// SPDX-License-Identifier: GPL-2.0
/*
* drivers/base/power/main.c - Where the driver meets power management.
*
* Copyright (c) 2003 Patrick Mochel
* Copyright (c) 2003 Open Source Development Lab
*
* The driver model core calls device_pm_add() when a device is registered.
* This will initialize the embedded device_pm_info object in the device
* and add it to the list of power-controlled devices. sysfs entries for
* controlling device power management will also be added.
*
* A separate list is used for keeping track of power info, because the power
* domain dependencies may differ from the ancestral dependencies that the
* subsystem list maintains.
*/
#define pr_fmt(fmt) "PM: " fmt
#define dev_fmt pr_fmt
#include <linux/device.h>
#include <linux/export.h>
#include <linux/mutex.h>
#include <linux/pm.h>
#include <linux/pm_runtime.h>
#include <linux/pm-trace.h>
#include <linux/pm_wakeirq.h>
#include <linux/interrupt.h>
#include <linux/sched.h>
#include <linux/sched/debug.h>
#include <linux/async.h>
#include <linux/suspend.h>
#include <trace/events/power.h>
#include <linux/cpufreq.h>
#include <linux/devfreq.h>
#include <linux/timer.h>
#include "../base.h"
#include "power.h"
typedef int (*pm_callback_t)(struct device *);
#define list_for_each_entry_rcu_locked(pos, head, member) \
list_for_each_entry_rcu(pos, head, member, \
device_links_read_lock_held())
/*
* The entries in the dpm_list list are in a depth first order, simply
* because children are guaranteed to be discovered after parents, and
* are inserted at the back of the list on discovery.
*
* Since device_pm_add() may be called with a device lock held,
* we must never try to acquire a device lock while holding
* dpm_list_mutex.
*/
LIST_HEAD(dpm_list);
static LIST_HEAD(dpm_prepared_list);
static LIST_HEAD(dpm_suspended_list);
static LIST_HEAD(dpm_late_early_list);
static LIST_HEAD(dpm_noirq_list);
static DEFINE_MUTEX(dpm_list_mtx);
static pm_message_t pm_transition;
static int async_error;
static const char *pm_verb(int event)
{
switch (event) {
case PM_EVENT_SUSPEND:
return "suspend";
case PM_EVENT_RESUME:
return "resume";
case PM_EVENT_FREEZE:
return "freeze";
case PM_EVENT_QUIESCE:
return "quiesce";
case PM_EVENT_HIBERNATE:
return "hibernate";
case PM_EVENT_THAW:
return "thaw";
case PM_EVENT_RESTORE:
return "restore";
case PM_EVENT_RECOVER:
return "recover";
default:
return "(unknown PM event)";
}
}
/**
* device_pm_sleep_init - Initialize system suspend-related device fields.
* @dev: Device object being initialized.
*/
void device_pm_sleep_init(struct device *dev)
{
dev->power.is_prepared = false;
dev->power.is_suspended = false;
dev->power.is_noirq_suspended = false;
dev->power.is_late_suspended = false;
init_completion(&dev->power.completion);
complete_all(&dev->power.completion);
dev->power.wakeup = NULL;
INIT_LIST_HEAD(&dev->power.entry);
}
/**
* device_pm_lock - Lock the list of active devices used by the PM core.
*/
void device_pm_lock(void)
{
mutex_lock(&dpm_list_mtx);
}
/**
* device_pm_unlock - Unlock the list of active devices used by the PM core.
*/
void device_pm_unlock(void)
{
mutex_unlock(&dpm_list_mtx);
}
/**
* device_pm_add - Add a device to the PM core's list of active devices.
* @dev: Device to add to the list.
*/
void device_pm_add(struct device *dev)
{
/* Skip PM setup/initialization. */
if (device_pm_not_required(dev))
return;
pr_debug("Adding info for %s:%s\n",
dev->bus ? dev->bus->name : "No Bus", dev_name(dev));
device_pm_check_callbacks(dev);
mutex_lock(&dpm_list_mtx);
if (dev->parent && dev->parent->power.is_prepared)
dev_warn(dev, "parent %s should not be sleeping\n",
dev_name(dev->parent));
list_add_tail(&dev->power.entry, &dpm_list);
dev->power.in_dpm_list = true;
mutex_unlock(&dpm_list_mtx);
}
/**
* device_pm_remove - Remove a device from the PM core's list of active devices.
* @dev: Device to be removed from the list.
*/
void device_pm_remove(struct device *dev)
{
if (device_pm_not_required(dev))
return;
pr_debug("Removing info for %s:%s\n",
dev->bus ? dev->bus->name : "No Bus", dev_name(dev));
complete_all(&dev->power.completion);
mutex_lock(&dpm_list_mtx);
list_del_init(&dev->power.entry);
dev->power.in_dpm_list = false;
mutex_unlock(&dpm_list_mtx);
device_wakeup_disable(dev);
pm_runtime_remove(dev);
device_pm_check_callbacks(dev);
}
/**
* device_pm_move_before - Move device in the PM core's list of active devices.
* @deva: Device to move in dpm_list.
* @devb: Device @deva should come before.
*/
void device_pm_move_before(struct device *deva, struct device *devb)
{
pr_debug("Moving %s:%s before %s:%s\n",
deva->bus ? deva->bus->name : "No Bus", dev_name(deva),
devb->bus ? devb->bus->name : "No Bus", dev_name(devb));
/* Delete deva from dpm_list and reinsert before devb. */
list_move_tail(&deva->power.entry, &devb->power.entry);
}
/**
* device_pm_move_after - Move device in the PM core's list of active devices.
* @deva: Device to move in dpm_list.
* @devb: Device @deva should come after.
*/
void device_pm_move_after(struct device *deva, struct device *devb)
{
pr_debug("Moving %s:%s after %s:%s\n",
deva->bus ? deva->bus->name : "No Bus", dev_name(deva),
devb->bus ? devb->bus->name : "No Bus", dev_name(devb));
/* Delete deva from dpm_list and reinsert after devb. */
list_move(&deva->power.entry, &devb->power.entry);
}
/**
* device_pm_move_last - Move device to end of the PM core's list of devices.
* @dev: Device to move in dpm_list.
*/
void device_pm_move_last(struct device *dev)
{
pr_debug("Moving %s:%s to end of list\n",
dev->bus ? dev->bus->name : "No Bus", dev_name(dev));
list_move_tail(&dev->power.entry, &dpm_list);
}
static ktime_t initcall_debug_start(struct device *dev, void *cb)
{
if (!pm_print_times_enabled)
return 0;
dev_info(dev, "calling %ps @ %i, parent: %s\n", cb,
task_pid_nr(current),
dev->parent ? dev_name(dev->parent) : "none");
return ktime_get();
}
static void initcall_debug_report(struct device *dev, ktime_t calltime,
void *cb, int error)
{
ktime_t rettime;
if (!pm_print_times_enabled)
return;
rettime = ktime_get();
dev_info(dev, "%ps returned %d after %Ld usecs\n", cb, error,
(unsigned long long)ktime_us_delta(rettime, calltime));
}
/**
* dpm_wait - Wait for a PM operation to complete.
