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, 1 insertions, 0 deletions

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index ae3df46eaabf..183fddaa38b7 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -554,6 +554,7 @@ pci_power_t pci_choose_state(struct pci_dev *dev, pm_message_t state)
         case PM_EVENT_PRETHAW:
                 /* REVISIT both freeze and pre-thaw "should" use D0 */
         case PM_EVENT_SUSPEND:
+        case PM_EVENT_HIBERNATE:
                 return PCI_D3hot;
         default:
                 printk("Unrecognized suspend event %d\n", state.event);