The ath9k hardware reports whenever an frame was part of an A-MPDU. MAC80211 already provides the necessary API to pass this additional information along to whomever needs it. --- Knowing whenever a received frame was part of an A-MPDU allows mac80211 to react to A-MPDUs which have no valid BA agreement in place. This patch (together with the mac80211 part in: <http://www.spinics.net/lists/linux-wireless/msg101717.html>) helps to improve network stability. The new code implements parts of the recommendations from 802.11-2012 10.5.4 "Error recovery upon a peer failure". While this patch works OK, I think it still needs be improved further: - ath9k_apply_ampdu_details is a separate subroutine and it is called a bit 'late'. However, I'm not sure if moving it to a different place like ath9k_rx_skb_preprocess would be any better. it's because we need to have access to ampdu_ref, which is currently stored in ath_softc.rx. - What about the MPDU delimiter crc? Is it possible to retrieve it from the rx header, or is it lost? - (How to handle zero length subframes? This would be a nice to have feature [i.e.: if someone wants to check if a HT peer really cares about the ampdu density]. However it should be disabled unless we have a running monitor interface.) BTW: Support for the AMPDU_DETAILS radiotap extension has already been added to wireshark. Just make sure you get the latest svn/git source (1.9.0). Regards, Chr --- drivers/net/wireless/ath/ath9k/ath9k.h | 2 ++ drivers/net/wireless/ath/ath9k/recv.c | 21 +++++++++++++++++++++ 2 files changed, 23 insertions(+) diff --git a/drivers/net/wireless/ath/ath9k/ath9k.h b/drivers/net/wireless/ath/ath9k/ath9k.h index 094a932..262fb71 100644 --- a/drivers/net/wireless/ath/ath9k/ath9k.h +++ b/drivers/net/wireless/ath/ath9k/ath9k.h @@ -320,6 +320,8 @@ struct ath_rx { struct ath_rx_edma rx_edma[ATH9K_RX_QUEUE_MAX]; struct sk_buff *frag; + + u32 ampdu_ref; }; int ath_startrecv(struct ath_softc *sc); diff --git a/drivers/net/wireless/ath/ath9k/recv.c b/drivers/net/wireless/ath/ath9k/recv.c index 45f2d47..775cafd 100644 --- a/drivers/net/wireless/ath/ath9k/recv.c +++ b/drivers/net/wireless/ath/ath9k/recv.c @@ -1128,6 +1128,24 @@ static void ath_process_fft(struct ath_softc *sc, struct ieee80211_hdr *hdr, #endif } +static void ath9k_apply_ampdu_details(struct ath_softc *sc, + struct ath_rx_status *rs, struct ieee80211_rx_status *rxs) +{ + if (rs->rs_isaggr) { + rxs->flag |= RX_FLAG_AMPDU_DETAILS | RX_FLAG_AMPDU_LAST_KNOWN; + + rxs->ampdu_reference = sc->rx.ampdu_ref; + + if (!rs->rs_moreaggr) { + rxs->flag |= RX_FLAG_AMPDU_IS_LAST; + sc->rx.ampdu_ref++; + } + + if (rs->rs_flags & ATH9K_RX_DELIM_CRC_PRE) + rxs->flag |= RX_FLAG_AMPDU_DELIM_CRC_ERROR; + } +} + int ath_rx_tasklet(struct ath_softc *sc, int flush, bool hp) { struct ath_buf *bf; @@ -1343,6 +1362,8 @@ int ath_rx_tasklet(struct ath_softc *sc, int flush, bool hp) if ((ah->caps.hw_caps & ATH9K_HW_CAP_ANT_DIV_COMB) && sc->ant_rx == 3) ath_ant_comb_scan(sc, &rs); + ath9k_apply_ampdu_details(sc, &rs, rxs); + ieee80211_rx(hw, skb); requeue_drop_frag: -- 1.7.10.4 -- 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
