PM: introduce hibernation and suspend notifiers

Make it possible to register hibernation and suspend notifiers, so that
subsystems can perform hibernation-related or suspend-related operations that
should not be carried out by device drivers' .suspend() and .resume()
routines.

[akpm@linux-foundation.org: build fixes]
[akpm@linux-foundation.org: cleanups]
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@ucw.cz>
Cc: Nigel Cunningham <nigel@nigel.suspend2.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 8 insertions, 3 deletions

diff --git a/kernel/power/user.c b/kernel/power/user.c
index 1f24f30b951b..7f19afe01b48 100644
--- a/kernel/power/user.c
+++ b/kernel/power/user.c
@@ -151,10 +151,14 @@ static int snapshot_ioctl(struct inode *inode, struct file *filp,
                 if (data->frozen)
                         break;
                 mutex_lock(&pm_mutex);
-                if (freeze_processes()) {
-                        thaw_processes();
-                        error = -EBUSY;
+                error = pm_notifier_call_chain(PM_HIBERNATION_PREPARE);
+                if (!error) {
+                        error = freeze_processes();
+                        if (error)
+                                thaw_processes();
                 }
+                if (error)
+                        pm_notifier_call_chain(PM_POST_HIBERNATION);
                 mutex_unlock(&pm_mutex);
                 if (!error)
                         data->frozen = 1;
@@ -165,6 +169,7 @@ static int snapshot_ioctl(struct inode *inode, struct file *filp,
                         break;
                 mutex_lock(&pm_mutex);
                 thaw_processes();
+                pm_notifier_call_chain(PM_POST_HIBERNATION);
                 mutex_unlock(&pm_mutex);
                 data->frozen = 0;
                 break;