network: Allow auto_wifi_off on kindle & remarkable

They expose a network sysfs entry so we can track usage

Works for me on kindle, but i stop the amazon framework

frontend/ui/network/manager.lua

@@ -497,7 +497,6 @@ function NetworkMgr:getPowersaveMenuTable()
         text = _("Disable Wi-Fi connection when inactive"),
         help_text = _([[This will automatically turn Wi-Fi off after a generous period of network inactivity, without disrupting workflows that require a network connection, so you can just keep reading without worrying about battery drain.]]),
         checked_func = function() return G_reader_settings:isTrue("auto_disable_wifi") end,
-        enabled_func = function() return Device:hasWifiManager() end,
         callback = function()
             G_reader_settings:flipNilOrFalse("auto_disable_wifi")
             -- NOTE: Well, not exactly, but the activity check wouldn't be (un)scheduled until the next Network(Dis)Connected event...
@@ -608,8 +607,12 @@ function NetworkMgr:getMenuTable(common_settings)
     common_settings.network_proxy = self:getProxyMenuTable()
     common_settings.network_info = self:getInfoMenuTable()
 
-    if Device:hasWifiManager() or Device:isEmulator() then
+    -- Allow auto_disable_wifi on devices where the net sysfs entry is exposed.
+    if self:getNetworkInterfaceName() then
         common_settings.network_powersave = self:getPowersaveMenuTable()
+    end
+
+    if Device:hasWifiManager() or Device:isEmulator() then
         common_settings.network_restore = self:getRestoreMenuTable()
         common_settings.network_dismiss_scan = self:getDismissScanMenuTable()
         common_settings.network_before_wifi_action = self:getBeforeWifiActionMenuTable()

frontend/ui/network/networklistener.lua

@@ -115,8 +115,8 @@ local network_activity_noise_margin = 12 -- unscaled_size_check: ignore
 
 -- Read the statistics/tx_packets sysfs entry for the current network interface.
 -- It *should* be the least noisy entry on an idle network...
--- The fact that auto_disable_wifi is only available on Device:hasWifiManager()
--- allows us to get away with a Linux-only solution.
+-- The fact that auto_disable_wifi is only available on devices that expose a
+-- net sysfs entry allows us to get away with a Linux-only solution.
 function NetworkListener:_getTxPackets()
     -- read tx_packets stats from sysfs (for the right network if)
     local file = io.open("/sys/class/net/" .. NetworkMgr:getNetworkInterfaceName() .. "/statistics/tx_packets", "rb")
@@ -198,14 +198,12 @@ end
 
 function NetworkListener:onNetworkConnected()
     logger.dbg("NetworkListener: onNetworkConnected")
-    if not Device:hasWifiManager() then
-        return
+    if Device:hasWifiManager() then
+        -- This is for the sake of events that don't emanate from NetworkMgr itself...
+        NetworkMgr:setWifiState(true)
+        NetworkMgr:setConnectionState(true)
     end
 
-    -- This is for the sake of events that don't emanate from NetworkMgr itself...
-    NetworkMgr:setWifiState(true)
-    NetworkMgr:setConnectionState(true)
-
     if not G_reader_settings:isTrue("auto_disable_wifi") then
         return
     end
@@ -218,13 +216,11 @@ end
 
 function NetworkListener:onNetworkDisconnected()
     logger.dbg("NetworkListener: onNetworkDisconnected")
-    if not Device:hasWifiManager() then
-        return
+    if Device:hasWifiManager() then
+        NetworkMgr:setWifiState(false)
+        NetworkMgr:setConnectionState(false)
     end
 
-    NetworkMgr:setWifiState(false)
-    NetworkMgr:setConnectionState(false)
-
     if not G_reader_settings:isTrue("auto_disable_wifi") then
         return
     end