From 522e66464467543c0d88d023336eec4df03ad40b Mon Sep 17 00:00:00 2001 From: Fenghua Yu Date: Wed, 23 Oct 2013 18:30:12 -0700 Subject: [PATCH] x86/apic: Disable I/O APIC before shutdown of the local APIC In reboot and crash path, when we shut down the local APIC, the I/O APIC is still active. This may cause issues because external interrupts can still come in and disturb the local APIC during shutdown process. To quiet external interrupts, disable I/O APIC before shutdown local APIC. Signed-off-by: Fenghua Yu Link: http://lkml.kernel.org/r/1382578212-4677-1-git-send-email-fenghua.yu@intel.com Cc: [ I suppose the 'issue' is a hang during shutdown. It's a fine change nevertheless. ] Signed-off-by: Ingo Molnar --- arch/x86/kernel/crash.c | 2 +- arch/x86/kernel/reboot.c | 8 ++++---- 2 files changed, 5 insertions(+), 5 deletions(-) diff --git a/arch/x86/kernel/crash.c b/arch/x86/kernel/crash.c index e0e0841eef45..18677a90d6a3 100644 --- a/arch/x86/kernel/crash.c +++ b/arch/x86/kernel/crash.c @@ -127,12 +127,12 @@ void native_machine_crash_shutdown(struct pt_regs *regs) cpu_emergency_vmxoff(); cpu_emergency_svm_disable(); - lapic_shutdown(); #ifdef CONFIG_X86_IO_APIC /* Prevent crash_kexec() from deadlocking on ioapic_lock. */ ioapic_zap_locks(); disable_IO_APIC(); #endif + lapic_shutdown(); #ifdef CONFIG_HPET_TIMER hpet_disable(); #endif diff --git a/arch/x86/kernel/reboot.c b/arch/x86/kernel/reboot.c index 7e920bff99a3..618ce264b237 100644 --- a/arch/x86/kernel/reboot.c +++ b/arch/x86/kernel/reboot.c @@ -550,6 +550,10 @@ static void native_machine_emergency_restart(void) void native_machine_shutdown(void) { /* Stop the cpus and apics */ +#ifdef CONFIG_X86_IO_APIC + disable_IO_APIC(); +#endif + #ifdef CONFIG_SMP /* * Stop all of the others. Also disable the local irq to @@ -562,10 +566,6 @@ void native_machine_shutdown(void) lapic_shutdown(); -#ifdef CONFIG_X86_IO_APIC - disable_IO_APIC(); -#endif - #ifdef CONFIG_HPET_TIMER hpet_disable(); #endif -- 2.20.1