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: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 46 insertions, 17 deletions

diff --git a/kernel/power/disk.c b/kernel/power/disk.c
index e50f4da18fd5..8b15f777010a 100644
--- a/kernel/power/disk.c
+++ b/kernel/power/disk.c
@@ -278,21 +278,50 @@ 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)
+                goto Resume_console;
+
+        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) {
+                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();
         /*