rtl8187: Improve wireless statistics for RTL8187

The current wireless statistics for the RTL8187 poorly indicate the signal
strength and quality. With testing, I found that the AGC value is inversely
correlated with the strength as in the RTL8187B. By implementing a similar
calculation, much more code becomes common to the two devices.

Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Tested by: Martín Ernesto Barreyro <barreyromartin@gmail.com>
Acked-by: Hin-Tak Leung <htl10@users.sourceforge.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

diff --git a/drivers/net/wireless/rtl818x/rtl8187_dev.c b/drivers/net/wireless/rtl818x/rtl8187_dev.c
index dbf52e8bbd7a6da1164e73ecc13453aa74ce98b4..417a2d7b57648da4130bbcd7df18d09ba31aa175 100644 (file)
--- a/drivers/net/wireless/rtl818x/rtl8187_dev.c
+++ b/drivers/net/wireless/rtl818x/rtl8187_dev.c
@@ -313,29 +313,14 @@ static void rtl8187_rx_cb(struct urb *urb)
                struct rtl8187_rx_hdr *hdr =
                        (typeof(hdr))(skb_tail_pointer(skb) - sizeof(*hdr));
                flags = le32_to_cpu(hdr->flags);
-               signal = hdr->signal & 0x7f;
+               /* As with the RTL8187B below, the AGC is used to calculate
+                * signal strength and quality. In this case, the scaling
+                * constants are derived from the output of p54usb.
+                */
+               quality = 130 - ((41 * hdr->agc) >> 6);
+               signal = -4 - ((27 * hdr->agc) >> 6);
                rx_status.antenna = (hdr->signal >> 7) & 1;
-               rx_status.noise = hdr->noise;
                rx_status.mactime = le64_to_cpu(hdr->mac_time);
-               priv->quality = signal;
-               rx_status.qual = priv->quality;
-               priv->noise = hdr->noise;
-               rate = (flags >> 20) & 0xF;
-               if (rate > 3) { /* OFDM rate */
-                       if (signal > 90)
-                               signal = 90;
-                       else if (signal < 25)
-                               signal = 25;
-                       signal = 90 - signal;
-               } else {        /* CCK rate */
-                       if (signal > 95)
-                               signal = 95;
-                       else if (signal < 30)
-                               signal = 30;
-                       signal = 95 - signal;
-               }
-               rx_status.signal = signal;
-               priv->signal = signal;
        } else {
                struct rtl8187b_rx_hdr *hdr =
                        (typeof(hdr))(skb_tail_pointer(skb) - sizeof(*hdr));
@@ -353,18 +338,18 @@ static void rtl8187_rx_cb(struct urb *urb)
                 */
                flags = le32_to_cpu(hdr->flags);
                quality = 170 - hdr->agc;
-               if (quality > 100)
-                       quality = 100;
                signal = 14 - hdr->agc / 2;
-               rx_status.qual = quality;
-               priv->quality = quality;
-               rx_status.signal = signal;
-               priv->signal = signal;
                rx_status.antenna = (hdr->rssi >> 7) & 1;
                rx_status.mactime = le64_to_cpu(hdr->mac_time);
-               rate = (flags >> 20) & 0xF;
        }
 
+       if (quality > 100)
+               quality = 100;
+       rx_status.qual = quality;
+       priv->quality = quality;
+       rx_status.signal = signal;
+       priv->signal = signal;
+       rate = (flags >> 20) & 0xF;
        skb_trim(skb, flags & 0x0FFF);
        rx_status.rate_idx = rate;
        rx_status.freq = dev->conf.channel->center_freq;
@@ -1293,6 +1278,7 @@ static int __devinit rtl8187_probe(struct usb_interface *intf,
 
        priv->mode = NL80211_IFTYPE_MONITOR;
        dev->flags = IEEE80211_HW_HOST_BROADCAST_PS_BUFFERING |
+                    IEEE80211_HW_SIGNAL_DBM |
                     IEEE80211_HW_RX_INCLUDES_FCS;
 
        eeprom.data = dev;
@@ -1408,13 +1394,8 @@ static int __devinit rtl8187_probe(struct usb_interface *intf,
                (*channel++).hw_value = txpwr >> 8;
        }
 
-       if (priv->is_rtl8187b) {
+       if (priv->is_rtl8187b)
                printk(KERN_WARNING "rtl8187: 8187B chip detected.\n");
-               dev->flags |= IEEE80211_HW_SIGNAL_DBM;
-       } else {
-               dev->flags |= IEEE80211_HW_SIGNAL_UNSPEC;
-               dev->max_signal = 65;
-       }
 
        /*
         * XXX: Once this driver supports anything that requires