WifiStateMachine: remove scan related code

Now that we have ScanRequestProxy hooked up with WifiServiceImpl, we no
longer need scan request/result handling in WSM.

Bug: 31444878
Bug: 31445200
Bug: 70359905
Test: frameworks/opt/net/wifi/tests/wifitests/runtests.sh
Test: Wifi Integration tests
Change-Id: I63ab7efe1f43310faf92c927c31bdcfa6d8bb7da

2 files changed, 9 insertions, 469 deletions

diff --git a/service/java/com/android/server/wifi/WifiStateMachine.java b/service/java/com/android/server/wifi/WifiStateMachine.java
index 783f59510..fe181877d 100644
--- a/service/java/com/android/server/wifi/WifiStateMachine.java
+++ b/service/java/com/android/server/wifi/WifiStateMachine.java
@@ -61,14 +61,11 @@ import android.net.dhcp.DhcpClient;
 import android.net.ip.IpClient;
 import android.net.wifi.RssiPacketCountInfo;
 import android.net.wifi.ScanResult;
-import android.net.wifi.ScanSettings;
 import android.net.wifi.SupplicantState;
-import android.net.wifi.WifiChannel;
 import android.net.wifi.WifiConfiguration;
 import android.net.wifi.WifiEnterpriseConfig;
 import android.net.wifi.WifiInfo;
 import android.net.wifi.WifiManager;
-import android.net.wifi.WifiScanner;
 import android.net.wifi.WifiSsid;
 import android.net.wifi.hotspot2.IProvisioningCallback;
 import android.net.wifi.hotspot2.OsuProvider;
@@ -110,7 +107,6 @@ import com.android.server.wifi.hotspot2.AnqpEvent;
 import com.android.server.wifi.hotspot2.IconEvent;
 import com.android.server.wifi.hotspot2.NetworkDetail;
 import com.android.server.wifi.hotspot2.PasspointManager;
-import com.android.server.wifi.hotspot2.Utils;
 import com.android.server.wifi.hotspot2.WnmData;
 import com.android.server.wifi.nano.WifiMetricsProto;
 import com.android.server.wifi.nano.WifiMetricsProto.StaEvent;
@@ -133,10 +129,7 @@ import java.net.Inet6Address;
 import java.net.InetAddress;
 import java.util.ArrayList;
 import java.util.Arrays;
-import java.util.HashSet;
-import java.util.LinkedList;
 import java.util.List;
-import java.util.Queue;
 import java.util.Set;
 import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.concurrent.atomic.AtomicInteger;
@@ -225,15 +218,6 @@ public class WifiStateMachine extends StateMachine {
 
     private final McastLockManagerFilterController mMcastLockManagerFilterController;
 
-    /* Scan results handling */
-    private List<ScanDetail> mScanResults = new ArrayList<>();
-    private final Object mScanResultsLock = new Object();
-
-    // For debug, number of known scan results that were found as part of last scan result event,
-    // as well the number of scans results returned by the supplicant with that message
-    private int mNumScanResultsKnown;
-    private int mNumScanResultsReturned;
-
     private boolean mScreenOn = false;
 
     private String mInterfaceName;
@@ -312,21 +296,10 @@ public class WifiStateMachine extends StateMachine {
     * In SCAN_ONLY_WIFI_OFF_MODE, the STA can only scan for access points with wifi toggle being off
     */
     private int mOperationalMode = DISABLED_MODE;
-    private boolean mIsScanOngoing = false;
-    private boolean mIsFullScanOngoing = false;
 
     // variable indicating we are expecting a mode switch - do not attempt recovery for failures
     private boolean mModeChange = false;
 
-    private final Queue<Message> mBufferedScanMsg = new LinkedList<>();
-    private static final int UNKNOWN_SCAN_SOURCE = -1;
-    private static final int ADD_OR_UPDATE_SOURCE = -3;
-
-    private static final int SCAN_REQUEST_BUFFER_MAX_SIZE = 10;
-    private static final String CUSTOMIZED_SCAN_SETTING = "customized_scan_settings";
-    private static final String CUSTOMIZED_SCAN_WORKSOURCE = "customized_scan_worksource";
-    private static final String SCAN_REQUEST_TIME = "scan_request_time";
-
     private boolean mBluetoothConnectionActive = false;
 
     private PowerManager.WakeLock mSuspendWakeLock;
@@ -467,8 +440,6 @@ public class WifiStateMachine extends StateMachine {
     // Used to initiate a connection with WifiP2pService
     private AsyncChannel mWifiP2pChannel;
 
