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 3.4-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-3.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From d8c3245c97490cb68ceaa983b5fce19055b4e331 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> [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx> Cc: Rui Xiang <rui.xiang@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- arch/x86/kernel/crash.c | 2 +- arch/x86/kernel/reboot.c | 11 +++++++---- 2 files changed, 8 insertions(+), 5 deletions(-) --- a/arch/x86/kernel/crash.c +++ b/arch/x86/kernel/crash.c @@ -95,10 +95,10 @@ void native_machine_crash_shutdown(struc cpu_emergency_vmxoff(); cpu_emergency_svm_disable(); - lapic_shutdown(); #if defined(CONFIG_X86_IO_APIC) 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 @@ -668,6 +668,13 @@ void native_machine_shutdown(void) /* The boot cpu is always logical cpu 0 */ int reboot_cpu_id = 0; +#endif + +#ifdef CONFIG_X86_IO_APIC + disable_IO_APIC(); +#endif + +#ifdef CONFIG_SMP #ifdef CONFIG_X86_32 /* See if there has been given a command line override */ @@ -691,10 +698,6 @@ 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-3.4/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