From: Benjamin Berg <benjamin.berg@xxxxxxxxxxxxx> Beacons were not send out at (timestamp % beacon_time == 0) for interfaces other than the primary one. To send out beacons with the correct timestamp according to 10.1.3.2 of the 802.11 standard the tsf_adjustment has to be set to the negative time difference instead of positive. This way the later beacons get corrected to have a lower (and similar) timestamp with regard to the beacon from slot 0. I am not aware about any issues that have been caused by this. Signed-off-by: Benjamin Berg <benjamin.berg@xxxxxxxxxxxxx> --- drivers/net/wireless/ath/ath9k/beacon.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/drivers/net/wireless/ath/ath9k/beacon.c b/drivers/net/wireless/ath/ath9k/beacon.c index 5cf0cd7..800c96b 100644 --- a/drivers/net/wireless/ath/ath9k/beacon.c +++ b/drivers/net/wireless/ath/ath9k/beacon.c @@ -279,17 +279,21 @@ static void ath9k_set_tsfadjust(struct ath_softc *sc, struct ieee80211_vif *vif) struct ath_common *common = ath9k_hw_common(sc->sc_ah); struct ath_vif *avp = (void *)vif->drv_priv; struct ath_beacon_config *cur_conf = &avp->chanctx->beacon; - u32 tsfadjust; + s64 tsfadjust; if (avp->av_bslot == 0) return; + /* tsf_adjust is added to the TSF value. We send out the beacon late, + * so need to adjust the TSF starting point to be later in time (i.e. + * the theoretical first beacon has a TSF of 0 after correction). + */ tsfadjust = cur_conf->beacon_interval * avp->av_bslot; - tsfadjust = TU_TO_USEC(tsfadjust) / ATH_BCBUF; + tsfadjust = -TU_TO_USEC(tsfadjust) / ATH_BCBUF; avp->tsf_adjust = cpu_to_le64(tsfadjust); - ath_dbg(common, CONFIG, "tsfadjust is: %llu for bslot: %d\n", - (unsigned long long)tsfadjust, avp->av_bslot); + ath_dbg(common, CONFIG, "tsfadjust is: %lld for bslot: %d\n", + (signed long long)tsfadjust, avp->av_bslot); } bool ath9k_csa_is_finished(struct ath_softc *sc, struct ieee80211_vif *vif) -- 2.8.1 -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
