diff options
Diffstat (limited to 'drivers/base/power/runtime.c')
| -rw-r--r-- | drivers/base/power/runtime.c | 1314 |
1 files changed, 873 insertions, 441 deletions
diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c index f8b044e8aef..67c7938e430 100644 --- a/drivers/base/power/runtime.c +++ b/drivers/base/power/runtime.c @@ -1,18 +1,92 @@ /* - * drivers/base/power/runtime.c - Helper functions for device run-time PM + * drivers/base/power/runtime.c - Helper functions for device runtime PM * * Copyright (c) 2009 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc. + * Copyright (C) 2010 Alan Stern <stern@rowland.harvard.edu> * * This file is released under the GPLv2. */ #include <linux/sched.h> +#include <linux/export.h> #include <linux/pm_runtime.h> -#include <linux/jiffies.h> +#include <trace/events/rpm.h> +#include "power.h" + +#define RPM_GET_CALLBACK(dev, cb) \ +({ \ + int (*__rpm_cb)(struct device *__d); \ + \ + if (dev->pm_domain) \ + __rpm_cb = dev->pm_domain->ops.cb; \ + else if (dev->type && dev->type->pm) \ + __rpm_cb = dev->type->pm->cb; \ + else if (dev->class && dev->class->pm) \ + __rpm_cb = dev->class->pm->cb; \ + else if (dev->bus && dev->bus->pm) \ + __rpm_cb = dev->bus->pm->cb; \ + else \ + __rpm_cb = NULL; \ + \ + if (!__rpm_cb && dev->driver && dev->driver->pm) \ + __rpm_cb = dev->driver->pm->cb; \ + \ + __rpm_cb; \ +}) + +static int (*rpm_get_suspend_cb(struct device *dev))(struct device *) +{ + return RPM_GET_CALLBACK(dev, runtime_suspend); +} + +static int (*rpm_get_resume_cb(struct device *dev))(struct device *) +{ + return RPM_GET_CALLBACK(dev, runtime_resume); +} + +#ifdef CONFIG_PM_RUNTIME +static int (*rpm_get_idle_cb(struct device *dev))(struct device *) +{ + return RPM_GET_CALLBACK(dev, runtime_idle); +} + +static int rpm_resume(struct device *dev, int rpmflags); +static int rpm_suspend(struct device *dev, int rpmflags); + +/** + * update_pm_runtime_accounting - Update the time accounting of power states + * @dev: Device to update the accounting for + * + * In order to be able to have time accounting of the various power states + * (as used by programs such as PowerTOP to show the effectiveness of runtime + * PM), we need to track the time spent in each state. + * update_pm_runtime_accounting must be called each time before the + * runtime_status field is updated, to account the time in the old state + * correctly. + */ +void update_pm_runtime_accounting(struct device *dev) +{ + unsigned long now = jiffies; + unsigned long delta; + + delta = now - dev->power.accounting_timestamp; + + dev->power.accounting_timestamp = now; + + if (dev->power.disable_depth > 0) + return; -static int __pm_runtime_resume(struct device *dev, bool from_wq); -static int __pm_request_idle(struct device *dev); -static int __pm_request_resume(struct device *dev); + if (dev->power.runtime_status == RPM_SUSPENDED) + dev->power.suspended_jiffies += delta; + else + dev->power.active_jiffies += delta; +} + +static void __update_runtime_status(struct device *dev, enum rpm_status status) +{ + update_pm_runtime_accounting(dev); + dev->power.runtime_status = status; +} /** * pm_runtime_deactivate_timer - Deactivate given device's suspend timer. @@ -40,146 +114,376 @@ static void pm_runtime_cancel_pending(struct device *dev) dev->power.request = RPM_REQ_NONE; } -/** - * __pm_runtime_idle - Notify device bus type if the device can be suspended. - * @dev: Device to notify the bus type about. +/* + * pm_runtime_autosuspend_expiration - Get a device's autosuspend-delay expiration time. + * @dev: Device to handle. * - * This function must be called under dev->power.lock with interrupts disabled. + * Compute the autosuspend-delay expiration