diff mbox

[3.11.y.z,extended,stable] Patch "x86/apic: Disable I/O APIC before shutdown of the local APIC" has been added to staging queue

Message ID 1389268949-28378-1-git-send-email-luis.henriques@canonical.com
State New
Headers show

Commit Message

Luis Henriques Jan. 9, 2014, 12:02 p.m. UTC 
This is a note to let you know that I have just added a patch titled

    x86/apic: Disable I/O APIC before shutdown of the local APIC

to the linux-3.11.y-queue branch of the 3.11.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.11.y-queue

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.11.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

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From 6933e21d9af71e1dbe9ad6d56eb163d8e0196022 Mon Sep 17 00:00:00 2001
From: Fenghua Yu <fenghua.yu@intel.com>
Date: Wed, 23 Oct 2013 18:30:12 -0700
Subject: x86/apic: Disable I/O APIC before shutdown of the local APIC

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@intel.com>
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 <mingo@kernel.org>
[ luis: backported to 3.11: adjusted context ]
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
---
 arch/x86/kernel/crash.c  | 2 +-
 arch/x86/kernel/reboot.c | 8 ++++----
 2 files changed, 5 insertions(+), 5 deletions(-)

--
1.8.3.2
diff mbox

Patch

diff --git a/arch/x86/kernel/crash.c b/arch/x86/kernel/crash.c
index 74467fe..0b9d44d 100644
--- a/arch/x86/kernel/crash.c
+++ b/arch/x86/kernel/crash.c
@@ -127,10 +127,10 @@  void native_machine_crash_shutdown(struct pt_regs *regs)
 	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
diff --git a/arch/x86/kernel/reboot.c b/arch/x86/kernel/reboot.c
index 5f4ad27..ca1787b 100644
--- a/arch/x86/kernel/reboot.c
+++ b/arch/x86/kernel/reboot.c
@@ -542,6 +542,10 @@  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
@@ -554,10 +558,6 @@  void native_machine_shutdown(void)

 	lapic_shutdown();

-#ifdef CONFIG_X86_IO_APIC
-	disable_IO_APIC();
-#endif
-
 #ifdef CONFIG_HPET_TIMER
 	hpet_disable();
 #endif