diff --git a/core/java/android/service/dreams/DreamManagerInternal.java b/core/java/android/service/dreams/DreamManagerInternal.java
index 6956cd4cae6b8..295171ca9bbd2 100644
--- a/core/java/android/service/dreams/DreamManagerInternal.java
+++ b/core/java/android/service/dreams/DreamManagerInternal.java
@@ -29,16 +29,18 @@ public abstract class DreamManagerInternal {
      *
      * @param doze If true, starts the doze dream component if one has been configured,
      * otherwise starts the user-specified dream.
+     * @param reason The reason to start dreaming, which is logged to help debugging.
      */
-    public abstract void startDream(boolean doze);
+    public abstract void startDream(boolean doze, String reason);
 
     /**
      * Called by the power manager to stop a dream.
      *
      * @param immediate If true, ends the dream summarily, otherwise gives it some time
      * to perform a proper exit transition.
+     * @param reason The reason to stop dreaming, which is logged to help debugging.
      */
-    public abstract void stopDream(boolean immediate);
+    public abstract void stopDream(boolean immediate, String reason);
 
     /**
      * Called by the power manager to determine whether a dream is running.
diff --git a/services/core/java/com/android/server/dreams/DreamManagerService.java b/services/core/java/com/android/server/dreams/DreamManagerService.java
index df3a5e3b7b358..7964fd550266f 100644
--- a/services/core/java/com/android/server/dreams/DreamManagerService.java
+++ b/services/core/java/com/android/server/dreams/DreamManagerService.java
@@ -856,13 +856,13 @@ public final class DreamManagerService extends SystemService {
 
     private final class LocalService extends DreamManagerInternal {
         @Override
-        public void startDream(boolean doze) {
-            startDreamInternal(doze, "dream manager request" /*reason*/);
+        public void startDream(boolean doze, String reason) {
+            startDreamInternal(doze, reason);
         }
 
         @Override
-        public void stopDream(boolean immediate) {
-            stopDreamInternal(immediate, "dream manager request" /*reason*/);
+        public void stopDream(boolean immediate, String reason) {
+            stopDreamInternal(immediate, reason);
         }
 
         @Override
diff --git a/services/core/java/com/android/server/policy/PhoneWindowManager.java b/services/core/java/com/android/server/policy/PhoneWindowManager.java
index 05cb42973a00c..62b21ed0171af 100644
--- a/services/core/java/com/android/server/policy/PhoneWindowManager.java
+++ b/services/core/java/com/android/server/policy/PhoneWindowManager.java
@@ -1597,7 +1597,7 @@ public class PhoneWindowManager implements WindowManagerPolicy {
         // If there's a dream running then use home to escape the dream
         // but don't actually go home.
         if (mDreamManagerInternal != null && mDreamManagerInternal.isDreaming()) {
-            mDreamManagerInternal.stopDream(false /*immediate*/);
+            mDreamManagerInternal.stopDream(false /*immediate*/, "short press on home" /*reason*/);
             return;
         }
 
diff --git a/services/core/java/com/android/server/power/PowerManagerService.java b/services/core/java/com/android/server/power/PowerManagerService.java
index dbf05f1cd7c7f..097a66e0a2536 100644
--- a/services/core/java/com/android/server/power/PowerManagerService.java
+++ b/services/core/java/com/android/server/power/PowerManagerService.java
@@ -3218,8 +3218,10 @@ public final class PowerManagerService extends SystemService
         if (mDreamManager != null) {
             // Restart the dream whenever the sandman is summoned.
             if (startDreaming) {
-                mDreamManager.stopDream(/* immediate= */ false);
-                mDreamManager.startDream(wakefulness == WAKEFULNESS_DOZING);
+                mDreamManager.stopDream(/* immediate= */ false,
+                        "power manager request before starting dream" /*reason*/);
+                mDreamManager.startDream(wakefulness == WAKEFULNESS_DOZING,
+                        "power manager request" /*reason*/);
             }
             isDreaming = mDreamManager.isDreaming();
         } else {
@@ -3304,7 +3306,7 @@ public final class PowerManagerService extends SystemService
 
         // Stop dream.
         if (isDreaming) {
-            mDreamManager.stopDream(/* immediate= */ false);
+            mDreamManager.stopDream(/* immediate= */ false, "power manager request" /*reason*/);
         }
     }
 
diff --git a/services/tests/servicestests/src/com/android/server/power/PowerManagerServiceTest.java b/services/tests/servicestests/src/com/android/server/power/PowerManagerServiceTest.java
index 9ff7d69e09a61..2a6e6d8765999 100644
--- a/services/tests/servicestests/src/com/android/server/power/PowerManagerServiceTest.java
+++ b/services/tests/servicestests/src/com/android/server/power/PowerManagerServiceTest.java
@@ -731,7 +731,7 @@ public class PowerManagerServiceTest {
         doAnswer(inv -> {
             when(mDreamManagerInternalMock.isDreaming()).thenReturn(true);
             return null;
-        }).when(mDreamManagerInternalMock).startDream(anyBoolean());
+        }).when(mDreamManagerInternalMock).startDream(anyBoolean(), anyString());
 
         setMinimumScreenOffTimeoutConfig(5);
         createService();
@@ -753,7 +753,7 @@ public class PowerManagerServiceTest {
         doAnswer(inv -> {
             when(mDreamManagerInternalMock.isDreaming()).thenReturn(true);
             return null;
-        }).when(mDreamManagerInternalMock).startDream(anyBoolean());
+        }).when(mDreamManagerInternalMock).startDream(anyBoolean(), anyString());
 
         setMinimumScreenOffTimeoutConfig(5);
         createService();
@@ -1168,7 +1168,7 @@ public class PowerManagerServiceTest {
         doAnswer(inv -> {
             when(mDreamManagerInternalMock.isDreaming()).thenReturn(true);
             return null;
-        }).when(mDreamManagerInternalMock).startDream(anyBoolean());
+        }).when(mDreamManagerInternalMock).startDream(anyBoolean(), anyString());
 
         final String pkg = mContextSpy.getOpPackageName();
         final Binder token = new Binder();
@@ -1662,7 +1662,7 @@ public class PowerManagerServiceTest {
         forceDozing();
         // Allow handleSandman() to be called asynchronously
         advanceTime(500);
-        verify(mDreamManagerInternalMock).startDream(eq(true));
+        verify(mDreamManagerInternalMock).startDream(eq(true), anyString());
     }
 
     @Test
@@ -1700,7 +1700,7 @@ public class PowerManagerServiceTest {
 
         // Allow handleSandman() to be called asynchronously
         advanceTime(500);
-        verify(mDreamManagerInternalMock).startDream(eq(true));
+        verify(mDreamManagerInternalMock).startDream(eq(true), anyString());
     }
 
     @Test