* @dev: Device to wait for.
* @async: If unset, wait only if the device's power.async_suspend flag is set.
*/
static void dpm_wait(struct device *dev, bool async)
{
if (!dev)
return;
if (async || (pm_async_enabled && dev->power.async_suspend))
wait_for_completion(&dev->power.completion);
}
static int dpm_wait_fn(struct device *dev, void *async_ptr)
{
dpm_wait(dev, *((bool *)async_ptr));
return 0;
}
static void dpm_wait_for_children(struct device *dev, bool async)
{
device_for_each_child(dev, &async, dpm_wait_fn);
}
static void dpm_wait_for_suppliers(struct device *dev, bool async)
{
struct device_link *link;
int idx;
idx = device_links_read_lock();
/*
* If the supplier goes away right after we've checked the link to it,
* we'll wait for its completion to change the state, but that's fine,
* because the only things that will block as a result are the SRCU
* callbacks freeing the link objects for the links in the list we're
* walking.
*/
list_for_each_entry_rcu_locked(link, &dev->links.suppliers, c_node)
if (READ_ONCE(link->status) != DL_STATE_DORMANT)
dpm_wait(link->supplier, async);
device_links_read_unlock(idx);
}
static bool dpm_wait_for_superior(struct device *dev, bool async)
{
struct device *parent;
/*
* If the device is resumed asynchronously and the parent's callback
* deletes both the device and the parent itself, the parent object may
* be freed while this function is running, so avoid that by reference
* counting the parent once more unless the device has been deleted
* already (in which case return right away).
*/
mutex_lock(&dpm_list_mtx);
if (!device_pm_initialized(dev)) {
mutex_unlock(&dpm_list_mtx);
return false;
}
parent = get_device(dev->parent);
mutex_unlock(&dpm_list_mtx);
dpm_wait(parent, async);
put_device(parent);
dpm_wait_for_suppliers(dev, async);
/*
* If the parent's callback has deleted the device, attempting to resume
* it would be invalid, so avoid doing that then.
*/
return device_pm_initialized(dev);
}
static void dpm_wait_for_consumers(struct device *dev, bool async)
{
struct device_link *link;
int idx;
idx = device_links_read_lock();
/*
* The status of a device link can only be changed from "dormant" by a
* probe, but that cannot happen during system suspend/resume. In
* theory it can change to "dormant" at that time, but then it is
* reasonable to wait for the target device anyway (eg. if it goes
* away, it's better to wait for it to go away completely and then
* continue instead of trying to continue in parallel with its
* unregistration).
*/
list_for_each_entry_rcu_locked(link, &dev->links.consumers, s_node)
if (READ_ONCE(link->status) != DL_STATE_DORMANT)
dpm_wait(link->consumer, async);
device_links_read_unlock(idx);
}
static void dpm_wait_for_subordinate(struct device *dev, bool async)
{
dpm_wait_for_children(dev, async);
dpm_wait_for_consumers(dev, async);
}
/**
* pm_op - Return the PM operation appropriate for given PM event.
* @ops: PM operations to choose from.
* @state: PM transition of the system being carried out.
*/
static pm_callback_t pm_op(const struct dev_pm_ops *ops, pm_message_t state)
{
switch (state.event) {
#ifdef CONFIG_SUSPEND
case PM_EVENT_SUSPEND:
return ops->suspend;
case PM_EVENT_RESUME:
return ops->resume;
#endif /* CONFIG_SUSPEND */
#ifdef CONFIG_HIBERNATE_CALLBACKS
case PM_EVENT_FREEZE:
case PM_EVENT_QUIESCE:
return ops->freeze;
case PM_EVENT_HIBERNATE:
return ops->poweroff;
case PM_EVENT_THAW:
case PM_EVENT_RECOVER:
return ops->thaw;
case PM_EVENT_RESTORE:
return ops->restore;
#endif /* CONFIG_HIBERNATE_CALLBACKS */
}
return NULL;
}
/**
* pm_late_early_op - Return the PM operation appropriate for given PM event.
* @ops: PM operations to choose from.
* @state: PM transition of the system being carried out.
*
* Runtime PM is disabled for @dev while this function is being executed.
*/
static pm_callback_t pm_late_early_op(const struct dev_pm_ops *ops,
pm_message_t state)
{
switch (state.event) {
#ifdef CONFIG_SUSPEND
case PM_EVENT_SUSPEND:
return ops->suspend_late;
case PM_EVENT_RESUME:
return ops->resume_early;
#endif /* CONFIG_SUSPEND */
#ifdef CONFIG_HIBERNATE_CALLBACKS
case PM_EVENT_FREEZE:
case PM_EVENT_QUIESCE:
return ops->freeze_late;
case PM_EVENT_HIBERNATE:
return ops->poweroff_late;
case PM_EVENT_THAW:
case PM_EVENT_RECOVER:
return ops->thaw_early;
case PM_EVENT_RESTORE:
return ops->restore_early;
#endif /* CONFIG_HIBERNATE_CALLBACKS */
}
return NULL;
}
/**
* pm_noirq_op - Return the PM operation appropriate for given PM event.
* @ops: PM operations to choose from.
* @state: PM transition of the system being carried out.
*
* The driver of @dev will not receive interrupts while this function is being
* executed.
*/
static pm_callback_t pm_noirq_op(const struct dev_pm_ops *ops, pm_message_t state)
{
switch (state.event) {
#ifdef CONFIG_SUSPEND
case PM_EVENT_SUSPEND:
return ops->suspend_noirq;
case PM_EVENT_RESUME:
return ops->resume_noirq;
#endif /* CONFIG_SUSPEND */
#ifdef CONFIG_HIBERNATE_CALLBACKS
case PM_EVENT_FREEZE:
case PM_EVENT_QUIESCE:
return ops->freeze_noirq;
case PM_EVENT_HIBERNATE:
return ops->poweroff_noirq;
case PM_EVENT_THAW:
case PM_EVENT_RECOVER:
return ops->thaw_noirq;
case PM_EVENT_RESTORE:
return ops->restore_noirq;
#endif /* CONFIG_HIBERNATE_CALLBACKS */
}
return NULL;
}
static void pm_dev_dbg(struct device *dev, pm_message_t state, const char *info)
{
dev_dbg(dev, "%s%s%s driver flags: %x\n", info, pm_verb(state.event),
((state.event & PM_EVENT_SLEEP) && device_may_wakeup(dev)) ?
