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Commit 9cd9a005 authored by Rafael J. Wysocki's avatar Rafael J. Wysocki Committed by Linus Torvalds
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Hibernation: Enter platform hibernation state in a consistent way 

Make hibernation_platform_enter() execute the enter-a-sleep-state sequence
instead of the mixed shutdown-with-entering-S4 thing.

Replace the shutting down of devices done by kernel_shutdown_prepare(), before
entering the ACPI S4 sleep state, with suspending them and the shutting down
of sysdevs with calling device_power_down(PMSG_SUSPEND) (just like before
entering S1 or S3, but the target state is now S4).   Also, disable the
nonboot CPUs before entering the sleep state (S4), which generally always is a
good idea.

This is known to fix the "double disk spin down during hibernation" on some
machines, eg.  HPC nx6325 (ref.  http://lkml.org/lkml/2007/8/7/316

 and the
following thread).   Moreover, it has been reported to make
/sys/class/rtc/rtc0/wakealarm work correctly with hibernation for some users.
It also generally causes the hibernation state (ACPI S4) to be entered faster.

Signed-off-by: default avatarRafael J. Wysocki <rjw@sisk.pl>
Acked-by: default avatarPavel Machek <pavel@ucw.cz>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent c7e0831d

kernel/power/disk.c

+46 −17
Original line number Diff line number Diff line
@@ -278,21 +278,50 @@ int hibernation_platform_enter(void) 
{

	int error;



	if (hibernation_ops) {

		kernel_shutdown_prepare(SYSTEM_SUSPEND_DISK);

	if (!hibernation_ops)

		return -ENOSYS;



	/*

	 * We have cancelled the power transition by running

		 * hibernation_ops->finish() before saving the image, so we

		 * should let the firmware know that we're going to enter the

		 * sleep state after all

	 * hibernation_ops->finish() before saving the image, so we should let

	 * the firmware know that we're going to enter the sleep state after all

	 */

	error = hibernation_ops->start();

	if (error)

		return error;



	suspend_console();

	error = device_suspend(PMSG_SUSPEND);

	if (error)

		goto Resume_console;



	error = hibernation_ops->prepare();

		sysdev_shutdown();

		if (!error)

			error = hibernation_ops->enter();

	} else {

		error = -ENOSYS;

	if (error)

		goto Resume_devices;



	error = disable_nonboot_cpus();

	if (error)

		goto Finish;



	local_irq_disable();

	error = device_power_down(PMSG_SUSPEND);

	if (!error) {

		hibernation_ops->enter();

		/* We should never get here */

		while (1);

	}

	local_irq_enable();



	/*

	 * We don't need to reenable the nonboot CPUs or resume consoles, since

	 * the system is going to be halted anyway.

	 */

 Finish:

	hibernation_ops->finish();

 Resume_devices:

	device_resume();

 Resume_console:

	resume_console();

	return error;

}
@@ -309,14 +338,14 @@ static void power_down(void) 
	case HIBERNATION_TEST:

	case HIBERNATION_TESTPROC:

		break;

	case HIBERNATION_SHUTDOWN:

		kernel_power_off();

		break;

	case HIBERNATION_REBOOT:

		kernel_restart(NULL);

		break;

	case HIBERNATION_PLATFORM:

		hibernation_platform_enter();

	case HIBERNATION_SHUTDOWN:

		kernel_power_off();

		break;

	}

	kernel_halt();

	/*