time based on the device's + * power.last_busy time. If the delay has already expired or is disabled + * (negative) or the power.use_autosuspend flag isn't set, return 0. + * Otherwise return the expiration time in jiffies (adjusted to be nonzero). + * + * This function may be called either with or without dev->power.lock held. + * Either way it can be racy, since power.last_busy may be updated at any time. */ -static int __pm_runtime_idle(struct device *dev) - __releases(&dev->power.lock) __acquires(&dev->power.lock) +unsigned long pm_runtime_autosuspend_expiration(struct device *dev) +{ + int autosuspend_delay; + long elapsed; + unsigned long last_busy; + unsigned long expires = 0; + + if (!dev->power.use_autosuspend) + goto out; + + autosuspend_delay = ACCESS_ONCE(dev->power.autosuspend_delay); + if (autosuspend_delay < 0) + goto out; + + last_busy = ACCESS_ONCE(dev->power.last_busy); + elapsed = jiffies - last_busy; + if (elapsed < 0) + goto out; /* jiffies has wrapped around. */ + + /* + * If the autosuspend_delay is >= 1 second, align the timer by rounding + * up to the nearest second. + */ + expires = last_busy + msecs_to_jiffies(autosuspend_delay); + if (autosuspend_delay >= 1000) + expires = round_jiffies(expires); + expires += !expires; + if (elapsed >= expires - last_busy) + expires = 0; /* Already expired. */ + + out: + return expires; +} +EXPORT_SYMBOL_GPL(pm_runtime_autosuspend_expiration); + +static int dev_memalloc_noio(struct device *dev, void *data) +{ + return dev->power.memalloc_noio; +} + +/* + * pm_runtime_set_memalloc_noio - Set a device's memalloc_noio flag. + * @dev: Device to handle. + * @enable: True for setting the flag and False for clearing the flag. + * + * Set the flag for all devices in the path from the device to the + * root device in the device tree if @enable is true, otherwise clear + * the flag for devices in the path whose siblings don't set the flag. + * + * The function should only be called by block device, or network + * device driver for solving the deadlock problem during runtime + * resume/suspend: + * + * If memory allocation with GFP_KERNEL is called inside runtime + * resume/suspend callback of any one of its ancestors(or the + * block device itself), the deadlock may be triggered inside the + * memory allocation since it might not complete until the block + * device becomes active and the involed page I/O finishes. The + * situation is pointed out first by Alan Stern. Network device + * are involved in iSCSI kind of situation. + * + * The lock of dev_hotplug_mutex is held in the function for handling + * hotplug race because pm_runtime_set_memalloc_noio() may be called + * in async probe(). + * + * The function should be called between device_add() and device_del() + * on the affected device(block/network device). + */ +void pm_runtime_set_memalloc_noio(struct device *dev, bool enable) +{ + static DEFINE_MUTEX(dev_hotplug_mutex); + + mutex_lock(&dev_hotplug_mutex); + for (;;) { + bool enabled; + + /* hold power lock since bitfield is not SMP-safe. */ + spin_lock_irq(&dev->power.lock); + enabled = dev->power.memalloc_noio; + dev->power.memalloc_noio = enable; + spin_unlock_irq(&dev->power.lock); + + /* + * not need to enable ancestors any more if the device + * has been enabled. + */ + if (enabled && enable) + break; + + dev = dev->parent; + + /* + * clear flag of the parent device only if all the + * children don't set the flag because ancestor's + * flag was set by any one of the descendants. + */ + if (!dev || (!enable && + device_for_each_child(dev, NULL, + dev_memalloc_noio))) + break; + } + mutex_unlock(&dev_hotplug_mutex); +} +EXPORT_SYMBOL_GPL(pm_runtime_set_memalloc_noio); + +/** + * rpm_check_suspend_allowed - Test whether a device may be suspended. + * @dev: Device to test. + */ +static int rpm_check_suspend_allowed(struct device *dev) { int retval = 0; if (dev->power.runtime_error) retval = -EINVAL; - else if (dev->power.idle_notification) - retval = -EINPROGRESS; - else if (atomic_read(&dev->power.usage_count) > 0 - || dev->power.disable_depth > 0 - || dev->power.runtime_status != RPM_ACTIVE) + else if (dev->power.disable_depth > 0) + retval = -EACCES; + else if (atomic_read(&dev->power.usage_count) > 0) retval = -EAGAIN; else if (!pm_children_suspended(dev)) retval = -EBUSY; - if (retval) - goto out; - if (dev->power.request_pending) { - /* - * If an idle notification request is pending, cancel it. Any - * other pending request takes precedence over us. - */ - if (dev->power.request == RPM_REQ_IDLE) { - dev->power.request = RPM_REQ_NONE; - } else if (dev->power.request != RPM_REQ_NONE) { - retval = -EAGAIN; - goto out; - } - } + /* Pending resume requests take precedence over suspends. */ + else if ((dev->power.deferred_resume + && dev->power.runtime_status == RPM_SUSPENDING) + || (dev->power.request_pending + && dev->power.request == RPM_REQ_RESUME)) + retval = -EAGAIN; + else if (__dev_pm_qos_read_value(dev) < 0) + retval = -EPERM; + else if (dev->power.runtime_status == RPM_SUSPENDED) + retval = 1; - dev->power.idle_notification = true; + return retval; +} - if (dev->bus && dev->bus->pm && dev->bus->pm->runtime_idle) { +/** + * __rpm_callback - Run a given runtime PM callback for a given device. + * @cb: Runtime PM callback to run. + * @dev: Device to run the callback for. + */ +static int __rpm_callback(int (*cb)(struct device *), struct device *dev) + __releases(&dev->power.lock) __acquires(&dev->power.lock) +{ + int retval; + + if (dev->power.irq_safe) + spin_unlock(&dev->power.lock); + else spin_unlock_irq(&dev->power.lock); - dev->bus->pm->runtime_idle(dev); + retval = cb(dev); + if (dev->power.irq_safe) + spin_lock(&dev->power.lock); + else spin_lock_irq(&dev->power.lock); - } else if (dev->type && dev->type->pm && dev->type->pm->runtime_idle) { - spin_unlock_irq(&dev->power.lock); - dev->type->pm->runtime_idle(dev); + return retval; +} - spin_lock_irq(&dev->power.lock); - } else if (dev->class && dev->class->pm - && dev->class->pm->runtime_idle) { - spin_unlock_irq(&dev->power.lock); +/** + * rpm_idle - Notify device bus type if the device can be suspended. + * @dev: Device to notify the bus type about. + * @rpmflags: Flag bits. + * + * Check if the device's runtime PM status allows it to be suspended. If + * another idle notification has been started earlier, return immediately. If + * the RPM_ASYNC flag is set then queue an idle-notification request; otherwise + * run the ->runtime_idle() callback directly. If the ->runtime_idle callback + * doesn't exist or if it returns 0, call rpm_suspend with the RPM_AUTO flag. + * + * This function must be called under dev->power.lock with interrupts disabled. + */ +static int rpm_idle(struct device *dev, int rpmflags) +{ + int (*callback)(struct device *); + int retval; + + trace_rpm_idle(dev, rpmflags); + retval = rpm_check_suspend_allowed(dev); + if (retval < 0) + ; /* Conditions are wrong. */ - dev->class->pm->runtime_idle(dev); + /* Idle notifications are allowed only in the RPM_ACTIVE state. */ + else if (dev->power.runtime_status != RPM_ACTIVE) + retval = -EAGAIN; - spin_lock_irq(&dev->power.lock); + /* + * Any pending request other than an idle notification takes + * precedence over us, except that the timer may be running. + */ + else if (dev->power.request_pending && + dev->power.request > RPM_REQ_IDLE) + retval = -EAGAIN; + + /* Act as