Commit 3a2d5b70 authored by Rafael J. Wysocki's avatar Rafael J. Wysocki Committed by Linus Torvalds
Browse files

PM: Introduce PM_EVENT_HIBERNATE callback state 

During the last step of hibernation in the "platform" mode (with the
help of ACPI) we use the suspend code, including the devices'
->suspend() methods, to prepare the system for entering the ACPI S4
system sleep state.

But at least for some devices the operations performed by the
->suspend() callback in that case must be different from its operations
during regular suspend.

For this reason, introduce the new PM event type PM_EVENT_HIBERNATE and
pass it to the device drivers' ->suspend() methods during the last phase
of hibernation, so that they can distinguish this case and handle it as
appropriate.  Modify the drivers that handle PM_EVENT_SUSPEND in a
special way and need to handle PM_EVENT_HIBERNATE in the same way.

These changes are necessary to fix a hibernation regression related
to the i915 driver (ref. http://lkml.org/lkml/2008/2/22/488

).

Signed-off-by: default avatarRafael J. Wysocki <rjw@sisk.pl>
Acked-by: default avatarPavel Machek <pavel@ucw.cz>
Tested-by: default avatarJeff Chua <jeff.chua.linux@gmail.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 39273b58

Documentation/power/devices.txt

+8 −5
Original line number Diff line number Diff line
@@ -310,9 +310,12 @@ used with suspend-to-disk: 
    PM_EVENT_SUSPEND -- quiesce the driver and put hardware into a low-power

	state.  When used with system sleep states like "suspend-to-RAM" or

	"standby", the upcoming resume() call will often be able to rely on

	state kept in hardware, or issue system wakeup events.  When used

	instead with suspend-to-disk, few devices support this capability;

	most are completely powered off.

	state kept in hardware, or issue system wakeup events.



    PM_EVENT_HIBERNATE -- Put hardware into a low-power state and enable wakeup

	events as appropriate.  It is only used with hibernation

	(suspend-to-disk) and few devices are able to wake up the system from

	this state; most are completely powered off.



    PM_EVENT_FREEZE -- quiesce the driver, but don't necessarily change into

	any low power mode.  A system snapshot is about to be taken, often
@@ -329,8 +332,8 @@ used with suspend-to-disk: 
	wakeup events nor DMA are allowed.



To enter "standby" (ACPI S1) or "Suspend to RAM" (STR, ACPI S3) states, or

the similarly named APM states, only PM_EVENT_SUSPEND is used; for "Suspend

to Disk" (STD, hibernate, ACPI S4), all of those event codes are used.

the similarly named APM states, only PM_EVENT_SUSPEND is used; the other event

codes are used for hibernation ("Suspend to Disk", STD, ACPI S4).



There's also PM_EVENT_ON, a value which never appears as a suspend event

but is sometimes used to record the "not suspended" device state.

drivers/ata/ahci.c

+1 −1
Original line number Diff line number Diff line
@@ -1932,7 +1932,7 @@ static int ahci_pci_device_suspend(struct pci_dev *pdev, pm_message_t mesg) 
	void __iomem *mmio = host->iomap[AHCI_PCI_BAR];

	u32 ctl;



	if (mesg.event == PM_EVENT_SUSPEND) {

	if (mesg.event & PM_EVENT_SLEEP) {

		/* AHCI spec rev1.1 section 8.3.3:

		 * Software must disable interrupts prior to requesting a

		 * transition of the HBA to D3 state.

drivers/ata/ata_piix.c

+1 −1
Original line number Diff line number Diff line
@@ -1339,7 +1339,7 @@ static int piix_pci_device_suspend(struct pci_dev *pdev, pm_message_t mesg) 
	 * cycles and power trying to do something to the sleeping

	 * beauty.

	 */

	if (piix_broken_suspend() && mesg.event == PM_EVENT_SUSPEND) {

	if (piix_broken_suspend() && (mesg.event & PM_EVENT_SLEEP)) {

		pci_save_state(pdev);



		/* mark its power state as "unknown", since we don't

drivers/ata/libata-core.c

+1 −1
Original line number Diff line number Diff line
@@ -7368,7 +7368,7 @@ void ata_pci_device_do_suspend(struct pci_dev *pdev, pm_message_t mesg) 
	pci_save_state(pdev);

	pci_disable_device(pdev);



	if (mesg.event == PM_EVENT_SUSPEND)

	if (mesg.event & PM_EVENT_SLEEP)

		pci_set_power_state(pdev, PCI_D3hot);

}

drivers/ide/ppc/pmac.c

+2 −2
Original line number Diff line number Diff line
@@ -1254,7 +1254,7 @@ pmac_ide_macio_suspend(struct macio_dev *mdev, pm_message_t mesg) 
	int		rc = 0;



	if (mesg.event != mdev->ofdev.dev.power.power_state.event

			&& mesg.event == PM_EVENT_SUSPEND) {

			&& (mesg.event & PM_EVENT_SLEEP)) {

		rc = pmac_ide_do_suspend(hwif);

		if (rc == 0)

			mdev->ofdev.dev.power.power_state = mesg;
@@ -1364,7 +1364,7 @@ pmac_ide_pci_suspend(struct pci_dev *pdev, pm_message_t mesg) 
	int		rc = 0;

	

	if (mesg.event != pdev->dev.power.power_state.event

			&& mesg.event == PM_EVENT_SUSPEND) {

			&& (mesg.event & PM_EVENT_SLEEP)) {

		rc = pmac_ide_do_suspend(hwif);

		if (rc == 0)

			pdev->dev.power.power_state = mesg;

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