[PATCH] bcm43xx: improved statistics

This patch improves the statistics returned from
bcm43xx_get_wireless_stats. The signal level comes from smoothing the
"rssi" value returned by the firmware after it is converted into a
dBm value by the driver. The quality value is a hack derived from the
smoothed level and an assumed RX_POWER_MAX of -10 dBM. The noise value
is still the one calculated from the clean-room formula. On my system,
this is roughly -65 dBm, which seems too high.

The revised version uses the ieee80211 spinlock to protect traversing
of the network list.
Signed-Off-By: NLarry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

drivers/net/wireless/bcm43xx/bcm43xx_wx.c

@@ -47,6 +47,9 @@
 #define BCM43xx_WX_VERSION	18
 
 #define MAX_WX_STRING		80
+/* FIXME: the next line is a guess as to what the maximum value of RX power
+          (in dBm) might be */
+#define RX_POWER_MAX		-10
 
 
 static int bcm43xx_wx_get_name(struct net_device *net_dev,
@@ -228,14 +231,14 @@ static int bcm43xx_wx_get_rangeparams(struct net_device *net_dev,
 
 	range->max_qual.qual = 100;
 	/* TODO: Real max RSSI */
-	range->max_qual.level = 3;
-	range->max_qual.noise = 100;
-	range->max_qual.updated = 7;
+	range->max_qual.level = 0;
+	range->max_qual.noise = 0;
+	range->max_qual.updated = IW_QUAL_ALL_UPDATED;
 
-	range->avg_qual.qual = 70;
-	range->avg_qual.level = 2;
-	range->avg_qual.noise = 40;
-	range->avg_qual.updated = 7;
+	range->avg_qual.qual = 50;
+	range->avg_qual.level = 0;
+	range->avg_qual.noise = 0;
+	range->avg_qual.updated = IW_QUAL_ALL_UPDATED;
 
 	range->min_rts = BCM43xx_MIN_RTS_THRESHOLD;
 	range->max_rts = BCM43xx_MAX_RTS_THRESHOLD;
@@ -840,6 +843,9 @@ static struct iw_statistics *bcm43xx_get_wireless_stats(struct net_device *net_d
 	struct bcm43xx_private *bcm = bcm43xx_priv(net_dev);
 	struct ieee80211softmac_device *mac = ieee80211_priv(net_dev);
 	struct iw_statistics *wstats;
+	struct ieee80211_network *network = NULL;
+	static int tmp_level = 0;
+	unsigned long flags;
 
 	wstats = &bcm->stats.wstats;
 	if (!mac->associated) {
@@ -857,16 +863,25 @@ static struct iw_statistics *bcm43xx_get_wireless_stats(struct net_device *net_d
 		wstats->qual.level = 0;
 		wstats->qual.noise = 0;
 		wstats->qual.updated = 7;
-		wstats->qual.updated |= IW_QUAL_NOISE_INVALID |
-			IW_QUAL_QUAL_INVALID | IW_QUAL_LEVEL_INVALID;
+		wstats->qual.updated |= IW_QUAL_ALL_UPDATED;
 		return wstats;
 	}
 	/* fill in the real statistics when iface associated */
-	wstats->qual.qual = 100;     // TODO: get the real signal quality
-	wstats->qual.level = 3 - bcm->stats.link_quality;
+	spin_lock_irqsave(&mac->ieee->lock, flags);
+	list_for_each_entry(network, &mac->ieee->network_list, list) {
+		if (!memcmp(mac->associnfo.bssid, network->bssid, ETH_ALEN)) {
+			if (!tmp_level)		/* get initial value */
+				tmp_level = network->stats.rssi;
+			else			/* smooth results */
+				tmp_level = (7 * tmp_level + network->stats.rssi)/8;
+			break;
+		}
+	}
+	spin_unlock_irqrestore(&mac->ieee->lock, flags);
+	wstats->qual.level = tmp_level;
+	wstats->qual.qual = 100 + tmp_level - RX_POWER_MAX; // TODO: get the real signal quality
 	wstats->qual.noise = bcm->stats.noise;
-	wstats->qual.updated = IW_QUAL_QUAL_UPDATED | IW_QUAL_LEVEL_UPDATED |
-			IW_QUAL_NOISE_UPDATED;
+	wstats->qual.updated = IW_QUAL_ALL_UPDATED;
 	wstats->discard.code = bcm->ieee->ieee_stats.rx_discards_undecryptable;
 	wstats->discard.retries = bcm->ieee->ieee_stats.tx_retry_limit_exceeded;
 	wstats->discard.nwid = bcm->ieee->ieee_stats.tx_discards_wrong_sa;