Fix wifi power offset calculation. (#265)

files/usr/lib/lua/aredn/hardware.lua

@@ -84,6 +84,27 @@ function hardware.wifi_maxpower(channel)
     return 27 -- if all else fails
 end
 
+function hardware.wifi_poweroffset(wifiintf)
+    local doesiwoffset = nil
+    local f = io.popen("iwinfo " .. wifiintf .. " info")
+    if f then
+        for line in f:lines()
+        do
+            doesiwoffset = tonumber(line:match("TX power offset: (%d+)"))
+            if doesiwoffset then
+                f:close()
+                return doesiwoffset
+            end
+        end
+        f:close()
+    end
+    local radio = hardware.get_radio()
+    if radio and tonumber(radio.pwroffset) then
+         return tonumber(radio.pwroffset)
+    end
+    return 0 -- if all else fails
+end
+
 function hardware.get_board_id()
     local name = ""
     if hardware.get_board().model.name:match("^(%S*)") == "Ubiquiti" then

files/www/cgi-bin/setup

@@ -133,14 +133,6 @@ function rf_channels_list(wifiintf)
     return channels
 end
 
-function wifi_txpoweroffset(wifiintf)
-    local doesiwoffset = capture_and_match("iwinfo " .. wifiintf .. " info", "TX power offset: (%d+)")
-    if doesiwoffset then
-        return tonumber(doesiwoffset)
-    end
-    return 0
-end
-
 function reboot()
     local node = aredn_info.get_nvram("node")
     if node == "" then
@@ -1042,7 +1034,7 @@ if wifi_enable == "1" then
 
     html.print("<tr><td colspan=2 align=center><hr><small>Active Settings</small></td></tr>")
     html.print("<tr><td><nobr>Tx Power</nobr></td><td><select name=wifi_txpower>")
-    local txpoweroffset = wifi_txpoweroffset(wifiintf)
+    local txpoweroffset = aredn.hardware.wifi_poweroffset(wifiintf)
     for i = aredn.hardware.wifi_maxpower(wifi_channel),1,-1
     do
         html.print("<option value='" .. i .. "'".. (i == tonumber(wifi_txpower) and " selected" or "") .. ">" .. (txpoweroffset + i) .. " dBm</option>")