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authorIngo Molnar <mingo@kernel.org>2014-01-05 12:34:29 +0100
committerIngo Molnar <mingo@kernel.org>2014-01-05 12:34:29 +0100
commitef0b8b9a521c65201bfca9747ee1bf374296133c (patch)
tree644c3390c07d06fb7807182a4935f7c3f675b157 /arch/x86/kernel/reboot.c
parent5c12af0c41e3417e1939095325920463b5f8e726 (diff)
parentd6e0a2dd12f4067a5bcefb8bbd8ddbeff800afbc (diff)
Merge tag 'v3.13-rc7' into x86/efi-kexec to resolve conflicts
Conflicts: arch/x86/platform/efi/efi.c drivers/firmware/efi/Kconfig Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/kernel/reboot.c')
-rw-r--r--arch/x86/kernel/reboot.c11
1 files changed, 11 insertions, 0 deletions
diff --git a/arch/x86/kernel/reboot.c b/arch/x86/kernel/reboot.c
index da3c599584a..c752cb43e52 100644
--- a/arch/x86/kernel/reboot.c
+++ b/arch/x86/kernel/reboot.c
@@ -558,6 +558,17 @@ void native_machine_shutdown(void)
{
/* Stop the cpus and apics */
#ifdef CONFIG_X86_IO_APIC
+ /*
+ * Disabling IO APIC before local APIC is a workaround for
+ * erratum AVR31 in "Intel Atom Processor C2000 Product Family
+ * Specification Update". In this situation, interrupts that target
+ * a Logical Processor whose Local APIC is either in the process of
+ * being hardware disabled or software disabled are neither delivered
+ * nor discarded. When this erratum occurs, the processor may hang.
+ *
+ * Even without the erratum, it still makes sense to quiet IO APIC
+ * before disabling Local APIC.
+ */
disable_IO_APIC();
#endif