diff -pNau5 driver.orig/8250_core.c driver/8250_core.c
--- driver.orig/8250_core.c	2021-06-29 11:09:04.090688628 -0400
+++ driver/8250_core.c	2021-06-29 11:09:31.918364916 -0400
@@ -47,10 +47,15 @@
 #include <asm/io.h>
 #include <asm/irq.h>
 
 #include "8250.h"
 
+#ifndef ASYNC_INITIALIZED
+/* ArchLinuxPatch-0002-Begin */
+/* ArchLinuxPatch-0002-End */
+#endif
+
 #include "cti485.h"
 
 #define MAX_PORTS 128
 
 #ifndef MIN
diff -pNau5 driver.orig/serial_core.c driver/serial_core.c
--- driver.orig/serial_core.c	2019-04-02 11:23:14.000000000 -0400
+++ driver/serial_core.c	2021-06-29 11:09:39.398635744 -0400
@@ -37,10 +37,15 @@
 #include <linux/mutex.h>
 
 #include <asm/irq.h>
 #include <asm/uaccess.h>
 
+#ifndef ASYNC_INITIALIZED
+/* ArchLinuxPatch-0002-Begin */
+/* ArchLinuxPatch-0002-End */
+#endif
+
 #include "cti485.h"
 
 #define REVISION "1.43"
 
 /*