x86: nmi - fix incorrect NMI watchdog used by default

The commit

	commit 4b82b277707a39b97271439c475f186f63ec4692
	Author: Cyrill Gorcunov <gorcunov@gmail.com>
	Date:   Sat May 24 19:36:35 2008 +0400

set nmi_watchdog to NMI_IO_APIC as by default. This causes hangs on some
machines with buggy watchdogs. Fix it - i.e. restore old behaviour.

Thanks to Sitsofe Wheeler and Adrian Bunk for catching the problem
and Maciej W. Rozycki for explanation what is going on there.

Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
CC: Maciej W. Rozycki <macro@linux-mips.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 3 insertions, 1 deletions

diff --git a/include/asm-x86/nmi.h b/include/asm-x86/nmi.h
index 1e8f34d7ab68..6f4d44fc051f 100644
--- a/include/asm-x86/nmi.h
+++ b/include/asm-x86/nmi.h
@@ -38,9 +38,11 @@ static inline void unset_nmi_pm_callback(struct pm_dev *dev)
 
 #ifdef CONFIG_X86_64
 extern void default_do_nmi(struct pt_regs *);
+extern void nmi_watchdog_default(void);
+#else
+#define nmi_watchdog_default(void) do {} while (0)
 #endif
 
-extern void nmi_watchdog_default(void);
 extern void die_nmi(char *str, struct pt_regs *regs, int do_panic);
 extern int check_nmi_watchdog(void);
 extern int nmi_watchdog_enabled;