", may wakeup" : "", dev->power.driver_flags);
}
static void pm_dev_err(struct device *dev, pm_message_t state, const char *info,
int error)
{
dev_err(dev, "failed to %s%s: error %d\n", pm_verb(state.event), info,
error);
}
static void dpm_show_time(ktime_t starttime, pm_message_t state, int error,
const char *info)
{
ktime_t calltime;
u64 usecs64;
int usecs;
calltime = ktime_get();
usecs64 = ktime_to_ns(ktime_sub(calltime, starttime));
do_div(usecs64, NSEC_PER_USEC);
usecs = usecs64;
if (usecs == 0)
usecs = 1;
pm_pr_dbg("%s%s%s of devices %s after %ld.%03ld msecs\n",
info ?: "", info ? " " : "", pm_verb(state.event),
error ? "aborted" : "complete",
usecs / USEC_PER_MSEC, usecs % USEC_PER_MSEC);
}
static int dpm_run_callback(pm_callback_t cb, struct device *dev,
pm_message_t state, const char *info)
{
ktime_t calltime;
int error;
if (!cb)
return 0;
calltime = initcall_debug_start(dev, cb);
pm_dev_dbg(dev, state, info);
trace_device_pm_callback_start(dev, info, state.event);
error = cb(dev);
trace_device_pm_callback_end(dev, error);
suspend_report_result(dev, cb, error);
initcall_debug_report(dev, calltime, cb, error);
return error;
}
#ifdef CONFIG_DPM_WATCHDOG
struct dpm_watchdog {
struct device *dev;
struct task_struct *tsk;
struct timer_list timer;
};
#define DECLARE_DPM_WATCHDOG_ON_STACK(wd) \
struct dpm_watchdog wd
/**
* dpm_watchdog_handler - Driver suspend / resume watchdog handler.
* @t: The timer that PM watchdog depends on.
*
* Called when a driver has timed out suspending or resuming.
* There's not much we can do here to recover so panic() to
* capture a crash-dump in pstore.
*/
static void dpm_watchdog_handler(struct timer_list *t)
{
struct dpm_watchdog *wd = from_timer(wd, t, timer);
dev_emerg(wd->dev, "**** DPM device timeout ****\n");
show_stack(wd->tsk, NULL, KERN_EMERG);
panic("%s %s: unrecoverable failure\n",
dev_driver_string(wd->dev), dev_name(wd->dev));
}
/**
* dpm_watchdog_set - Enable pm watchdog for given device.
* @wd: Watchdog. Must be allocated on the stack.
* @dev: Device to handle.
*/
static void dpm_watchdog_set(struct dpm_watchdog *wd, struct device *dev)
{
struct timer_list *timer = &wd->timer;
wd->dev = dev;
wd->tsk = current;
timer_setup_on_stack(timer, dpm_watchdog_handler, 0);
/* use same timeout value for both suspend and resume */
timer->expires = jiffies + HZ * CONFIG_DPM_WATCHDOG_TIMEOUT;
add_timer(timer);
}
/**
* dpm_watchdog_clear - Disable suspend/resume watchdog.
* @wd: Watchdog to disable.
*/
static void dpm_watchdog_clear(struct dpm_watchdog *wd)
{
struct timer_list *timer = &wd->timer;
del_timer_sync(timer);
destroy_timer_on_stack(timer);
}
#else
#define DECLARE_DPM_WATCHDOG_ON_STACK(wd)
#define dpm_watchdog_set(x, y)
#define dpm_watchdog_clear(x)
#endif
/*------------------------- Resume routines -------------------------*/
/**
* dev_pm_skip_resume - System-wide device resume optimization check.
* @dev: Target device.
*
* Return:
* - %false if the transition under way is RESTORE.
* - Return value of dev_pm_skip_suspend() if the transition under way is THAW.
* - The logical negation of %power.must_resume otherwise (that is, when the
* transition under way is RESUME).
*/
bool dev_pm_skip_resume(struct device *dev)
{
if (pm_transition.event == PM_EVENT_RESTORE)
return false;
if (pm_transition.event == PM_EVENT_THAW)
return dev_pm_skip_suspend(dev);
return !dev->power.must_resume;
}
static bool is_async(struct device *dev)
{
return dev->power.async_suspend && pm_async_enabled
&& !pm_trace_is_enabled();
}
static bool dpm_async_fn(struct device *dev, async_func_t func)
{
reinit_completion(&dev->power.completion);
if (is_async(dev)) {
dev->power.async_in_progress = true;
get_device(dev);
if (async_schedule_dev_nocall(func, dev))
return true;
put_device(dev);
}
/*
* Because async_schedule_dev_nocall() above has returned false or it
* has not been called at all, func() is not running and it is safe to
* update the async_in_progress flag without extra synchronization.
*/
dev->power.async_in_progress = false;
return false;
}
/**
* device_resume_noirq - Execute a "noirq resume" callback for given device.
* @dev: Device to handle.
* @state: PM transition of the system being carried out.
* @async: If true, the device is being resumed asynchronously.
*
* The driver of @dev will not receive interrupts while this function is being
* executed.
*/
static void device_resume_noirq(struct device *dev, pm_message_t state, bool async)
{
pm_callback_t callback = NULL;
const char *info = NULL;
bool skip_resume;
int error = 0;
TRACE_DEVICE(dev);
TRACE_RESUME(0);
if (dev->power.syscore || dev->power.direct_complete)
goto Out;
if (!dev->power.is_noirq_suspended)
goto Out;
if (!dpm_wait_for_superior(dev, async))
goto Out;
skip_resume = dev_pm_skip_resume(dev);
/*
* If the driver callback is skipped below or by the middle layer
* callback and device_resume_early() also skips the driver callback for
* this device later, it needs to appear as "suspended" to PM-runtime,
* so change its status accordingly.
*
* Otherwise, the device is going to be resumed, so set its PM-runtime
* status to "active", but do that only if DPM_FLAG_SMART_SUSPEND is set
* to avoid confusing drivers that don't use it.
*/
if (skip_resume)
pm_runtime_set_suspended(dev);
else if (dev_pm_skip_suspend(dev))
pm_runtime_set_active(dev);
if (dev->pm_domain) {
info = "noirq power domain ";
callback = pm_noirq_op(&dev->pm_domain->ops, state);
} else if (dev->type && dev->type->pm) {
info = "noirq type ";
callback = pm_noirq_op(dev->type->pm, state);
} else if (dev->class && dev->class->pm) {
info = "noirq class ";
callback = pm_noirq_op(dev->class->pm, state);
} else if (dev->bus && dev->bus->pm) {
info = "noirq bus ";
callback = pm_noirq_op(dev->bus->pm, state);
}
if (callback)
goto Run;
if (skip_resume)
goto Skip;
if (dev->driver && dev->driver->pm) {
info = "noirq driver ";
callback = pm_noirq_op(dev->driver->pm, state);
}
Run:
error = dpm_run_callback(callback, dev, state, info);
Skip:
dev->power.is_noirq_suspended = false;
Out:
complete_all(&dev->power.completion);
TRACE_RESUME(error);
if (error) {
async_error = error;
dpm_save_failed_dev(dev_name(dev));
pm_dev_err(dev, state, async ? " async noirq" : " noirq", error);
}
}
static void async_resume_noirq(void *data, async_cookie_t cookie)
{
struct device *dev = data;
device_resume_noirq(dev, pm_transition, true);
put_device(dev);
}
static void dpm_noirq_resume_devices(pm_message_t state)
{
struct device *dev;
ktime_t starttime = ktime_get();
trace_suspend_resume(TPS("dpm_resume_noirq"), state.event, true);
async_error = 0;
pm_transition = state;
mutex_lock(&dpm_list_mtx);
/*
* Trigger the resume of "async" devices upfront so they don't have to
* wait for the "non-async" ones they don't depend on.
