From patchwork Sat Jan 26 20:37:25 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Thomas Pedersen X-Patchwork-Id: 2050261 Return-Path: X-Original-To: patchwork-linux-wireless@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork2.kernel.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by patchwork2.kernel.org (Postfix) with ESMTP id A9DBBE01EC for ; Sat, 26 Jan 2013 20:38:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754128Ab3AZUie (ORCPT ); Sat, 26 Jan 2013 15:38:34 -0500 Received: from mail-pa0-f52.google.com ([209.85.220.52]:50326 "EHLO mail-pa0-f52.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754120Ab3AZUid (ORCPT ); Sat, 26 Jan 2013 15:38:33 -0500 Received: by mail-pa0-f52.google.com with SMTP id fb1so839090pad.25 for ; Sat, 26 Jan 2013 12:38:33 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20120113; h=x-received:from:to:cc:subject:date:message-id:x-mailer :x-gm-message-state; bh=JkO92iUnMGo6eXzjTXJpORKYPgkvMxpVTKTqFGva8+o=; b=V1MP5stGeXYqFB4IhYZKiqefOmO5shLMMUMRVIKIxfq3az2ofznT6vKnKTVBjfwx/z x+5xbsRYyf+QgP0RsqP6d2D8Ll/fEBmOBLFNIxIgWoSHAUUily3q1koeZIAzuRUKUxFf IUv5SdoDS+8edj6SyOHDapnhVQTSQMQs4i3vJbBrgmNF/EZzFGH5rzgHnq8sNbcrZ/0u QNYq7XRzu4KPX9V0dvDUJ5EBCCZmihXoR+4fnX2YH7pZjLr3YLfMYJHC+/e699EIG7Az ZkOuzTPDNZvlZ6eVZla4xZNs02J2LuS/7AhOLlPBii/F0LEFJT4oV5XenZkUgjBAPT2h E4dQ== X-Received: by 10.66.89.132 with SMTP id bo4mr23720197pab.62.1359232713200; Sat, 26 Jan 2013 12:38:33 -0800 (PST) Received: from cable.lan (70-35-43-50.static.wiline.com. [70.35.43.50]) by mx.google.com with ESMTPS id o5sm3396845paz.32.2013.01.26.12.38.30 (version=TLSv1.2 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Sat, 26 Jan 2013 12:38:31 -0800 (PST) From: Thomas Pedersen To: johannes@sipsolutions.net Cc: linux-wireless@vger.kernel.org, devel@lists.open80211s.org, Thomas Pedersen Subject: [PATCH v2] mac80211: dynamic short slot time for MBSSs Date: Sat, 26 Jan 2013 12:37:25 -0800 Message-Id: <1359232645-10563-1-git-send-email-thomas@cozybit.com> X-Mailer: git-send-email 1.7.10.4 X-Gm-Message-State: ALoCoQn0J+r42kg+9zBmodkCV1X9XjiIAVYLg4UAX6IaLeAn/R38Qu1LWbIyE34jOjaH7XBXPbb8 Sender: linux-wireless-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org The standard mandates mesh STAs to set the ERP Short Slot Time capability info bit in beacons to 0. Even though this is their way of disallowing short slot time for mesh STAs, there should be no harm in enabling it if we determine all STAs in the current MBSS support ERP rates. Increases throughput about 20% for legacy rates when enabled. Signed-off-by: Thomas Pedersen --- v2: fix survey logic net/mac80211/mesh.c | 5 ---- net/mac80211/mesh_plink.c | 67 +++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 67 insertions(+), 5 deletions(-) diff --git a/net/mac80211/mesh.c b/net/mac80211/mesh.c index 694e273..f920da1 100644 --- a/net/mac80211/mesh.c +++ b/net/mac80211/mesh.c @@ -629,11 +629,6 @@ void ieee80211_start_mesh(struct ieee80211_sub_if_data *sdata) sdata->vif.bss_conf.basic_rates = ieee80211_mandatory_rates(local, band); - if (band == IEEE80211_BAND_5GHZ) { - sdata->vif.bss_conf.use_short_slot = true; - changed |= BSS_CHANGED_ERP_SLOT; - } - ieee80211_bss_info_change_notify(sdata, changed); netif_carrier_on(sdata->dev); diff --git a/net/mac80211/mesh_plink.c b/net/mac80211/mesh_plink.c index 4e1d406..f79ab88 100644 --- a/net/mac80211/mesh_plink.c +++ b/net/mac80211/mesh_plink.c @@ -55,6 +55,70 @@ static inline void mesh_plink_fsm_restart(struct sta_info *sta) sta->plink_retries = 0; } +/* + * mesh_set_short_slot_time - enable / disable ERP short slot time. + * + * The standard indirectly mandates mesh STAs to turn off short slot time by + * disallowing advertising this (802.11-2012 8.4.1.4), but that doesn't mean we + * can't be sneaky about it. Enable short slot time if all mesh STAs in the + * MBSS support ERP rates. + * + * Returns BSS_CHANGED_ERP_SLOT or 0 for no change. + */ +static u32 mesh_set_short_slot_time(struct ieee80211_sub_if_data *sdata) +{ + struct ieee80211_local *local = sdata->local; + enum ieee80211_band band = ieee80211_get_sdata_band(sdata); + struct ieee80211_rate *bitrates; + struct ieee80211_supported_band *sband; + struct sta_info *sta; + u32 rates, changed = 0; + int i; + bool short_slot = false; + + if (band == IEEE80211_BAND_5GHZ) { + /* (IEEE 802.11-2012 19.4.5) */ + short_slot = true; + goto out; + } else if (band != IEEE80211_BAND_2GHZ || + (band == IEEE80211_BAND_2GHZ && + local->hw.flags & IEEE80211_HW_2GHZ_SHORT_SLOT_INCAPABLE)) + goto out; + + sband = local->hw.wiphy->bands[band]; + bitrates = sband->bitrates; + + rcu_read_lock(); + list_for_each_entry_rcu(sta, &local->sta_list, list) { + if (sdata != sta->sdata || + sta->plink_state != NL80211_PLINK_ESTAB) + continue; + + short_slot = false; + rates = sta->sta.supp_rates[band]; + for_each_set_bit(i, (unsigned long *)&rates, + sizeof(rates) * BITS_PER_BYTE) { + if (bitrates[i].flags & IEEE80211_RATE_ERP_G) { + short_slot = true; + break; + } + } + + if (!short_slot) + break; + } + rcu_read_unlock(); + +out: + if (sdata->vif.bss_conf.use_short_slot != short_slot) { + sdata->vif.bss_conf.use_short_slot = short_slot; + changed = BSS_CHANGED_ERP_SLOT; + mpl_dbg(sdata, "mesh_plink %pM: ERP short slot time %d\n", + sdata->vif.addr, short_slot); + } + return changed; +} + /** * mesh_set_ht_prot_mode - set correct HT protection mode * @@ -894,6 +958,7 @@ void mesh_rx_plink_frame(struct ieee80211_sub_if_data *sdata, struct ieee80211_m spin_unlock_bh(&sta->lock); changed |= mesh_plink_inc_estab_count(sdata); changed |= mesh_set_ht_prot_mode(sdata); + changed |= mesh_set_short_slot_time(sdata); mpl_dbg(sdata, "Mesh plink with %pM ESTABLISHED\n", sta->sta.addr); break; @@ -929,6 +994,7 @@ void mesh_rx_plink_frame(struct ieee80211_sub_if_data *sdata, struct ieee80211_m spin_unlock_bh(&sta->lock); changed |= mesh_plink_inc_estab_count(sdata); changed |= mesh_set_ht_prot_mode(sdata); + changed |= mesh_set_short_slot_time(sdata); mpl_dbg(sdata, "Mesh plink with %pM ESTABLISHED\n", sta->sta.addr); mesh_plink_frame_tx(sdata, @@ -952,6 +1018,7 @@ void mesh_rx_plink_frame(struct ieee80211_sub_if_data *sdata, struct ieee80211_m mod_plink_timer(sta, mshcfg->dot11MeshHoldingTimeout); spin_unlock_bh(&sta->lock); changed |= mesh_set_ht_prot_mode(sdata); + changed |= mesh_set_short_slot_time(sdata); mesh_plink_frame_tx(sdata, WLAN_SP_MESH_PEERING_CLOSE, sta->sta.addr, llid, plid, reason); break;