Merge changes from topic "revert-2370228-legacy_iwlan_removal-UKSFKVXSIS"

* changes:
  [RESTRICT AUTOMERGE] Revert "Removed IWLAN legacy mode support"
  [RESTRICT AUTOMERGE] Revert "Fix to set transportType when creating DataServiceManager."

6 files changed, 198 insertions, 43 deletions

diff --git a/src/java/com/android/internal/telephony/ServiceStateTracker.java b/src/java/com/android/internal/telephony/ServiceStateTracker.java
index 2d092deea2..85c4b31c46 100755
--- a/src/java/com/android/internal/telephony/ServiceStateTracker.java
+++ b/src/java/com/android/internal/telephony/ServiceStateTracker.java
@@ -669,7 +669,7 @@ public class ServiceStateTracker extends Handler {
 
         mAccessNetworksManager = mPhone.getAccessNetworksManager();
         mOutOfServiceSS = new ServiceState();
-        mOutOfServiceSS.setOutOfService(false);
+        mOutOfServiceSS.setOutOfService(mAccessNetworksManager.isInLegacyMode(), false);
 
         for (int transportType : mAccessNetworksManager.getAvailableTransports()) {
             mRegStateManagers.append(transportType, new NetworkRegistrationManager(
@@ -771,9 +771,9 @@ public class ServiceStateTracker extends Handler {
         }
 
         mSS = new ServiceState();
-        mSS.setOutOfService(false);
+        mSS.setOutOfService(mAccessNetworksManager.isInLegacyMode(), false);
         mNewSS = new ServiceState();
-        mNewSS.setOutOfService(false);
+        mNewSS.setOutOfService(mAccessNetworksManager.isInLegacyMode(), false);
         mLastCellInfoReqTime = 0;
         mLastCellInfoList = null;
         mStartedGprsRegCheck = false;
@@ -3341,7 +3341,7 @@ public class ServiceStateTracker extends Handler {
                 nri = mNewSS.getNetworkRegistrationInfo(
                         NetworkRegistrationInfo.DOMAIN_PS,
                         AccessNetworkConstants.TRANSPORT_TYPE_WLAN);
-                mNewSS.setOutOfService(false);
+                mNewSS.setOutOfService(mAccessNetworksManager.isInLegacyMode(), false);
                 // Add the IWLAN registration info back to service state.
                 if (nri != null) {
                     mNewSS.addNetworkRegistrationInfo(nri);
@@ -3358,7 +3358,7 @@ public class ServiceStateTracker extends Handler {
                 nri = mNewSS.getNetworkRegistrationInfo(
                         NetworkRegistrationInfo.DOMAIN_PS,
                         AccessNetworkConstants.TRANSPORT_TYPE_WLAN);
-                mNewSS.setOutOfService(true);
+                mNewSS.setOutOfService(mAccessNetworksManager.isInLegacyMode(), true);
                 // Add the IWLAN registration info back to service state.
                 if (nri != null) {
                     mNewSS.addNetworkRegistrationInfo(nri);
@@ -3485,10 +3485,14 @@ public class ServiceStateTracker extends Handler {
                 mSS.getState() == ServiceState.STATE_POWER_OFF
                         && mNewSS.getState() != ServiceState.STATE_POWER_OFF;
 
-        SparseBooleanArray hasDataAttached = new SparseBooleanArray();
-        SparseBooleanArray hasDataDetached = new SparseBooleanArray();
-        SparseBooleanArray hasRilDataRadioTechnologyChanged = new SparseBooleanArray();
-        SparseBooleanArray hasDataRegStateChanged = new SparseBooleanArray();
+        SparseBooleanArray hasDataAttached = new SparseBooleanArray(
+                mAccessNetworksManager.getAvailableTransports().length);
+        SparseBooleanArray hasDataDetached = new SparseBooleanArray(
+                mAccessNetworksManager.getAvailableTransports().length);
+        SparseBooleanArray hasRilDataRadioTechnologyChanged = new SparseBooleanArray(
+                mAccessNetworksManager.getAvailableTransports().length);
+        SparseBooleanArray hasDataRegStateChanged = new SparseBooleanArray(
+                mAccessNetworksManager.getAvailableTransports().length);
         boolean anyDataRegChanged = false;
         boolean anyDataRatChanged = false;
         boolean hasAlphaRawChanged =
@@ -3678,7 +3682,7 @@ public class ServiceStateTracker extends Handler {
         ServiceState oldMergedSS = new ServiceState(mPhone.getServiceState());
         mSS = new ServiceState(mNewSS);
 
