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| author | Rob Herring <robh@kernel.org> | 2014-01-17 16:01:27 -0600 |
|---|---|---|
| committer | Rob Herring <robh@kernel.org> | 2014-01-17 16:01:27 -0600 |
| commit | 361128fcbf30f590a05c8e8789155364f37367db (patch) | |
| tree | 7f7973599e286dfd48ea724a5b7fb4bca76b294e /arch/x86/kernel/reboot.c | |
| parent | e2897d7e0b0460dca91b52d55ce41c888363502d (diff) | |
| parent | 482c43419fc204b4b658fa4acb80cd502e5fcbac (diff) | |
| download | linux-361128fcbf30f590a05c8e8789155364f37367db.tar.bz2 | |
Merge remote-tracking branch 'grant/devicetree/next' into for-3.14
Diffstat (limited to 'arch/x86/kernel/reboot.c')
| -rw-r--r-- | arch/x86/kernel/reboot.c | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/arch/x86/kernel/reboot.c b/arch/x86/kernel/reboot.c index da3c599584a3..c752cb43e52f 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 |