[RFC][PATCH 1/3] Hibernation: Enter platform hibernation state in a consisten way (rev. 2)

Rafael J. Wysocki
2007-08-26T23:45:24Z

From: Rafael J. Wysocki <rjw@sisk.pl>

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). It also generally causes the hibernation state (ACPI S4) to
be entered faster.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
---
kernel/power/disk.c | 55 ++++++++++++++++++++++++++++++++++++++--------------
1 file changed, 41 insertions(+), 14 deletions(-)

Index: linux-2.6.23-rc3/kernel/power/disk.c
===================================================================
--- linux-2.6.23-rc3.orig/kernel/power/disk.c
+++ linux-2.6.23-rc3/kernel/power/disk.c
@@ -222,21 +222,48 @@ int hibernation_platform_enter(void)
{
int error;

- if (hibernation_ops) {
- kernel_shutdown_prepare(SYSTEM_SUSPEND_DISK);
- /*
- * 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
- */
- error = hibernation_ops->prepare();
- sysdev_shutdown();
- if (!error)
- error = hibernation_ops->enter();
- } else {
- error = -ENOSYS;
+ 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
+ */
+ error = hibernation_ops->start();
+ if (error)
+ return error;
+
+ suspend_console();
+ error = device_suspend(PMSG_SUSPEND);
+ if (error)
+ return error;
+
+ error = hibernation_ops->prepare();
+ if (error)
+ goto Resume_devices;
+
+ error = disable_nonboot_cpus();
+ if (error)
+ goto Finish;
+
+ local_irq_disable();
+ error = device_power_down(PMSG_SUSPEND);
+ if (!error) {
+ error = hibernation_ops->enter();
+ /* We should never get here */
+ device_power_up();
}
+ 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();
return error;
}