-        mNewSS.setOutOfService(false);
+        mNewSS.setOutOfService(mAccessNetworksManager.isInLegacyMode(), false);
 
         mCellIdentity = primaryCellIdentity;
         if (mSS.getState() == ServiceState.STATE_IN_SERVICE && primaryCellIdentity != null) {
@@ -5565,7 +5569,8 @@ public class ServiceStateTracker extends Handler {
 
 
     /**
-     * This method makes some adjustments when the device camps on IWLAN in airplane mode.
+     * This method adds IWLAN registration info for legacy mode devices camped on IWLAN. It also
+     * makes some adjustments when the device camps on IWLAN in airplane mode.
      */
     private void processIwlanRegistrationInfo() {
         if (mCi.getRadioState() == TelephonyManager.RADIO_POWER_OFF) {
@@ -5579,7 +5584,7 @@ public class ServiceStateTracker extends Handler {
             }
             // operator info should be kept in SS
             String operator = mNewSS.getOperatorAlphaLong();
-            mNewSS.setOutOfService(true);
+            mNewSS.setOutOfService(mAccessNetworksManager.isInLegacyMode(), true);
             if (resetIwlanRatVal) {
                 mNewSS.setDataRegState(ServiceState.STATE_IN_SERVICE);
                 NetworkRegistrationInfo nri = new NetworkRegistrationInfo.Builder()
@@ -5589,6 +5594,17 @@ public class ServiceStateTracker extends Handler {
                         .setRegistrationState(NetworkRegistrationInfo.REGISTRATION_STATE_HOME)
                         .build();
                 mNewSS.addNetworkRegistrationInfo(nri);
+                if (mAccessNetworksManager.isInLegacyMode()) {
+                    // If in legacy mode, simulate the behavior that IWLAN registration info
+                    // is reported through WWAN transport.
+                    nri = new NetworkRegistrationInfo.Builder()
+                            .setTransportType(AccessNetworkConstants.TRANSPORT_TYPE_WWAN)
+                            .setDomain(NetworkRegistrationInfo.DOMAIN_PS)
+                            .setAccessNetworkTechnology(TelephonyManager.NETWORK_TYPE_IWLAN)
+                            .setRegistrationState(NetworkRegistrationInfo.REGISTRATION_STATE_HOME)
+                            .build();
+                    mNewSS.addNetworkRegistrationInfo(nri);
+                }
                 mNewSS.setOperatorAlphaLong(operator);
                 // Since it's in airplane mode, cellular must be out of service. The only possible
                 // transport for data to go through is the IWLAN transport. Setting this to true
@@ -5598,6 +5614,31 @@ public class ServiceStateTracker extends Handler {
             }
             return;
         }
+
+        // If the device operates in legacy mode and camps on IWLAN, modem reports IWLAN as a RAT
+        // through WWAN registration info. To be consistent with the behavior with AP-assisted mode,
+        // we manually make a WLAN registration info for clients to consume. In this scenario,
+        // both WWAN and WLAN registration info are the IWLAN registration info and that's the
+        // unfortunate limitation we have when the device operates in legacy mode. In AP-assisted
+        // mode, the WWAN registration will correctly report the actual cellular registration info
+        // when the device camps on IWLAN.
+        if (mAccessNetworksManager.isInLegacyMode()) {
+            NetworkRegistrationInfo wwanNri = mNewSS.getNetworkRegistrationInfo(
+                    NetworkRegistrationInfo.DOMAIN_PS, AccessNetworkConstants.TRANSPORT_TYPE_WWAN);
+            if (wwanNri != null && wwanNri.getAccessNetworkTechnology()
+                    == TelephonyManager.NETWORK_TYPE_IWLAN) {
+                NetworkRegistrationInfo wlanNri = new NetworkRegistrationInfo.Builder()
+                        .setTransportType(AccessNetworkConstants.TRANSPORT_TYPE_WLAN)
+                        .setDomain(NetworkRegistrationInfo.DOMAIN_PS)
+                        .setRegistrationState(wwanNri.getNetworkRegistrationState())
+                        .setAccessNetworkTechnology(TelephonyManager.NETWORK_TYPE_IWLAN)
+                        .setRejectCause(wwanNri.getRejectCause())
+                        .setEmergencyOnly(wwanNri.isEmergencyEnabled())
+                        .setAvailableServices(wwanNri.getAvailableServices())
+                        .build();
+                mNewSS.addNetworkRegistrationInfo(wlanNri);
+            }
+        }
     }
 
