diff options
Diffstat (limited to 'drivers/base/power/main.c')
| -rw-r--r-- | drivers/base/power/main.c | 1690 |
1 files changed, 1456 insertions, 234 deletions
diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c index d887d5cb5be..bf412961a93 100644 --- a/drivers/base/power/main.c +++ b/drivers/base/power/main.c @@ -8,471 +8,1693 @@ * * * The driver model core calls device_pm_add() when a device is registered. - * This will intialize the embedded device_pm_info object in the device + * 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 different set of lists than the global subsystem list are used to - * keep track of power info because we use different lists to hold - * devices based on what stage of the power management process they - * are in. The power domain dependencies may also differ from the - * ancestral dependencies that the subsystem list maintains. + * 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. */ #include <linux/device.h> #include <linux/kallsyms.h> +#include <linux/export.h> #include <linux/mutex.h> #include <linux/pm.h> +#include <linux/pm_runtime.h> #include <linux/resume-trace.h> -#include <linux/rwsem.h> +#include <linux/interrupt.h> +#include <linux/sched.h> +#include <linux/async.h> +#include <linux/suspend.h> +#include <trace/events/power.h> +#include <linux/cpufreq.h> +#include <linux/cpuidle.h> +#include <linux/timer.h> #include "../base.h" #include "power.h" +typedef int (*pm_callback_t)(struct device *); + /* - * The entries in the dpm_active list are in a depth first order, simply + * 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. * - * All the other lists are kept in the same order, for consistency. - * However the lists aren't always traversed in the same order. - * Semaphores must be acquired from the top (i.e., front) down - * and released in the opposite order. Devices must be suspended - * from the bottom (i.e., end) up and resumed in the opposite order. - * That way no parent will be suspended while it still has an active - * child. - * - * Since device_pm_add() may be called with a device semaphore held, - * we must never try to acquire a device semaphore while holding + * 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_active); -static LIST_HEAD(dpm_off); -static LIST_HEAD(dpm_off_irq); -static LIST_HEAD(dpm_destroy); +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); +struct suspend_stats suspend_stats; static DEFINE_MUTEX(dpm_list_mtx); +static pm_message_t pm_transition; -static DECLARE_RWSEM(pm_sleep_rwsem); +static int async_error; -int (*platform_enable_wakeup)(struct device *dev, int is_on); +static 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_add - add a device to the list of active devices - * @dev: Device to be added to the list + * 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) { pr_debug("PM: Adding info for %s:%s\n", - dev->bus ? dev->bus->name : "No Bus", - kobject_name(&dev->kobj)); + dev->bus ? dev->bus->name : "No Bus", dev_name(dev)); mutex_lock(&dpm_list_mtx); - list_add_tail(&dev->power.entry, &dpm_active); + 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); mutex_unlock(&dpm_list_mtx); } /** - * device_pm_remove - remove a device from the list of active devices - * @dev: Device to be removed from the list - * - * This function also removes the device's PM-related sysfs attributes. + * 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) { pr_debug("PM: Removing info for %s:%s\n", - dev->bus ? dev->bus->name : "No Bus", - kobject_name(&dev->kobj)); + dev->bus ? dev->bus->name : "No Bus", dev_name(dev)); + complete_all(&dev->power.completion); mutex_lock(&dpm_list_mtx); - dpm_sysfs_remove(dev); list_del_init(&dev->power.entry); mutex_unlock(&dpm_list_mtx); + device_wakeup_disable(dev); + pm_runtime_remove(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("PM: 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_schedule_removal - schedule the removal of a suspended device - * @dev: Device to destroy + * 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("PM: 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("PM: 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) +{ + ktime_t calltime = ktime_set(0, 0); + + if (pm_print_times_enabled) { + pr_info("calling %s+ @ %i, parent: %s\n", + dev_name(dev), task_pid_nr(current), + dev->parent ? dev_name(dev->parent) : "none"); + calltime = ktime_get(); + } + + return calltime; +} + +static void initcall_debug_report(struct device *dev, ktime_t calltime, + int error, pm_message_t state, char *info) +{ + ktime_t rettime; + s64 nsecs; + + rettime = ktime_get(); + nsecs = (s64) ktime_to_ns(ktime_sub(rettime, calltime)); + + if (pm_print_times_enabled) { + pr_info("call %s+ returned %d after %Ld usecs\n", dev_name(dev), + error, (unsigned long long)nsecs >> 10); + } +} + +/** + * 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); +} + +/** + * 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; + break; + 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. * - * Moves the device to the dpm_destroy list for further processing by - * unregister_dropped_devices(). + * Runtime PM is disabled for @dev while this function is being executed. */ -void device_pm_schedule_removal(struct device *dev) +static pm_callback_t pm_late_early_op(const struct dev_pm_ops *ops, + pm_message_t state) { - pr_debug("PM: Preparing for removal: %s:%s\n", - dev->bus ? dev->bus->name : "No Bus", - kobject_name(&dev->kobj)); - mutex_lock(&dpm_list_mtx); - list_move_tail(&dev->power.entry, &dpm_destroy); - mutex_unlock(&dpm_list_mtx); + 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; } -EXPORT_SYMBOL_GPL(device_pm_schedule_removal); /** - * pm_sleep_lock - mutual exclusion for registration and suspend + * 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. * - * Returns 0 if no suspend is underway and device registration - * may proceed, otherwise -EBUSY. + * The driver of @dev will not receive interrupts while this function is being + * executed. */ -int pm_sleep_lock(void) +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, char *info) +{ + dev_dbg(dev, "%s%s%s\n", info, pm_verb(state.event), + ((state.event & PM_EVENT_SLEEP) && device_may_wakeup(dev)) ? + ", may wakeup" : ""); +} + +static void pm_dev_err(struct device *dev, pm_message_t state, char *info, + int error) { - if (down_read_trylock(&pm_sleep_rwsem)) + printk(KERN_ERR "PM: Device %s failed to %s%s: error %d\n", + dev_name(dev), pm_verb(state.event), info, error); +} + +static void dpm_show_time(ktime_t starttime, pm_message_t state, 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; + pr_info("PM: %s%s%s of devices complete after %ld.%03ld msecs\n", + info ?: "", info ? " " : "", pm_verb(state.event), + usecs / USEC_PER_MSEC, usecs % USEC_PER_MSEC); +} + +static int dpm_run_callback(pm_callback_t cb, struct device *dev, + pm_message_t state, char *info) +{ + ktime_t calltime; + int error; + + if (!cb) return 0; - return -EBUSY; + calltime = initcall_debug_start(dev); + + 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(cb, error); + + initcall_debug_report(dev, calltime, error, state, info); + + 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 + /** - * pm_sleep_unlock - mutual exclusion for registration and suspend + * dpm_watchdog_handler - Driver suspend / resume watchdog handler. + * @data: Watchdog object address. * - * This routine undoes the effect of device_pm_add_lock - * when a device's registration is complete. + * 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(unsigned long data) +{ + struct dpm_watchdog *wd = (void *)data; + + dev_emerg(wd->dev, "**** DPM device timeout ****\n"); + show_stack(wd->tsk, NULL); + 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. */ -void pm_sleep_unlock(void) +static void dpm_watchdog_set(struct dpm_watchdog *wd, struct device *dev) { - up_read(&pm_sleep_rwsem); + struct timer_list *timer = &wd->timer; + + wd->dev = dev; + wd->tsk = current; + + init_timer_on_stack(timer); + /* use same timeout value for both suspend and resume */ + timer->expires = jiffies + HZ * CONFIG_DPM_WATCHDOG_TIMEOUT; + timer->function = dpm_watchdog_handler; + timer->data = (unsigned long)wd; + 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 -------------------------*/ /** - * resume_device_early - Power on one device (early resume). - * @dev: Device. + * device_resume_noirq - Execute an "early resume" callback for given device. + * @dev: Device to handle. + * @state: PM transition of the system being carried out. * - * Must be called with interrupts disabled. + * The driver of @dev will not receive interrupts while this function is being + * executed. */ -static int resume_device_early(struct device *dev) +static int device_resume_noirq(struct device *dev, pm_message_t state, bool async) { + pm_callback_t callback = NULL; + char *info = NULL; int error = 0; TRACE_DEVICE(dev); TRACE_RESUME(0); - if (dev->bus && dev->bus->resume_early) { - dev_dbg(dev, "EARLY resume\n"); - error = dev->bus->resume_early(dev); + if (dev->power.syscore || dev->power.direct_complete) + goto Out; + + if (!dev->power.is_noirq_suspended) + goto Out; + + dpm_wait(dev->parent, async); + + 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 && dev->driver && dev->driver->pm) { + info = "noirq driver "; + callback = pm_noirq_op(dev->driver->pm, state); } + error = dpm_run_callback(callback, dev, state, info); + dev->power.is_noirq_suspended = false; + + Out: + complete_all(&dev->power.completion); TRACE_RESUME(error); return error; } +static bool is_async(struct device *dev) +{ + return dev->power.async_suspend && pm_async_enabled + && !pm_trace_is_enabled(); +} + +static void async_resume_noirq(void *data, async_cookie_t cookie) +{ + struct device *dev = (struct device *)data; + int error; + + error = device_resume_noirq(dev, pm_transition, true); + if (error) + pm_dev_err(dev, pm_transition, " async", error); + + put_device(dev); +} + /** - * dpm_power_up - Power on all regular (non-sysdev) devices. + * dpm_resume_noirq - Execute "noirq resume" callbacks for all devices. + * @state: PM transition of the system being carried out. * - * Walk the dpm_off_irq list and power each device up. This - * is used for devices that required they be powered down with - * interrupts disabled. As devices are powered on, they are moved - * to the dpm_off list. - * - * Must be called with interrupts disabled and only one CPU running. + * Call the "noirq" resume handlers for all devices in dpm_noirq_list and + * enable device drivers to receive interrupts. */ -static void dpm_power_up(void) +static void dpm_resume_noirq(pm_message_t state) { + struct device *dev; + ktime_t starttime = ktime_get(); - while (!list_empty(&dpm_off_irq)) { - struct list_head *entry = dpm_off_irq.next; - struct device *dev = to_device(entry); + trace_suspend_resume(TPS("dpm_resume_noirq"), state.event, true); + mutex_lock(&dpm_list_mtx); + pm_transition = state; - list_move_tail(entry, &dpm_off); - resume_device_early(dev); + /* + * Advanced the async threads upfront, + * in case the starting of async threads is + * delayed by non-async resuming devices. + */ + list_for_each_entry(dev, &dpm_noirq_list, power.entry) { + reinit_completion(&dev->power.completion); + if (is_async(dev)) { + get_device(dev); + async_schedule(async_resume_noirq, dev); + } } + + while (!list_empty(&dpm_noirq_list)) { + dev = to_device(dpm_noirq_list.next); + get_device(dev); + list_move_tail(&dev->power.entry, &dpm_late_early_list); + mutex_unlock(&dpm_list_mtx); + + if (!is_async(dev)) { + int error; + + error = device_resume_noirq(dev, state, false); + if (error) { + suspend_stats.failed_resume_noirq++; + dpm_save_failed_step(SUSPEND_RESUME_NOIRQ); + dpm_save_failed_dev(dev_name(dev)); + pm_dev_err(dev, state, " noirq", error); + } + } + + mutex_lock(&dpm_list_mtx); + put_device(dev); + } + mutex_unlock(&dpm_list_mtx); + async_synchronize_full(); + dpm_show_time(starttime, state, "noirq"); + resume_device_irqs(); + cpuidle_resume(); + trace_suspend_resume(TPS("dpm_resume_noirq"), state.event, false); } /** - * device_power_up - Turn on all devices that need special attention. + * device_resume_early - Execute an "early resume" callback for given device. + * @dev: Device to handle. + * @state: PM transition of the system being carried out. * - * Power on system devices, then devices that required we shut them down - * with interrupts disabled. - * - * Must be called with interrupts disabled. + * Runtime PM is disabled for @dev while this function is being executed. */ -void device_power_up(void) +static int device_resume_early(struct device *dev, pm_message_t state, bool async) +{ + pm_callback_t callback = NULL; + 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; + + dpm_wait(dev->parent, async); + + 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 && dev->driver && dev->driver->pm) { + info = "early driver "; + callback = pm_late_early_op(dev->driver->pm, state); + } + + error = dpm_run_callback(callback, dev, state, info); + dev->power.is_late_suspended = false; + + Out: + TRACE_RESUME(error); + + pm_runtime_enable(dev); + complete_all(&dev->power.completion); + return error; +} + +static void async_resume_early(void *data, async_cookie_t cookie) { - sysdev_resume(); - dpm_power_up(); + struct device *dev = (struct device *)data; + int error; + + error = device_resume_early(dev, pm_transition, true); + if (error) + pm_dev_err(dev, pm_transition, " async", error); + + put_device(dev); } -EXPORT_SYMBOL_GPL(device_power_up); /** - * resume_device - Restore state for one device. - * @dev: Device. - * + * dpm_resume_early - Execute "early resume" callbacks for all devices. + * @state: PM transition of the system being carried out. */ -static int resume_device(struct device *dev) +static 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); + mutex_lock(&dpm_list_mtx); + pm_transition = state; + + /* + * Advanced the async threads upfront, + * in case the starting of async threads is + * delayed by non-async