-    private WifiScanner mWifiScanner;
-
     @GuardedBy("mWifiReqCountLock")
     private int mConnectionReqCount = 0;
     private WifiNetworkFactory mNetworkFactory;
@@ -530,8 +501,6 @@ public class WifiStateMachine extends StateMachine {
     /* Get Link Layer Stats thru HAL */
     static final int CMD_GET_LINK_LAYER_STATS                           = BASE + 63;
     /* Supplicant commands after driver start*/
-    /* Initiate a scan */
-    static final int CMD_START_SCAN                                     = BASE + 71;
     /* Set operational mode. CONNECT, SCAN ONLY, SCAN_ONLY with Wi-Fi off mode */
     static final int CMD_SET_OPERATIONAL_MODE                           = BASE + 72;
     /* Disconnect from a network */
@@ -1097,8 +1066,6 @@ public class WifiStateMachine extends StateMachine {
                 getHandler());
         mWifiMonitor.registerHandler(mInterfaceName, WifiMonitor.RX_HS20_ANQP_ICON_EVENT,
                 getHandler());
-        mWifiMonitor.registerHandler(mInterfaceName, WifiMonitor.SCAN_FAILED_EVENT, getHandler());
-        mWifiMonitor.registerHandler(mInterfaceName, WifiMonitor.SCAN_RESULTS_EVENT, getHandler());
         mWifiMonitor.registerHandler(mInterfaceName, WifiMonitor.SUP_CONNECTION_EVENT, getHandler());
         mWifiMonitor.registerHandler(mInterfaceName, WifiMonitor.SUP_DISCONNECTION_EVENT,
                 getHandler());
@@ -1333,25 +1300,6 @@ public class WifiStateMachine extends StateMachine {
         return new Messenger(getHandler());
     }
 
-    /**
-     * Initiate a wifi scan. If workSource is not null, blame is given to it, otherwise blame is
-     * given to callingUid.
-     *
-     * @param callingUid The uid initiating the wifi scan. Blame will be given here unless
-     *                   workSource is specified.
-     * @param workSource If not null, blame is given to workSource.
-     * @param settings   Scan settings, see {@link ScanSettings}.
-     * TODO(b/70359905): Remove this method & it's dependencies since it's not used anymore.
-     */
-    public void startScan(int callingUid, int scanCounter,
-                          ScanSettings settings, WorkSource workSource) {
-        Bundle bundle = new Bundle();
-        bundle.putParcelable(CUSTOMIZED_SCAN_SETTING, settings);
-        bundle.putParcelable(CUSTOMIZED_SCAN_WORKSOURCE, workSource);
-        bundle.putLong(SCAN_REQUEST_TIME, mClock.getWallClockMillis());
-        sendMessage(CMD_START_SCAN, callingUid, scanCounter, bundle);
-    }
-
     private long mDisconnectedTimeStamp = 0;
 
     public long getDisconnectedTimeMilli() {
@@ -1524,132 +1472,6 @@ public class WifiStateMachine extends StateMachine {
         return mWifiNative.stopRssiMonitoring(mInterfaceName);
     }
 
