Fix signal calculation for WEXT-based drivers

This patch introduces a behavior change. Previously the
'SignalStrength' role was interpreted as dBm. This was working
fine for nl80211 based drivers, for WEXT-based drivers it
contained garbage values. Now the 'SignalStrength' role will
always be interpreted as percentage.

The wpa_supplicant passes back only the 'level' of the scanned
BSS, which with nl80211-based driver is almost always dBm (val < 0).
WEXT-based driver has its own interpretation of 'level' - it
can contain dBm, percentage [0-100] (and some other values for
historical reasons, but these are converted by the wpa_supplicant
to dBm). This is what I have concluded from looking at NetworkManager
and wpa_supplicant sources and git history. Even the official GUI tool
wpa_gui for the wpa_supplicant is out-of-date and can not be used as
a referance.

Change-Id: I70d15e26e0a1700ad0f7d19d23cbade2d3d46054
Reviewed-by: Eirik Aavitsland <eirik.aavitsland@theqtcompany.com>

1 files changed, 5 insertions, 5 deletions

diff --git a/src/wifi/qwifimanager.cpp b/src/wifi/qwifimanager.cpp
index 7585cf2..2a5cfff 100644
--- a/src/wifi/qwifimanager.cpp
+++ b/src/wifi/qwifimanager.cpp
@@ -212,11 +212,11 @@ void QWifiManagerPrivate::updateLastError(const QString &error)
 
     \value SSID informal (human) name of a Wifi network (QString)
     \value BSSID basic service set identification of a network, used to uniquely identify BSS (QString)
-    \value SignalStrength strength of a Wifi signal, measured in dBm (int)
-    \value WPASupported holds whether network access point supports WPA security protocol (QString)
-    \value WPA2Supported holds whether network access point supports WPA2 security protocol (QString)
-    \value WEPSupported holds whether network access point supports WEP security protocol (QString)
-    \value WPSSupported holds whether network access point supports WPS security protocol (QString)
+    \value SignalStrength strength of a Wifi signal represented as percentage (0-100) (int)
+    \value WPASupported holds whether network access point supports WPA security protocol (bool)
+    \value WPA2Supported holds whether network access point supports WPA2 security protocol (bool)
+    \value WEPSupported holds whether network access point supports WEP security protocol (bool)
+    \value WPSSupported holds whether network access point supports WPS security protocol (bool)
 */
 
 QWifiManager* QWifiManager::m_instance = 0;