diff --git a/res/values/strings.xml b/res/values/strings.xml
index f79b432..8e7d087 100644
--- a/res/values/strings.xml
+++ b/res/values/strings.xml
@@ -1761,6 +1761,9 @@
     <string name="call_barring_settings">Call barring settings</string>
     <!-- Call barring settings screen, deactivate all call barring settings -->
     <string name="call_barring_deactivate_all_no_password">Deactivate all call barring settings?</string>
+    <!-- In-call screen: error message shown when the user attempts to place a call, but the network
+         does not have enough resources (e.g. it is busy) and the call cannot be placed. -->
+    <string name="callFailed_NetworkBusy">Network is busy.  Please try your call again later.</string>
     <!-- Message displayed to the user when an outgoing call is deflected.  This means that the
          party the user is calling has chosen to send the call to another phone number. -->
     <string name="supp_service_notification_call_deflected">Call deflected.</string>
diff --git a/src/com/android/phone/CallFeaturesSetting.java b/src/com/android/phone/CallFeaturesSetting.java
index e31577d..c9fd205 100644
--- a/src/com/android/phone/CallFeaturesSetting.java
+++ b/src/com/android/phone/CallFeaturesSetting.java
@@ -37,6 +37,7 @@
 import android.telecom.TelecomManager;
 import android.telephony.CarrierConfigManager;
 import android.telephony.PhoneStateListener;
+import android.telephony.SubscriptionManager;
 import android.telephony.TelephonyManager;
 import android.telephony.ims.ProvisioningManager;
 import android.telephony.ims.feature.ImsFeature;
@@ -418,6 +419,10 @@
         } else if (!mImsMgr.isWfcEnabledByPlatform() || !mImsMgr.isWfcProvisionedOnDevice()) {
             prefSet.removePreference(mButtonWifiCalling);
         } else {
+            String title = SubscriptionManager.getResourcesForSubId(mPhone.getContext(),
+                    mPhone.getSubId()).getString(R.string.wifi_calling);
+            mButtonWifiCalling.setTitle(title);
+
             int resId = com.android.internal.R.string.wifi_calling_off_summary;
             if (mImsMgr.isWfcEnabledByUser()) {
                 boolean isRoaming = telephonyManager.isNetworkRoaming();
diff --git a/src/com/android/phone/EmergencyAssistanceHelper.java b/src/com/android/phone/EmergencyAssistanceHelper.java
index 9e1ac21..a98d81d 100644
--- a/src/com/android/phone/EmergencyAssistanceHelper.java
+++ b/src/com/android/phone/EmergencyAssistanceHelper.java
@@ -16,6 +16,8 @@
 
 package com.android.phone;
 
+import android.app.role.RoleManager;
+import android.app.role.RoleManagerCallback;
 import android.content.ComponentName;
 import android.content.Context;
 import android.content.Intent;
@@ -23,10 +25,15 @@
 import android.content.pm.PackageInfo;
 import android.content.pm.PackageManager;
 import android.content.pm.ResolveInfo;
-import android.provider.Settings;
+import android.os.AsyncTask;
+import android.os.Binder;
+import android.os.Process;
 import android.telephony.TelephonyManager;
 import android.text.TextUtils;
 import android.util.FeatureFlagUtils;
+import android.util.Log;
+
+import com.android.internal.util.CollectionUtils;
 
 import java.util.List;
 
@@ -34,7 +41,7 @@
  * A helper to query activities of emergency assistance.
  */
 public class EmergencyAssistanceHelper {
-
+    private static final String TAG = EmergencyAssistanceHelper.class.getSimpleName();
     /**
      * Get intent action of target emergency app.
      *
@@ -61,8 +68,8 @@
      * or null if there is no installed system application of emergency assistance.
      */
     public static List<ResolveInfo> resolveAssistPackageAndQueryActivities(Context context) {
-        List<ResolveInfo> infos = queryAssistActivities(context);
-
+        final String assistPackage = getDefaultEmergencyPackage(context);
+        List<ResolveInfo> infos = queryAssistActivities(context, assistPackage);
         if (infos == null || infos.isEmpty()) {
             PackageManager packageManager = context.getPackageManager();
             Intent queryIntent = new Intent(getIntentAction(context));
@@ -86,9 +93,8 @@
             }
 
             if (bestMatch != null) {
-                Settings.Secure.putString(context.getContentResolver(),
-                        Settings.Secure.EMERGENCY_ASSISTANCE_APPLICATION, bestMatch.packageName);
-                return queryAssistActivities(context);
+                setDefaultEmergencyPackageAsync(context, bestMatch.packageName);
+                return queryAssistActivities(context, bestMatch.packageName);
             } else {
                 return null;
             }
@@ -106,9 +112,7 @@
                 resolveInfo.activityInfo.name);
     }
 