-    private void handleScanRequest(Message message) {
-        ScanSettings settings = null;
-        WorkSource workSource = null;
-
-        // unbundle parameters
-        Bundle bundle = (Bundle) message.obj;
-
-        if (bundle != null) {
-            settings = bundle.getParcelable(CUSTOMIZED_SCAN_SETTING);
-            workSource = bundle.getParcelable(CUSTOMIZED_SCAN_WORKSOURCE);
-        }
-
-        Set<Integer> freqs = null;
-        if (settings != null && settings.channelSet != null) {
-            freqs = new HashSet<>();
-            for (WifiChannel channel : settings.channelSet) {
-                freqs.add(channel.freqMHz);
-            }
-        }
-
-        // Retrieve the list of hidden network SSIDs to scan for.
-        List<WifiScanner.ScanSettings.HiddenNetwork> hiddenNetworks =
-                mWifiConfigManager.retrieveHiddenNetworkList();
-
-        // call wifi native to start the scan
-        if (startScanNative(freqs, hiddenNetworks, workSource)) {
-            // a full scan covers everything, clearing scan request buffer
-            if (freqs == null)
-                mBufferedScanMsg.clear();
-            messageHandlingStatus = MESSAGE_HANDLING_STATUS_OK;
-            return;
-        }
-
-        // if reach here, scan request is rejected
-
-        if (!mIsScanOngoing) {
-            // if rejection is NOT due to ongoing scan (e.g. bad scan parameters),
-
-            // discard this request and pop up the next one
-            if (mBufferedScanMsg.size() > 0) {
-                sendMessage(mBufferedScanMsg.remove());
-            }
-            messageHandlingStatus = MESSAGE_HANDLING_STATUS_DISCARD;
-        } else if (!mIsFullScanOngoing) {
-            // if rejection is due to an ongoing scan, and the ongoing one is NOT a full scan,
-            // buffer the scan request to make sure specified channels will be scanned eventually
-            if (freqs == null)
-                mBufferedScanMsg.clear();
-            if (mBufferedScanMsg.size() < SCAN_REQUEST_BUFFER_MAX_SIZE) {
-                Message msg = obtainMessage(CMD_START_SCAN,
-                        message.arg1, message.arg2, bundle);
-                mBufferedScanMsg.add(msg);
-            } else {
-                // if too many requests in buffer, combine them into a single full scan
-                bundle = new Bundle();
-                bundle.putParcelable(CUSTOMIZED_SCAN_SETTING, null);
-                bundle.putParcelable(CUSTOMIZED_SCAN_WORKSOURCE, workSource);
-                Message msg = obtainMessage(CMD_START_SCAN, message.arg1, message.arg2, bundle);
-                mBufferedScanMsg.clear();
-                mBufferedScanMsg.add(msg);
-            }
-            messageHandlingStatus = MESSAGE_HANDLING_STATUS_LOOPED;
-        } else {
-            // mIsScanOngoing and mIsFullScanOngoing
-            messageHandlingStatus = MESSAGE_HANDLING_STATUS_FAIL;
-        }
-    }
-
-
-    // TODO this is a temporary measure to bridge between WifiScanner and WifiStateMachine until
-    // scan functionality is refactored out of WifiStateMachine.
-    /**
-     * return true iff scan request is accepted
-     */
-    private boolean startScanNative(final Set<Integer> freqs,
-            List<WifiScanner.ScanSettings.HiddenNetwork> hiddenNetworkList,
-            WorkSource workSource) {
-        if (mWifiScanner == null) {
-            Log.e(TAG, "startScanNative is called when mWifiScanner is null");
-            return false;
-        }
-        WifiScanner.ScanSettings settings = new WifiScanner.ScanSettings();
-        if (freqs == null) {
-            settings.band = WifiScanner.WIFI_BAND_BOTH_WITH_DFS;
-        } else {
-            settings.band = WifiScanner.WIFI_BAND_UNSPECIFIED;
-            int index = 0;
-            settings.channels = new WifiScanner.ChannelSpec[freqs.size()];
-            for (Integer freq : freqs) {
-                settings.channels[index++] = new WifiScanner.ChannelSpec(freq);
-            }
-        }
-        settings.reportEvents = WifiScanner.REPORT_EVENT_AFTER_EACH_SCAN
-                | WifiScanner.REPORT_EVENT_FULL_SCAN_RESULT;
-
-        settings.hiddenNetworks =
-                hiddenNetworkList.toArray(
-                        new WifiScanner.ScanSettings.HiddenNetwork[hiddenNetworkList.size()]);
-
-        WifiScanner.ScanListener nativeScanListener = new WifiScanner.ScanListener() {
-                // ignore all events since WifiStateMachine is registered for the supplicant events
-                @Override
-                public void onSuccess() {
-                }
-                @Override
-                public void onFailure(int reason, String description) {
-                    mIsScanOngoing = false;
-                    mIsFullScanOngoing = false;
-                }
-                @Override
-                public void onResults(WifiScanner.ScanData[] results) {
-                }
-                @Override
-                public void onFullResult(ScanResult fullScanResult) {
-                }
-                @Override
-                public void onPeriodChanged(int periodInMs) {
-                }
-            };
-        mWifiScanner.startScan(settings, nativeScanListener, workSource);
-        mIsScanOngoing = true;
-        mIsFullScanOngoing = (freqs == null);
-        lastScanFreqs = freqs;
-        return true;
-    }
-
     /**
      * TODO: doc
      */
@@ -1805,19 +1627,6 @@ public class WifiStateMachine extends StateMachine {
         return mMcastLockManagerFilterController;
     }
 
