diff options
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/net/wireless/ath5k/base.c | 59 |
1 files changed, 45 insertions, 14 deletions
diff --git a/drivers/net/wireless/ath5k/base.c b/drivers/net/wireless/ath5k/base.c index 5eacc7cdd9e..b5c0a0d7a81 100644 --- a/drivers/net/wireless/ath5k/base.c +++ b/drivers/net/wireless/ath5k/base.c @@ -1715,8 +1715,10 @@ ath5k_rx_decrypted(struct ath5k_softc *sc, struct ath5k_desc *ds, static void -ath5k_check_ibss_hw_merge(struct ath5k_softc *sc, struct sk_buff *skb) +ath5k_check_ibss_tsf(struct ath5k_softc *sc, struct sk_buff *skb, + struct ieee80211_rx_status *rxs) { + u64 tsf, bc_tstamp; u32 hw_tu; struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *)skb->data; @@ -1727,16 +1729,45 @@ ath5k_check_ibss_hw_merge(struct ath5k_softc *sc, struct sk_buff *skb) le16_to_cpu(mgmt->u.beacon.capab_info) & WLAN_CAPABILITY_IBSS && memcmp(mgmt->bssid, sc->ah->ah_bssid, ETH_ALEN) == 0) { /* - * Received an IBSS beacon with the same BSSID. Hardware might - * have updated the TSF, check if we need to update timers. + * Received an IBSS beacon with the same BSSID. Hardware *must* + * have updated the local TSF. We have to work around various + * hardware bugs, though... */ - hw_tu = TSF_TO_TU(ath5k_hw_get_tsf64(sc->ah)); - if (hw_tu >= sc->nexttbtt) { - ath5k_beacon_update_timers(sc, - le64_to_cpu(mgmt->u.beacon.timestamp)); + tsf = ath5k_hw_get_tsf64(sc->ah); + bc_tstamp = le64_to_cpu(mgmt->u.beacon.timestamp); + hw_tu = TSF_TO_TU(tsf); + + ATH5K_DBG_UNLIMIT(sc, ATH5K_DEBUG_BEACON, + "beacon %llx mactime %llx (diff %lld) tsf now %llx\n", + bc_tstamp, rxs->mactime, + (rxs->mactime - bc_tstamp), tsf); + + /* + * Sometimes the HW will give us a wrong tstamp in the rx + * status, causing the timestamp extension to go wrong. + * (This seems to happen especially with beacon frames bigger + * than 78 byte (incl. FCS)) + * But we know that the receive timestamp must be later than the + * timestamp of the beacon since HW must have synced to that. + * + * NOTE: here we assume mactime to be after the frame was + * received, not like mac80211 which defines it at the start. + */ + if (bc_tstamp > rxs->mactime) { ATH5K_DBG_UNLIMIT(sc, ATH5K_DEBUG_BEACON, - "detected HW merge from received beacon\n"); + "fixing mactime from %llx to %llx\n", + rxs->mactime, tsf); + rxs->mactime = tsf; } + + /* + * Local TSF might have moved higher than our beacon timers, + * in that case we have to update them to continue sending + * beacons. This also takes care of synchronizing beacon sending + * times with other stations. + */ + if (hw_tu >= sc->nexttbtt) + ath5k_beacon_update_timers(sc, bc_tstamp); } } @@ -1885,7 +1916,7 @@ accept: /* check beacons in IBSS mode */ if (sc->opmode == IEEE80211_IF_TYPE_IBSS) - ath5k_check_ibss_hw_merge(sc, skb); + ath5k_check_ibss_tsf(sc, skb, &rxs); __ieee80211_rx(sc->hw, skb, &rxs); sc->led_rxrate = rs.rs_rate; @@ -2118,7 +2149,7 @@ ath5k_beacon_send(struct ath5k_softc *sc) * beacon timer registers. * * This is called in a variety of situations, e.g. when a beacon is received, - * when a HW merge has been detected, but also when an new IBSS is created or + * when a TSF update has been detected, but also when an new IBSS is created or * when we otherwise know we have to update the timers, but we keep it in this * function to have it all together in one place. */ @@ -2218,7 +2249,7 @@ ath5k_beacon_update_timers(struct ath5k_softc *sc, u64 bc_tsf) * another AP to associate with. * * In IBSS mode we use a self-linked tx descriptor if possible. We enable SWBA - * interrupts to detect HW merges only. + * interrupts to detect TSF updates only. * * AP mode is missing. */ @@ -2238,7 +2269,7 @@ ath5k_beacon_config(struct ath5k_softc *sc) * hardware send the beacons automatically. We have to load it * only once here. * We use the SWBA interrupt only to keep track of the beacon - * timers in order to detect HW merges (automatic TSF updates). + * timers in order to detect automatic TSF updates. */ ath5k_beaconq_config(sc); @@ -2451,8 +2482,8 @@ ath5k_intr(int irq, void *dev_id) * * In IBSS mode we use this interrupt just to * keep track of the next TBTT (target beacon - * transmission time) in order to detect hardware - * merges (TSF updates). + * transmission time) in order to detect wether + * automatic TSF updates happened. */ if (sc->opmode == IEEE80211_IF_TYPE_IBSS) { /* XXX: only if VEOL suppported */ |