Hi Nicolas, On Tue, Dec 4, 2012 at 7:08 PM, Nicolas Cavallari <Nicolas.Cavallari@xxxxxx> wrote: > On 04/12/2012 00:00, Julian Calaby wrote: >> Hi Simon, >> >> On Tue, Dec 4, 2012 at 8:21 AM, Simon Wunderlich >> <simon.wunderlich@xxxxxxxxxxxxxxxxxxxx> wrote: >>> 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 <siwu@xxxxxxxxxxxxxxxxxx> >>> Signed-off-by: Mathias Kretschmer <mathias.kretschmer@xxxxxxxxxxxxxxxxxxx> >>> --- >>> net/mac80211/ibss.c | 13 +++++++++++++ >>> 1 file changed, 13 insertions(+) >>> >>> diff --git a/net/mac80211/ibss.c b/net/mac80211/ibss.c >>> index fa862b2..1a5d29c 100644 >>> --- a/net/mac80211/ibss.c >>> +++ b/net/mac80211/ibss.c >>> @@ -201,6 +201,19 @@ 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; >>> + >> >> I don't know if this is done elsewhere, but this code doesn't match >> the comment - there is no test for IBSS mode. >> >> Thanks, >> > > Do you happen to know any code path that calls > __ieee80211_sta_join_ibss() without being in IBSS mode ? Groan. I clearly need to read patches better. Thanks, -- Julian Calaby Email: julian.calaby@xxxxxxxxx Profile: http://www.google.com/profiles/julian.calaby/ .Plan: http://sites.google.com/site/juliancalaby/ -- 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