resuming devices. + */ + list_for_each_entry(dev, &dpm_late_early_list, power.entry) { + reinit_completion(&dev->power.completion); + if (is_async(dev)) { + get_device(dev); + async_schedule(async_resume_early, dev); + } + } + + while (!list_empty(&dpm_late_early_list)) { + dev = to_device(dpm_late_early_list.next); + get_device(dev); + list_move_tail(&dev->power.entry, &dpm_suspended_list); + mutex_unlock(&dpm_list_mtx); + + if (!is_async(dev)) { + int error; + + error = device_resume_early(dev, state, false); + if (error) { + suspend_stats.failed_resume_early++; + dpm_save_failed_step(SUSPEND_RESUME_EARLY); + dpm_save_failed_dev(dev_name(dev)); + pm_dev_err(dev, state, " early", error); + } + } + mutex_lock(&dpm_list_mtx); + put_device(dev); + } + mutex_unlock(&dpm_list_mtx); + async_synchronize_full(); + dpm_show_time(starttime, state, "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 int device_resume(struct device *dev, pm_message_t state, bool async) +{ + pm_callback_t callback = NULL; + char *info = NULL; int error = 0; + DECLARE_DPM_WATCHDOG_ON_STACK(wd); TRACE_DEVICE(dev); TRACE_RESUME(0); - down(&dev->sem); + if (dev->power.syscore) + goto Complete; - if (dev->bus && dev->bus->resume) { - dev_dbg(dev,"resuming\n"); - error = dev->bus->resume(dev); + if (dev->power.direct_complete) { + /* Match the pm_runtime_disable() in __device_suspend(). */ + pm_runtime_enable(dev); + goto Complete; } - if (!error && dev->type && dev->type->resume) { - dev_dbg(dev,"resuming\n"); - error = dev->type->resume(dev); + dpm_wait(dev->parent, async); + 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) { + if (dev->class->pm) { + info = "class "; + callback = pm_op(dev->class->pm, state); + goto Driver; + } else if (dev->class->resume) { + info = "legacy class "; + callback = dev->class->resume; + goto End; + } } - if (!error && dev->class && dev->class->resume) { - dev_dbg(dev,"class resume\n"); - error = dev->class->resume(dev); + 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); } - up(&dev->sem); + 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); + return error; } +static void async_resume(void *data, async_cookie_t cookie) +{ + struct device *dev = (struct device *)data; + int error; + + error = device_resume(dev, pm_transition, true); + if (error) + pm_dev_err(dev, pm_transition, " async", error); + put_device(dev); +} + /** - * dpm_resume - Resume every device. - * - * Resume the devices that have either not gone through - * the late suspend, or that did go through it but also - * went through the early resume. + * dpm_resume - Execute "resume" callbacks for non-sysdev devices. + * @state: PM transition of the system being carried out. * - * Take devices from the dpm_off_list, resume them, - * and put them on the dpm_locked list. + * Execute the appropriate "resume" callback for all devices whose status + * indicates that they are suspended. */ -static void dpm_resume(void) +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(); + mutex_lock(&dpm_list_mtx); - while(!list_empty(&dpm_off)) { - struct list_head *entry = dpm_off.next; - struct device *dev = to_device(entry); + pm_transition = state; + async_error = 0; - list_move_tail(entry, &dpm_active); - mutex_unlock(&dpm_list_mtx); - resume_device(dev); - mutex_lock(&dpm_list_mtx); + list_for_each_entry(dev, &dpm_suspended_list, power.entry) { + reinit_completion(&dev->power.completion); + if (is_async(dev)) { + get_device(dev); + async_schedule(async_resume, dev); + } + } + + while (!list_empty(&dpm_suspended_list)) { + dev = to_device(dpm_suspended_list.next); + get_device(dev); + if (!is_async(dev)) { + int error; + + mutex_unlock(&dpm_list_mtx); + + error = device_resume(dev, state, false); + if (error) { + suspend_stats.failed_resume++; + dpm_save_failed_step(SUSPEND_RESUME); + dpm_save_failed_dev(dev_name(dev)); + pm_dev_err(dev, state, "", error); + } + + mutex_lock(&dpm_list_mtx); + } + if (!list_empty(&dev->power.entry)) + list_move_tail(&dev->power.entry, &dpm_prepared_list); + put_device(dev); } mutex_unlock(&dpm_list_mtx); + async_synchronize_full(); + dpm_show_time(starttime, state, NULL); + + cpufreq_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; + char *info = NULL; + + if (dev->power.syscore) + return; + + 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); + trace_device_pm_callback_start(dev, info, state.event); + callback(dev); + trace_device_pm_callback_end(dev, 0); + } + + device_unlock(dev); + + pm_runtime_put(dev); } /** - * unregister_dropped_devices - Unregister devices scheduled for removal + * dpm_complete - Complete a PM transition for all non-sysdev devices. + * @state: PM transition of the