Commit 338c17ae authored by Johannes Berg's avatar Johannes Berg
Browse files

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: default avatarJohannes Berg <johannes.berg@intel.com>
parent 8ec6d978

net/mac80211/ieee80211_i.h

+3 −7
Original line number Diff line number Diff line
@@ -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

net/mac80211/mlme.c

+6 −14
Original line number Diff line number Diff line
@@ -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;

net/mac80211/util.c

+1 −1
Original line number Diff line number Diff line
@@ -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);

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