*/
list_for_each_entry(dev, &dpm_noirq_list, power.entry)
dpm_async_fn(dev, async_resume_noirq);
while (!list_empty(&dpm_noirq_list)) {
dev = to_device(dpm_noirq_list.next);
list_move_tail(&dev->power.entry, &dpm_late_early_list);
if (!dev->power.async_in_progress) {
get_device(dev);
mutex_unlock(&dpm_list_mtx);
device_resume_noirq(dev, state, false);
put_device(dev);
mutex_lock(&dpm_list_mtx);
}
}
mutex_unlock(&dpm_list_mtx);
async_synchronize_full();
dpm_show_time(starttime, state, 0, "noirq");
if (async_error)
dpm_save_failed_step(SUSPEND_RESUME_NOIRQ);
trace_suspend_resume(TPS("dpm_resume_noirq"), state.event, false);
}
/**
* dpm_resume_noirq - Execute "noirq resume" callbacks for all devices.
* @state: PM transition of the system being carried out.
*
* Invoke the "noirq" resume callbacks for all devices in dpm_noirq_list and
* allow device drivers' interrupt handlers to be called.
*/
void dpm_resume_noirq(pm_message_t state)
{
dpm_noirq_resume_devices(state);
resume_device_irqs();
device_wakeup_disarm_wake_irqs();
}
/**
* device_resume_early - Execute an "early resume" callback for given device.
* @dev: Device to handle.
* @state: PM transition of the system being carried out.
* @async: If true, the device is being resumed asynchronously.
*
* Runtime PM is disabled for @dev while this function is being executed.
*/
static void device_resume_early(struct device *dev, pm_message_t state, bool async)
{
pm_callback_t callback = NULL;
const char *info = NULL;
int error = 0;
TRACE_DEVICE(dev);
TRACE_RESUME(0);
if (dev->power.syscore || dev->power.direct_complete)
goto Out;
if (!dev->power.is_late_suspended)
goto Out;
if (!dpm_wait_for_superior(dev, async))
goto Out;
if (dev->pm_domain) {
info = "early power domain ";
callback = pm_late_early_op(&dev->pm_domain->ops, state);
} else if (dev->type && dev->type->pm) {
info = "early type ";
callback = pm_late_early_op(dev->type->pm, state);
} else if (dev->class && dev->class->pm) {
info = "early class ";
callback = pm_late_early_op(dev->class->pm, state);
} else if (dev->bus && dev->bus->pm) {
info = "early bus ";
callback = pm_late_early_op(dev->bus->pm, state);
}
if (callback)
goto Run;
if (dev_pm_skip_resume(dev))
goto Skip;
if (dev->driver && dev->driver->pm) {
info = "early driver ";
callback = pm_late_early_op(dev->driver->pm, state);
}
Run:
error = dpm_run_callback(callback, dev, state, info);
Skip:
dev->power.is_late_suspended = false;
Out:
TRACE_RESUME(error);
pm_runtime_enable(dev);
complete_all(&dev->power.completion);
if (error) {
async_error = error;
dpm_save_failed_dev(dev_name(dev));
pm_dev_err(dev, state, async ? " async early" : " early", error);
}
}
static void async_resume_early(void *data, async_cookie_t cookie)
{
struct device *dev = data;
device_resume_early(dev, pm_transition, true);
put_device(dev);
}
/**
* dpm_resume_early - Execute "early resume" callbacks for all devices.
* @state: PM transition of the system being carried out.
*/
void dpm_resume_early(pm_message_t state)
{
struct device *dev;
ktime_t starttime = ktime_get();
trace_suspend_resume(TPS("dpm_resume_early"), state.event, true);
async_error = 0;
pm_transition = state;
mutex_lock(&dpm_list_mtx);
/*
* Trigger the resume of "async" devices upfront so they don't have to
* wait for the "non-async" ones they don't depend on.
*/
list_for_each_entry(dev, &dpm_late_early_list, power.entry)
dpm_async_fn(dev, async_resume_early);
while (!list_empty(&dpm_late_early_list)) {
dev = to_device(dpm_late_early_list.next);
list_move_tail(&dev->power.entry, &dpm_suspended_list);
if (!dev->power.async_in_progress) {
get_device(dev);
mutex_unlock(&dpm_list_mtx);
device_resume_early(dev, state, false);
put_device(dev);
mutex_lock(&dpm_list_mtx);
}
}
mutex_unlock(&dpm_list_mtx);
async_synchronize_full();
dpm_show_time(starttime, state, 0, "early");
if (async_error)
dpm_save_failed_step(SUSPEND_RESUME_EARLY);
trace_suspend_resume(TPS("dpm_resume_early"), state.event, false);
}
/**
* dpm_resume_start - Execute "noirq" and "early" device callbacks.
* @state: PM transition of the system being carried out.
*/
void dpm_resume_start(pm_message_t state)
{
dpm_resume_noirq(state);
dpm_resume_early(state);
}
EXPORT_SYMBOL_GPL(dpm_resume_start);
/**
* device_resume - Execute "resume" callbacks for given device.
* @dev: Device to handle.
* @state: PM transition of the system being carried out.
* @async: If true, the device is being resumed asynchronously.
*/
static void device_resume(struct device *dev, pm_message_t state, bool async)
{
pm_callback_t callback = NULL;
const char *info = NULL;
int error = 0;
DECLARE_DPM_WATCHDOG_ON_STACK(wd);
TRACE_DEVICE(dev);
TRACE_RESUME(0);
if (dev->power.syscore)
goto Complete;
if (dev->power.direct_complete) {
/* Match the pm_runtime_disable() in __device_suspend(). */
pm_runtime_enable(dev);
goto Complete;
}
if (!dpm_wait_for_superior(dev, async))
goto Complete;
dpm_watchdog_set(&wd, dev);
device_lock(dev);
/*
* This is a fib. But we'll allow new children to be added below
* a resumed device, even if the device hasn't been completed yet.
