From: Rafael J. Wysocki 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 Acked-by: Pavel Machek Signed-off-by: Andrew Morton --- 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(-) diff -puN drivers/acpi/sleep/main.c~hibernation-check-if-acpi-is-enabled-during-restore-in-the-right-place drivers/acpi/sleep/main.c --- a/drivers/acpi/sleep/main.c~hibernation-check-if-acpi-is-enabled-during-restore-in-the-right-place +++ a/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, }; diff -puN include/linux/suspend.h~hibernation-check-if-acpi-is-enabled-during-restore-in-the-right-place include/linux/suspend.h --- a/include/linux/suspend.h~hibernation-check-if-acpi-is-enabled-during-restore-in-the-right-place +++ a/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); }; diff -puN kernel/power/disk.c~hibernation-check-if-acpi-is-enabled-during-restore-in-the-right-place kernel/power/disk.c --- a/kernel/power/disk.c~hibernation-check-if-acpi-is-enabled-during-restore-in-the-right-place +++ a/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"); diff -puN kernel/power/power.h~hibernation-check-if-acpi-is-enabled-during-restore-in-the-right-place kernel/power/power.h --- a/kernel/power/power.h~hibernation-check-if-acpi-is-enabled-during-restore-in-the-right-place +++ a/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); diff -puN kernel/power/swsusp.c~hibernation-check-if-acpi-is-enabled-during-restore-in-the-right-place kernel/power/swsusp.c --- a/kernel/power/swsusp.c~hibernation-check-if-acpi-is-enabled-during-restore-in-the-right-place +++ a/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; _