Hibernation: Check if ACPI is enabled during restore in the right place

The following scenario leads to total confusion of the platform firmware on
some boxes (eg. HPC nx6325):
* Hibernate with ACPI enabled
* Resume passing "acpi=off" to the boot kernel

To prevent this from happening it's necessary to check if ACPI is enabled (and
enable it if that's not the case) _right_ _after_ control has been transfered
from the boot kernel to the image kernel, before device_power_up() is called
(ie.  with interrupts disabled).   Enabling ACPI after calling
device_power_up() turns out to be insufficient.

For this reason, introduce new hibernation callback ->leave() that will be
executed before device_power_up() by the restored image kernel.   To make it
work, it also is necessary to move swsusp_suspend() from swsusp.c to disk.c
(it's name is changed to "create_image", which is more up to the point).

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, 0 insertions, 33 deletions

diff --git a/kernel/power/swsusp.c b/kernel/power/swsusp.c
index 5da304c8f1f6..e1722d3155f1 100644
--- a/kernel/power/swsusp.c
+++ b/kernel/power/swsusp.c
@@ -270,39 +270,6 @@ int swsusp_shrink_memory(void)
         return 0;
 }
 
-int swsusp_suspend(void)
-{
-        int error;
-
-        if ((error = arch_prepare_suspend()))
-                return error;
-
-        local_irq_disable();
-        /* At this point, device_suspend() has been called, but *not*
-         * device_power_down(). We *must* device_power_down() now.
-         * Otherwise, drivers for some devices (e.g. interrupt controllers)
-         * become desynchronized with the actual state of the hardware
-         * at resume time, and evil weirdness ensues.
-         */
-        if ((error = device_power_down(PMSG_FREEZE))) {
-                printk(KERN_ERR "Some devices failed to power down, aborting suspend\n");
-                goto Enable_irqs;
-        }
-
-        save_processor_state();
-        if ((error = swsusp_arch_suspend()))
-                printk(KERN_ERR "Error %d suspending\n", error);
-        /* Restore control flow magically appears here */
-        restore_processor_state();
-        /* NOTE:  device_power_up() is just a resume() for devices
-         * that suspended with irqs off ... no overall powerup.
-         */
-        device_power_up();
- Enable_irqs:
-        local_irq_enable();
-        return error;
-}
-
 int swsusp_resume(void)
 {
         int error;