     /**
diff --git a/src/java/com/android/internal/telephony/data/AccessNetworksManager.java b/src/java/com/android/internal/telephony/data/AccessNetworksManager.java
index d51f586932..d034abdf3a 100644
--- a/src/java/com/android/internal/telephony/data/AccessNetworksManager.java
+++ b/src/java/com/android/internal/telephony/data/AccessNetworksManager.java
@@ -19,6 +19,7 @@ package com.android.internal.telephony.data;
 import android.annotation.CallbackExecutor;
 import android.annotation.NonNull;
 import android.annotation.Nullable;
+import android.annotation.StringDef;
 import android.content.BroadcastReceiver;
 import android.content.ComponentName;
 import android.content.Context;
@@ -33,6 +34,7 @@ import android.os.PersistableBundle;
 import android.os.Registrant;
 import android.os.RegistrantList;
 import android.os.RemoteException;
+import android.os.SystemProperties;
 import android.os.UserHandle;
 import android.telephony.AccessNetworkConstants;
 import android.telephony.AccessNetworkConstants.AccessNetworkType;
@@ -54,11 +56,14 @@ import android.util.LocalLog;
 import android.util.SparseArray;
 
 import com.android.internal.telephony.Phone;
+import com.android.internal.telephony.RIL;
 import com.android.internal.telephony.SlidingWindowEventCounter;
 import com.android.telephony.Rlog;
 
 import java.io.FileDescriptor;
 import java.io.PrintWriter;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
@@ -76,6 +81,35 @@ import java.util.stream.Collectors;
  */
 public class AccessNetworksManager extends Handler {
     private static final boolean DBG = false;
+    public static final String SYSTEM_PROPERTIES_IWLAN_OPERATION_MODE =
+            "ro.telephony.iwlan_operation_mode";
+
+    @Retention(RetentionPolicy.SOURCE)
+    @StringDef(prefix = {"IWLAN_OPERATION_MODE_"},
+            value = {
+                    IWLAN_OPERATION_MODE_DEFAULT,
+                    IWLAN_OPERATION_MODE_LEGACY,
+                    IWLAN_OPERATION_MODE_AP_ASSISTED})
+    public @interface IwlanOperationMode {}
+
+    /**
+     * IWLAN default mode. On device that has IRadio 1.4 or above, it means
+     * {@link #IWLAN_OPERATION_MODE_AP_ASSISTED}. On device that has IRadio 1.3 or below, it means
+     * {@link #IWLAN_OPERATION_MODE_LEGACY}.
+     */
+    public static final String IWLAN_OPERATION_MODE_DEFAULT = "default";
+
+    /**
+     * IWLAN legacy mode. IWLAN is completely handled by the modem, and when the device is on
+     * IWLAN, modem reports IWLAN as a RAT.
+     */
+    public static final String IWLAN_OPERATION_MODE_LEGACY = "legacy";
+
+    /**
+     * IWLAN application processor assisted mode. IWLAN is handled by the bound IWLAN data service
+     * and network service separately.
+     */
+    public static final String IWLAN_OPERATION_MODE_AP_ASSISTED = "AP-assisted";
 
     /**
      * The counters to detect frequent QNS attempt to change preferred network transport by ApnType.
@@ -332,19 +366,28 @@ public class AccessNetworksManager extends Handler {
                 Context.CARRIER_CONFIG_SERVICE);
         mLogTag = "ANM-" + mPhone.getPhoneId();
         mApnTypeToQnsChangeNetworkCounter = new SparseArray<>();
-        mAvailableTransports = new int[]{AccessNetworkConstants.TRANSPORT_TYPE_WWAN,
-                AccessNetworkConstants.TRANSPORT_TYPE_WLAN};
-        IntentFilter intentFilter = new IntentFilter();
-        intentFilter.addAction(CarrierConfigManager.ACTION_CARRIER_CONFIG_CHANGED);
-        try {
-            Context contextAsUser = phone.getContext().createPackageContextAsUser(
-                    phone.getContext().getPackageName(), 0, UserHandle.ALL);
-            contextAsUser.registerReceiver(mConfigChangedReceiver, intentFilter,
-                    null /* broadcastPermission */, null);
-        } catch (PackageManager.NameNotFoundException e) {
-            loge("Package name not found: ", e);
+
+        if (isInLegacyMode()) {
+            log("operates in legacy mode.");
+            // For legacy mode, WWAN is the only transport to handle all data connections, even
+            // the IWLAN ones.
+            mAvailableTransports = new int[]{AccessNetworkConstants.TRANSPORT_TYPE_WWAN};
+        } else {
+            log("operates in AP-assisted mode.");
+            mAvailableTransports = new int[]{AccessNetworkConstants.TRANSPORT_TYPE_WWAN,
+                    AccessNetworkConstants.TRANSPORT_TYPE_WLAN};
+            IntentFilter intentFilter = new IntentFilter();
+            intentFilter.addAction(CarrierConfigManager.ACTION_CARRIER_CONFIG_CHANGED);
+            try {
+                Context contextAsUser = phone.getContext().createPackageContextAsUser(
+                        phone.getContext().getPackageName(), 0, UserHandle.ALL);
+                contextAsUser.registerReceiver(mConfigChangedReceiver, intentFilter,
+                        null /* broadcastPermission */, null);
+            } catch (PackageManager.NameNotFoundException e) {
+                loge("Package name not found: ", e);
+            }
+            bindQualifiedNetworksService();
         }
-        bindQualifiedNetworksService();
 
