diff --git a/Documentation/power/devices.txt b/Documentation/power/devices.txt
index 1971bcf48a602fd5466bd3c1e440b666115f2a8a..88880839ece4e84f8101b4cfd50e3e22b8024515 100644
--- a/Documentation/power/devices.txt
+++ b/Documentation/power/devices.txt
@@ -279,11 +279,15 @@ When the system goes into the standby or memory sleep state, the phases are:
time.) Unlike the other suspend-related phases, during the prepare
phase the device tree is traversed top-down.
- The prepare phase uses only a bus callback. After the callback method
- returns, no new children may be registered below the device. The method
- may also prepare the device or driver in some way for the upcoming
- system power transition, but it should not put the device into a
- low-power state.
+ In addition to that, if device drivers need to allocate additional
+ memory to be able to hadle device suspend correctly, that should be
+ done in the prepare phase.
+
+ After the prepare callback method returns, no new children may be
+ registered below the device. The method may also prepare the device or
+ driver in some way for the upcoming system power transition (for
+ example, by allocating additional memory required for this purpose), but
+ it should not put the device into a low-power state.
2. The suspend methods should quiesce the device to stop it from performing
I/O. They also may save the device registers and put it into the
diff --git a/Documentation/power/notifiers.txt b/Documentation/power/notifiers.txt
index cf980709122aa25cfaef984e60da0f2f7218e92e..c2a4a346c0d98597d3375c5a9f160c012fded709 100644
--- a/Documentation/power/notifiers.txt
+++ b/Documentation/power/notifiers.txt
@@ -1,46 +1,41 @@
Suspend notifiers
- (C) 2007 Rafael J. Wysocki <rjw@sisk.pl>, GPL
-
-There are some operations that device drivers may want to carry out in their
-.suspend() routines, but shouldn't, because they can cause the hibernation or
-suspend to fail. For example, a driver may want to allocate a substantial amount
-of memory (like 50 MB) in .suspend(), but that shouldn't be done after the
-swsusp's memory shrinker has run.
-
-Also, there may be some operations, that subsystems want to carry out before a
-hibernation/suspend or after a restore/resume, requiring the system to be fully
-functional, so the drivers' .suspend() and .resume() routines are not suitable
-for this purpose. For example, device drivers may want to upload firmware to
-their devices after a restore from a hibernation image, but they cannot do it by
-calling request_firmware() from their .resume() routines (user land processes
-are frozen at this point). The solution may be to load the firmware into
-memory before processes are frozen and upload it from there in the .resume()
-routine. Of course, a hibernation notifier may be used for this purpose.
-
-The subsystems that have such needs can register suspend notifiers that will be
-called upon the following events by the suspend core:
+ (C) 2007-2011 Rafael J. Wysocki <rjw@sisk.pl>, GPL
+
+There are some operations that subsystems or drivers may want to carry out
+before hibernation/suspend or after restore/resume, but they require the system
+to be fully functional, so the drivers' and subsystems' .suspend() and .resume()
+or even .prepare() and .complete() callbacks are not suitable for this purpose.
+For example, device drivers may want to upload firmware to their devices after
+resume/restore, but they cannot do it by calling request_firmware() from their
+.resume() or .complete() routines (user land processes are frozen at these
+points). The solution may be to load the firmware into memory before processes
+are frozen and upload it from there in the .resume() routine.
+A suspend/hibernation notifier may be used for this purpose.
+
+The subsystems or drivers having such needs can register suspend notifiers that
+will be called upon the following events by the PM core:
PM_HIBERNATION_PREPARE The system is going to hibernate or suspend, tasks will
be frozen immediately.
PM_POST_HIBERNATION The system memory state has been restored from a
- hibernation image or an error occurred during the
- hibernation. Device drivers' .resume() callbacks have
+ hibernation image or an error occurred during
+ hibernation. Device drivers' restore callbacks have
been executed and tasks have been thawed.
PM_RESTORE_PREPARE The system is going to restore a hibernation image.
- If all goes well the restored kernel will issue a
+ If all goes well, the restored kernel will issue a
PM_POST_HIBERNATION notification.
-PM_POST_RESTORE An error occurred during the hibernation restore.
- Device drivers' .resume() callbacks have been executed
+PM_POST_RESTORE An error occurred during restore from hibernation.
+ Device drivers' restore callbacks have been executed
and tasks have been thawed.
-PM_SUSPEND_PREPARE The system is preparing for a suspend.
+PM_SUSPEND_PREPARE The system is preparing for suspend.
PM_POST_SUSPEND The system has just resumed or an error occurred during
- the suspend. Device drivers' .resume() callbacks have
- been executed and tasks have been thawed.
+ suspend. Device drivers' resume callbacks have been
+ executed and tasks have been thawed.
