From 934820867eedeb05541dfd4102b7736bbdea6c68 Mon Sep 17 00:00:00 2001
From: Stanislaw Gruszka <sgruszka@redhat.com>
Date: Mon, 16 Apr 2018 13:56:17 +0200
Subject: [PATCH] mt7601u: use EWMA to calculate avg_rssi
avr_rssi is not calculated correctly as we do not divide result
by 256 (mt76 sum avg_rssi1 and avg_rssi2 and divide by 512).
However dividing by 256 will make avg_rssi almost the same as
last rssi value - not really an average. So use EWMA to calculate
avg_rssi. I've chosen weight_rcp=4 to convergence quicker on signal
strength changes.
Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Acked-by: Jakub Kicinski <kubakici@wp.pl>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
---
drivers/net/wireless/mediatek/mt7601u/mac.c | 4 ++--
drivers/net/wireless/mediatek/mt7601u/mt7601u.h | 5 ++++-
drivers/net/wireless/mediatek/mt7601u/phy.c | 10 +++++++---
3 files changed, 13 insertions(+), 6 deletions(-)
diff --git a/drivers/net/wireless/mediatek/mt7601u/mac.c b/drivers/net/wireless/mediatek/mt7601u/mac.c
index d55d7040a56d3..148c36d3d2e59 100644
--- a/drivers/net/wireless/mediatek/mt7601u/mac.c
+++ b/drivers/net/wireless/mediatek/mt7601u/mac.c
@@ -453,7 +453,7 @@ mt7601u_rx_monitor_beacon(struct mt7601u_dev *dev, struct mt7601u_rxwi *rxwi,
{
dev->bcn_freq_off = rxwi->freq_off;
dev->bcn_phy_mode = FIELD_GET(MT_RXWI_RATE_PHY, rate);
- dev->avg_rssi = (dev->avg_rssi * 15) / 16 + (rssi << 8);
+ ewma_rssi_add(&dev->avg_rssi, -rssi);
}
static int
@@ -503,7 +503,7 @@ u32 mt76_mac_process_rx(struct mt7601u_dev *dev, struct sk_buff *skb,
if (mt7601u_rx_is_our_beacon(dev, data))
mt7601u_rx_monitor_beacon(dev, rxwi, rate, rssi);
else if (rxwi->rxinfo & cpu_to_le32(MT_RXINFO_U2M))
- dev->avg_rssi = (dev->avg_rssi * 15) / 16 + (rssi << 8);
+ ewma_rssi_add(&dev->avg_rssi, -rssi);
spin_unlock_bh(&dev->con_mon_lock);
return len;
diff --git a/drivers/net/wireless/mediatek/mt7601u/mt7601u.h b/drivers/net/wireless/mediatek/mt7601u/mt7601u.h
index 9233744451a93..db317d8c16527 100644
--- a/drivers/net/wireless/mediatek/mt7601u/mt7601u.h
+++ b/drivers/net/wireless/mediatek/mt7601u/mt7601u.h
@@ -23,6 +23,7 @@
#include <linux/completion.h>
#include <net/mac80211.h>
#include <linux/debugfs.h>
+#include <linux/average.h>
#include "regs.h"
@@ -138,6 +139,8 @@ enum {
MT7601U_STATE_MORE_STATS,
};
+DECLARE_EWMA(rssi, 10, 4);
+
/**
* struct mt7601u_dev - adapter structure
* @lock: protects @wcid->tx_rate.
@@ -220,7 +223,7 @@ struct mt7601u_dev {
s8 bcn_freq_off;
u8 bcn_phy_mode;
- int avg_rssi; /* starts at 0 and converges */
+ struct ewma_rssi avg_rssi;
u8 agc_save;
diff --git a/drivers/net/wireless/mediatek/mt7601u/phy.c b/drivers/net/wireless/mediatek/mt7601u/phy.c
index 9a90f1f09fb0d..9d2f9a776ef18 100644
--- a/drivers/net/wireless/mediatek/mt7601u/phy.c
+++ b/drivers/net/wireless/mediatek/mt7601u/phy.c
@@ -975,6 +975,7 @@ void mt7601u_agc_restore(struct mt7601u_dev *dev)
static void mt7601u_agc_tune(struct mt7601u_dev *dev)
{
u8 val = mt7601u_agc_default(dev);
+ long avg_rssi;
if (test_bit(MT7601U_STATE_SCANNING, &dev->state))
return;
@@ -984,9 +985,12 @@ static void mt7601u_agc_tune(struct mt7601u_dev *dev)
* Rssi updates are only on beacons and U2M so should work...
*/
spin_lock_bh(&dev->con_mon_lock);
- if (dev->avg_rssi <= -70)
+ avg_rssi = ewma_rssi_read(&dev->avg_rssi);
+ WARN_ON_ONCE(avg_rssi == 0);
+ avg_rssi = -avg_rssi;
+ if (avg_rssi <= -70)
val -= 0x20;
- else if (dev->avg_rssi <= -60)
+ else if (avg_rssi <= -60)
val -= 0x10;
spin_unlock_bh(&dev->con_mon_lock);
@@ -1102,7 +1106,7 @@ void mt7601u_phy_con_cal_onoff(struct mt7601u_dev *dev,
/* Start/stop collecting beacon data */
spin_lock_bh(&dev->con_mon_lock);
ether_addr_copy(dev->ap_bssid, info->bssid);
- dev->avg_rssi = 0;
+ ewma_rssi_init(&dev->avg_rssi);
dev->bcn_freq_off = MT_FREQ_OFFSET_INVALID;
spin_unlock_bh(&dev->con_mon_lock);
--
2.39.5