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>

drivers/video/chipsfb.c

@@ -459,7 +459,7 @@ static int chipsfb_pci_suspend(struct pci_dev *pdev, pm_message_t state)
 
 	if (state.event == pdev->dev.power.power_state.event)
 		return 0;
-	if (state.event != PM_EVENT_SUSPEND)
+	if (!(state.event & PM_EVENT_SLEEP))
 		goto done;
 
 	acquire_console_sem();

drivers/video/nvidia/nvidia.c

@@ -1066,7 +1066,7 @@ static int nvidiafb_suspend(struct pci_dev *dev, pm_message_t mesg)
 	acquire_console_sem();
 	par->pm_state = mesg.event;
 
-	if (mesg.event == PM_EVENT_SUSPEND) {
+	if (mesg.event & PM_EVENT_SLEEP) {
 		fb_set_suspend(info, 1);
 		nvidiafb_blank(FB_BLANK_POWERDOWN, info);
 		nvidia_write_regs(par, &par->SavedReg);