Enhancements for avoiding poor connection on wifi

- Avoid flapping
- Increase thresholds and monitor rssi more closely to detect consistently weak signal

Change-Id: I6139a20b7306839b345146a72ce690020a2e00b8

Author: isheriff

core/java/android/provider/Settings.java

@@ -3128,6 +3128,14 @@ public static final String getBluetoothInputDevicePriorityKey(String address) {
         public static final String WIFI_WATCHDOG_ARP_CHECK_INTERVAL_MS =
                 "wifi_watchdog_arp_interval_ms";
 
+        /**
+         * ms delay interval between rssi polling when the signal is known to be weak
+         * @hide
+         */
+        public static final String WIFI_WATCHDOG_RSSI_FETCH_INTERVAL_MS =
+                "wifi_watchdog_rssi_fetch_interval_ms";
+
+
         /**
          * ms delay before rechecking a connect SSID for walled garden with a http download.
          * @hide

wifi/java/android/net/wifi/WifiStateMachine.java

@@ -1852,6 +1852,9 @@ public boolean processMessage(Message message) {
                     replyToMessage(message, WifiManager.DISABLE_NETWORK_FAILED,
                             WifiManager.BUSY);
                     break;
+                case WifiWatchdogStateMachine.RSSI_FETCH:
+                    replyToMessage(message, WifiWatchdogStateMachine.RSSI_FETCH_FAILED);
+                    break;
                 default:
                     loge("Error! unhandled message" + message);
                     break;
@@ -2998,6 +3001,12 @@ public boolean processMessage(Message message) {
                                 mRssiPollToken, 0), POLL_RSSI_INTERVAL_MSECS);
                     }
                     break;
+                case WifiWatchdogStateMachine.RSSI_FETCH:
+                    eventLoggingEnabled = false;
+                    fetchRssiAndLinkSpeedNative();
+                    replyToMessage(message, WifiWatchdogStateMachine.RSSI_FETCH_SUCCEEDED,
+                            mWifiInfo.getRssi());
+                    break;
                 default:
                     return NOT_HANDLED;
             }