Return-path: Received: from nbd.name ([46.4.11.11]:46776 "EHLO nbd.name" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756334AbcBXVYO (ORCPT ); Wed, 24 Feb 2016 16:24:14 -0500 From: Felix Fietkau To: linux-wireless@vger.kernel.org Cc: johannes@sipsolutions.net, egrumbach@gmail.com Subject: [PATCH v2 2/2] mac80211: minstrel_ht: set A-MSDU tx limits based on selected max_prob_rate Date: Wed, 24 Feb 2016 10:29:00 +0100 Message-Id: <1456306140-78485-2-git-send-email-nbd@openwrt.org> (sfid-20160224_222418_599211_6B778756) In-Reply-To: <1456306140-78485-1-git-send-email-nbd@openwrt.org> References: <1456306140-78485-1-git-send-email-nbd@openwrt.org> Sender: linux-wireless-owner@vger.kernel.org List-ID: Prevents excessive A-MSDU aggregation at low data rates or bad conditions. Signed-off-by: Felix Fietkau --- net/mac80211/rc80211_minstrel_ht.c | 34 ++++++++++++++++++++++++++++++++++ 1 file changed, 34 insertions(+) diff --git a/net/mac80211/rc80211_minstrel_ht.c b/net/mac80211/rc80211_minstrel_ht.c index 3928dbd..ad8859c 100644 --- a/net/mac80211/rc80211_minstrel_ht.c +++ b/net/mac80211/rc80211_minstrel_ht.c @@ -882,6 +882,39 @@ minstrel_ht_set_rate(struct minstrel_priv *mp, struct minstrel_ht_sta *mi, ratetbl->rate[offset].flags = flags; } +static int +minstrel_ht_get_max_amsdu_len(struct minstrel_ht_sta *mi) +{ + int group = mi->max_prob_rate / MCS_GROUP_RATES; + const struct mcs_group *g = &minstrel_mcs_groups[group]; + int rate = mi->max_prob_rate % MCS_GROUP_RATES; + + /* Disable A-MSDU if max_prob_rate is bad */ + if (mi->groups[group].rates[rate].prob_ewma < MINSTREL_FRAC(50, 100)) + return 1; + + /* If the rate is slower than single-stream MCS1, make A-MSDU limit small */ + if (g->duration[rate] > MCS_DURATION(1, 0, 52)) + return 500; + + /* + * If the rate is slower than single-stream MCS4, limit A-MSDU to usual + * data packet size + */ + if (g->duration[rate] > MCS_DURATION(1, 0, 104)) + return 1500; + + /* + * If the rate is slower than single-stream MCS7, limit A-MSDU to twice + * the usual data packet size + */ + if (g->duration[rate] > MCS_DURATION(1, 0, 260)) + return 3000; + + /* unlimited */ + return 0; +} + static void minstrel_ht_update_rates(struct minstrel_priv *mp, struct minstrel_ht_sta *mi) { @@ -906,6 +939,7 @@ minstrel_ht_update_rates(struct minstrel_priv *mp, struct minstrel_ht_sta *mi) minstrel_ht_set_rate(mp, mi, rates, i++, mi->max_prob_rate); } + mi->sta->max_rc_amsdu_len = minstrel_ht_get_max_amsdu_len(mi); rates->rate[i].idx = -1; rate_control_set_rates(mp->hw, mi->sta, rates); } -- 2.2.2