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: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@ucw.cz>
Tested-by: Jeff Chua <jeff.chua.linux@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 2 insertions, 2 deletions

diff --git a/kernel/power/disk.c b/kernel/power/disk.c
index 859a8e59773..14a656cdc65 100644
--- a/kernel/power/disk.c
+++ b/kernel/power/disk.c
@@ -391,7 +391,7 @@ int hibernation_platform_enter(void)
 		goto Close;
 
 	suspend_console();
-	error = device_suspend(PMSG_SUSPEND);
+	error = device_suspend(PMSG_HIBERNATE);
 	if (error)
 		goto Resume_console;
 
@@ -404,7 +404,7 @@ int hibernation_platform_enter(void)
 		goto Finish;
 
 	local_irq_disable();
-	error = device_power_down(PMSG_SUSPEND);
+	error = device_power_down(PMSG_HIBERNATE);
 	if (!error) {
 		hibernation_ops->enter();
 		/* We should never get here */