This is a note to let you know that I've just added the patch titled x86/apic: Disable I/O APIC before shutdown of the local APIC to the 3.12-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: x86-apic-disable-i-o-apic-before-shutdown-of-the-local-apic.patch and it can be found in the queue-3.12 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 522e66464467543c0d88d023336eec4df03ad40b Mon Sep 17 00:00:00 2001 From: Fenghua Yu <fenghua.yu@xxxxxxxxx> Date: Wed, 23 Oct 2013 18:30:12 -0700 Subject: x86/apic: Disable I/O APIC before shutdown of the local APIC From: Fenghua Yu <fenghua.yu@xxxxxxxxx> commit 522e66464467543c0d88d023336eec4df03ad40b upstream. 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 <fenghua.yu@xxxxxxxxx> Link: http://lkml.kernel.org/r/1382578212-4677-1-git-send-email-fenghua.yu@xxxxxxxxx [ I suppose the 'issue' is a hang during shutdown. It's a fine change nevertheless. ] Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- arch/x86/kernel/crash.c | 2 +- arch/x86/kernel/reboot.c | 8 ++++---- 2 files changed, 5 insertions(+), 5 deletions(-) --- a/arch/x86/kernel/crash.c +++ b/arch/x86/kernel/crash.c @@ -127,12 +127,12 @@ void native_machine_crash_shutdown(struc 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 --- a/arch/x86/kernel/reboot.c +++ b/arch/x86/kernel/reboot.c @@ -550,6 +550,10 @@ static void native_machine_emergency_res 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 Patches currently in stable-queue which might be from fenghua.yu@xxxxxxxxx are queue-3.12/x86-apic-disable-i-o-apic-before-shutdown-of-the-local-apic.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html