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 <j@xxxxx>
---
net/mac80211/ieee80211_i.h | 7 +++++++
net/mac80211/mlme.c | 9 +++++++++
2 files changed, 16 insertions(+)
--- wireless-testing.orig/net/mac80211/ieee80211_i.h 2010-08-17 11:43:06.000000000 +0300
+++ wireless-testing/net/mac80211/ieee80211_i.h 2010-08-27 21:43:44.000000000 +0300
@@ -375,6 +375,13 @@ 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
* generated for the current association.
--- wireless-testing.orig/net/mac80211/mlme.c 2010-08-27 21:43:37.000000000 +0300
+++ wireless-testing/net/mac80211/mlme.c 2010-08-27 21:43:44.000000000 +0300
@@ -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
@@ -1550,13 +1556,16 @@ static void ieee80211_rx_mgmt_beacon(str
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;
--
Jouni Malinen PGP id EFC895FA
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