From 00d21de5c685ab450ef376acdd1b733badb6b50d Mon Sep 17 00:00:00 2001 From: Zhu Yi Date: Thu, 13 Apr 2006 17:19:02 +0800 Subject: [PATCH] ipw2200: Exponential averaging for signal and noise Level This patch replaces sliding averaging by exponential averaging for reporting the wireless statistics for signal and noise level for ipw2200. See details from: http://www.ces.clemson.edu/linux/ipw2200_averages.shtml Signed-off-by: Bill Moss Signed-off-by: Zhu Yi Signed-off-by: John W. Linville --- drivers/net/wireless/ipw2200.c | 34 ++++++++++++++++++++-------------- 1 file changed, 20 insertions(+), 14 deletions(-) (limited to 'drivers/net/wireless/ipw2200.c') diff --git a/drivers/net/wireless/ipw2200.c b/drivers/net/wireless/ipw2200.c index bca89cff85a..a879edba5fa 100644 --- a/drivers/net/wireless/ipw2200.c +++ b/drivers/net/wireless/ipw2200.c @@ -3771,6 +3771,13 @@ static void inline average_init(struct average *avg) memset(avg, 0, sizeof(*avg)); } +#define DEPTH_RSSI 8 +#define DEPTH_NOISE 16 +static s16 exponential_average(s16 prev_avg, s16 val, u8 depth) +{ + return ((depth-1)*prev_avg + val)/depth; +} + static void average_add(struct average *avg, s16 val) { avg->sum -= avg->entries[avg->pos]; @@ -3800,8 +3807,8 @@ static void ipw_reset_stats(struct ipw_priv *priv) priv->quality = 0; average_init(&priv->average_missed_beacons); - average_init(&priv->average_rssi); - average_init(&priv->average_noise); + priv->exp_avg_rssi = -60; + priv->exp_avg_noise = -85 + 0x100; priv->last_rate = 0; priv->last_missed_beacons = 0; @@ -4008,7 +4015,7 @@ static void ipw_gather_stats(struct ipw_priv *priv) IPW_DEBUG_STATS("Tx quality : %3d%% (%u errors, %u packets)\n", tx_quality, tx_failures_delta, tx_packets_delta); - rssi = average_value(&priv->average_rssi); + rssi = priv->exp_avg_rssi; signal_quality = (100 * (priv->ieee->perfect_rssi - priv->ieee->worst_rssi) * @@ -4023,7 +4030,7 @@ static void ipw_gather_stats(struct ipw_priv *priv) else if (signal_quality < 1) signal_quality = 0; - IPW_DEBUG_STATS("Signal level : %3d%% (%d dBm)\n", + IPW_ERROR("Signal level : %3d%% (%d dBm)\n", signal_quality, rssi); quality = min(beacon_quality, @@ -4577,11 +4584,10 @@ static void ipw_rx_notification(struct ipw_priv *priv, case HOST_NOTIFICATION_NOISE_STATS:{ if (notif->size == sizeof(u32)) { - priv->last_noise = - (u8) (le32_to_cpu(notif->u.noise.value) & - 0xff); - average_add(&priv->average_noise, - priv->last_noise); + priv->exp_avg_noise = + exponential_average(priv->exp_avg_noise, + (u8) (le32_to_cpu(notif->u.noise.value) & 0xff), + DEPTH_NOISE); break; } @@ -7837,9 +7843,9 @@ static void ipw_rx(struct ipw_priv *priv) if (network_packet && priv->assoc_network) { priv->assoc_network->stats.rssi = stats.rssi; - average_add(&priv->average_rssi, - stats.rssi); - priv->last_rx_rssi = stats.rssi; + priv->exp_avg_rssi = + exponential_average(priv->exp_avg_rssi, + stats.rssi, DEPTH_RSSI); } IPW_DEBUG_RX("Frame: len=%u\n", @@ -9579,8 +9585,8 @@ static struct iw_statistics *ipw_get_wireless_stats(struct net_device *dev) } wstats->qual.qual = priv->quality; - wstats->qual.level = average_value(&priv->average_rssi); - wstats->qual.noise = average_value(&priv->average_noise); + wstats->qual.level = priv->exp_avg_rssi; + wstats->qual.noise = priv->exp_avg_noise; wstats->qual.updated = IW_QUAL_QUAL_UPDATED | IW_QUAL_LEVEL_UPDATED | IW_QUAL_NOISE_UPDATED | IW_QUAL_DBM; -- cgit v1.2.3