It is generally assumed that whatever the notifiers do for
PM_HIBERNATION_PREPARE, should be undone for PM_POST_HIBERNATION. Analogously,
diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c
index 3b354560f30607b1f96dd62fb70e8e1331cad901..aa6320207745d636641178f3d9ca89c2d489fe6e 100644
--- a/drivers/base/power/main.c
+++ b/drivers/base/power/main.c
@@ -579,11 +579,13 @@ static bool is_async(struct device *dev)
* Execute the appropriate "resume" callback for all devices whose status
* indicates that they are suspended.
*/
-static void dpm_resume(pm_message_t state)
+void dpm_resume(pm_message_t state)
{
struct device *dev;
ktime_t starttime = ktime_get();
+ might_sleep();
+
mutex_lock(&dpm_list_mtx);
pm_transition = state;
async_error = 0;
@@ -656,10 +658,12 @@ static void device_complete(struct device *dev, pm_message_t state)
* Execute the ->complete() callbacks for all devices whose PM status is not
* DPM_ON (this allows new devices to be registered).
*/
-static void dpm_complete(pm_message_t state)
+void dpm_complete(pm_message_t state)
{
struct list_head list;
+ might_sleep();
+
INIT_LIST_HEAD(&list);
mutex_lock(&dpm_list_mtx);
while (!list_empty(&dpm_prepared_list)) {
@@ -688,7 +692,6 @@ static void dpm_complete(pm_message_t state)
*/
void dpm_resume_end(pm_message_t state)
{
- might_sleep();
dpm_resume(state);
dpm_complete(state);
}
@@ -912,11 +915,13 @@ static int device_suspend(struct device *dev)
* dpm_suspend - Execute "suspend" callbacks for all non-sysdev devices.
* @state: PM transition of the system being carried out.
*/
-static int dpm_suspend(pm_message_t state)
+int dpm_suspend(pm_message_t state)
{
ktime_t starttime = ktime_get();
int error = 0;
+ might_sleep();
+
mutex_lock(&dpm_list_mtx);
pm_transition = state;
async_error = 0;
@@ -1003,10 +1008,12 @@ static int device_prepare(struct device *dev, pm_message_t state)
*
* Execute the ->prepare() callback(s) for all devices.
*/
-static int dpm_prepare(pm_message_t state)
+int dpm_prepare(pm_message_t state)
{
int error = 0;
+ might_sleep();
+
mutex_lock(&dpm_list_mtx);
while (!list_empty(&dpm_list)) {
struct device *dev = to_device(dpm_list.next);
@@ -1055,7 +1062,6 @@ int dpm_suspend_start(pm_message_t state)
{
int error;
- might_sleep();
error = dpm_prepare(state);
if (!error)
error = dpm_suspend(state);
diff --git a/include/linux/pm.h b/include/linux/pm.h
index 3cc3e7e589f070ee30a34277785ab997818e5729..dce7c71487714ccbfbf2fdad7b8ceb06388770ef 100644
--- a/include/linux/pm.h
+++ b/include/linux/pm.h
@@ -533,10 +533,14 @@ struct dev_power_domain {
extern void device_pm_lock(void);
extern void dpm_resume_noirq(pm_message_t state);
extern void dpm_resume_end(pm_message_t state);
+extern void dpm_resume(pm_message_t state);
+extern void dpm_complete(pm_message_t state);
extern void device_pm_unlock(void);
extern int dpm_suspend_noirq(pm_message_t state);
extern int dpm_suspend_start(pm_message_t state);
+extern int dpm_suspend(pm_message_t state);
+extern int dpm_prepare(pm_message_t state);
extern void __suspend_report_result(const char *function, void *fn, int ret);
diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c
index 95a2ac40f48ca558ce0851c8c2391ba56b592feb..f9bec56d88258992b61e8f9fb3306dd010e652e1 100644
--- a/kernel/power/hibernate.c
+++ b/kernel/power/hibernate.c
@@ -327,20 +327,25 @@ static int create_image(int platform_mode)
int hibernation_snapshot(int platform_mode)
{
+ pm_message_t msg = PMSG_RECOVER;
int error;
error = platform_begin(platform_mode);
if (error)
goto Close;
+ error = dpm_prepare(PMSG_FREEZE);
+ if (error)
+ goto Complete_devices;
+
/* Preallocate image memory before shutting down devices. */
error = hibernate_preallocate_memory();
if (error)
- goto Close;
+ goto Complete_devices;
suspend_console();
pm_restrict_gfp_mask();
- error = dpm_suspend_start(PMSG_FREEZE);
+ error = dpm_suspend(PMSG_FREEZE);
if (error)
goto Recover_platform;
@@ -358,13 +363,17 @@ int hibernation_snapshot(int platform_mode)
if (error || !in_suspend)
swsusp_free();
- dpm_resume_end(in_suspend ?
- (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE);
+ msg = in_suspend ? (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE;
+ dpm_resume(msg);
if (error || !in_suspend)
pm_restore_gfp_mask();
resume_console();
+
+ Complete_devices:
+ dpm_complete(msg);
+
Close:
platform_end(platform_mode);
return error;