diff --git a/kernel/async.c b/kernel/async.c
index f565891f2c9b..968ef9457d4e 100644
--- a/kernel/async.c
+++ b/kernel/async.c
@@ -49,6 +49,7 @@ asynchronous and synchronous parts of the kernel.
 */
 
 #include <linux/async.h>
+#include <linux/bug.h>
 #include <linux/module.h>
 #include <linux/wait.h>
 #include <linux/sched.h>
@@ -387,20 +388,11 @@ static int async_manager_thread(void *unused)
 
 static int __init async_init(void)
 {
-	if (async_enabled)
-		if (IS_ERR(kthread_run(async_manager_thread, NULL,
-				       "async/mgr")))
-			async_enabled = 0;
+	async_enabled =
+		!IS_ERR(kthread_run(async_manager_thread, NULL, "async/mgr"));
+
+	WARN_ON(!async_enabled);
 	return 0;
 }
 
-static int __init setup_async(char *str)
-{
-	async_enabled = 1;
-	return 1;
-}
-
-__setup("fastboot", setup_async);
-
-
 core_initcall(async_init);