diff --git a/services/companion/java/com/android/server/companion/CompanionApplicationController.java b/services/companion/java/com/android/server/companion/CompanionApplicationController.java
index ec4bfe09e415b..f32eebc2a31f6 100644
--- a/services/companion/java/com/android/server/companion/CompanionApplicationController.java
+++ b/services/companion/java/com/android/server/companion/CompanionApplicationController.java
@@ -108,8 +108,16 @@ class CompanionApplicationController {
 
         final List<ComponentName> companionServices =
                 mCompanionServicesRegister.forPackage(userId, packageName);
-        final List<CompanionDeviceServiceConnector> serviceConnectors;
+        if (companionServices.isEmpty()) {
+            Slog.w(TAG, "Can not bind companion applications u" + userId + "/" + packageName + ": "
+                    + "eligible CompanionDeviceService not found.\n"
+                    + "A CompanionDeviceService should declare an intent-filter for "
+                    + "\"android.companion.CompanionDeviceService\" action and require "
+                    + "\"android.permission.BIND_COMPANION_DEVICE_SERVICE\" permission.");
+            return;
+        }
 
+        final List<CompanionDeviceServiceConnector> serviceConnectors;
         synchronized (mBoundCompanionApplications) {
             if (mBoundCompanionApplications.containsValueForPackage(userId, packageName)) {
                 if (DEBUG) Log.e(TAG, "u" + userId + "/" + packageName + " is ALREADY bound.");
@@ -118,13 +126,6 @@ class CompanionApplicationController {
 
             serviceConnectors = CollectionUtils.map(companionServices, componentName ->
                             new CompanionDeviceServiceConnector(mContext, userId, componentName));
-
-            if (serviceConnectors.isEmpty()) {
-                Slog.e(TAG, "Can't find CompanionDeviceService implementer in package: "
-                        + packageName + ". Please check if they are correctly declared.");
-                return;
-            }
-
             mBoundCompanionApplications.setValueForPackage(userId, packageName, serviceConnectors);
         }
 
@@ -145,7 +146,11 @@ class CompanionApplicationController {
             serviceConnectors = mBoundCompanionApplications.removePackage(userId, packageName);
         }
         if (serviceConnectors == null) {
-            if (DEBUG) Log.e(TAG, "u" + userId + "/" + packageName + " is NOT bound");
+            if (DEBUG) {
+                Log.e(TAG, "unbindCompanionApplication(): "
+                        + "u" + userId + "/" + packageName + " is NOT bound");
+                Log.d(TAG, "Stacktrace", new Throwable());
+            }
             return;
         }
 
@@ -191,7 +196,11 @@ class CompanionApplicationController {
         final CompanionDeviceServiceConnector primaryServiceConnector =
                 getPrimaryServiceConnector(userId, packageName);
         if (primaryServiceConnector == null) {
-            if (DEBUG) Log.e(TAG, "u" + userId + "/" + packageName + " is NOT bound.");
+            if (DEBUG) {
+                Log.e(TAG, "notify_CompanionApplicationDevice_Appeared(): "
+                        + "u" + userId + "/" + packageName + " is NOT bound.");
+                Log.d(TAG, "Stacktrace", new Throwable());
+            }
             return;
         }
 
@@ -209,7 +218,11 @@ class CompanionApplicationController {
         final CompanionDeviceServiceConnector primaryServiceConnector =
                 getPrimaryServiceConnector(userId, packageName);
         if (primaryServiceConnector == null) {
-            if (DEBUG) Log.e(TAG, "u" + userId + "/" + packageName + " is NOT bound.");
+            if (DEBUG) {
+                Log.e(TAG, "notify_CompanionApplicationDevice_Disappeared(): "
+                        + "u" + userId + "/" + packageName + " is NOT bound.");
+                Log.d(TAG, "Stacktrace", new Throwable());
+            }
             return;
         }
 
@@ -253,12 +266,6 @@ class CompanionApplicationController {
             return forUser(userId).getOrDefault(packageName, Collections.emptyList());
         }
 
-        synchronized @NonNull ComponentName primaryForPackage(
-                @UserIdInt int userId, @NonNull String packageName) {
-            // The primary service is always at the head of the list.
-            return forPackage(userId, packageName).get(0);
-        }
-
         synchronized void invalidate(@UserIdInt int userId) {
             remove(userId);
         }