Commit 6f389a8f authored Apr 07, 2013 by Huacai Chen Committed by Rafael J. Wysocki Apr 08, 2013

PM / reboot: call syscore_shutdown() after disable_nonboot_cpus()



As commit 40dc166c (PM / Core: Introduce struct syscore_ops for core
subsystems PM) say, syscore_ops operations should be carried with one
CPU on-line and interrupts disabled. However, after commit f96972f2
(kernel/sys.c: call disable_nonboot_cpus() in kernel_restart()),
syscore_shutdown() is called before disable_nonboot_cpus(), so break
the rules. We have a MIPS machine with a 8259A PIC, and there is an
external timer (HPET) linked at 8259A. Since 8259A has been shutdown
too early (by syscore_shutdown()), disable_nonboot_cpus() runs without
timer interrupt, so it hangs and reboot fails. This patch call
syscore_shutdown() a little later (after disable_nonboot_cpus()) to
avoid reboot failure, this is the same way as poweroff does.

For consistency, add disable_nonboot_cpus() to kernel_halt().

Signed-off-by: Huacai Chen <chenhc@lemote.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

parent ec376a2a

kernel/sys.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -324,7 +324,6 @@ void kernel_restart_prepare(char *cmd)
		system_state = SYSTEM_RESTART;
		usermodehelper_disable();
		device_shutdown();
		syscore_shutdown();
		}

		/**
		@@ -370,6 +369,7 @@ void kernel_restart(char *cmd)
		{
		kernel_restart_prepare(cmd);
		disable_nonboot_cpus();
		syscore_shutdown();
		if (!cmd)
		printk(KERN_EMERG "Restarting system.\n");
		else
		@@ -395,6 +395,7 @@ static void kernel_shutdown_prepare(enum system_states state)
		void kernel_halt(void)
		{
		kernel_shutdown_prepare(SYSTEM_HALT);
		disable_nonboot_cpus();
		syscore_shutdown();
		printk(KERN_EMERG "System halted.\n");
		kmsg_dump(KMSG_DUMP_HALT);

Admin message