         // Using post to delay the registering because data retry manager and data config
         // manager instances are created later than access networks manager.
@@ -447,7 +490,8 @@ public class AccessNetworksManager extends Handler {
     /**
      * Get the qualified network service package.
      *
-     * @return package name of the qualified networks service package.
+     * @return package name of the qualified networks service package. Return empty string when in
+     * legacy mode (i.e. Dedicated IWLAN data/network service is not supported).
      */
     private String getQualifiedNetworksServicePackageName() {
         // Read package name from the resource
@@ -524,9 +568,30 @@ public class AccessNetworksManager extends Handler {
     }
 
     /**
-     * @return The available transports.
+     * @return {@code true} if the device operates in legacy mode, otherwise {@code false}.
      */
-    public @NonNull int[] getAvailableTransports() {
+    public boolean isInLegacyMode() {
+        // Get IWLAN operation mode from the system property. If the system property is configured
+        // to default or not configured, the mode is tied to IRadio version. For 1.4 or above, it's
+        // AP-assisted mode, for 1.3 or below, it's legacy mode.
+        String mode = SystemProperties.get(SYSTEM_PROPERTIES_IWLAN_OPERATION_MODE);
+
+        if (mode.equals(IWLAN_OPERATION_MODE_AP_ASSISTED)) {
+            return false;
+        } else if (mode.equals(IWLAN_OPERATION_MODE_LEGACY)) {
+            return true;
+        }
+
+        return mPhone.getHalVersion().less(RIL.RADIO_HAL_VERSION_1_4);
+    }
+
+    /**
+     * @return The available transports. Note that on legacy devices, the only available transport
+     * would be WWAN only. If the device is configured as AP-assisted mode, the available transport
+     * will always be WWAN and WLAN (even if the device is not camped on IWLAN).
+     * See {@link #isInLegacyMode()} for mode details.
+     */
+    public synchronized @NonNull int[] getAvailableTransports() {
         return mAvailableTransports;
     }
 
@@ -561,6 +626,11 @@ public class AccessNetworksManager extends Handler {
      * @return The preferred transport.
      */
     public @TransportType int getPreferredTransport(@ApnType int apnType) {
+        // In legacy mode, always preferred on cellular.
+        if (isInLegacyMode()) {
+            return AccessNetworkConstants.TRANSPORT_TYPE_WWAN;
+        }
+
         return mPreferredTransports.get(apnType) == null
                 ? AccessNetworkConstants.TRANSPORT_TYPE_WWAN : mPreferredTransports.get(apnType);
     }
@@ -663,6 +733,9 @@ public class AccessNetworksManager extends Handler {
         }
 
