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, 2 deletions

diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index 37df8bbe7f46..7aee64dbfbeb 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -1835,8 +1835,7 @@ static int sd_suspend(struct device *dev, pm_message_t mesg)
                         goto done;
         }
 
-        if (mesg.event == PM_EVENT_SUSPEND &&
-            sdkp->device->manage_start_stop) {
+        if ((mesg.event & PM_EVENT_SLEEP) && sdkp->device->manage_start_stop) {
                 sd_printk(KERN_NOTICE, sdkp, "Stopping disk\n");
                 ret = sd_start_stop_device(sdkp, 0);
         }