*/
dev->power.is_prepared = false;
if (!dev->power.is_suspended)
goto Unlock;
if (dev->pm_domain) {
info = "power domain ";
callback = pm_op(&dev->pm_domain->ops, state);
goto Driver;
}
if (dev->type && dev->type->pm) {
info = "type ";
callback = pm_op(dev->type->pm, state);
goto Driver;
}
if (dev->class && dev->class->pm) {
info = "class ";
callback = pm_op(dev->class->pm, state);
goto Driver;
}
if (dev->bus) {
if (dev->bus->pm) {
info = "bus ";
callback = pm_op(dev->bus->pm, state);
} else if (dev->bus->resume) {
info = "legacy bus ";
callback = dev->bus->resume;
goto End;
}
}
Driver:
if (!callback && dev->driver && dev->driver->pm) {
info = "driver ";
callback = pm_op(dev->driver->pm, state);
}
End:
error = dpm_run_callback(callback, dev, state, info);
dev->power.is_suspended = false;
Unlock:
device_unlock(dev);
dpm_watchdog_clear(&wd);
Complete:
complete_all(&dev->power.completion);
TRACE_RESUME(error);
if (error) {
async_error = error;
dpm_save_failed_dev(dev_name(dev));
pm_dev_err(dev, state, async ? " async" : "", error);
}
}
static void async_resume(void *data, async_cookie_t cookie)
{
struct device *dev = data;
device_resume(dev, pm_transition, true);
put_device(dev);
}
/**
* dpm_resume - Execute "resume" callbacks for non-sysdev devices.
* @state: PM transition of the system being carried out.
*
* Execute the appropriate "resume" callback for all devices whose status
* indicates that they are suspended.
*/
void dpm_resume(pm_message_t state)
{
struct device *dev;
ktime_t starttime = ktime_get();
trace_suspend_resume(TPS("dpm_resume"), state.event, true);
might_sleep();
pm_transition = state;
async_error = 0;
mutex_lock(&dpm_list_mtx);
/*
* Trigger the resume of "async" devices upfront so they don't have to
* wait for the "non-async" ones they don't depend on.
*/
list_for_each_entry(dev, &dpm_suspended_list, power.entry)
dpm_async_fn(dev, async_resume);
while (!list_empty(&dpm_suspended_list)) {
dev = to_device(dpm_suspended_list.next);
list_move_tail(&dev->power.entry, &dpm_prepared_list);
if (!dev->power.async_in_progress) {
get_device(dev);
mutex_unlock(&dpm_list_mtx);
device_resume(dev, state, false);
put_device(dev);
mutex_lock(&dpm_list_mtx);
}
}
mutex_unlock(&dpm_list_mtx);
async_synchronize_full();
dpm_show_time(starttime, state, 0, NULL);
if (async_error)
dpm_save_failed_step(SUSPEND_RESUME);
cpufreq_resume();
devfreq_resume();
trace_suspend_resume(TPS("dpm_resume"), state.event, false);
}
/**
* device_complete - Complete a PM transition for given device.
* @dev: Device to handle.
* @state: PM transition of the system being carried out.
*/
static void device_complete(struct device *dev, pm_message_t state)
{
void (*callback)(struct device *) = NULL;
const char *info = NULL;
if (dev->power.syscore)
goto out;
device_lock(dev);
if (dev->pm_domain) {
info = "completing power domain ";
callback = dev->pm_domain->ops.complete;
} else if (dev->type && dev->type->pm) {
info = "completing type ";
callback = dev->type->pm->complete;
} else if (dev->class && dev->class->pm) {
info = "completing class ";
callback = dev->class->pm->complete;
} else if (dev->bus && dev->bus->pm) {
info = "completing bus ";
callback = dev->bus->pm->complete;
}
if (!callback && dev->driver && dev->driver->pm) {
info = "completing driver ";
callback = dev->driver->pm->complete;
}
if (callback) {
pm_dev_dbg(dev, state, info);
callback(dev);
}
device_unlock(dev);
out:
pm_runtime_put(dev);
}
/**
* dpm_complete - Complete a PM transition for all non-sysdev devices.
* @state: PM transition of the system being carried out.
*
* Execute the ->complete() callbacks for all devices whose PM status is not
* DPM_ON (this allows new devices to be registered).
*/
void dpm_complete(pm_message_t state)
{
struct list_head list;
trace_suspend_resume(TPS("dpm_complete"), state.event, true);
might_sleep();
INIT_LIST_HEAD(&list);
mutex_lock(&dpm_list_mtx);
while (!list_empty(&dpm_prepared_list)) {
struct device *dev = to_device(dpm_prepared_list.prev);
get_device(dev);
dev->power.is_prepared = false;
list_move(&dev->power.entry, &list);
mutex_unlock(&dpm_list_mtx);
trace_device_pm_callback_start(dev, "", state.event);
device_complete(dev, state);
trace_device_pm_callback_end(dev, 0);
put_device(dev);
mutex_lock(&dpm_list_mtx);
}
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);
}
/**
* dpm_resume_end - Execute "resume" callbacks and complete system transition.
* @state: PM transition of the system being carried out.
*
* Execute "resume" callbacks for all devices and complete the PM transition of
* the system.
*/
void dpm_resume_end(pm_message_t state)
{
dpm_resume(state);
dpm_complete(state);
}
EXPORT_SYMBOL_GPL(dpm_resume_end);
/*------------------------- Suspend routines -------------------------*/
/**
* resume_event - Return a "resume" message for given "suspend" sleep state.
* @sleep_state: PM message representing a sleep state.
*
* Return a PM message representing the resume event corresponding to given
* sleep state.
*/
static pm_message_t resume_event(pm_message_t sleep_state)
{
switch (sleep_state.event) {
case PM_EVENT_SUSPEND:
return PMSG_RESUME;
case PM_EVENT_FREEZE:
case PM_EVENT_QUIESCE:
return PMSG_RECOVER;
case PM_EVENT_HIBERNATE:
return PMSG_RESTORE;
}
return PMSG_ON;
}
static void dpm_superior_set_must_resume(struct device *dev)
{
struct device_link *link;
int idx;
if (dev->parent)
dev->parent->power.must_resume = true;
idx = device_links_read_lock();
list_for_each_entry_rcu_locked(link, &dev->links.suppliers, c_node)
link->supplier->power.must_resume = true;
device_links_read_unlock(idx);
}
/**
* device_suspend_noirq - Execute a "noirq suspend" callback for given device.
* @dev: Device to handle.
* @state: PM transition of the system being carried out.
* @async: If true, the device is being suspended asynchronously.
*
* The driver of @dev will not receive interrupts while this function is being
* executed.