system being carried out. * - * Unregister all devices on the dpm_destroy list. + * Execute the ->complete() callbacks for all devices whose PM status is not + * DPM_ON (this allows new devices to be registered). */ -static void unregister_dropped_devices(void) +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_destroy)) { - struct list_head *entry = dpm_destroy.next; - struct device *dev = to_device(entry); + 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); - /* This also removes the device from the list */ - device_unregister(dev); + + device_complete(dev, state); + mutex_lock(&dpm_list_mtx); + put_device(dev); } + list_splice(&list, &dpm_list); mutex_unlock(&dpm_list_mtx); + trace_suspend_resume(TPS("dpm_complete"), state.event, false); } /** - * device_resume - Restore state of each device in system. + * dpm_resume_end - Execute "resume" callbacks and complete system transition. + * @state: PM transition of the system being carried out. * - * Resume all the devices, unlock them all, and allow new - * devices to be registered once again. + * Execute "resume" callbacks for all devices and complete the PM transition of + * the system. */ -void device_resume(void) +void dpm_resume_end(pm_message_t state) { - might_sleep(); - dpm_resume(); - unregister_dropped_devices(); - up_write(&pm_sleep_rwsem); + dpm_resume(state); + dpm_complete(state); } -EXPORT_SYMBOL_GPL(device_resume); +EXPORT_SYMBOL_GPL(dpm_resume_end); /*------------------------- Suspend routines -------------------------*/ -static inline char *suspend_verb(u32 event) +/** + * 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 (event) { - case PM_EVENT_SUSPEND: return "suspend"; - case PM_EVENT_FREEZE: return "freeze"; - case PM_EVENT_PRETHAW: return "prethaw"; - default: return "(unknown suspend event)"; + 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 -suspend_device_dbg(struct device *dev, pm_message_t state, char *info) +/** + * device_suspend_noirq - Execute a "late suspend" callback for given device. + * @dev: Device to handle. + * @state: PM transition of the system being carried out. + * + * 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) { - dev_dbg(dev, "%s%s%s\n", info, suspend_verb(state.event), - ((state.event == PM_EVENT_SUSPEND) && device_may_wakeup(dev)) ? - ", may wakeup" : ""); + pm_callback_t callback = NULL; + char *info = NULL; + int error = 0; + + if (async_error) + goto Complete; + + if (pm_wakeup_pending()) { + async_error = -EBUSY; + goto Complete; + } + + if (dev->power.syscore || dev->power.direct_complete) + goto Complete; + + dpm_wait_for_children(dev, async); + + 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 && dev->driver && dev->driver->pm) { + info = "noirq driver "; + callback = pm_noirq_op(dev->driver->pm, state); + } + + error = dpm_run_callback(callback, dev, state, info); + if (!error) + dev->power.is_noirq_suspended = true; + else + async_error = error; + +Complete: + complete_all(&dev->power.completion); + return error; +} + +static void async_suspend_noirq(void *data, async_cookie_t cookie) +{ + struct device *dev = (struct device *)data; + int error; + + error = __device_suspend_noirq(dev, pm_transition, true); + if (error) { + dpm_save_failed_dev(dev_name(dev)); + pm_dev_err(dev, pm_transition, " async", error); + } + + put_device(dev); +} + +static int device_suspend_noirq(struct device *dev) +{ + reinit_completion(&dev->power.completion); + + if (pm_async_enabled && dev->power.async_suspend) { + get_device(dev); + async_schedule(async_suspend_noirq, dev); + return 0; + } + return __device_suspend_noirq(dev, pm_transition, false); } /** - * suspend_device_late - Shut down one device (late suspend). - * @dev: Device. - * @state: Power state device is entering. + * dpm_suspend_noirq - Execute "noirq suspend" callbacks for all devices. + * @state: PM transition of the system being carried out. * - * This is called with interrupts off and only a single CPU running. + * Prevent device drivers from receiving interrupts and call the "noirq" suspend + * handlers for all non-sysdev devices. */ -static int suspend_device_late(struct device *dev, pm_message_t state) +static int dpm_suspend_noirq(pm_message_t state) { + ktime_t starttime = ktime_get(); int error = 0; - if (dev->bus && dev->bus->suspend_late) { - suspend_device_dbg(dev, state, "LATE "); - error = dev->bus->suspend_late(dev, state); - suspend_report_result(dev->bus->suspend_late, error); + trace_suspend_resume(TPS("dpm_suspend_noirq"), state.event, true); + cpuidle_pause(); + suspend_device_irqs(); + mutex_lock(&dpm_list_mtx); + pm_transition = state; + async_error = 0; + + while (!list_empty(&dpm_late_early_list)) { + struct