-    private static List<ResolveInfo> queryAssistActivities(Context context) {
-        final String assistPackage = Settings.Secure.getString(context.getContentResolver(),
-                Settings.Secure.EMERGENCY_ASSISTANCE_APPLICATION);
+    private static List<ResolveInfo> queryAssistActivities(Context context, String assistPackage) {
         List<ResolveInfo> infos = null;
 
         if (!TextUtils.isEmpty(assistPackage)) {
@@ -123,4 +127,34 @@
         return info.applicationInfo != null
                 && (info.applicationInfo.flags & ApplicationInfo.FLAG_SYSTEM) != 0;
     }
+
+    private static String getDefaultEmergencyPackage(Context context) {
+        long identity = Binder.clearCallingIdentity();
+        try {
+            return CollectionUtils.firstOrNull(context.getSystemService(RoleManager.class)
+                    .getRoleHolders(RoleManager.ROLE_EMERGENCY));
+        } finally {
+            Binder.restoreCallingIdentity(identity);
+        }
+    }
+
+    private static boolean setDefaultEmergencyPackageAsync(Context context, String pkgName) {
+        long identity = Binder.clearCallingIdentity();
+        try {
+            context.getSystemService(RoleManager.class).addRoleHolderAsUser(
+                    RoleManager.ROLE_EMERGENCY, pkgName, 0, Process.myUserHandle(),
+                    AsyncTask.THREAD_POOL_EXECUTOR, new RoleManagerCallback() {
+                        @Override
+                        public void onSuccess() {
+                        }
+                        @Override
+                        public void onFailure() {
+                            Log.e(TAG, "Failed to set emergency default app.");
+                        }
+                    });
+        } finally {
+            Binder.restoreCallingIdentity(identity);
+        }
+        return true;
+    }
 }
diff --git a/src/com/android/phone/EmergencyDialer.java b/src/com/android/phone/EmergencyDialer.java
index 65edcf9..9e40ffe 100644
--- a/src/com/android/phone/EmergencyDialer.java
+++ b/src/com/android/phone/EmergencyDialer.java
@@ -111,13 +111,6 @@
         EmergencyInfoGroup.OnConfirmClickListener {
 
     private class MetricsWriter {
-        // Metrics constants indicating the entry type that user opened emergency dialer.
-        // This info is sent from system UI with EXTRA_ENTRY_TYPE. Please make them being
-        // in sync with those in com.android.systemui.util.EmergencyDialerConstants.
-        public static final int ENTRY_TYPE_UNKNOWN = 0;
-        public static final int ENTRY_TYPE_LOCKSCREEN_BUTTON = 1;
-        public static final int ENTRY_TYPE_POWER_MENU = 2;
-
         // Metrics constants indicating the UI that user made phone call.
         public static final int CALL_SOURCE_DIALPAD = 0;
         public static final int CALL_SOURCE_SHORTCUT = 1;
@@ -140,11 +133,10 @@
                 return;
             }
 
-            int entryType = getIntent().getIntExtra(EXTRA_ENTRY_TYPE, ENTRY_TYPE_UNKNOWN);
             KeyguardManager keyguard = (KeyguardManager) getSystemService(Context.KEYGUARD_SERVICE);
             mMetricsLogger.write(new LogMaker(MetricsEvent.EMERGENCY_DIALER)
                     .setType(MetricsEvent.TYPE_OPEN)
-                    .setSubtype(entryType)
+                    .setSubtype(mEntryType)
                     .addTaggedData(MetricsEvent.FIELD_EMERGENCY_DIALER_IS_SCREEN_LOCKED,
                             keyguard.isKeyguardLocked() ? 1 : 0));
         }
@@ -154,11 +146,10 @@
                 return;
             }
 
-            int entryType = getIntent().getIntExtra(EXTRA_ENTRY_TYPE, ENTRY_TYPE_UNKNOWN);
             long userStayDuration = SystemClock.elapsedRealtime() - mUserEnterTimeMillis;
             mMetricsLogger.write(new LogMaker(MetricsEvent.EMERGENCY_DIALER)
                     .setType(MetricsEvent.TYPE_CLOSE)
-                    .setSubtype(entryType)
+                    .setSubtype(mEntryType)
                     .addTaggedData(MetricsEvent.FIELD_EMERGENCY_DIALER_USER_ACTIONS, mUserActions)
                     .addTaggedData(
                             MetricsEvent.FIELD_EMERGENCY_DIALER_DURATION_MS, userStayDuration));
@@ -195,6 +186,13 @@
     public static final String EXTRA_ENTRY_TYPE =
             "com.android.phone.EmergencyDialer.extra.ENTRY_TYPE";
 
