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

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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>
This commit is contained in:
Rafael J. Wysocki
2007-10-18 03:04:55 -07:00
committed by Linus Torvalds
parent efa4d2fb04
commit c7e0831d38
5 changed files with 74 additions and 35 deletions
Download Patch File Download Diff File Expand all files Collapse all files

58
kernel/power/disk.c
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@@ -92,6 +92,17 @@ static int platform_pre_snapshot(int platform_mode)
hibernation_ops->pre_snapshot() : 0;
}
/**
* platform_leave - prepare the machine for switching to the normal mode
* of operation using the platform driver (called with interrupts disabled)
*/
static void platform_leave(int platform_mode)
{
if (platform_mode && hibernation_ops)
hibernation_ops->leave();
}
/**
* platform_finish - switch the machine to the normal mode of operation
* using the platform driver (must be called after platform_prepare())
@@ -128,6 +139,51 @@ static void platform_restore_cleanup(int platform_mode)
hibernation_ops->restore_cleanup();
}
/**
* create_image - freeze devices that need to be frozen with interrupts
* off, create the hibernation image and thaw those devices. Control
* reappears in this routine after a restore.
*/
int create_image(int platform_mode)
{
int error;
error = arch_prepare_suspend();
if (error)
return error;
local_irq_disable();
/* At this point, device_suspend() has been called, but *not*
* device_power_down(). We *must* call 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.
*/
error = device_power_down(PMSG_FREEZE);
if (error) {
printk(KERN_ERR "Some devices failed to power down, "
KERN_ERR "aborting suspend\n");
goto Enable_irqs;
}
save_processor_state();
error = swsusp_arch_suspend();
if (error)
printk(KERN_ERR "Error %d while creating the image\n", error);
/* Restore control flow magically appears here */
restore_processor_state();
if (!in_suspend)
platform_leave(platform_mode);
/* 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;
}
/**
* hibernation_snapshot - quiesce devices and create the hibernation
* snapshot image.
@@ -163,7 +219,7 @@ int hibernation_snapshot(int platform_mode)
if (!error) {
if (hibernation_mode != HIBERNATION_TEST) {
in_suspend = 1;
error = swsusp_suspend();
error = create_image(platform_mode);
/* Control returns here after successful restore */
} else {
printk("swsusp debug: Waiting for 5 seconds.\n");