         pw.decreaseIndent();
+        pw.println("isInLegacy=" + isInLegacyMode());
+        pw.println("IWLAN operation mode="
+                + SystemProperties.get(SYSTEM_PROPERTIES_IWLAN_OPERATION_MODE));
         pw.println("Local logs=");
         pw.increaseIndent();
         mLocalLog.dump(fd, pw, args);
diff --git a/src/java/com/android/internal/telephony/data/DataNetwork.java b/src/java/com/android/internal/telephony/data/DataNetwork.java
index 7dee6dc7cb..7b1f6fb303 100644
--- a/src/java/com/android/internal/telephony/data/DataNetwork.java
+++ b/src/java/com/android/internal/telephony/data/DataNetwork.java
@@ -912,9 +912,8 @@ public class DataNetwork extends StateMachine {
         mDataAllowedReason = dataAllowedReason;
         dataProfile.setLastSetupTimestamp(SystemClock.elapsedRealtime());
         mAttachedNetworkRequestList.addAll(networkRequestList);
-        for (int transportType : mAccessNetworksManager.getAvailableTransports()) {
-            mCid.put(transportType, INVALID_CID);
-        }
+        mCid.put(AccessNetworkConstants.TRANSPORT_TYPE_WWAN, INVALID_CID);
+        mCid.put(AccessNetworkConstants.TRANSPORT_TYPE_WLAN, INVALID_CID);
         mTelephonyDisplayInfo = mPhone.getDisplayInfoController().getTelephonyDisplayInfo();
         mTcpBufferSizes = mDataConfigManager.getTcpConfigString(mTelephonyDisplayInfo);
 
diff --git a/src/java/com/android/internal/telephony/data/DataNetworkController.java b/src/java/com/android/internal/telephony/data/DataNetworkController.java
index d693885cf3..e45b88d435 100644
--- a/src/java/com/android/internal/telephony/data/DataNetworkController.java
+++ b/src/java/com/android/internal/telephony/data/DataNetworkController.java
@@ -781,10 +781,13 @@ public class DataNetworkController extends Handler {
         log("DataNetworkController created.");
 
         mAccessNetworksManager = phone.getAccessNetworksManager();
-        for (int transport : mAccessNetworksManager.getAvailableTransports()) {
-            mDataServiceManagers.put(transport, new DataServiceManager(mPhone, looper, transport));
+        mDataServiceManagers.put(AccessNetworkConstants.TRANSPORT_TYPE_WWAN,
+                new DataServiceManager(mPhone, looper, AccessNetworkConstants.TRANSPORT_TYPE_WWAN));
+        if (!mAccessNetworksManager.isInLegacyMode()) {
+            mDataServiceManagers.put(AccessNetworkConstants.TRANSPORT_TYPE_WLAN,
+                    new DataServiceManager(mPhone, looper,
+                            AccessNetworkConstants.TRANSPORT_TYPE_WLAN));
         }
-
         mDataConfigManager = new DataConfigManager(mPhone, looper);
 
         // ========== Anomaly counters ==========
@@ -988,10 +991,12 @@ public class DataNetworkController extends Handler {
         mDataServiceManagers.get(AccessNetworkConstants.TRANSPORT_TYPE_WWAN)
                 .registerForServiceBindingChanged(this, EVENT_DATA_SERVICE_BINDING_CHANGED);
 
-        mPhone.getServiceStateTracker().registerForServiceStateChanged(this,
-                EVENT_SERVICE_STATE_CHANGED, null);
-        mDataServiceManagers.get(AccessNetworkConstants.TRANSPORT_TYPE_WLAN)
-                .registerForServiceBindingChanged(this, EVENT_DATA_SERVICE_BINDING_CHANGED);
+        if (!mAccessNetworksManager.isInLegacyMode()) {
+            mPhone.getServiceStateTracker().registerForServiceStateChanged(this,
+                    EVENT_SERVICE_STATE_CHANGED, null);
+            mDataServiceManagers.get(AccessNetworkConstants.TRANSPORT_TYPE_WLAN)
+                    .registerForServiceBindingChanged(this, EVENT_DATA_SERVICE_BINDING_CHANGED);
+        }
 
         mPhone.getContext().getSystemService(TelephonyRegistryManager.class)
                 .addOnSubscriptionsChangedListener(new OnSubscriptionsChangedListener() {
diff --git a/src/java/com/android/internal/telephony/data/DataRetryManager.java b/src/java/com/android/internal/telephony/data/DataRetryManager.java
index c2b3b9ae3b..0beea1fdb3 100644
--- a/src/java/com/android/internal/telephony/data/DataRetryManager.java
+++ b/src/java/com/android/internal/telephony/data/DataRetryManager.java
@@ -958,9 +958,10 @@ public class DataRetryManager extends Handler {
                 DataRetryManager.this.onCarrierConfigUpdated();
             }
         });
-
-        for (int transport : mPhone.getAccessNetworksManager().getAvailableTransports()) {
-            mDataServiceManagers.get(transport)
+        mDataServiceManagers.get(AccessNetworkConstants.TRANSPORT_TYPE_WWAN)
+                .registerForApnUnthrottled(this, EVENT_DATA_PROFILE_UNTHROTTLED);
+        if (!mPhone.getAccessNetworksManager().isInLegacyMode()) {
+            mDataServiceManagers.get(AccessNetworkConstants.TRANSPORT_TYPE_WLAN)
                     .registerForApnUnthrottled(this, EVENT_DATA_PROFILE_UNTHROTTLED);
         }
         mDataProfileManager.registerCallback(new DataProfileManagerCallback(this::post) {
diff --git a/src/java/com/android/internal/telephony/imsphone/ImsPhone.java b/src/java/com/android/internal/telephony/imsphone/ImsPhone.java
index a986b6c2ce..5c14b0ebf5 100644
--- a/src/java/com/android/internal/telephony/imsphone/ImsPhone.java
+++ b/src/java/com/android/internal/telephony/imsphone/ImsPhone.java
@@ -458,7 +458,11 @@ public class ImsPhone extends ImsPhoneBase {
         mCT.registerPhoneStateListener(mExternalCallTracker);
         mExternalCallTracker.setCallPuller(mCT);
 
