From c7e0831d385d620a58d95b25e4afa9b643f9a411 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Thu, 18 Oct 2007 03:04:55 -0700 Subject: Hibernation: Check if ACPI is enabled during restore in the right place MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 Signed-off-by: Linus Torvalds --- drivers/acpi/sleep/main.c | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'drivers/acpi/sleep/main.c') diff --git a/drivers/acpi/sleep/main.c b/drivers/acpi/sleep/main.c index acfb01b8ec8..048295ec370 100644 --- a/drivers/acpi/sleep/main.c +++ b/drivers/acpi/sleep/main.c @@ -257,6 +257,15 @@ static int acpi_hibernation_enter(void) return ACPI_SUCCESS(status) ? 0 : -EFAULT; } +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); @@ -288,6 +297,7 @@ static struct platform_hibernation_ops acpi_hibernation_ops = { .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, }; -- cgit v1.2.3-70-g09d2