DO NOT MERGE Add support for background scanning

Background scanning (preferred network offload) allows us the
host to sleep while the dongle monitors the presence of any
preferred networks. This allows us for significant power savings
since the system does not have to wake up often to initiate
a scan

Bug: 3453021
Change-Id: I73dcf4e1c9ab4de280c40b6df6147a74ac003123

1 files changed, 12 insertions, 0 deletions

diff --git a/services/java/com/android/server/WifiService.java b/services/java/com/android/server/WifiService.java
index d2f2ec7..22583f7 100644
--- a/services/java/com/android/server/WifiService.java
+++ b/services/java/com/android/server/WifiService.java
@@ -94,6 +94,9 @@ public class WifiService extends IWifiManager.Stub {
     private boolean mDeviceIdle;
     private int mPluggedType;
 
+    /* Chipset supports background scan */
+    private final boolean mBackgroundScanSupported;
+
     // true if the user enabled Wifi while in airplane mode
     private AtomicBoolean mAirplaneModeOverwridden = new AtomicBoolean(false);
 
@@ -305,6 +308,9 @@ public class WifiService extends IWifiManager.Stub {
                 Settings.Secure.WIFI_NETWORKS_AVAILABLE_REPEAT_DELAY, 900) * 1000l;
         mNotificationEnabledSettingObserver = new NotificationEnabledSettingObserver(new Handler());
         mNotificationEnabledSettingObserver.register();
+
+        mBackgroundScanSupported = mContext.getResources().getBoolean(
+                com.android.internal.R.bool.config_wifi_background_scan_support);
     }
 
     /**
@@ -874,6 +880,9 @@ public class WifiService extends IWifiManager.Stub {
                 // because of any locks so clear that tracking immediately.
                 reportStartWorkSource();
                 mWifiStateMachine.enableRssiPolling(true);
+                if (mBackgroundScanSupported) {
+                    mWifiStateMachine.enableBackgroundScan(false);
+                }
                 mWifiStateMachine.enableAllNetworks();
                 updateWifiState();
             } else if (action.equals(Intent.ACTION_SCREEN_OFF)) {
@@ -882,6 +891,9 @@ public class WifiService extends IWifiManager.Stub {
                 }
                 mScreenOff = true;
                 mWifiStateMachine.enableRssiPolling(false);
+                if (mBackgroundScanSupported) {
+                    mWifiStateMachine.enableBackgroundScan(true);
+                }
                 /*
                  * Set a timer to put Wi-Fi to sleep, but only if the screen is off
                  * AND the "stay on while plugged in" setting doesn't match the