-    /**
-     * TODO: doc
-     */
-    public List<ScanResult> syncGetScanResultsList() {
-        synchronized (mScanResultsLock) {
-            List<ScanResult> scanList = new ArrayList<>();
-            for (ScanDetail result : mScanResults) {
-                scanList.add(new ScanResult(result.getScanResult()));
-            }
-            return scanList;
-        }
-    }
-
     public boolean syncQueryPasspointIcon(AsyncChannel channel, long bssid, String fileName) {
         Bundle bundle = new Bundle();
         bundle.putLong(EXTRA_OSU_ICON_QUERY_BSSID, bssid);
@@ -2301,42 +2110,6 @@ public class WifiStateMachine extends StateMachine {
         sb.append(" rt=").append(mClock.getUptimeSinceBootMillis());
         sb.append("/").append(mClock.getElapsedSinceBootMillis());
         switch (msg.what) {
-            case CMD_START_SCAN:
-                now = mClock.getWallClockMillis();
-                sb.append(" ");
-                sb.append(Integer.toString(msg.arg1));
-                sb.append(" ");
-                sb.append(Integer.toString(msg.arg2));
-                sb.append(" ic=");
-                sb.append(Integer.toString(sScanAlarmIntentCount));
-                if (msg.obj != null) {
-                    Bundle bundle = (Bundle) msg.obj;
-                    Long request = bundle.getLong(SCAN_REQUEST_TIME, 0);
-                    if (request != 0) {
-                        sb.append(" proc(ms):").append(now - request);
-                    }
-                }
-                if (mIsScanOngoing) sb.append(" onGoing");
-                if (mIsFullScanOngoing) sb.append(" full");
-                sb.append(" rssi=").append(mWifiInfo.getRssi());
-                sb.append(" f=").append(mWifiInfo.getFrequency());
-                sb.append(" sc=").append(mWifiInfo.score);
-                sb.append(" link=").append(mWifiInfo.getLinkSpeed());
-                sb.append(String.format(" tx=%.1f,", mWifiInfo.txSuccessRate));
-                sb.append(String.format(" %.1f,", mWifiInfo.txRetriesRate));
-                sb.append(String.format(" %.1f ", mWifiInfo.txBadRate));
-                sb.append(String.format(" rx=%.1f", mWifiInfo.rxSuccessRate));
-                if (lastScanFreqs != null) {
-                    sb.append(" list=");
-                    for(int freq : lastScanFreqs) {
-                        sb.append(freq).append(",");
-                    }
-                }
-                report = reportOnTime();
-                if (report != null) {
-                    sb.append(" ").append(report);
-                }
-                break;
             case WifiMonitor.SUPPLICANT_STATE_CHANGE_EVENT:
                 sb.append(" ");
                 sb.append(Integer.toString(msg.arg1));
@@ -2414,27 +2187,6 @@ public class WifiStateMachine extends StateMachine {
                 }
                 sb.append(" blacklist=" + Boolean.toString(didBlackListBSSID));
                 break;
-            case WifiMonitor.SCAN_RESULTS_EVENT:
-                sb.append(" ");
-                sb.append(Integer.toString(msg.arg1));
-                sb.append(" ");
-                sb.append(Integer.toString(msg.arg2));
-                if (mScanResults != null) {
-                    sb.append(" found=");
-                    sb.append(mScanResults.size());
-                }
-                sb.append(" known=").append(mNumScanResultsKnown);
-                sb.append(" got=").append(mNumScanResultsReturned);
-                sb.append(String.format(" bcn=%d", mRunningBeaconCount));
-                sb.append(String.format(" con=%d", mConnectionReqCount));
-                sb.append(String.format(" untrustedcn=%d", mUntrustedReqCount));
-                key = mWifiConfigManager.getLastSelectedNetworkConfigKey();
-                if (key != null) {
-                    sb.append(" last=").append(key);
-                }
-                break;
-            case WifiMonitor.SCAN_FAILED_EVENT:
-                break;
             case WifiMonitor.NETWORK_CONNECTION_EVENT:
                 sb.append(" ");
                 sb.append(Integer.toString(msg.arg1));
@@ -2888,35 +2640,6 @@ public class WifiStateMachine extends StateMachine {
         if (mVerboseLoggingEnabled) log("setWifiApState: " + syncGetWifiApStateByName());
     }
 