*/
static int device_suspend_noirq(struct device *dev, pm_message_t state, bool async)
{
pm_callback_t callback = NULL;
const char *info = NULL;
int error = 0;
TRACE_DEVICE(dev);
TRACE_SUSPEND(0);
dpm_wait_for_subordinate(dev, async);
if (async_error)
goto Complete;
if (dev->power.syscore || dev->power.direct_complete)
goto Complete;
if (dev->pm_domain) {
info = "noirq power domain ";
callback = pm_noirq_op(&dev->pm_domain->ops, state);
} else if (dev->type && dev->type->pm) {
info = "noirq type ";
callback = pm_noirq_op(dev->type->pm, state);
} else if (dev->class && dev->class->pm) {
info = "noirq class ";
callback = pm_noirq_op(dev->class->pm, state);
} else if (dev->bus && dev->bus->pm) {
info = "noirq bus ";
callback = pm_noirq_op(dev->bus->pm, state);
}
if (callback)
goto Run;
if (dev_pm_skip_suspend(dev))
goto Skip;
if (dev->driver && dev->driver->pm) {
info = "noirq driver ";
callback = pm_noirq_op(dev->driver->pm, state);
}
Run:
error = dpm_run_callback(callback, dev, state, info);
if (error) {
async_error = error;
dpm_save_failed_dev(dev_name(dev));
pm_dev_err(dev, state, async ? " async noirq" : " noirq", error);
goto Complete;
}
Skip:
dev->power.is_noirq_suspended = true;
/*
* Skipping the resume of devices that were in use right before the
* system suspend (as indicated by their PM-runtime usage counters)
* would be suboptimal. Also resume them if doing that is not allowed
* to be skipped.
*/
if (atomic_read(&dev->power.usage_count) > 1 ||
!(dev_pm_test_driver_flags(dev, DPM_FLAG_MAY_SKIP_RESUME) &&
dev->power.may_skip_resume))
dev->power.must_resume = true;
if (dev->power.must_resume)
dpm_superior_set_must_resume(dev);
Complete:
complete_all(&dev->power.completion);
TRACE_SUSPEND(error);
return error;
}
static void async_suspend_noirq(void *data, async_cookie_t cookie)
{
struct device *dev = data;
device_suspend_noirq(dev, pm_transition, true);
put_device(dev);
}
static int dpm_noirq_suspend_devices(pm_message_t state)
{
ktime_t starttime = ktime_get();
int error = 0;
trace_suspend_resume(TPS("dpm_suspend_noirq"), state.event, true);
pm_transition = state;
async_error = 0;
mutex_lock(&dpm_list_mtx);
while (!list_empty(&dpm_late_early_list)) {
struct device *dev = to_device(dpm_late_early_list.prev);
list_move(&dev->power.entry, &dpm_noirq_list);
if (dpm_async_fn(dev, async_suspend_noirq))
continue;
get_device(dev);
mutex_unlock(&dpm_list_mtx);
error = device_suspend_noirq(dev, state, false);
put_device(dev);
mutex_lock(&dpm_list_mtx);
if (error || async_error)
break;
}
mutex_unlock(&dpm_list_mtx);
async_synchronize_full();
if (!error)
error = async_error;
if (error)
dpm_save_failed_step(SUSPEND_SUSPEND_NOIRQ);
dpm_show_time(starttime, state, error, "noirq");
trace_suspend_resume(TPS("dpm_suspend_noirq"), state.event, false);
return error;
}
/**
* dpm_suspend_noirq - Execute "noirq suspend" callbacks for all devices.
* @state: PM transition of the system being carried out.
*
* Prevent device drivers' interrupt handlers from being called and invoke
* "noirq" suspend callbacks for all non-sysdev devices.
*/
int dpm_suspend_noirq(pm_message_t state)
{
int ret;
device_wakeup_arm_wake_irqs();
suspend_device_irqs();
ret = dpm_noirq_suspend_devices(state);
if (ret)
dpm_resume_noirq(resume_event(state));
return ret;
}
static void dpm_propagate_wakeup_to_parent(struct device *dev)
{
struct device *parent = dev->parent;
if (!parent)
return;
spin_lock_irq(&parent->power.lock);
if (device_wakeup_path(dev) && !parent->power.ignore_children)
parent->power.wakeup_path = true;
spin_unlock_irq(&parent->power.lock);
}
/**
* device_suspend_late - Execute a "late suspend" callback for given device.
* @dev: Device to handle.
* @state: PM transition of the system being carried out.
* @async: If true, the device is being suspended asynchronously.
*
* Runtime PM is disabled for @dev while this function is being executed.
*/
static int device_suspend_late(struct device *dev, pm_message_t state, bool async)
{
pm_callback_t callback = NULL;
const char *info = NULL;
int error = 0;
TRACE_DEVICE(dev);
TRACE_SUSPEND(0);
__pm_runtime_disable(dev, false);
dpm_wait_for_subordinate(dev, async);
if (async_error)
goto Complete;
if (pm_wakeup_pending()) {
async_error = -EBUSY;
goto Complete;
}
if (dev->power.syscore || dev->power.direct_complete)
goto Complete;
if (dev->pm_domain) {
info = "late power domain ";
callback = pm_late_early_op(&dev->pm_domain->ops, state);
} else if (dev->type && dev->type->pm) {
info = "late type ";
callback = pm_late_early_op(dev->type->pm, state);
} else if (dev->class && dev->class->pm) {
info = "late class ";
callback = pm_late_early_op(dev->class->pm, state);
} else if (dev->bus && dev->bus->pm) {
info = "late bus ";
callback = pm_late_early_op(dev->bus->pm, state);
}
if (callback)
goto Run;
if (dev_pm_skip_suspend(dev))
goto Skip;
if (dev->driver && dev->driver->pm) {
info = "late driver ";
callback = pm_late_early_op(dev->driver->pm, state);
}
Run:
error = dpm_run_callback(callback, dev, state, info);
if (error) {
async_error = error;
dpm_save_failed_dev(dev_name(dev));
pm_dev_err(dev, state, async ? " async late" : " late", error);
goto Complete;
}
dpm_propagate_wakeup_to_parent(dev);
Skip:
dev->power.is_late_suspended = true;
Complete:
TRACE_SUSPEND(error);
complete_all(&dev->power.completion);
return error;
}
static void async_suspend_late(void *data, async_cookie_t cookie)
{
struct device *dev = data;
device_suspend_late(dev, pm_transition, true);
put_device(dev);
}
/**
* dpm_suspend_late - Execute "late suspend" callbacks for all devices.
* @state: PM transition of the system being carried out.
