From 338c17ae311e6b5a439573a4043fd2d9237cd1d5 Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Fri, 28 Aug 2015 10:52:54 +0200 Subject: [PATCH] mac80211: use DECLARE_EWMA for ave_beacon_signal It doesn't seem problematic to change the weight for the average beacon signal from 3 to 4, so use DECLARE_EWMA. This also makes the code easier to maintain since bugs like the one fixed in the previous patch can't happen as easily. With a fix from Avraham Stern to invert the sign since EMWA uses unsigned values only. Signed-off-by: Johannes Berg --- net/mac80211/ieee80211_i.h | 10 +++------- net/mac80211/mlme.c | 20 ++++++-------------- net/mac80211/util.c | 2 +- 3 files changed, 10 insertions(+), 22 deletions(-) diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h index 9482f323fd19..f0aee764d9cd 100644 --- a/net/mac80211/ieee80211_i.h +++ b/net/mac80211/ieee80211_i.h @@ -419,6 +419,8 @@ struct ieee80211_sta_tx_tspec { bool downgraded; }; +DECLARE_EWMA(beacon_signal, 16, 4) + struct ieee80211_if_managed { struct timer_list timer; struct timer_list conn_mon_timer; @@ -490,13 +492,7 @@ struct ieee80211_if_managed { s16 p2p_noa_index; - /* - * Weighted average of the signal strength from Beacon frames in the - * current BSS. This is in units of 1/16 of the signal unit to maintain - * accuracy and to speed up calculations, i.e., the value need to be - * divided by 16 to get the actual value. - */ - int ave_beacon_signal; + struct ewma_beacon_signal ave_beacon_signal; /* * Number of Beacon frames used in ave_beacon_signal. This can be used diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c index 79cfc2b35ef0..c7d316b440ef 100644 --- a/net/mac80211/mlme.c +++ b/net/mac80211/mlme.c @@ -81,13 +81,6 @@ MODULE_PARM_DESC(probe_wait_ms, "Maximum time(ms) to wait for probe response" " before disconnecting (reason 4)."); -/* - * Weight given to the latest Beacon frame when calculating average signal - * strength for Beacon frames received in the current BSS. This must be - * between 1 and 15. - */ -#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. @@ -3366,21 +3359,19 @@ static void ieee80211_rx_mgmt_beacon(struct ieee80211_sub_if_data *sdata, /* Track average RSSI from the Beacon frames of the current AP */ if (ifmgd->flags & IEEE80211_STA_RESET_SIGNAL_AVE) { ifmgd->flags &= ~IEEE80211_STA_RESET_SIGNAL_AVE; - ifmgd->ave_beacon_signal = rx_status->signal * 16; + ewma_beacon_signal_init(&ifmgd->ave_beacon_signal); ifmgd->last_cqm_event_signal = 0; ifmgd->count_beacon_signal = 1; ifmgd->last_ave_beacon_signal = 0; } 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++; } + ewma_beacon_signal_add(&ifmgd->ave_beacon_signal, -rx_status->signal); + if (ifmgd->rssi_min_thold != ifmgd->rssi_max_thold && ifmgd->count_beacon_signal >= IEEE80211_SIGNAL_AVE_MIN_COUNT) { - int sig = ifmgd->ave_beacon_signal / 16; + int sig = -ewma_beacon_signal_read(&ifmgd->ave_beacon_signal); int last_sig = ifmgd->last_ave_beacon_signal; struct ieee80211_event event = { .type = RSSI_EVENT, @@ -3407,10 +3398,11 @@ static void ieee80211_rx_mgmt_beacon(struct ieee80211_sub_if_data *sdata, if (bss_conf->cqm_rssi_thold && ifmgd->count_beacon_signal >= IEEE80211_SIGNAL_AVE_MIN_COUNT && !(sdata->vif.driver_flags & IEEE80211_VIF_SUPPORTS_CQM_RSSI)) { - int sig = ifmgd->ave_beacon_signal / 16; + int sig = -ewma_beacon_signal_read(&ifmgd->ave_beacon_signal); int last_event = ifmgd->last_cqm_event_signal; int thold = bss_conf->cqm_rssi_thold; int hyst = bss_conf->cqm_rssi_hyst; + if (sig < thold && (last_event == 0 || sig < last_event - hyst)) { ifmgd->last_cqm_event_signal = sig; diff --git a/net/mac80211/util.c b/net/mac80211/util.c index f16705675339..9cabf076d718 100644 --- a/net/mac80211/util.c +++ b/net/mac80211/util.c @@ -2543,7 +2543,7 @@ int ieee80211_ave_rssi(struct ieee80211_vif *vif) /* non-managed type inferfaces */ return 0; } - return ifmgd->ave_beacon_signal / 16; + return -ewma_beacon_signal_read(&ifmgd->ave_beacon_signal); } EXPORT_SYMBOL_GPL(ieee80211_ave_rssi); -- 2.39.5