-        mSS.setOutOfService(false);
+        boolean legacyMode = true;
+        if (mDefaultPhone.getAccessNetworksManager() != null) {
+            legacyMode = mDefaultPhone.getAccessNetworksManager().isInLegacyMode();
+        }
+        mSS.setOutOfService(legacyMode, false);
 
         mPhoneId = mDefaultPhone.getPhoneId();
 
@@ -2367,7 +2371,7 @@ public class ImsPhone extends ImsPhoneBase {
     /**
      * Update roaming state and WFC mode in the following situations:
      *     1) voice is in service.
-     *     2) data is in service.
+     *     2) data is in service and it is not IWLAN (if in legacy mode).
      * @param ss non-null ServiceState
      */
     private void updateRoamingState(ServiceState ss) {
@@ -2388,7 +2392,15 @@ public class ImsPhone extends ImsPhoneBase {
             logi("updateRoamingState: we are not IN_SERVICE, ignoring roaming change.");
             return;
         }
-
+        // We ignore roaming changes when moving to IWLAN because it always sets the roaming
+        // mode to home and masks the actual cellular roaming status if voice is not registered. If
+        // we just moved to IWLAN because WFC roaming mode is IWLAN preferred and WFC home mode is
+        // cell preferred, we can get into a condition where the modem keeps bouncing between
+        // IWLAN->cell->IWLAN->cell...
+        if (isCsNotInServiceAndPsWwanReportingWlan(ss)) {
+            logi("updateRoamingState: IWLAN masking roaming, ignore roaming change.");
+            return;
+        }
         if (mCT.getState() == PhoneConstants.State.IDLE) {
             if (DBG) logd("updateRoamingState now: " + newRoamingState);
             mLastKnownRoamingState = newRoamingState;
@@ -2407,6 +2419,30 @@ public class ImsPhone extends ImsPhoneBase {
         }
     }
 
+    /**
+     * In legacy mode, data registration will report IWLAN when we are using WLAN for data,
+     * effectively masking the true roaming state of the device if voice is not registered.
+     *
+     * @return true if we are reporting not in service for CS domain over WWAN transport and WLAN
+     * for PS domain over WWAN transport.
+     */
+    private boolean isCsNotInServiceAndPsWwanReportingWlan(ServiceState ss) {
+        // We can not get into this condition if we are in AP-Assisted mode.
+        if (mDefaultPhone.getAccessNetworksManager() == null
+                || !mDefaultPhone.getAccessNetworksManager().isInLegacyMode()) {
+            return false;
+        }
+        NetworkRegistrationInfo csInfo = ss.getNetworkRegistrationInfo(
+                NetworkRegistrationInfo.DOMAIN_CS, AccessNetworkConstants.TRANSPORT_TYPE_WWAN);
+        NetworkRegistrationInfo psInfo = ss.getNetworkRegistrationInfo(
+                NetworkRegistrationInfo.DOMAIN_PS, AccessNetworkConstants.TRANSPORT_TYPE_WWAN);
+        // We will return roaming state correctly if the CS domain is in service because
+        // ss.getRoaming() returns isVoiceRoaming||isDataRoaming result and isDataRoaming==false
+        // when the modem reports IWLAN RAT.
+        return psInfo != null && csInfo != null && !csInfo.isInService()
+                && psInfo.getAccessNetworkTechnology() == TelephonyManager.NETWORK_TYPE_IWLAN;
+    }
+
     public RegistrationManager.RegistrationCallback getImsMmTelRegistrationCallback() {
         return mImsMmTelRegistrationHelper.getCallback();
     }