-    private void setScanResults() {
-        mNumScanResultsKnown = 0;
-        mNumScanResultsReturned = 0;
-
-        ArrayList<ScanDetail> scanResults = mWifiNative.getScanResults(mInterfaceName);
-
-        if (scanResults.isEmpty()) {
-            mScanResults = new ArrayList<>();
-            return;
-        }
-
-        // TODO(b/31065385): mWifiConfigManager.trimANQPCache(false);
-
-        boolean connected = mLastBssid != null;
-        long activeBssid = 0L;
-        if (connected) {
-            try {
-                activeBssid = Utils.parseMac(mLastBssid);
-            } catch (IllegalArgumentException iae) {
-                connected = false;
-            }
-        }
-
-        synchronized (mScanResultsLock) {
-            mScanResults = scanResults;
-            mNumScanResultsReturned = mScanResults.size();
-        }
-    }
-
     /*
      * Fetch RSSI, linkspeed, and frequency on current connection
      */
@@ -3846,10 +3569,6 @@ public class WifiStateMachine extends StateMachine {
                 case CMD_SCREEN_STATE_CHANGED:
                     handleScreenStateChanged(message.arg1 != 0);
                     break;
-                    /* Discard */
-                case CMD_START_SCAN:
-                    messageHandlingStatus = MESSAGE_HANDLING_STATUS_DISCARD;
-                    break;
                 case CMD_START_SUPPLICANT:
                 case CMD_STOP_SUPPLICANT:
                 case CMD_DRIVER_START_TIMED_OUT:
@@ -3864,8 +3583,6 @@ public class WifiStateMachine extends StateMachine {
                 case WifiMonitor.SUP_DISCONNECTION_EVENT:
                 case WifiMonitor.NETWORK_CONNECTION_EVENT:
                 case WifiMonitor.NETWORK_DISCONNECTION_EVENT:
-                case WifiMonitor.SCAN_RESULTS_EVENT:
-                case WifiMonitor.SCAN_FAILED_EVENT:
                 case WifiMonitor.SUPPLICANT_STATE_CHANGE_EVENT:
                 case WifiMonitor.AUTHENTICATION_FAILURE_EVENT:
                 case WifiMonitor.ASSOCIATION_REJECTION_EVENT:
@@ -4198,12 +3915,6 @@ public class WifiStateMachine extends StateMachine {
             setRandomMacOui();
             mCountryCode.setReadyForChange(true);
 
-            // We can't do this in the constructor because WifiStateMachine is created before the
-            // wifi scanning service is initialized
-            if (mWifiScanner == null) {
-                mWifiScanner = mWifiInjector.getWifiScanner();
-            }
-
             if (mWifiConnectivityManager == null) {
                 synchronized (mWifiReqCountLock) {
                     mWifiConnectivityManager =
@@ -4282,21 +3993,6 @@ public class WifiStateMachine extends StateMachine {
                     sendMessage(CMD_START_SUPPLICANT);
                     transitionTo(mInitialState);
                     break;
-                case CMD_START_SCAN:
-                    // TODO: remove scan request path (b/31445200)
-                    handleScanRequest(message);
-                    break;
-                case WifiMonitor.SCAN_RESULTS_EVENT:
-                case WifiMonitor.SCAN_FAILED_EVENT:
-                    // TODO: remove handing of SCAN_RESULTS_EVENT and SCAN_FAILED_EVENT when scan
-                    // results are retrieved from WifiScanner (b/31444878)
-                    maybeRegisterNetworkFactory(); // Make sure our NetworkFactory is registered
-                    setScanResults();
-                    mIsScanOngoing = false;
-                    mIsFullScanOngoing = false;
-                    if (mBufferedScanMsg.size() > 0)
-                        sendMessage(mBufferedScanMsg.remove());
-                    break;
                 case CMD_TARGET_BSSID:
                     // Trying to associate to this BSSID
                     if (message.obj != null) {
@@ -4401,9 +4097,6 @@ public class WifiStateMachine extends StateMachine {
 
