From 391a200a89bf85bd38f117f34898c24299e3d53d Mon Sep 17 00:00:00 2001 From: Jouni Malinen Date: Fri, 27 Aug 2010 22:22:00 +0300 Subject: [PATCH] mac80211: Do not generate CQM events based on first Beacon frames The signal strength value in a single RX frame is not that reliable, so it is better to delay start of CQM events until there is a real average signal strength from more than a single Beacon frame available. Signed-off-by: Jouni Malinen Signed-off-by: John W. Linville --- net/mac80211/ieee80211_i.h | 7 +++++++ net/mac80211/mlme.c | 9 +++++++++ 2 files changed, 16 insertions(+) diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h index 9af50fbcd48b..16f7fb164c2d 100644 --- a/net/mac80211/ieee80211_i.h +++ b/net/mac80211/ieee80211_i.h @@ -368,6 +368,13 @@ struct ieee80211_if_managed { */ int ave_beacon_signal; + /* + * Number of Beacon frames used in ave_beacon_signal. This can be used + * to avoid generating less reliable cqm events that would be based + * only on couple of received frames. + */ + unsigned int count_beacon_signal; + /* * Last Beacon frame signal strength average (ave_beacon_signal / 16) * that triggered a cqm event. 0 indicates that no event has been diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c index 7915726d791e..0cb822cc12e9 100644 --- a/net/mac80211/mlme.c +++ b/net/mac80211/mlme.c @@ -54,6 +54,12 @@ */ #define IEEE80211_SIGNAL_AVE_WEIGHT 3 +/* + * How many Beacon frames need to have been used in average signal strength + * before starting to indicate signal change events. + */ +#define IEEE80211_SIGNAL_AVE_MIN_COUNT 4 + #define TMR_RUNNING_TIMER 0 #define TMR_RUNNING_CHANSW 1 @@ -1555,13 +1561,16 @@ static void ieee80211_rx_mgmt_beacon(struct ieee80211_sub_if_data *sdata, ifmgd->flags &= ~IEEE80211_STA_RESET_SIGNAL_AVE; ifmgd->ave_beacon_signal = rx_status->signal * 16; ifmgd->last_cqm_event_signal = 0; + ifmgd->count_beacon_signal = 1; } else { ifmgd->ave_beacon_signal = (IEEE80211_SIGNAL_AVE_WEIGHT * rx_status->signal * 16 + (16 - IEEE80211_SIGNAL_AVE_WEIGHT) * ifmgd->ave_beacon_signal) / 16; + ifmgd->count_beacon_signal++; } if (bss_conf->cqm_rssi_thold && + ifmgd->count_beacon_signal >= IEEE80211_SIGNAL_AVE_MIN_COUNT && !(local->hw.flags & IEEE80211_HW_SUPPORTS_CQM_RSSI)) { int sig = ifmgd->ave_beacon_signal / 16; int last_event = ifmgd->last_cqm_event_signal; -- 2.20.1