From: Rafael J. Wysocki <rjw@xxxxxxx>
The following scenario leads to total confusion of the platform firmware on
some boxes (eg. HPC nx6325):
* Hibernate with ACPI enabled
* Pass "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@xxxxxxx>
---
drivers/acpi/sleep/main.c | 7 ++++-
include/linux/suspend.h | 7 +++++
kernel/power/disk.c | 58 +++++++++++++++++++++++++++++++++++++++++++++-
kernel/power/power.h | 1
kernel/power/swsusp.c | 33 --------------------------
5 files changed, 70 insertions(+), 36 deletions(-)
Index: linux-2.6.23-rc4-mm1/drivers/acpi/sleep/main.c
===================================================================
--- linux-2.6.23-rc4-mm1.orig/drivers/acpi/sleep/main.c
+++ linux-2.6.23-rc4-mm1/drivers/acpi/sleep/main.c
@@ -231,13 +231,17 @@ static int acpi_hibernation_enter(void)
return ACPI_SUCCESS(status) ? 0 : -EFAULT;
}
-static void acpi_hibernation_finish(void)
+static void acpi_hibernation_leave(void)
{
/*
* If ACPI is not enabled by the BIOS and the boot kernel, we need to
* enable it here.
*/
acpi_enable();
+}
+
+static void acpi_hibernation_finish(void)
+{
acpi_leave_sleep_state(ACPI_STATE_S4);
acpi_disable_wakeup_device(ACPI_STATE_S4);
@@ -267,6 +271,7 @@ static struct platform_hibernation_ops a
.finish = acpi_hibernation_finish,
.prepare = acpi_hibernation_prepare,
.enter = acpi_hibernation_enter,
+ .leave = acpi_hibernation_leave,
.pre_restore = acpi_hibernation_pre_restore,
.restore_cleanup = acpi_hibernation_restore_cleanup,
};
Index: linux-2.6.23-rc4-mm1/include/linux/suspend.h
===================================================================
--- linux-2.6.23-rc4-mm1.orig/include/linux/suspend.h
+++ linux-2.6.23-rc4-mm1/include/linux/suspend.h
@@ -156,6 +156,12 @@ extern void mark_free_pages(struct zone
* Called after the nonboot CPUs have been disabled and all of the low
* level devices have been shut down (runs with IRQs off).
*
+ * @leave: Perform the first stage of the cleanup after the system sleep state
+ * indicated by @set_target() has been left.
+ * Called right after the control has been passed from the boot kernel to
+ * the image kernel, before the nonboot CPUs are enabled and before devices
+ * are resumed. Executed with interrupts disabled.
+ *
* @pre_restore: Prepare system for the restoration from a hibernation image.
* Called right after devices have been frozen and before the nonboot
* CPUs are disabled (runs with IRQs on).
@@ -170,6 +176,7 @@ struct platform_hibernation_ops {
void (*finish)(void);
int (*prepare)(void);
int (*enter)(void);
+ void (*leave)(void);
int (*pre_restore)(void);
void (*restore_cleanup)(void);
};
Index: linux-2.6.23-rc4-mm1/kernel/power/disk.c
===================================================================
--- linux-2.6.23-rc4-mm1.orig/kernel/power/disk.c
+++ linux-2.6.23-rc4-mm1/kernel/power/disk.c
@@ -93,6 +93,17 @@ static int platform_pre_snapshot(int pla
}
/**
+ * 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 @@ static void platform_restore_cleanup(int
}
/**
+ * 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 @@ int hibernation_snapshot(int platform_mo
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");
Index: linux-2.6.23-rc4-mm1/kernel/power/power.h
===================================================================
--- linux-2.6.23-rc4-mm1.orig/kernel/power/power.h
+++ linux-2.6.23-rc4-mm1/kernel/power/power.h
@@ -183,7 +183,6 @@ extern int swsusp_swap_in_use(void);
extern int swsusp_check(void);
extern int swsusp_shrink_memory(void);
extern void swsusp_free(void);
-extern int swsusp_suspend(void);
extern int swsusp_resume(void);
extern int swsusp_read(unsigned int *flags_p);
extern int swsusp_write(unsigned int flags);
Index: linux-2.6.23-rc4-mm1/kernel/power/swsusp.c
===================================================================
--- linux-2.6.23-rc4-mm1.orig/kernel/power/swsusp.c
+++ linux-2.6.23-rc4-mm1/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;
-
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