*/
int dpm_suspend_late(pm_message_t state)
{
ktime_t starttime = ktime_get();
int error = 0;
trace_suspend_resume(TPS("dpm_suspend_late"), state.event, true);
pm_transition = state;
async_error = 0;
wake_up_all_idle_cpus();
mutex_lock(&dpm_list_mtx);
while (!list_empty(&dpm_suspended_list)) {
struct device *dev = to_device(dpm_suspended_list.prev);
list_move(&dev->power.entry, &dpm_late_early_list);
if (dpm_async_fn(dev, async_suspend_late))
continue;
get_device(dev);
mutex_unlock(&dpm_list_mtx);
error = device_suspend_late(dev, state, false);
put_device(dev);
mutex_lock(&dpm_list_mtx);
if (error || async_error)
break;
}
mutex_unlock(&dpm_list_mtx);
async_synchronize_full();
if (!error)
error = async_error;
if (error) {
dpm_save_failed_step(SUSPEND_SUSPEND_LATE);
dpm_resume_early(resume_event(state));
}
dpm_show_time(starttime, state, error, "late");
trace_suspend_resume(TPS("dpm_suspend_late"), state.event, false);
return error;
}
/**
* dpm_suspend_end - Execute "late" and "noirq" device suspend callbacks.
* @state: PM transition of the system being carried out.
*/
int dpm_suspend_end(pm_message_t state)
{
ktime_t starttime = ktime_get();
int error;
error = dpm_suspend_late(state);
if (error)
goto out;
error = dpm_suspend_noirq(state);
if (error)
dpm_resume_early(resume_event(state));
out:
dpm_show_time(starttime, state, error, "end");
return error;
}
EXPORT_SYMBOL_GPL(dpm_suspend_end);
/**
* legacy_suspend - Execute a legacy (bus or class) suspend callback for device.
* @dev: Device to suspend.
* @state: PM transition of the system being carried out.
* @cb: Suspend callback to execute.
* @info: string description of caller.
*/
static int legacy_suspend(struct device *dev, pm_message_t state,
int (*cb)(struct device *dev, pm_message_t state),
const char *info)
{
int error;
ktime_t calltime;
calltime = initcall_debug_start(dev, cb);
trace_device_pm_callback_start(dev, info, state.event);
error = cb(dev, state);
trace_device_pm_callback_end(dev, error);
suspend_report_result(dev, cb, error);
initcall_debug_report(dev, calltime, cb, error);
return error;
}
static void dpm_clear_superiors_direct_complete(struct device *dev)
{
struct device_link *link;
int idx;
if (dev->parent) {
spin_lock_irq(&dev->parent->power.lock);
dev->parent->power.direct_complete = false;
spin_unlock_irq(&dev->parent->power.lock);
}
idx = device_links_read_lock();
list_for_each_entry_rcu_locked(link, &dev->links.suppliers, c_node) {
spin_lock_irq(&link->supplier->power.lock);
link->supplier->power.direct_complete = false;
spin_unlock_irq(&link->supplier->power.lock);
}
device_links_read_unlock(idx);
}
/**
* device_suspend - Execute "suspend" callbacks for given device.
* @dev: Device to handle.
* @state: PM transition of the system being carried out.
* @async: If true, the device is being suspended asynchronously.
*/
static int device_suspend(struct device *dev, pm_message_t state, bool async)
{
pm_callback_t callback = NULL;
const char *info = NULL;
int error = 0;
DECLARE_DPM_WATCHDOG_ON_STACK(wd);
TRACE_DEVICE(dev);
TRACE_SUSPEND(0);
dpm_wait_for_subordinate(dev, async);
if (async_error) {
dev->power.direct_complete = false;
goto Complete;
}
/*
* Wait for possible runtime PM transitions of the device in progress
* to complete and if there's a runtime resume request pending for it,
* resume it before proceeding with invoking the system-wide suspend
* callbacks for it.
*
* If the system-wide suspend callbacks below change the configuration
* of the device, they must disable runtime PM for it or otherwise
* ensure that its runtime-resume callbacks will not be confused by that
* change in case they are invoked going forward.
*/
pm_runtime_barrier(dev);
if (pm_wakeup_pending()) {
dev->power.direct_complete = false;
async_error = -EBUSY;
goto Complete;
}
if (dev->power.syscore)
goto Complete;
/* Avoid direct_complete to let wakeup_path propagate. */
if (device_may_wakeup(dev) || device_wakeup_path(dev))
dev->power.direct_complete = false;
if (dev->power.direct_complete) {
if (pm_runtime_status_suspended(dev)) {
pm_runtime_disable(dev);
if (pm_runtime_status_suspended(dev)) {
pm_dev_dbg(dev, state, "direct-complete ");
goto Complete;
}
pm_runtime_enable(dev);
}
dev->power.direct_complete = false;
}
dev->power.may_skip_resume = true;
dev->power.must_resume = !dev_pm_test_driver_flags(dev, DPM_FLAG_MAY_SKIP_RESUME);
dpm_watchdog_set(&wd, dev);
device_lock(dev);
if (dev->pm_domain) {
info = "power domain ";
callback = pm_op(&dev->pm_domain->ops, state);
goto Run;
}
if (dev->type && dev->type->pm) {
info = "type ";
callback = pm_op(dev->type->pm, state);
goto Run;
}
if (dev->class && dev->class->pm) {
info = "class ";
callback = pm_op(dev->class->pm, state);
goto Run;
}
if (dev->bus) {
if (dev->bus->pm) {
info = "bus ";
callback = pm_op(dev->bus->pm, state);
} else if (dev->bus->suspend) {
pm_dev_dbg(dev, state, "legacy bus ");
error = legacy_suspend(dev, state, dev->bus->suspend,
"legacy bus ");
goto End;
}
}
Run:
if (!callback && dev->driver && dev->driver->pm) {
info = "driver ";
callback = pm_op(dev->driver->pm, state);
}
error = dpm_run_callback(callback, dev, state, info);
End:
if (!error) {
dev->power.is_suspended = true;
if (device_may_wakeup(dev))
dev->power.wakeup_path = true;
dpm_propagate_wakeup_to_parent(dev);
dpm_clear_superiors_direct_complete(dev);
}
device_unlock(dev);
dpm_watchdog_clear(&wd);
Complete:
if (error) {
async_error = error;
dpm_save_failed_dev(dev_name(dev));
pm_dev_err(dev, state, async ? " async" : "", error);
}
complete_all(&dev->power.completion);
TRACE_SUSPEND(error);
return error;
}
static void async_suspend(void *data, async_cookie_t cookie)
{
struct device *dev = data;
device_suspend(dev, pm_transition, true);
put_device(dev);
}
/**
* dpm_suspend - Execute "suspend" callbacks for all non-sysdev devices.
* @state: PM transition of the system being carried out.
*/
int dpm_suspend(pm_message_t state)
{
ktime_t starttime = ktime_get();
int error = 0;
trace_suspend_resume(TPS("dpm_suspend"), state.event, true);
might_sleep();
devfreq_suspend();
cpufreq_suspend();
pm_transition = state;
async_error = 0;
mutex_lock(&dpm_list_mtx);
while (!list_empty(&dpm_prepared_list)) {
struct device *dev = to_device(dpm_prepared_list.prev);
list_move(&dev->power.entry, &dpm_suspended_list);
if (dpm_async_fn(dev, async_suspend))
continue;
get_device(dev);
mutex_unlock(&dpm_list_mtx);
error = device_suspend(dev, state, false);
put_device(dev);
mutex_lock(&dpm_list_mtx);
if (error || async_error)
break;
}
mutex_unlock(&dpm_list_mtx);
async_synchronize_full();
if (!error)
error = async_error;
if (error)
dpm_save_failed_step(SUSPEND_SUSPEND);
dpm_show_time(starttime, state, error, NULL);
trace_suspend_resume(TPS("dpm_suspend"), state.event, false);
return error;
}
/**
* device_prepare - Prepare a device for system power transition.
