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Commit 522e6646 authored by Fenghua Yu's avatar Fenghua Yu Committed by Ingo Molnar
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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: default avatarFenghua Yu <fenghua.yu@intel.com>
Link: http://lkml.kernel.org/r/1382578212-4677-1-git-send-email-fenghua.yu@intel.com


Cc: <stable@kernel.org>
[ I suppose the 'issue' is a hang during shutdown. It's a fine change nevertheless. ]
Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 5e01dc7b

arch/x86/kernel/crash.c

+1 −1
Original line number Diff line number Diff line
@@ -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

arch/x86/kernel/reboot.c

+4 −4
Original line number Diff line number Diff line
@@ -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