Commit d89d7ff9 authored by Rafael J. Wysocki's avatar Rafael J. Wysocki

Merge branches 'pm-sleep' and 'pm-runtime' into pm-core

......@@ -131,6 +131,8 @@ extern void device_remove_groups(struct device *dev,
extern char *make_class_name(const char *name, struct kobject *kobj);
extern int devres_release_all(struct device *dev);
extern void device_block_probing(void);
extern void device_unblock_probing(void);
/* /sys/devices directory */
extern struct kset *devices_kset;
......
......@@ -54,6 +54,13 @@ static LIST_HEAD(deferred_probe_active_list);
static struct workqueue_struct *deferred_wq;
static atomic_t deferred_trigger_count = ATOMIC_INIT(0);
/*
* In some cases, like suspend to RAM or hibernation, It might be reasonable
* to prohibit probing of devices as it could be unsafe.
* Once defer_all_probes is true all drivers probes will be forcibly deferred.
*/
static bool defer_all_probes;
/*
* deferred_probe_work_func() - Retry probing devices in the active list.
*/
......@@ -171,6 +178,30 @@ static void driver_deferred_probe_trigger(void)
queue_work(deferred_wq, &deferred_probe_work);
}
/**
* device_block_probing() - Block/defere device's probes
*
* It will disable probing of devices and defer their probes instead.
*/
void device_block_probing(void)
{
defer_all_probes = true;
/* sync with probes to avoid races. */
wait_for_device_probe();
}
/**
* device_unblock_probing() - Unblock/enable device's probes
*
* It will restore normal behavior and trigger re-probing of deferred
* devices.
*/
void device_unblock_probing(void)
{
defer_all_probes = false;
driver_deferred_probe_trigger();
}
/**
* deferred_probe_initcall() - Enable probing of deferred devices
*
......@@ -277,9 +308,20 @@ static DECLARE_WAIT_QUEUE_HEAD(probe_waitqueue);
static int really_probe(struct device *dev, struct device_driver *drv)
{
int ret = 0;
int ret = -EPROBE_DEFER;
int local_trigger_count = atomic_read(&deferred_trigger_count);
if (defer_all_probes) {
/*
* Value of defer_all_probes can be set only by
* device_defer_all_probes_enable() which, in turn, will call
* wait_for_device_probe() right after that to avoid any races.
*/
dev_dbg(dev, "Driver %s force probe deferral\n", drv->name);
driver_deferred_probe_add(dev);
return ret;
}
atomic_inc(&probe_count);
pr_debug("bus: '%s': %s: probing driver %s with device %s\n",
drv->bus->name, __func__, drv->name, dev_name(dev));
......@@ -340,6 +382,7 @@ static int really_probe(struct device *dev, struct device_driver *drv)
dev_set_drvdata(dev, NULL);
if (dev->pm_domain && dev->pm_domain->dismiss)
dev->pm_domain->dismiss(dev);
pm_runtime_reinit(dev);
switch (ret) {
case -EPROBE_DEFER:
......@@ -393,6 +436,10 @@ int driver_probe_done(void)
*/
void wait_for_device_probe(void)
{
/* wait for the deferred probe workqueue to finish */
if (driver_deferred_probe_enable)
flush_workqueue(deferred_wq);
/* wait for the known devices to complete their probing */
wait_event(probe_waitqueue, atomic_read(&probe_count) == 0);
async_synchronize_full();
......@@ -695,6 +742,7 @@ static void __device_release_driver(struct device *dev)
dev_set_drvdata(dev, NULL);
if (dev->pm_domain && dev->pm_domain->dismiss)
dev->pm_domain->dismiss(dev);
pm_runtime_reinit(dev);
klist_remove(&dev->p->knode_driver);
if (dev->bus)
......
......@@ -963,6 +963,9 @@ void dpm_complete(pm_message_t state)
}
list_splice(&list, &dpm_list);
mutex_unlock(&dpm_list_mtx);
/* Allow device probing and trigger re-probing of deferred devices */
device_unblock_probing();
trace_suspend_resume(TPS("dpm_complete"), state.event, false);
}
......@@ -1624,6 +1627,20 @@ int dpm_prepare(pm_message_t state)
trace_suspend_resume(TPS("dpm_prepare"), state.event, true);
might_sleep();
/*
* Give a chance for the known devices to complete their probes, before
* disable probing of devices. This sync point is important at least
* at boot time + hibernation restore.
*/
wait_for_device_probe();
/*
* It is unsafe if probing of devices will happen during suspend or
* hibernation and system behavior will be unpredictable in this case.
* So, let's prohibit device's probing here and defer their probes
* instead. The normal behavior will be restored in dpm_complete().
*/
device_block_probing();
mutex_lock(&dpm_list_mtx);
while (!list_empty(&dpm_list)) {
struct device *dev = to_device(dpm_list.next);
......
......@@ -18,6 +18,7 @@ static inline void pm_runtime_early_init(struct device *dev)
}
extern void pm_runtime_init(struct device *dev);
extern void pm_runtime_reinit(struct device *dev);
extern void pm_runtime_remove(struct device *dev);
struct wake_irq {
......@@ -84,6 +85,7 @@ static inline void pm_runtime_early_init(struct device *dev)
}
static inline void pm_runtime_init(struct device *dev) {}
static inline void pm_runtime_reinit(struct device *dev) {}
static inline void pm_runtime_remove(struct device *dev) {}
static inline int dpm_sysfs_add(struct device *dev) { return 0; }
......
......@@ -1389,6 +1389,25 @@ void pm_runtime_init(struct device *dev)
init_waitqueue_head(&dev->power.wait_queue);
}
/**
* pm_runtime_reinit - Re-initialize runtime PM fields in given device object.
* @dev: Device object to re-initialize.
*/
void pm_runtime_reinit(struct device *dev)
{
if (!pm_runtime_enabled(dev)) {
if (dev->power.runtime_status == RPM_ACTIVE)
pm_runtime_set_suspended(dev);
if (dev->power.irq_safe) {
spin_lock_irq(&dev->power.lock);
dev->power.irq_safe = 0;
spin_unlock_irq(&dev->power.lock);
if (dev->parent)
pm_runtime_put(dev->parent);
}
}
}
/**
* pm_runtime_remove - Prepare for removing a device from device hierarchy.
* @dev: Device object being removed from device hierarchy.
......@@ -1396,12 +1415,7 @@ void pm_runtime_init(struct device *dev)
void pm_runtime_remove(struct device *dev)
{
__pm_runtime_disable(dev, false);
/* Change the status back to 'suspended' to match the initial status. */
if (dev->power.runtime_status == RPM_ACTIVE)
pm_runtime_set_suspended(dev);
if (dev->power.irq_safe && dev->parent)
pm_runtime_put(dev->parent);
pm_runtime_reinit(dev);
}
/**
......
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