1.7.5.4
Also <asm/system.h> is gone for most architectures since v3.4-rc1~54^2.
---- rt-tests-1.0/src/backfire/backfire.c.orig 2017-03-29 18:54:44.833362351 +0200
-+++ rt-tests-1.0/src/backfire/backfire.c 2017-03-29 18:56:06.890028082 +0200
-@@ -31,7 +31,6 @@
+--- rt-tests-1.6/src/backfire/backfire.c.orig 2020-02-09 10:27:54.181066040 +0100
++++ rt-tests-1.6/src/backfire/backfire.c 2020-02-09 10:29:12.863973111 +0100
+@@ -16,8 +16,6 @@
#include <linux/spinlock.h>
+ #include <linux/uaccess.h>
- #include <asm/uaccess.h>
-#include <asm/system.h>
-
+-
#define BACKFIRE_MINOR MISC_DYNAMIC_MINOR
+ static DEFINE_SPINLOCK(backfire_state_lock);