* @dev: Device to handle.
* @state: PM transition of the system being carried out.
*
* Execute the ->prepare() callback(s) for given device. No new children of the
* device may be registered after this function has returned.
*/
static int device_prepare(struct device *dev, pm_message_t state)
{
int (*callback)(struct device *) = NULL;
int ret = 0;
/*
* If a device's parent goes into runtime suspend at the wrong time,
* it won't be possible to resume the device. To prevent this we
* block runtime suspend here, during the prepare phase, and allow
* it again during the complete phase.
*/
pm_runtime_get_noresume(dev);
if (dev->power.syscore)
return 0;
device_lock(dev);
dev->power.wakeup_path = false;
if (dev->power.no_pm_callbacks)
goto unlock;
if (dev->pm_domain)
callback = dev->pm_domain->ops.prepare;
else if (dev->type && dev->type->pm)
callback = dev->type->pm->prepare;
else if (dev->class && dev->class->pm)
callback = dev->class->pm->prepare;
else if (dev->bus && dev->bus->pm)
callback = dev->bus->pm->prepare;
if (!callback && dev->driver && dev->driver->pm)
callback = dev->driver->pm->prepare;
if (callback)
ret = callback(dev);
unlock:
device_unlock(dev);
if (ret < 0) {
suspend_report_result(dev, callback, ret);
pm_runtime_put(dev);
return ret;
}
/*
* A positive return value from ->prepare() means "this device appears
* to be runtime-suspended and its state is fine, so if it really is
* runtime-suspended, you can leave it in that state provided that you
* will do the same thing with all of its descendants". This only
* applies to suspend transitions, however.
*/
spin_lock_irq(&dev->power.lock);
dev->power.direct_complete = state.event == PM_EVENT_SUSPEND &&
(ret > 0 || dev->power.no_pm_callbacks) &&
!dev_pm_test_driver_flags(dev, DPM_FLAG_NO_DIRECT_COMPLETE);
spin_unlock_irq(&dev->power.lock);
return 0;
}
/**
* dpm_prepare - Prepare all non-sysdev devices for a system PM transition.
* @state: PM transition of the system being carried out.
*
* Execute the ->prepare() callback(s) for all devices.
*/
int dpm_prepare(pm_message_t state)
{
int error = 0;
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) && !error) {
struct device *dev = to_device(dpm_list.next);
get_device(dev);
mutex_unlock(&dpm_list_mtx);
trace_device_pm_callback_start(dev, "", state.event);
error = device_prepare(dev, state);
trace_device_pm_callback_end(dev, error);
mutex_lock(&dpm_list_mtx);
if (!error) {
dev->power.is_prepared = true;
if (!list_empty(&dev->power.entry))
list_move_tail(&dev->power.entry, &dpm_prepared_list);
} else if (error == -EAGAIN) {
error = 0;
} else {
dev_info(dev, "not prepared for power transition: code %d\n",
error);
}
mutex_unlock(&dpm_list_mtx);
put_device(dev);
mutex_lock(&dpm_list_mtx);
}
mutex_unlock(&dpm_list_mtx);
trace_suspend_resume(TPS("dpm_prepare"), state.event, false);
return error;
}
/**
* dpm_suspend_start - Prepare devices for PM transition and suspend them.
* @state: PM transition of the system being carried out.
*
* Prepare all non-sysdev devices for system PM transition and execute "suspend"
* callbacks for them.
*/
int dpm_suspend_start(pm_message_t state)
{
ktime_t starttime = ktime_get();
int error;
error = dpm_prepare(state);
if (error)
dpm_save_failed_step(SUSPEND_PREPARE);
else
error = dpm_suspend(state);
dpm_show_time(starttime, state, error, "start");
return error;
}
EXPORT_SYMBOL_GPL(dpm_suspend_start);
void __suspend_report_result(const char *function, struct device *dev, void *fn, int ret)
{
if (ret)
dev_err(dev, "%s(): %ps returns %d\n", function, fn, ret);
}
EXPORT_SYMBOL_GPL(__suspend_report_result);
/**
* device_pm_wait_for_dev - Wait for suspend/resume of a device to complete.
* @subordinate: Device that needs to wait for @dev.
* @dev: Device to wait for.
*/
int device_pm_wait_for_dev(struct device *subordinate, struct device *dev)
{
dpm_wait(dev, subordinate->power.async_suspend);
return async_error;
}
EXPORT_SYMBOL_GPL(device_pm_wait_for_dev);
/**
* dpm_for_each_dev - device iterator.
* @data: data for the callback.
* @fn: function to be called for each device.
*
* Iterate over devices in dpm_list, and call @fn for each device,
* passing it @data.
*/
void dpm_for_each_dev(void *data, void (*fn)(struct device *, void *))
{
struct device *dev;
if (!fn)
return;
device_pm_lock();
list_for_each_entry(dev, &dpm_list, power.entry)
fn(dev, data);
device_pm_unlock();
}
EXPORT_SYMBOL_GPL(dpm_for_each_dev);
static bool pm_ops_is_empty(const struct dev_pm_ops *ops)
{
if (!ops)
return true;
return !ops->prepare &&
!ops->suspend &&
!ops->suspend_late &&
!ops->suspend_noirq &&
!ops->resume_noirq &&
!ops->resume_early &&
!ops->resume &&
!ops->complete;
}
void device_pm_check_callbacks(struct device *dev)
{
unsigned long flags;
spin_lock_irqsave(&dev->power.lock, flags);
dev->power.no_pm_callbacks =
(!dev->bus || (pm_ops_is_empty(dev->bus->pm) &&
!dev->bus->suspend && !dev->bus->resume)) &&
(!dev->class || pm_ops_is_empty(dev->class->pm)) &&
(!dev->type || pm_ops_is_empty(dev->type->pm)) &&
(!dev->pm_domain || pm_ops_is_empty(&dev->pm_domain->ops)) &&
(!dev->driver || (pm_ops_is_empty(dev->driver->pm) &&
!dev->driver->suspend && !dev->driver->resume));
spin_unlock_irqrestore(&dev->power.lock, flags);
}
bool dev_pm_skip_suspend(struct device *dev)
{
return dev_pm_test_driver_flags(dev, DPM_FLAG_SMART_SUSPEND) &&
pm_runtime_status_suspended(dev);
}
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