Return-path: Received: from ebb06.tieto.com ([131.207.168.38]:62717 "EHLO ebb06.tieto.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752983Ab3JDIRp (ORCPT ); Fri, 4 Oct 2013 04:17:45 -0400 From: Michal Kazior To: CC: , Sujith Manoharan , Michal Kazior Subject: [PATCH v2 1/2] ath10k: Fix bug in max. VHT A-MPDU size Date: Fri, 4 Oct 2013 10:17:09 +0200 Message-ID: <1380874630-14280-2-git-send-email-michal.kazior@tieto.com> (sfid-20131004_101750_919478_75FF7C49) In-Reply-To: <1380874630-14280-1-git-send-email-michal.kazior@tieto.com> References: <1380874630-14280-1-git-send-email-michal.kazior@tieto.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-wireless-owner@vger.kernel.org List-ID: From: Sujith Manoharan For VHT peers, the maximum A-MPDU size has to be calculated from the VHT capabilities element and not the HT-cap. The formula is the same, but a higher value is used in VHT, allowing larger aggregates to be transmitted. The patch contains a workaround for some Netgear/Linksys APs that report Rx A-MPDU factor incorrectly. Signed-off-by: Sujith Manoharan Signed-off-by: Michal Kazior --- drivers/net/wireless/ath/ath10k/mac.c | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-) diff --git a/drivers/net/wireless/ath/ath10k/mac.c b/drivers/net/wireless/ath/ath10k/mac.c index 8684e03..7e06e75 100644 --- a/drivers/net/wireless/ath/ath10k/mac.c +++ b/drivers/net/wireless/ath/ath10k/mac.c @@ -1033,14 +1033,26 @@ static void ath10k_peer_assoc_h_vht(struct ath10k *ar, struct wmi_peer_assoc_complete_arg *arg) { const struct ieee80211_sta_vht_cap *vht_cap = &sta->vht_cap; + u8 ampdu_factor; if (!vht_cap->vht_supported) return; arg->peer_flags |= WMI_PEER_VHT; - arg->peer_vht_caps = vht_cap->cap; + ampdu_factor = + (vht_cap->cap & IEEE80211_VHT_CAP_MAX_A_MPDU_LENGTH_EXPONENT_MASK) >> + IEEE80211_VHT_CAP_MAX_A_MPDU_LENGTH_EXPONENT_SHIFT; + + /* Workaround: Some Netgear/Linksys 11ac APs set Rx A-MPDU factor to + * zero in VHT IE. Using it would result in degraded throughput. + * arg->peer_max_mpdu at this point contains HT max_mpdu so keep + * it if VHT max_mpdu is smaller. */ + arg->peer_max_mpdu = max(arg->peer_max_mpdu, + (1 << (IEEE80211_HT_MAX_AMPDU_FACTOR + + ampdu_factor)) - 1); + if (sta->bandwidth == IEEE80211_STA_RX_BW_80) arg->peer_flags |= WMI_PEER_80MHZ; -- 1.7.9.5