Avoid quick shutdown after a driver start

Causes problems on our wext driver and potentially on cfg
based driver as well.

NLP can trigger very quick acquire and release within seconds
leading to driver switching between start and stop state.

We now keep driver up for atleast couple of minutes after a start

Bug: 5478196
Change-Id: I1b261578252c5fb9a65446241b51e5686d4d9cc3

1 files changed, 37 insertions, 12 deletions

diff --git a/wifi/java/android/net/wifi/WifiStateMachine.java b/wifi/java/android/net/wifi/WifiStateMachine.java
index e981da7..caf07c3 100644
--- a/wifi/java/android/net/wifi/WifiStateMachine.java
+++ b/wifi/java/android/net/wifi/WifiStateMachine.java
@@ -211,7 +211,7 @@ public class WifiStateMachine extends StateMachine {
     static final int CMD_STOP_SUPPLICANT                  = BASE + 12;
     /* Start the driver */
     static final int CMD_START_DRIVER                     = BASE + 13;
-    /* Start the driver */
+    /* Stop the driver */
     static final int CMD_STOP_DRIVER                      = BASE + 14;
     /* Indicates Static IP succeded */
     static final int CMD_STATIC_IP_SUCCESS                = BASE + 15;
@@ -219,6 +219,9 @@ public class WifiStateMachine extends StateMachine {
     static final int CMD_STATIC_IP_FAILURE                = BASE + 16;
     /* Indicates supplicant stop failed */
     static final int CMD_STOP_SUPPLICANT_FAILED           = BASE + 17;
+    /* Delayed stop to avoid shutting down driver too quick*/
+    static final int CMD_DELAYED_STOP_DRIVER              = BASE + 18;
+
 
     /* Start the soft access point */
     static final int CMD_START_AP                         = BASE + 21;
@@ -389,6 +392,13 @@ public class WifiStateMachine extends StateMachine {
     private static final int MIN_INTERVAL_ENABLE_ALL_NETWORKS_MS = 10 * 60 * 1000; /* 10 minutes */
     private long mLastEnableAllNetworksTime;
 
+    /**
+     * Starting and shutting down driver too quick causes problems leading to driver
+     * being in a bad state. Delay driver stop.
+     */
+    private static final int DELAYED_DRIVER_STOP_MS = 2 * 60 * 1000; /* 2 minutes */
+    private int mDelayedStopCounter;
+    private boolean mInDelayedStop = false;
 
     private static final int MIN_RSSI = -200;
     private static final int MAX_RSSI = 256;
@@ -1779,6 +1789,7 @@ public class WifiStateMachine extends StateMachine {
                 case CMD_STOP_SUPPLICANT_FAILED:
                 case CMD_START_DRIVER:
                 case CMD_STOP_DRIVER:
+                case CMD_DELAYED_STOP_DRIVER:
                 case CMD_START_AP:
                 case CMD_START_AP_SUCCESS:
                 case CMD_START_AP_FAILURE:
@@ -2441,6 +2452,7 @@ public class WifiStateMachine extends StateMachine {
             EventLog.writeEvent(EVENTLOG_WIFI_STATE_CHANGED, getName());
 
             mIsRunning = true;
+            mInDelayedStop = false;
             updateBatteryWorkSource(null);
 
             /**
@@ -2520,6 +2532,30 @@ public class WifiStateMachine extends StateMachine {
                     WifiNative.setBluetoothCoexistenceScanModeCommand(mBluetoothConnectionActive);
                     break;
                 case CMD_STOP_DRIVER:
+                    /* Already doing a delayed stop */
+                    if (mInDelayedStop) {
+                        if (DBG) log("Already in delayed stop");
+                        break;
+                    }
+                    mInDelayedStop = true;
+                    mDelayedStopCounter++;
+                    if (DBG) log("Delayed stop message " + mDelayedStopCounter);
+                    sendMessageDelayed(obtainMessage(CMD_DELAYED_STOP_DRIVER, mDelayedStopCounter,
+                            0), DELAYED_DRIVER_STOP_MS);
+                    break;
+                case CMD_START_DRIVER:
+                    if (mInDelayedStop) {
+                        mInDelayedStop = false;
+                        mDelayedStopCounter++;
+                        if (DBG) log("Delayed stop ignored due to start");
+                    }
+                    break;
+                case CMD_DELAYED_STOP_DRIVER:
+                    if (message.arg1 != mDelayedStopCounter) break;
+                    if (getCurrentState() != mDisconnectedState) {
+                        WifiNative.disconnectCommand();
+                        handleNetworkDisconnect();
+                    }
                     mWakeLock.acquire();
                     WifiNative.stopDriverCommand();
                     transitionTo(mDriverStoppingState);
@@ -2878,10 +2914,6 @@ public class WifiStateMachine extends StateMachine {
                   /* Ignore */
               case WifiMonitor.NETWORK_CONNECTION_EVENT:
                   break;
-              case CMD_STOP_DRIVER:
-                  sendMessage(CMD_DISCONNECT);
-                  deferMessage(message);
-                  break;
               case CMD_SET_SCAN_MODE:
                   if (message.arg1 == SCAN_ONLY_MODE) {
                       sendMessage(CMD_DISCONNECT);
@@ -2936,10 +2968,6 @@ public class WifiStateMachine extends StateMachine {
                     WifiNative.disconnectCommand();
                     transitionTo(mDisconnectingState);
                     break;
-                case CMD_STOP_DRIVER:
-                    sendMessage(CMD_DISCONNECT);
-                    deferMessage(message);
-                    break;
                 case CMD_REQUEST_CM_WAKELOCK:
                     checkAndSetConnectivityInstance();
                     mCm.requestNetworkTransitionWakelock(TAG);
@@ -3035,9 +3063,6 @@ public class WifiStateMachine extends StateMachine {
         public boolean processMessage(Message message) {
             if (DBG) log(getName() + message.toString() + "\n");
             switch (message.what) {
-                case CMD_STOP_DRIVER: /* Stop driver only after disconnect handled */
-                    deferMessage(message);
-                    break;
                 case CMD_SET_SCAN_MODE:
                     if (message.arg1 == SCAN_ONLY_MODE) {
                         deferMessage(message);