[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, 46 insertions, 15 deletions

diff --git a/drivers/net/wireless/zd1211rw/zd_chip.c b/drivers/net/wireless/zd1211rw/zd_chip.c
index da9d06bdb818..aa792821854e 100644
--- a/drivers/net/wireless/zd1211rw/zd_chip.c
+++ b/drivers/net/wireless/zd1211rw/zd_chip.c
@@ -1430,9 +1430,43 @@ static int ofdm_qual_db(u8 status_quality, u8 rate, unsigned int size)
                         break;
         }
 
+        switch (rate) {
+        case ZD_OFDM_RATE_6M:
+        case ZD_OFDM_RATE_9M:
+                i += 3;
+                break;
+        case ZD_OFDM_RATE_12M:
+        case ZD_OFDM_RATE_18M:
+                i += 5;
+                break;
+        case ZD_OFDM_RATE_24M:
+        case ZD_OFDM_RATE_36M:
+                i += 9;
+                break;
+        case ZD_OFDM_RATE_48M:
+        case ZD_OFDM_RATE_54M:
+                i += 15;
+                break;
+        default:
+                return -EINVAL;
+        }
+
         return i;
 }
 
+static int ofdm_qual_percent(u8 status_quality, u8 rate, unsigned int size)
+{
+        int r;
+
+        r = ofdm_qual_db(status_quality, rate, size);
+        ZD_ASSERT(r >= 0);
+        if (r < 0)
+                r = 0;
+
+        r = (r * 100)/29;
+        return r <= 100 ? r : 100;
+}
+
 static unsigned int log10times100(unsigned int x)
 {
         static const u8 log10[] = {
@@ -1476,31 +1510,28 @@ static int cck_snr_db(u8 status_quality)
         return r;
 }
 
-static int rx_qual_db(const void *rx_frame, unsigned int size,
-                      const struct rx_status *status)
+static int cck_qual_percent(u8 status_quality)
 {
-        return (status->frame_status&ZD_RX_OFDM) ?
-                ofdm_qual_db(status->signal_quality_ofdm,
-                             zd_ofdm_plcp_header_rate(rx_frame),
-                             size) :
-                cck_snr_db(status->signal_quality_cck);
+        int r;
+
+        r = cck_snr_db(status_quality);
+        r = (100*r)/17;
+        return r <= 100 ? r : 100;
 }
 
 u8 zd_rx_qual_percent(const void *rx_frame, unsigned int size,
                       const struct rx_status *status)
 {
-        int r = rx_qual_db(rx_frame, size, status);
-        if (r < 0)
-                r = 0;
-        r = (r * 100) / 14;
-        if (r > 100)
-                r = 100;
-        return r;
+        return (status->frame_status&ZD_RX_OFDM) ?
+                ofdm_qual_percent(status->signal_quality_ofdm,
+                                  zd_ofdm_plcp_header_rate(rx_frame),
+                                  size) :
+                cck_qual_percent(status->signal_quality_cck);
 }
 
 u8 zd_rx_strength_percent(u8 rssi)
 {
-        int r = (rssi*100) / 30;
+        int r = (rssi*100) / 41;
         if (r > 100)
                 r = 100;
         return (u8) r;