device *dev = to_device(dpm_late_early_list.prev); + + get_device(dev); + mutex_unlock(&dpm_list_mtx); + + error = device_suspend_noirq(dev); + + mutex_lock(&dpm_list_mtx); + if (error) { + pm_dev_err(dev, state, " noirq", error); + dpm_save_failed_dev(dev_name(dev)); + put_device(dev); + break; + } + if (!list_empty(&dev->power.entry)) + list_move(&dev->power.entry, &dpm_noirq_list); + put_device(dev); + + if (async_error) + break; + } + mutex_unlock(&dpm_list_mtx); + async_synchronize_full(); + if (!error) + error = async_error; + + if (error) { + suspend_stats.failed_suspend_noirq++; + dpm_save_failed_step(SUSPEND_SUSPEND_NOIRQ); + dpm_resume_noirq(resume_event(state)); + } else { + dpm_show_time(starttime, state, "noirq"); } + trace_suspend_resume(TPS("dpm_suspend_noirq"), state.event, false); return error; } /** - * device_power_down - Shut down special devices. - * @state: Power state to enter. - * - * Power down devices that require interrupts to be disabled - * and move them from the dpm_off list to the dpm_off_irq list. - * Then power down system devices. + * device_suspend_late - Execute a "late suspend" callback for given device. + * @dev: Device to handle. + * @state: PM transition of the system being carried out. * - * Must be called with interrupts disabled and only one CPU running. + * Runtime PM is disabled for @dev while this function is being executed. */ -int device_power_down(pm_message_t state) +static int __device_suspend_late(struct device *dev, pm_message_t state, bool async) { + pm_callback_t callback = NULL; + char *info = NULL; int error = 0; - while (!list_empty(&dpm_off)) { - struct list_head *entry = dpm_off.prev; - struct device *dev = to_device(entry); + __pm_runtime_disable(dev, false); + + if (async_error) + goto Complete; + + if (pm_wakeup_pending()) { + async_error = -EBUSY; + goto Complete; + } + + if (dev->power.syscore || dev->power.direct_complete) + goto Complete; + + dpm_wait_for_children(dev, async); + + 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); + } - error = suspend_device_late(dev, state); + if (!callback && dev->driver && dev->driver->pm) { + info = "late driver "; + callback = pm_late_early_op(dev->driver->pm, state); + } + + error = dpm_run_callback(callback, dev, state, info); + if (!error) + dev->power.is_late_suspended = true; + else + async_error = error; + +Complete: + complete_all(&dev->power.completion); + return error; +} + +static void async_suspend_late(void *data, async_cookie_t cookie) +{ + struct device *dev = (struct device *)data; + int error; + + error = __device_suspend_late(dev, pm_transition, true); + if (error) { + dpm_save_failed_dev(dev_name(dev)); + pm_dev_err(dev, pm_transition, " async", error); + } + put_device(dev); +} + +static int device_suspend_late(struct device *dev) +{ + reinit_completion(&dev->power.completion); + + if (pm_async_enabled && dev->power.async_suspend) { + get_device(dev); + async_schedule(async_suspend_late, dev); + return 0; + } + + return __device_suspend_late(dev, pm_transition, false); +} + +/** + * dpm_suspend_late - Execute "late suspend" callbacks for all devices. + * @state: PM transition of the system being carried out. + */ +static 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); + mutex_lock(&dpm_list_mtx); + pm_transition = state; + async_error = 0; + + while (!list_empty(&dpm_suspended_list)) { + struct device *dev = to_device(dpm_suspended_list.prev); + + get_device(dev); + mutex_unlock(&dpm_list_mtx); + + error = device_suspend_late(dev); + + mutex_lock(&dpm_list_mtx); if (error) { - printk(KERN_ERR "Could not power down device %s: " - "error %d\n", - kobject_name(&dev->kobj), error); + pm_dev_err(dev, state, " late", error); + dpm_save_failed_dev(dev_name(dev)); + put_device(dev); break; } if (!list_empty(&dev->power.entry)) - list_move(&dev->power.entry, &dpm_off_irq); + list_move(&dev->power.entry, &dpm_late_early_list); + put_device(dev); + + if (async_error) + break; + } + mutex_unlock(&dpm_list_mtx); + async_synchronize_full(); + if (error) { + suspend_stats.failed_suspend_late++; + dpm_save_failed_step(SUSPEND_SUSPEND_LATE); + dpm_resume_early(resume_event(state)); + } else { + dpm_show_time(starttime, state, "late"); } + trace_suspend_resume(TPS("dpm_suspend_late"), state.event, false); + return error; +} - if (!error) - error = sysdev_suspend(state); +/** + * 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) +{ + int error = dpm_suspend_late(state); if (error) - dpm_power_up(); + return error; + + error = dpm_suspend_noirq(state); + if (error) { + dpm_resume_early(resume_event(state)); + return error; + } + + return 