * address of the next descriptor in the h/w chain.
716 * This allows the HAL to look ahead to see if the
717 * hardware is done with a descriptor by checking the
718 * done bit in the following descriptor and the address
719 * of the current descriptor the DMA engine is working
720 * on. All this is necessary because of our use of
721 * a self-linked list to avoid rx overruns.
723 retval = ath9k_hw_rxprocdesc(ah, ds,
725 PA2DESC(sc, ds->ds_link),
727 if (retval == -EINPROGRESS) {
729 struct ath_desc *tds;
731 if (list_is_last(&bf->list, &sc->rx.rxbuf)) {
732 sc->rx.rxlink = NULL;
736 tbf = list_entry(bf->list.next, struct ath_buf, list);
739 * On some hardware the descriptor status words could
740 * get corrupted, including the done bit. Because of
741 * this, check if the next descriptor's done bit is
744 * If the next descriptor's done bit is set, the current
745 * descriptor has been corrupted. Force s/w to discard
746 * this descriptor and continue...
750 retval = ath9k_hw_rxprocdesc(ah, tds, tbf->bf_daddr,
751 PA2DESC(sc, tds->ds_link), 0);
752 if (retval == -EINPROGRESS) {
762 * Synchronize the DMA transfer with CPU before
763 * 1. accessing the frame
764 * 2. requeueing the same buffer to h/w
766 dma_sync_single_for_cpu(sc->dev, bf->bf_buf_addr,
770 hdr = (struct ieee80211_hdr *) skb->data;
771 hw = ath_get_virt_hw(sc, hdr);
772 rx_stats = &ds->ds_rxstat;
775 * If we're asked to flush receive queue, directly
776 * chain it back at the queue without processing it.
781 if (!rx_stats->rs_datalen)
784 /* The status portion of the descriptor could get corrupted. */
785 if (sc->rx.bufsize < rx_stats->rs_datalen)
788 if (!ath_rx_prepare(common, hw, skb, rx_stats,
789 &rx_status, &decrypt_error))
792 /* Ensure we always have an skb to requeue once we are done
793 * processing the current buffer's skb */
794 requeue_skb = ath_rxbuf_alloc(common, sc->rx.bufsize, GFP_ATOMIC);
796 /* If there is no memory we ignore the current RX'd frame,
797 * tell hardware it can give us a new frame using the old
798 * skb and put it at the tail of the sc->rx.rxbuf list for
803 /* Unmap the frame */
804 dma_unmap_single(sc->dev, bf->bf_buf_addr,
808 skb_put(skb, rx_stats->rs_datalen);
810 /* see if any padding is done by the hw and remove it */
811 hdrlen = ieee80211_get_hdrlen_from_skb(skb);
812 fc = hdr->frame_control;
814 /* The MAC header is padded to have 32-bit boundary if the
815 * packet payload is non-zero. The general calculation for
816 * padsize would take into account odd header lengths:
817 * padsize = (4 - hdrlen % 4) % 4; However, since only
818 * even-length headers are used, padding can only be 0 or 2
819 * bytes and we can optimize this a bit. In addition, we must
820 * not try to remove padding from short control frames that do
821 * not have payload. */
822 padsize = hdrlen & 3;
823 if (padsize && hdrlen >= 24) {
824 memmove(skb->data + padsize, skb->data, hdrlen);
825 skb_pull(skb, padsize);
828 keyix = rx_stats->rs_keyix;
830 if (!(keyix == ATH9K_RXKEYIX_INVALID) && !decrypt_error) {
831 rx_status.flag |= RX_FLAG_DECRYPTED;
832 } else if (ieee80211_has_protected(fc)
833 && !decrypt_error && skb->len >= hdrlen + 4) {
834 keyix = skb->data[hdrlen + 3] >> 6;
836 if (test_bit(keyix, sc->keymap))
837 rx_status.flag |= RX_FLAG_DECRYPTED;
839 if (ah->sw_mgmt_crypto &&
840 (rx_status.flag & RX_FLAG_DECRYPTED) &&
841 ieee80211_is_mgmt(fc)) {
842 /* Use software decrypt for management frames. */
843 rx_status.flag &= ~RX_FLAG_DECRYPTED;
846 /* We will now give hardware our shiny new allocated skb */
847 bf->bf_mpdu = requeue_skb;
848 bf->bf_buf_addr = dma_map_single(sc->dev, requeue_skb->data,
851 if (unlikely(dma_mapping_error(sc->dev,
853 dev_kfree_skb_any(requeue_skb);
855 ath_print(common, ATH_DBG_FATAL,
856 "dma_mapping_error() on RX\n");
857 ath_rx_send_to_mac80211(hw, sc, skb, &rx_status);
860 bf->bf_dmacontext = bf->bf_buf_addr;
863 * change the default rx antenna if rx diversity chooses the
864 * other antenna 3 times in a row.
866 if (sc->rx.defant != ds->ds_rxstat.rs_antenna) {
867 if (++sc->rx.rxotherant >= 3)
868 ath_setdefantenna(sc, rx_stats->rs_antenna);
870 sc->rx.rxotherant = 0;
873 if (unlikely(sc->sc_flags & (SC_OP_WAIT_FOR_BEACON |
875 SC_OP_WAIT_FOR_PSPOLL_DATA)))
878 ath_rx_send_to_mac80211(hw, sc, skb, &rx_status);
881 list_move_tail(&bf->list, &sc->rx.rxbuf);
882 ath_rx_buf_link(sc, bf);
885 spin_unlock_bh(&sc->rx.rxbuflock);