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, 8 insertions, 1 deletions

diff --git a/include/linux/pm.h b/include/linux/pm.h
index eccf59ea2a77..015b735811b4 100644
--- a/include/linux/pm.h
+++ b/include/linux/pm.h
@@ -143,6 +143,9 @@ typedef struct pm_message {
  *              the upcoming system state (such as PCI_D3hot), and enable
  *              wakeup events as appropriate.
  *
+ * HIBERNATE    Enter a low power device state appropriate for the hibernation
+ *              state (eg. ACPI S4) and enable wakeup events as appropriate.
+ *
  * FREEZE       Quiesce operations so that a consistent image can be saved;
  *              but do NOT otherwise enter a low power device state, and do
  *              NOT emit system wakeup events.
@@ -166,11 +169,15 @@ typedef struct pm_message {
 #define PM_EVENT_ON 0
 #define PM_EVENT_FREEZE 1
 #define PM_EVENT_SUSPEND 2
-#define PM_EVENT_PRETHAW 3
+#define PM_EVENT_HIBERNATE 4
+#define PM_EVENT_PRETHAW 8
+
+#define PM_EVENT_SLEEP  (PM_EVENT_SUSPEND | PM_EVENT_HIBERNATE)
 
 #define PMSG_FREEZE     ((struct pm_message){ .event = PM_EVENT_FREEZE, })
 #define PMSG_PRETHAW    ((struct pm_message){ .event = PM_EVENT_PRETHAW, })
 #define PMSG_SUSPEND    ((struct pm_message){ .event = PM_EVENT_SUSPEND, })
+#define PMSG_HIBERNATE  ((struct pm_message){ .event = PM_EVENT_HIBERNATE, })
 #define PMSG_ON         ((struct pm_message){ .event = PM_EVENT_ON, })
 
 struct dev_pm_info {