diff --git a/include/linux/async.h b/include/linux/async.h
index 0a17cd27f348..cce4ad31e8fc 100644
--- a/include/linux/async.h
+++ b/include/linux/async.h
@@ -112,7 +112,6 @@ async_schedule_dev_domain(async_func_t func, struct device *dev,
 	return async_schedule_node_domain(func, dev, dev_to_node(dev), domain);
 }
 
-void async_unregister_domain(struct async_domain *domain);
 extern void async_synchronize_full(void);
 extern void async_synchronize_full_domain(struct async_domain *domain);
 extern void async_synchronize_cookie(async_cookie_t cookie);
diff --git a/kernel/async.c b/kernel/async.c
index 4b5971142922..b8d7a663497f 100644
--- a/kernel/async.c
+++ b/kernel/async.c
@@ -245,24 +245,6 @@ void async_synchronize_full(void)
 }
 EXPORT_SYMBOL_GPL(async_synchronize_full);
 
-/**
- * async_unregister_domain - ensure no more anonymous waiters on this domain
- * @domain: idle domain to flush out of any async_synchronize_full instances
- *
- * async_synchronize_{cookie|full}_domain() are not flushed since callers
- * of these routines should know the lifetime of @domain
- *
- * Prefer ASYNC_DOMAIN_EXCLUSIVE() declarations over flushing
- */
-void async_unregister_domain(struct async_domain *domain)
-{
-	spin_lock_irq(&async_lock);
-	WARN_ON(!domain->registered || !list_empty(&domain->pending));
-	domain->registered = 0;
-	spin_unlock_irq(&async_lock);
-}
-EXPORT_SYMBOL_GPL(async_unregister_domain);
-
 /**
  * async_synchronize_full_domain - synchronize all asynchronous function within a certain domain
  * @domain: the domain to synchronize