0; +} +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. + */ +static int legacy_suspend(struct device *dev, pm_message_t state, + int (*cb)(struct device *dev, pm_message_t state), + char *info) +{ + int error; + ktime_t calltime; + + calltime = initcall_debug_start(dev); + + trace_device_pm_callback_start(dev, info, state.event); + error = cb(dev, state); + trace_device_pm_callback_end(dev, error); + suspend_report_result(cb, error); + + initcall_debug_report(dev, calltime, error, state, info); + return error; } -EXPORT_SYMBOL_GPL(device_power_down); /** - * suspend_device - Save state of one device. - * @dev: Device. - * @state: Power state device is entering. + * 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 suspend_device(struct device *dev, pm_message_t state) +static int __device_suspend(struct device *dev, pm_message_t state, bool async) { + pm_callback_t callback = NULL; + char *info = NULL; int error = 0; + DECLARE_DPM_WATCHDOG_ON_STACK(wd); + + dpm_wait_for_children(dev, async); + + if (async_error) + goto Complete; - down(&dev->sem); + /* + * If a device configured to wake up the system from sleep states + * has been suspended at run time and there's a resume request pending + * for it, this is equivalent to the device signaling wakeup, so the + * system suspend operation should be aborted. + */ + if (pm_runtime_barrier(dev) && device_may_wakeup(dev)) + pm_wakeup_event(dev, 0); - if (dev->power.power_state.event) { - dev_dbg(dev, "PM: suspend %d-->%d\n", - dev->power.power_state.event, state.event); + if (pm_wakeup_pending()) { + async_error = -EBUSY; + goto Complete; } - if (dev->class && dev->class->suspend) { - suspend_device_dbg(dev, state, "class "); - error = dev->class->suspend(dev, state); - suspend_report_result(dev->class->suspend, error); + if (dev->power.syscore) + goto Complete; + + if (dev->power.direct_complete) { + if (pm_runtime_status_suspended(dev)) { + pm_runtime_disable(dev); + if (pm_runtime_suspended_if_enabled(dev)) + goto Complete; + + pm_runtime_enable(dev); + } + dev->power.direct_complete = false; + } + + 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) { + if (dev->class->pm) { + info = "class "; + callback = pm_op(dev->class->pm, state); + goto Run; + } else if (dev->class->suspend) { + pm_dev_dbg(dev, state, "legacy class "); + error = legacy_suspend(dev, state, dev->class->suspend, + "legacy class "); + goto End; + } + } + + 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; + } } - if (!error && dev->type && dev->type->suspend) { - suspend_device_dbg(dev, state, "type "); - error = dev->type->suspend(dev, state); - suspend_report_result(dev->type->suspend, error); + Run: + if (!callback && dev->driver && dev->driver->pm) { + info = "driver "; + callback = pm_op(dev->driver->pm, state); } - if (!error && dev->bus && dev->bus->suspend) { - suspend_device_dbg(dev, state, ""); - error = dev->bus->suspend(dev, state); - suspend_report_result(dev->bus->suspend, error); + error = dpm_run_callback(callback, dev, state, info); + + End: + if (!error) { + struct device *parent = dev->parent; + + dev->power.is_suspended = true; + if (parent) { + spin_lock_irq(&parent->power.lock); + + dev->parent->power.direct_complete = false; + if (dev->power.wakeup_path + && !dev->parent->power.ignore_children) + dev->parent->power.wakeup_path = true; + + spin_unlock_irq(&parent->power.lock); + } } - up(&dev->sem); + device_unlock(dev); + dpm_watchdog_clear(&wd); + + Complete: + complete_all(&dev->power.completion); + if (error) + async_error = error; return error; } +static void async_suspend(void *data, async_cookie_t cookie) +{ + struct device *dev = (struct device *)data; + int error; + + error = __device_suspend(dev, pm_transition, true); + if (error) { + dpm_save_failed_dev(dev_name(dev)); + pm_dev_err(dev, pm_transition, " async", error); + } + + put_device(dev); +} + +static int device_suspend(struct device *dev) +{ + reinit_completion(&dev->power.completion); + + if (pm_async_enabled && dev->power.async_suspend) { + get_device(dev); + async_schedule(async_suspend, dev); + return 0; + } + + return __device_suspend(dev, pm_transition, false); +} + /** - * dpm_suspend - Suspend every device. - * @state: Power state to put each device in. + * 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(); + + cpufreq_suspend(); + + mutex_lock(&dpm_list_mtx); + pm_transition = state; + async_error = 0; + while (!list_empty(&dpm_prepared_list)) { + struct device *dev = to_device(dpm_prepared_list.prev); + + get_device(dev); + mutex_unlock(&dpm_list_mtx); + + error = device_suspend(dev); + + mutex_lock(&dpm_list_mtx); + if (error) { + pm_dev_err(dev, state, "", error); + dpm_save_failed_dev(dev_name(dev)); + put_device(dev); + break; + } + if (!list_empty(&dev->power.entry)) + list_move(&dev->power.entry, &dpm_suspended_list); + put_device(dev); + if (async_error) + break; + } + mutex_unlock(&dpm_list_mtx); + async_synchronize_full(); + if (!error) + error = async_error; + if (error) { + suspend_stats.failed_suspend++; + dpm_save_failed_step(SUSPEND_SUSPEND); + } else + dpm_show_time(starttime, state, 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. * - * Walk the dpm_locked list. Suspend each device and move it - * to the dpm_off list. + * 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; + char *info = NULL; + int ret = 0; + + if (dev->power.syscore) + return 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); + + device_lock(dev); + + dev->power.wakeup_path = device_may_wakeup(dev); + + if (dev->pm_domain) { + info = "preparing power domain "; + callback = dev->pm_domain->ops.prepare; + } else if (dev->type && dev->type->pm) { + info = "preparing type "; + callback = dev->type->pm->prepare; + } else if (dev->class && dev->class->pm) { + info = "preparing class "; + callback = dev->class->pm->prepare; + } else if (dev->bus && dev->bus->pm) { + info = "preparing bus "; + callback = dev->bus->pm->prepare; + } + + if (!callback && dev->driver && dev->driver->pm) { + info = "preparing driver "; + callback = dev->driver->pm->prepare; + } + + if (callback) { + trace_device_pm_callback_start(dev, info, state.event); + ret = callback(dev); + trace_device_pm_callback_end(dev, ret); + } + + device_unlock(dev); + + if (ret < 0) { + suspend_report_result(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 = ret > 0 && state.event == PM_EVENT_SUSPEND; + 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. * - * (For historical reasons, if it returns -EAGAIN, that used to mean - * that the device would be called again with interrupts disabled. - * These days, we use the "suspend_late()" callback for that, so we - * print a warning and consider it an error). + * Execute the ->prepare() callback(s) for all devices. */ -static int dpm_suspend(pm_message_t state) +int dpm_prepare(pm_message_t state) { int error = 0; + trace_suspend_resume(TPS("dpm_prepare"), state.event, true); + might_sleep(); + mutex_lock(&dpm_list_mtx); - while (!list_empty(&dpm_active)) { - struct list_head *entry = dpm_active.prev; - struct device *dev = to_device(entry); + while (!list_empty(&dpm_list)) { + struct device *dev = to_device(dpm_list.next); + get_device(dev); mutex_unlock(&dpm_list_mtx); - error = suspend_device(dev, state); + + error = device_prepare(dev, state); + mutex_lock(&dpm_list_mtx); if (error) { - printk(KERN_ERR "Could not suspend device %s: " - "error %d%s\n", - kobject_name(&dev->kobj), - error, - (error == -EAGAIN ? - " (please convert to suspend_late)" : - "")); + if (error == -EAGAIN) { + put_device(dev); + error = 0; + continue; + } + printk(KERN_INFO "PM: Device %s not prepared " + "for power transition: code %d\n", + dev_name(dev), error); + put_device(dev); break; } + dev->power.is_prepared = true; if (!list_empty(&dev->power.entry)) - list_move(&dev->power.entry, &dpm_off); + list_move_tail(&dev->power.entry, &dpm_prepared_list); + put_device(dev); } mutex_unlock(&dpm_list_mtx); - + trace_suspend_resume(TPS("dpm_prepare"), state.event, false); return error; } /** - * device_suspend - Save state and stop all devices in system. - * @state: new power management state + * dpm_suspend_start - Prepare devices for PM transition and suspend them. + * @state: PM transition of the system being carried out. * - * Prevent new devices from being registered, then lock all devices - * and suspend them. + * Prepare all non-sysdev devices for system PM transition and execute "suspend" + * callbacks for them. */ -int device_suspend(pm_message_t state) +int dpm_suspend_start(pm_message_t state) { int error; - might_sleep(); - down_write(&pm_sleep_rwsem); - error = dpm_suspend(state); - if (error) - device_resume(); + error = dpm_prepare(state); + if (error) { + suspend_stats.failed_prepare++; + dpm_save_failed_step(SUSPEND_PREPARE); + } else + error = dpm_suspend(state); return error; } -EXPORT_SYMBOL_GPL(device_suspend); +EXPORT_SYMBOL_GPL(dpm_suspend_start); void __suspend_report_result(const char *function, void *fn, int ret) { - if (ret) { - printk(KERN_ERR "%s(): ", function); - print_fn_descriptor_symbol("%s() returns ", (unsigned long)fn); - printk("%d\n", ret); - } + if (ret) + printk(KERN_ERR "%s(): %pF 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. + * @dev: Device to wait for. + * @subordinate: Device that needs to wait for @dev. + */ +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); |