From 19ec673ced067316b9732bc6d1c4ff4052e5f795 Mon Sep 17 00:00:00 2001 From: Cyrill Gorcunov Date: Wed, 28 May 2008 23:00:47 +0400 Subject: [PATCH] x86: nmi - fix incorrect NMI watchdog used by default The commit commit 4b82b277707a39b97271439c475f186f63ec4692 Author: Cyrill Gorcunov 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 CC: Maciej W. Rozycki Signed-off-by: Ingo Molnar --- arch/x86/kernel/nmi.c | 16 +++++++++------- include/asm-x86/nmi.h | 4 +++- 2 files changed, 12 insertions(+), 8 deletions(-) diff --git a/arch/x86/kernel/nmi.c b/arch/x86/kernel/nmi.c index 69a839fc1eb..3671a9f3564 100644 --- a/arch/x86/kernel/nmi.c +++ b/arch/x86/kernel/nmi.c @@ -84,20 +84,15 @@ static inline unsigned int get_timer_irqs(int cpu) #endif } +#ifdef CONFIG_X86_64 /* Run after command line and cpu_init init, but before all other checks */ void nmi_watchdog_default(void) { if (nmi_watchdog != NMI_DEFAULT) return; -#ifdef CONFIG_X86_64 nmi_watchdog = NMI_NONE; -#else - if (lapic_watchdog_ok()) - nmi_watchdog = NMI_LOCAL_APIC; - else - nmi_watchdog = NMI_IO_APIC; -#endif } +#endif #ifdef CONFIG_SMP /* @@ -488,8 +483,15 @@ int proc_nmi_enabled(struct ctl_table *table, int write, struct file *file, return -EIO; } +#ifdef CONFIG_X86_64 /* if nmi_watchdog is not set yet, then set it */ nmi_watchdog_default(); +#else + if (lapic_watchdog_ok()) + nmi_watchdog = NMI_LOCAL_APIC; + else + nmi_watchdog = NMI_IO_APIC; +#endif if (nmi_watchdog == NMI_LOCAL_APIC) { if (nmi_watchdog_enabled) diff --git a/include/asm-x86/nmi.h b/include/asm-x86/nmi.h index 1e8f34d7ab6..6f4d44fc051 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; -- 2.41.0