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 --- kernel/power/disk.c | 58 ++++++++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 57 insertions(+), 1 deletion(-) (limited to 'kernel/power/disk.c') diff --git a/kernel/power/disk.c b/kernel/power/disk.c index 555c0f0b2f7..e50f4da18fd 100644 --- a/kernel/power/disk.c +++ b/kernel/power/disk.c @@ -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"); -- cgit v1.2.3