Index: sys/compat/linuxkpi/common/include/linux/spinlock.h
===================================================================
--- sys/compat/linuxkpi/common/include/linux/spinlock.h
+++ sys/compat/linuxkpi/common/include/linux/spinlock.h
@@ -37,6 +37,7 @@
 #include <sys/lock.h>
 #include <sys/mutex.h>
 #include <sys/kdb.h>
+#include <sys/proc.h>
 
 #include <linux/compiler.h>
 #include <linux/rwlock.h>
@@ -117,9 +118,12 @@
 	local_bh_disable();			\
 } while (0)
 
-#define	spin_lock_irqsave(_l, flags) do {	\
-	(flags) = 0;				\
-	spin_lock(_l);				\
+#define	spin_lock_irqsave(_l, flags) do {		\
+	(flags) = 0;					\
+	if (unlikely(curthread->td_critnest != 0))	\
+		while (!spin_trylock(_l)) {}		\
+	else						\
+		spin_lock(_l);				\
 } while (0)
 
 #define	spin_lock_irqsave_nested(_l, flags, _n) do {	\