From 1e806a7aac77f6f65ba299329e1fc452e0148b8d Mon Sep 17 00:00:00 2001
From: Mitchell Wills <mwills@google.com>
Date: Fri, 11 Mar 2016 17:16:50 -0800
Subject: Fix WifiScanner not recovering after Wifi is turned off

WifiScanner implementations could previously get in an inconsistent
state where they had not cleaned up from a previous scan that was
interrupted by turning Wifi off.

Bug: 27620477
Change-Id: I042e35d1aa8ee65e6ebfeb6f62a54c071a7be4ef
---
 .../com/android/server/wifi/HalWifiScannerImpl.java   |  7 +++++++
 .../server/wifi/SupplicantWifiScannerImpl.java        | 19 ++++++++++++++++++-
 .../java/com/android/server/wifi/WifiScannerImpl.java |  6 ++++++
 .../android/server/wifi/WifiScanningServiceImpl.java  |  1 +
 4 files changed, 32 insertions(+), 1 deletion(-)

(limited to 'service')

diff --git a/service/java/com/android/server/wifi/HalWifiScannerImpl.java b/service/java/com/android/server/wifi/HalWifiScannerImpl.java
index c678c7302..ebb5f36ed 100644
--- a/service/java/com/android/server/wifi/HalWifiScannerImpl.java
+++ b/service/java/com/android/server/wifi/HalWifiScannerImpl.java
@@ -75,6 +75,7 @@ public class HalWifiScannerImpl extends WifiScannerImpl implements Handler.Callb
                 } else {
                     Log.w(TAG, "Got single scan failed event without an active scan request");
                 }
+                mWifiNative.resumeBackgroundScan();
                 break;
             case WifiMonitor.SCAN_RESULTS_EVENT:
                 pollLatestSingleScanData();
@@ -173,6 +174,12 @@ public class HalWifiScannerImpl extends WifiScannerImpl implements Handler.Callb
         }
     }
 
+    @Override
+    public void cleanup() {
+        mSingleScanEventHandler = null;
+        mWifiNative.resumeBackgroundScan();
+    }
+
     @Override
     public boolean getScanCapabilities(WifiNative.ScanCapabilities capabilities) {
         return mWifiNative.getScanCapabilities(capabilities);
diff --git a/service/java/com/android/server/wifi/SupplicantWifiScannerImpl.java b/service/java/com/android/server/wifi/SupplicantWifiScannerImpl.java
index 05f602090..91747808a 100644
--- a/service/java/com/android/server/wifi/SupplicantWifiScannerImpl.java
+++ b/service/java/com/android/server/wifi/SupplicantWifiScannerImpl.java
@@ -114,6 +114,19 @@ public class SupplicantWifiScannerImpl extends WifiScannerImpl implements Handle
                 WifiMonitor.SCAN_RESULTS_EVENT, mEventHandler);
     }
 
+    @Override
+    public void cleanup() {
+        synchronized (mSettingsLock) {
+            mPendingSingleScanSettings = null;
+            mPendingSingleScanEventHandler = null;
+            stopPnoScan();
+            stopBatchedScan();
+            resetHotlist();
+            untrackSignificantWifiChange();
+            mLastScanSettings = null; // finally clear any active scan
+        }
+    }
+
     @Override
     public boolean getScanCapabilities(WifiNative.ScanCapabilities capabilities) {
         capabilities.max_scan_cache_size = Integer.MAX_VALUE;
@@ -213,6 +226,7 @@ public class SupplicantWifiScannerImpl extends WifiScannerImpl implements Handle
             mBackgroundScanPeriodPending = false;
             unscheduleScansLocked();
         }
+        processPendingScans();
     }
 
     @Override
@@ -236,6 +250,7 @@ public class SupplicantWifiScannerImpl extends WifiScannerImpl implements Handle
                 mPendingBackgroundScanEventHandler.onScanPaused(results);
             }
         }
+        processPendingScans();
     }
 
     @Override
@@ -312,7 +327,9 @@ public class SupplicantWifiScannerImpl extends WifiScannerImpl implements Handle
 
     private void unscheduleScansLocked() {
         mAlarmManager.cancel(mScanPeriodListener);
-        mLastScanSettings = null; // make sure that a running scan is marked as ended
+        if (mLastScanSettings != null) {
+            mLastScanSettings.backgroundScanActive = false;
+        }
     }
 
     private void handleScanPeriod() {
diff --git a/service/java/com/android/server/wifi/WifiScannerImpl.java b/service/java/com/android/server/wifi/WifiScannerImpl.java
index 41c356c29..c8d80fde5 100644
--- a/service/java/com/android/server/wifi/WifiScannerImpl.java
+++ b/service/java/com/android/server/wifi/WifiScannerImpl.java
@@ -62,6 +62,12 @@ public abstract class WifiScannerImpl {
         }
     };
 
+    /**
+     * Cleanup any ongoing operations. This may be called when the driver is unloaded.
+     * There is no expectation that failure events are returned for ongoing operations.
+     */
+    public abstract void cleanup();
+
     /**
      * Get the supported scan capabilities.
      *
diff --git a/service/java/com/android/server/wifi/WifiScanningServiceImpl.java b/service/java/com/android/server/wifi/WifiScanningServiceImpl.java
index 8de44f72f..58ddd579f 100644
--- a/service/java/com/android/server/wifi/WifiScanningServiceImpl.java
+++ b/service/java/com/android/server/wifi/WifiScanningServiceImpl.java
@@ -802,6 +802,7 @@ public class WifiScanningServiceImpl extends IWifiScanner.Stub {
             public void exit() {
                 sendPnoScanFailedToAllAndClear(
                         WifiScanner.REASON_UNSPECIFIED, "Scan was interrupted");
+                mScannerImpl.cleanup();
             }
 
             @Override
-- 
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