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>
diff --git a/kernel/power/disk.c b/kernel/power/disk.c
index 555c0f0..e50f4da 100644
--- a/kernel/power/disk.c
+++ b/kernel/power/disk.c
@@ -93,6 +93,17 @@
}
/**
+ * 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())
*/
@@ -129,6 +140,51 @@
}
/**
+ * 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.
* @platform_mode - if set, use the platform driver, if available, to
@@ -163,7 +219,7 @@
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");