+    // Constants indicating the entry type that user opened emergency dialer.
+    // This info is sent from system UI with EXTRA_ENTRY_TYPE. Please make them being
+    // in sync with those in com.android.systemui.util.EmergencyDialerConstants.
+    public static final int ENTRY_TYPE_UNKNOWN = 0;
+    public static final int ENTRY_TYPE_LOCKSCREEN_BUTTON = 1;
+    public static final int ENTRY_TYPE_POWER_MENU = 2;
+
     // List of dialer button IDs.
     private static final int[] DIALER_KEYS = new int[]{
             R.id.one, R.id.two, R.id.three,
@@ -292,6 +290,7 @@
     private boolean mIsWfcEmergencyCallingWarningEnabled;
     private float mDefaultDigitsTextSize;
 
+    private int mEntryType;
     private boolean mIsShortcutViewEnabled;
 
     private MetricsWriter mMetricsWriter;
@@ -344,6 +343,9 @@
     protected void onCreate(Bundle icicle) {
         super.onCreate(icicle);
 
+        mEntryType = getIntent().getIntExtra(EXTRA_ENTRY_TYPE, ENTRY_TYPE_UNKNOWN);
+        Log.d(LOG_TAG, "Launched from " + entryTypeToString(mEntryType));
+
         mMetricsWriter = new MetricsWriter();
         mSensorManager = (SensorManager) getSystemService(Context.SENSOR_SERVICE);
         if (mSensorManager != null) {
@@ -810,6 +812,10 @@
     }
 
     private boolean canEnableShortcutView(PersistableBundle carrierConfig) {
+        if (mEntryType != ENTRY_TYPE_POWER_MENU) {
+            Log.d(LOG_TAG, "Disables shortcut view since it's not launched from power menu");
+            return false;
+        }
         if (!carrierConfig.getBoolean(
                 CarrierConfigManager.KEY_SUPPORT_EMERGENCY_DIALER_SHORTCUT_BOOL)) {
             Log.d(LOG_TAG, "Disables shortcut view by carrier requirement");
@@ -903,6 +909,9 @@
     }
 
     private void placeCall(String number, int callSource, ShortcutViewUtils.PhoneInfo phone) {
+        Log.d(LOG_TAG, "Place emergency call from " + callSourceToString(callSource)
+                + ", entry = " + entryTypeToString(mEntryType));
+
         Bundle extras = new Bundle();
         extras.putInt(TelecomManager.EXTRA_CALL_SOURCE, callSource);
         /**
@@ -1338,4 +1347,26 @@
         }
         return isShortcut;
     }
+
+    private String entryTypeToString(int entryType) {
+        switch (entryType) {
+            case ENTRY_TYPE_LOCKSCREEN_BUTTON:
+                return "LockScreen";
+            case ENTRY_TYPE_POWER_MENU:
+                return "PowerMenu";
+            default:
+                return "Unknown-" + entryType;
+        }
+    }
+
+    private String callSourceToString(int callSource) {
+        switch (callSource) {
+            case ParcelableCallAnalytics.CALL_SOURCE_EMERGENCY_DIALPAD:
+                return "DialPad";
+            case ParcelableCallAnalytics.CALL_SOURCE_EMERGENCY_SHORTCUT:
+                return "Shortcut";
+            default:
+                return "Unknown-" + callSource;
+        }
+    }
 }
diff --git a/src/com/android/phone/MobileNetworkSettings.java b/src/com/android/phone/MobileNetworkSettings.java
index 73decd1..7ffa5cf 100644
--- a/src/com/android/phone/MobileNetworkSettings.java
+++ b/src/com/android/phone/MobileNetworkSettings.java
@@ -1920,6 +1920,10 @@
                 mWiFiCallingPref.setSummary(null);
                 mWiFiCallingPref.setIntent(intent);
             } else {
+                String title = SubscriptionManager.getResourcesForSubId(getContext(), mSubId)
+                        .getString(R.string.wifi_calling_settings_title);
+                mWiFiCallingPref.setTitle(title);
+
                 int resId = com.android.internal.R.string.wifi_calling_off_summary;
                 if (mImsMgr.isWfcEnabledByUser()) {
                     boolean isRoaming = mTelephonyManager.isNetworkRoaming();
diff --git a/src/com/android/phone/PhoneInterfaceManager.java b/src/com/android/phone/PhoneInterfaceManager.java
index b574848..62726b1 100755
--- a/src/com/android/phone/PhoneInterfaceManager.java
+++ b/src/com/android/phone/PhoneInterfaceManager.java
@@ -69,6 +69,7 @@
 import android.telephony.ModemActivityInfo;
 import android.telephony.NeighboringCellInfo;
 import android.telephony.NetworkScanRequest;
+import android.telephony.PhoneCapability;
 import android.telephony.PhoneNumberRange;
 import android.telephony.RadioAccessFamily;
 import android.telephony.Rlog;
@@ -2017,6 +2018,7 @@
                                 .setCallingPid(Binder.getCallingPid())
                                 .setCallingUid(Binder.getCallingUid())
                                 .setMethod("getAllCellInfo")
+                                .setMinSdkVersionForCoarse(Build.VERSION_CODES.BASE)
                                 .setMinSdkVersionForFine(Build.VERSION_CODES.Q)
                                 .build());
         switch (locationResult) {
@@ -6600,20 +6602,38 @@
     }
 
