diff --git a/services/core/java/com/android/server/wm/DisplayContent.java b/services/core/java/com/android/server/wm/DisplayContent.java
index 21be742..4f1f5bb 100644
--- a/services/core/java/com/android/server/wm/DisplayContent.java
+++ b/services/core/java/com/android/server/wm/DisplayContent.java
@@ -125,6 +125,7 @@
 import android.view.SurfaceControl;
 import android.view.WindowManagerPolicy;
 
+import com.android.internal.annotations.VisibleForTesting;
 import com.android.internal.util.ToBooleanFunction;
 import com.android.internal.view.IInputMethodClient;
 
@@ -1396,6 +1397,22 @@
         return null;
     }
 
+    @VisibleForTesting
+    int getStackCount() {
+        return mTaskStackContainers.size();
+    }
+
+    @VisibleForTesting
+    int getStaskPosById(int stackId) {
+        for (int i = mTaskStackContainers.size() - 1; i >= 0; --i) {
+            final TaskStack stack = mTaskStackContainers.get(i);
+            if (stack.mStackId == stackId) {
+                return i;
+            }
+        }
+        return -1;
+    }
+
     @Override
     void onConfigurationChanged(Configuration newParentConfig) {
         super.onConfigurationChanged(newParentConfig);
@@ -3263,8 +3280,9 @@
                     : requestedPosition >= topChildPosition;
             int targetPosition = requestedPosition;
 
-            if (toTop && isStackVisible(PINNED_STACK_ID) && stack.mStackId != PINNED_STACK_ID) {
-                // The pinned stack is always the top most stack (always-on-top) when it is visible.
+            if (toTop && stack.mStackId != PINNED_STACK_ID
+                    && getStackById(PINNED_STACK_ID) != null) {
+                // The pinned stack is always the top most stack (always-on-top) when it is present.
                 TaskStack topStack = mChildren.get(topChildPosition);
                 if (topStack.mStackId != PINNED_STACK_ID) {
                     throw new IllegalStateException("Pinned stack isn't top stack??? " + mChildren);