             mIsRunning = false;
             updateBatteryWorkSource(null);
-            mScanResults = new ArrayList<>();
-
-            mBufferedScanMsg.clear();
 
             mNetworkInfo.setIsAvailable(false);
             if (mNetworkAgent != null) mNetworkAgent.sendNetworkInfo(mNetworkInfo);
@@ -4427,37 +4120,16 @@ public class WifiStateMachine extends StateMachine {
         public boolean processMessage(Message message) {
             logStateAndMessage(message, this);
 
-            switch(message.what) {
-                case CMD_SET_OPERATIONAL_MODE:
-                    int operationMode = message.arg1;
-                    if (operationMode == SCAN_ONLY_MODE
-                            || operationMode == SCAN_ONLY_WITH_WIFI_OFF_MODE) {
-                        // nothing to do, stay here...
-                        return HANDLED;
-                    }
-                    return NOT_HANDLED;
-
-                    /*
-                    if (message.arg1 == CONNECT_MODE) {
-                        mOperationalMode = CONNECT_MODE;
-                        setWifiState(WIFI_STATE_ENABLING);
-                        transitionTo(mDisconnectedState);
-                    } else if (message.arg1 == DISABLED_MODE) {
-                        transitionTo(mSupplicantStoppingState);
-                    }
-                    // Nothing to do
-                    break;
-                    */
-                // Handle scan. All the connection related commands are
-                // handled only in ConnectModeState
-                case CMD_START_SCAN:
-                    // TODO b/31445200: as mentioned elsewhere, this needs to be moved out of WSM
-                    handleScanRequest(message);
-                    break;
-                default:
-                    return NOT_HANDLED;
+            if (message.what == CMD_SET_OPERATIONAL_MODE) {
+                int operationMode = message.arg1;
+                if (operationMode == SCAN_ONLY_MODE
+                        || operationMode == SCAN_ONLY_WITH_WIFI_OFF_MODE) {
+                    // nothing to do, stay here...
+                    return HANDLED;
+                }
+                return NOT_HANDLED;
             }
-            return HANDLED;
+            return NOT_HANDLED;
         }
     }
 
@@ -4499,12 +4171,6 @@ public class WifiStateMachine extends StateMachine {
             case WifiMonitor.SUP_DISCONNECTION_EVENT:
                 s = "SUP_DISCONNECTION_EVENT";
                 break;
-            case WifiMonitor.SCAN_RESULTS_EVENT:
-                s = "SCAN_RESULTS_EVENT";
-                break;
-            case WifiMonitor.SCAN_FAILED_EVENT:
-                s = "SCAN_FAILED_EVENT";
-                break;
             case WifiMonitor.SUPPLICANT_STATE_CHANGE_EVENT:
                 s = "SUPPLICANT_STATE_CHANGE_EVENT";
                 break;
@@ -5420,48 +5086,6 @@ public class WifiStateMachine extends StateMachine {
         return prefix + imsi + "@wlan.mnc" + mnc + ".mcc" + mcc + ".3gppnetwork.org";
     }
 
