diff --git a/drivers/counter/104-quad-8.c b/drivers/counter/104-quad-8.c
index 5c23a9a56921..f261a57af1c0 100644
--- a/drivers/counter/104-quad-8.c
+++ b/drivers/counter/104-quad-8.c
@@ -1230,12 +1230,13 @@ static ssize_t quad8_count_ceiling_write(struct counter_device *counter,
 	case 1:
 	case 3:
 		quad8_preset_register_set(priv, count->id, ceiling);
-		break;
+		mutex_unlock(&priv->lock);
+		return len;
 	}
 
 	mutex_unlock(&priv->lock);
 
-	return len;
+	return -EINVAL;
 }
 
 static ssize_t quad8_count_preset_enable_read(struct counter_device *counter,