From 2f91a96799d155d56a0663dbe00fc45c6721a763 Mon Sep 17 00:00:00 2001 From: Simon Wunderlich Date: Mon, 3 Dec 2012 22:21:30 +0100 Subject: [PATCH] mac80211: adapt slot time in IBSS mode In 5GHz/802.11a, we are allowed to use short slot times. Doing this may increases performance by 20% for legacy connections (54 MBit/s). I can confirm this in my tests (27% more throughput using iperf), and also have a small positive effect (5% more throughput) for HT rates, tested on 1 stream. Signed-off-by: Simon Wunderlich Signed-off-by: Mathias Kretschmer Signed-off-by: Johannes Berg --- net/mac80211/ibss.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/net/mac80211/ibss.c b/net/mac80211/ibss.c index 11a6a1bde2fd..700d0ed736c9 100644 --- a/net/mac80211/ibss.c +++ b/net/mac80211/ibss.c @@ -201,6 +201,20 @@ static void __ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata, bss_change |= BSS_CHANGED_BASIC_RATES; bss_change |= BSS_CHANGED_HT; bss_change |= BSS_CHANGED_IBSS; + + /* + * In 5 GHz/802.11a, we can always use short slot time. + * (IEEE 802.11-2012 18.3.8.7) + * + * In 2.4GHz, we must always use long slots in IBSS for compatibility + * reasons. + * (IEEE 802.11-2012 19.4.5) + * + * HT follows these specifications (IEEE 802.11-2012 20.3.18) + */ + sdata->vif.bss_conf.use_short_slot = chan->band == IEEE80211_BAND_5GHZ; + bss_change |= BSS_CHANGED_ERP_SLOT; + sdata->vif.bss_conf.ibss_joined = true; sdata->vif.bss_conf.ibss_creator = creator; ieee80211_bss_info_change_notify(sdata, bss_change); -- 2.39.5