-    boolean startScanForConfiguration(WifiConfiguration config) {
-        if (config == null)
-            return false;
-
-        // We are still seeing a fairly high power consumption triggered by autojoin scans
-        // Hence do partial scans only for PSK configuration that are roamable since the
-        // primary purpose of the partial scans is roaming.
-        // Full badn scans with exponential backoff for the purpose or extended roaming and
-        // network switching are performed unconditionally.
-        ScanDetailCache scanDetailCache =
-                mWifiConfigManager.getScanDetailCacheForNetwork(config.networkId);
-        if (scanDetailCache == null
-                || !config.allowedKeyManagement.get(WifiConfiguration.KeyMgmt.WPA_PSK)
-                || scanDetailCache.size() > 6) {
-            //return true but to not trigger the scan
-            return true;
-        }
-        Set<Integer> freqs =
-                mWifiConfigManager.fetchChannelSetForNetworkForPartialScan(
-                        config.networkId, ONE_HOUR_MILLI, mWifiInfo.getFrequency());
-        if (freqs != null && freqs.size() != 0) {
-            //if (mVerboseLoggingEnabled) {
-            logd("starting scan for " + config.configKey() + " with " + freqs);
-            //}
-            List<WifiScanner.ScanSettings.HiddenNetwork> hiddenNetworks = new ArrayList<>();
-            if (config.hiddenSSID) {
-                hiddenNetworks.add(new WifiScanner.ScanSettings.HiddenNetwork(config.SSID));
-            }
-            // Call wifi native to start the scan
-            if (startScanNative(freqs, hiddenNetworks, WIFI_WORK_SOURCE)) {
-                messageHandlingStatus = MESSAGE_HANDLING_STATUS_OK;
-            } else {
-                // used for debug only, mark scan as failed
-                messageHandlingStatus = MESSAGE_HANDLING_STATUS_HANDLING_ERROR;
-            }
-            return true;
-        } else {
-            if (mVerboseLoggingEnabled) logd("no channels for " + config.configKey());
-            return false;
-        }
-    }
-
     class L2ConnectedState extends State {
         class RssiEventHandler implements WifiNative.WifiRssiEventHandler {
             @Override
@@ -5814,11 +5438,6 @@ public class WifiStateMachine extends StateMachine {
                     messageHandlingStatus = MESSAGE_HANDLING_STATUS_DEFERRED;
                     deferMessage(message);
                     break;
-                    /* Defer scan request since we should not switch to other channels at DHCP */
-                case CMD_START_SCAN:
-                    messageHandlingStatus = MESSAGE_HANDLING_STATUS_DEFERRED;
-                    deferMessage(message);
-                    break;
                 default:
                     return NOT_HANDLED;
             }
@@ -6003,9 +5622,6 @@ public class WifiStateMachine extends StateMachine {
                         transitionTo(mDisconnectedState);
                     }
                     break;
-                case CMD_START_SCAN:
-                    deferMessage(message);
-                    break;
                 default:
                     return NOT_HANDLED;
             }
@@ -6232,9 +5848,6 @@ public class WifiStateMachine extends StateMachine {
         public boolean processMessage(Message message) {
             logStateAndMessage(message, this);
             switch (message.what) {
-                case CMD_START_SCAN:
-                    deferMessage(message);
-                    return HANDLED;
                 case CMD_DISCONNECT:
                     if (mVerboseLoggingEnabled) log("Ignore CMD_DISCONNECT when already disconnecting.");
                     break;
@@ -6313,15 +5926,6 @@ public class WifiStateMachine extends StateMachine {
                     /* ConnectModeState does the rest of the handling */
                     ret = NOT_HANDLED;
                     break;
-                case CMD_START_SCAN:
-                    if (!checkOrDeferScanAllowed(message)) {
-                        // The scan request was rescheduled
-                        messageHandlingStatus = MESSAGE_HANDLING_STATUS_REFUSED;
-                        return HANDLED;
-                    }
-
-                    ret = NOT_HANDLED;
-                    break;
                 case WifiP2pServiceImpl.P2P_CONNECTION_CHANGED:
                     NetworkInfo info = (NetworkInfo) message.obj;
                     mP2pConnected.set(info.isConnected());
diff --git a/tests/wifitests/src/com/android/server/wifi/WifiStateMachineTest.java b/tests/wifitests/src/com/android/server/wifi/WifiStateMachineTest.java
index 7aeccbef6..29f8b4847 100644
--- a/tests/wifitests/src/com/android/server/wifi/WifiStateMachineTest.java
+++ b/tests/wifitests/src/com/android/server/wifi/WifiStateMachineTest.java
@@ -108,9 +108,7 @@ import java.lang.reflect.InvocationTargetException;
 import java.lang.reflect.Method;
 import java.util.ArrayList;
 import java.util.Arrays;
-import java.util.HashSet;
 import java.util.List;
-import java.util.Set;
 import java.util.concurrent.CountDownLatch;
 import java.util.function.Consumer;
 