     @Override
-    public boolean isMultisimCarrierRestricted() {
-        enforceReadPrivilegedPermission("isMultisimCarrierRestricted");
+    public boolean isMultisimSupported(String callingPackage) {
+        if (!TelephonyPermissions.checkCallingOrSelfReadPhoneState(mApp,
+                getDefaultPhone().getSubId(), callingPackage, "isMultisimSupported")) {
+            return false;
+        }
 
         final long identity = Binder.clearCallingIdentity();
         try {
             // If the device has less than 2 SIM cards, indicate that multisim is restricted.
             int numPhysicalSlots = UiccController.getInstance().getUiccSlots().length;
             if (numPhysicalSlots < 2) {
-                loge("isMultisimCarrierRestricted: requires at least 2 cards");
-                return true;
+                loge("isMultisimSupported: requires at least 2 cards");
+                return false;
+            }
+            // Check if the hardware supports multisim functionality. If usage of multisim is not
+            // supported by the modem, indicate that it is restricted.
+            PhoneCapability staticCapability =
+                    mPhoneConfigurationManager.getStaticPhoneCapability();
+            if (staticCapability == null) {
+                loge("isMultisimSupported: no static configuration available");
+                return false;
+            }
+            if (staticCapability.logicalModemList.size() < 2) {
+                loge("isMultisimSupported: maximum number of modem is < 2");
+                return false;
+            }
+            // Check if support of multiple SIMs is restricted by carrier
+            if (mTelephonySharedPreferences.getBoolean(PREF_MULTI_SIM_RESTRICTED, false)) {
+                return false;
             }
 
-            // Default value is false. Multi SIM is allowed unless explicitly restricted.
-            return mTelephonySharedPreferences.getBoolean(PREF_MULTI_SIM_RESTRICTED, false);
+            return true;
         } finally {
             Binder.restoreCallingIdentity(identity);
         }
diff --git a/src/com/android/services/telephony/DisconnectCauseUtil.java b/src/com/android/services/telephony/DisconnectCauseUtil.java
index a92dea7..8ef9565 100644
--- a/src/com/android/services/telephony/DisconnectCauseUtil.java
+++ b/src/com/android/services/telephony/DisconnectCauseUtil.java
@@ -249,6 +249,10 @@
                 resourceId = R.string.callFailed_userBusy;
                 break;
 
+            case android.telephony.DisconnectCause.CDMA_REORDER:
+                resourceId = R.string.callFailed_NetworkBusy;
+                break;
+
             case android.telephony.DisconnectCause.CONGESTION:
                 resourceId = R.string.callFailed_congestion;
                 break;
@@ -557,6 +561,10 @@
                 resourceId = R.string.callFailed_cdma_activation;
                 break;
 
+            case android.telephony.DisconnectCause.CDMA_REORDER:
+                resourceId = R.string.callFailed_NetworkBusy;
+                break;
+
             case android.telephony.DisconnectCause.FDN_BLOCKED:
                 resourceId = R.string.callFailed_fdn_only;
                 break;
diff --git a/src/com/android/services/telephony/TelephonyConnection.java b/src/com/android/services/telephony/TelephonyConnection.java
index 85f0d48..7c09320 100644
--- a/src/com/android/services/telephony/TelephonyConnection.java
+++ b/src/com/android/services/telephony/TelephonyConnection.java
@@ -46,7 +46,6 @@
 import com.android.internal.telephony.Call;
 import com.android.internal.telephony.CallFailCause;
 import com.android.internal.telephony.CallStateException;
-import com.android.internal.telephony.Call.HoldingRequestState;
 import com.android.internal.telephony.Connection.Capability;
 import com.android.internal.telephony.Connection.PostDialListener;
 import com.android.internal.telephony.Phone;
@@ -953,7 +952,6 @@
                 // instead of actually putting it on hold.
                 if (ringingCall.getState() != Call.State.WAITING) {
                     phone.switchHoldingAndActive();
-                    mOriginalConnection.getCall().updateHoldingRequestState(HoldingRequestState.STARTED);
                 }
 
                 // TODO: Cdma calls are slightly different.