diff options
| -rw-r--r-- | Documentation/power/devices.txt | 14 | ||||
| -rw-r--r-- | Documentation/power/notifiers.txt | 51 | ||||
| -rw-r--r-- | drivers/base/power/main.c | 18 | ||||
| -rw-r--r-- | include/linux/pm.h | 4 | ||||
| -rw-r--r-- | kernel/power/hibernate.c | 17 |
5 files changed, 61 insertions, 43 deletions
diff --git a/Documentation/power/devices.txt b/Documentation/power/devices.txt index 1971bcf..8888083 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 cf98070..c2a4a34 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 3b35456..aa632020 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 3cc3e7e..dce7c71 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 95a2ac4..f9bec56 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; |
