[PATCH] zd1211rw: Fix of signal strength and quality measurement

Caused by a documentation issue I mixed up fields of the zd_status
structure. This patch fixes it and improves also the average
computation, which is now using only measurements of packets sent
by the access point.

Signed-off-by: Ulrich Kunitz <kune@deine-taler.de>
Signed-off-by: Daniel Drake <dsd@gentoo.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 35 insertions, 8 deletions

diff --git a/drivers/net/wireless/zd1211rw/zd_mac.c b/drivers/net/wireless/zd1211rw/zd_mac.c
index d6f3e02a0b54..a9bd80a08613 100644
--- a/drivers/net/wireless/zd1211rw/zd_mac.c
+++ b/drivers/net/wireless/zd1211rw/zd_mac.c
@@ -816,13 +816,25 @@ static int filter_rx(struct ieee80211_device *ieee,
         return -EINVAL;
 }
 
-static void update_qual_rssi(struct zd_mac *mac, u8 qual_percent, u8 rssi)
+static void update_qual_rssi(struct zd_mac *mac,
+                             const u8 *buffer, unsigned int length,
+                             u8 qual_percent, u8 rssi_percent)
 {
         unsigned long flags;
+        struct ieee80211_hdr_3addr *hdr;
+        int i;
+
+        hdr = (struct ieee80211_hdr_3addr *)buffer;
+        if (length < offsetof(struct ieee80211_hdr_3addr, addr3))
+                return;
+        if (memcmp(hdr->addr2, zd_mac_to_ieee80211(mac)->bssid, ETH_ALEN) != 0)
+                return;
 
         spin_lock_irqsave(&mac->lock, flags);
-        mac->qual_average = (7 * mac->qual_average + qual_percent) / 8;
-        mac->rssi_average = (7 * mac->rssi_average + rssi) / 8;
+        i = mac->stats_count % ZD_MAC_STATS_BUFFER_SIZE;
+        mac->qual_buffer[i] = qual_percent;
+        mac->rssi_buffer[i] = rssi_percent;
+        mac->stats_count++;
         spin_unlock_irqrestore(&mac->lock, flags);
 }
 
@@ -853,7 +865,6 @@ static int fill_rx_stats(struct ieee80211_rx_stats *stats,
         if (stats->rate)
                 stats->mask |= IEEE80211_STATMASK_RATE;
 
-        update_qual_rssi(mac, stats->signal, stats->rssi);
         return 0;
 }
 
@@ -877,6 +888,8 @@ int zd_mac_rx(struct zd_mac *mac, const u8 *buffer, unsigned int length)
                   sizeof(struct rx_status);
         buffer += ZD_PLCP_HEADER_SIZE;
 
+        update_qual_rssi(mac, buffer, length, stats.signal, stats.rssi);
+
         r = filter_rx(ieee, buffer, length, &stats);
         if (r <= 0)
                 return r;
@@ -981,17 +994,31 @@ struct iw_statistics *zd_mac_get_wireless_stats(struct net_device *ndev)
 {
         struct zd_mac *mac = zd_netdev_mac(ndev);
         struct iw_statistics *iw_stats = &mac->iw_stats;
+        unsigned int i, count, qual_total, rssi_total;
 
         memset(iw_stats, 0, sizeof(struct iw_statistics));
         /* We are not setting the status, because ieee->state is not updated
          * at all and this driver doesn't track authentication state.
          */
         spin_lock_irq(&mac->lock);
-        iw_stats->qual.qual = mac->qual_average;
-        iw_stats->qual.level = mac->rssi_average;
-        iw_stats->qual.updated = IW_QUAL_QUAL_UPDATED|IW_QUAL_LEVEL_UPDATED|
-                                 IW_QUAL_NOISE_INVALID;
+        count = mac->stats_count < ZD_MAC_STATS_BUFFER_SIZE ?
+                mac->stats_count : ZD_MAC_STATS_BUFFER_SIZE;
+        qual_total = rssi_total = 0;
+        for (i = 0; i < count; i++) {
+                qual_total += mac->qual_buffer[i];
+                rssi_total += mac->rssi_buffer[i];
+        }
         spin_unlock_irq(&mac->lock);
+        iw_stats->qual.updated = IW_QUAL_NOISE_INVALID;
+        if (count > 0) {
+                iw_stats->qual.qual = qual_total / count;
+                iw_stats->qual.level = rssi_total / count;
+                iw_stats->qual.updated |=
+                        IW_QUAL_QUAL_UPDATED|IW_QUAL_LEVEL_UPDATED;
+        } else {
+                iw_stats->qual.updated |=
+                        IW_QUAL_QUAL_INVALID|IW_QUAL_LEVEL_INVALID;
+        }
         /* TODO: update counter */
         return iw_stats;
 }