From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Ingo Molnar" , "Fenghua Yu" Date: Sun, 29 Dec 2013 03:08:43 +0100 Message-ID: Subject: [PATCH 3.2 037/185] x86/apic: Disable I/O APIC before shutdown of the local APIC In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.2.54-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Fenghua Yu 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 Link: http://lkml.kernel.org/r/1382578212-4677-1-git-send-email-fenghua.yu@intel.com [ I suppose the 'issue' is a hang during shutdown. It's a fine change nevertheless. ] Signed-off-by: Ingo Molnar [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings --- 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 @@ -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 @@ -652,6 +652,13 @@ 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 */ @@ -675,10 +682,6 @@ void native_machine_shutdown(void) lapic_shutdown(); -#ifdef CONFIG_X86_IO_APIC - disable_IO_APIC(); -#endif - #ifdef CONFIG_HPET_TIMER hpet_disable(); #endif