@@ -921,68 +919,6 @@ public class WifiStateMachineTest {
         return null;
     }
 
-    private void verifyScan(int band, int reportEvents, Set<String> hiddenNetworkSSIDSet) {
-        ArgumentCaptor<WifiScanner.ScanSettings> scanSettingsCaptor =
-                ArgumentCaptor.forClass(WifiScanner.ScanSettings.class);
-        ArgumentCaptor<WifiScanner.ScanListener> scanListenerCaptor =
-                ArgumentCaptor.forClass(WifiScanner.ScanListener.class);
-        verify(mWifiScanner).startScan(scanSettingsCaptor.capture(), scanListenerCaptor.capture(),
-                eq(null));
-        WifiScanner.ScanSettings actualSettings = scanSettingsCaptor.getValue();
-        assertEquals("band", band, actualSettings.band);
-        assertEquals("reportEvents", reportEvents, actualSettings.reportEvents);
-
-        if (hiddenNetworkSSIDSet == null) {
-            hiddenNetworkSSIDSet = new HashSet<>();
-        }
-        Set<String> actualHiddenNetworkSSIDSet = new HashSet<>();
-        if (actualSettings.hiddenNetworks != null) {
-            for (int i = 0; i < actualSettings.hiddenNetworks.length; ++i) {
-                actualHiddenNetworkSSIDSet.add(actualSettings.hiddenNetworks[i].ssid);
-            }
-        }
-        assertEquals("hidden networks", hiddenNetworkSSIDSet, actualHiddenNetworkSSIDSet);
-
-        when(mWifiNative.getScanResults(WIFI_IFACE_NAME)).thenReturn(getMockScanResults());
-        mWsm.sendMessage(WifiMonitor.SCAN_RESULTS_EVENT);
-
-        mLooper.dispatchAll();
-
-        List<ScanResult> reportedResults = mWsm.syncGetScanResultsList();
-        assertEquals(8, reportedResults.size());
-    }
-
-    @Test
-    public void scan() throws Exception {
-        initializeAndAddNetworkAndVerifySuccess();
-
-        mWsm.startScan(-1, 0, null, null);
-        mLooper.dispatchAll();
-
-        verifyScan(WifiScanner.WIFI_BAND_BOTH_WITH_DFS,
-                WifiScanner.REPORT_EVENT_AFTER_EACH_SCAN
-                | WifiScanner.REPORT_EVENT_FULL_SCAN_RESULT, null);
-    }
-
-    @Test
-    public void scanWithHiddenNetwork() throws Exception {
-        initializeAndAddNetworkAndVerifySuccess(true);
-
-        Set<String> hiddenNetworkSet = new HashSet<>();
-        hiddenNetworkSet.add(sSSID);
-        List<WifiScanner.ScanSettings.HiddenNetwork> hiddenNetworkList = new ArrayList<>();
-        hiddenNetworkList.add(new WifiScanner.ScanSettings.HiddenNetwork(sSSID));
-        when(mWifiConfigManager.retrieveHiddenNetworkList()).thenReturn(hiddenNetworkList);
-
-        mWsm.startScan(-1, 0, null, null);
-        mLooper.dispatchAll();
-
-        verifyScan(WifiScanner.WIFI_BAND_BOTH_WITH_DFS,
-                WifiScanner.REPORT_EVENT_AFTER_EACH_SCAN
-                | WifiScanner.REPORT_EVENT_FULL_SCAN_RESULT,
-                hiddenNetworkSet);
-    }
-
     private void setupAndStartConnectSequence(WifiConfiguration config) throws Exception {
         when(mWifiConfigManager.enableNetwork(eq(config.networkId), eq(true), anyInt()))
                 .thenReturn(true);