though RPM_NOWAIT is always set. */ + else if (dev->power.idle_notification) + retval = -EINPROGRESS; + if (retval) + goto out; + + /* Pending requests need to be canceled. */ + dev->power.request = RPM_REQ_NONE; + + if (dev->power.no_callbacks) + goto out; + + /* Carry out an asynchronous or a synchronous idle notification. */ + if (rpmflags & RPM_ASYNC) { + dev->power.request = RPM_REQ_IDLE; + if (!dev->power.request_pending) { + dev->power.request_pending = true; + queue_work(pm_wq, &dev->power.work); + } + trace_rpm_return_int(dev, _THIS_IP_, 0); + return 0; } + dev->power.idle_notification = true; + + callback = rpm_get_idle_cb(dev); + + if (callback) + retval = __rpm_callback(callback, dev); + dev->power.idle_notification = false; wake_up_all(&dev->power.wait_queue); out: - return retval; + trace_rpm_return_int(dev, _THIS_IP_, retval); + return retval ? retval : rpm_suspend(dev, rpmflags | RPM_AUTO); } /** - * pm_runtime_idle - Notify device bus type if the device can be suspended. - * @dev: Device to notify the bus type about. + * rpm_callback - Run a given runtime PM callback for a given device. + * @cb: Runtime PM callback to run. + * @dev: Device to run the callback for. */ -int pm_runtime_idle(struct device *dev) +static int rpm_callback(int (*cb)(struct device *), struct device *dev) { int retval; - spin_lock_irq(&dev->power.lock); - retval = __pm_runtime_idle(dev); - spin_unlock_irq(&dev->power.lock); + if (!cb) + return -ENOSYS; - return retval; + if (dev->power.memalloc_noio) { + unsigned int noio_flag; + + /* + * Deadlock might be caused if memory allocation with + * GFP_KERNEL happens inside runtime_suspend and + * runtime_resume callbacks of one block device's + * ancestor or the block device itself. Network + * device might be thought as part of iSCSI block + * device, so network device and its ancestor should + * be marked as memalloc_noio too. + */ + noio_flag = memalloc_noio_save(); + retval = __rpm_callback(cb, dev); + memalloc_noio_restore(noio_flag); + } else { + retval = __rpm_callback(cb, dev); + } + + dev->power.runtime_error = retval; + return retval != -EACCES ? retval : -EIO; } -EXPORT_SYMBOL_GPL(pm_runtime_idle); /** - * __pm_runtime_suspend - Carry out run-time suspend of given device. + * rpm_suspend - Carry out runtime suspend of given device. * @dev: Device to suspend. - * @from_wq: If set, the function has been called via pm_wq. + * @rpmflags: Flag bits. * - * Check if the device can be suspended and run the ->runtime_suspend() callback - * provided by its bus type. If another suspend has been started earlier, wait - * for it to finish. If an idle notification or suspend request is pending or - * scheduled, cancel it. + * Check if the device's runtime PM status allows it to be suspended. + * Cancel a pending idle notification, autosuspend or suspend. If + * another suspend has been started earlier, either return immediately + * or wait for it to finish, depending on the RPM_NOWAIT and RPM_ASYNC + * flags. If the RPM_ASYNC flag is set then queue a suspend request; + * otherwise run the ->runtime_suspend() callback directly. When + * ->runtime_suspend succeeded, if a deferred resume was requested while + * the callback was running then carry it out, otherwise send an idle + * notification for its parent (if the suspend succeeded and both + * ignore_children of parent->power and irq_safe of dev->power are not set). + * If ->runtime_suspend failed with -EAGAIN or -EBUSY, and if the RPM_AUTO + * flag is set and the next autosuspend-delay expiration time is in the + * future, schedule another autosuspend attempt. * * This function must be called under dev->power.lock with interrupts disabled. */ -int __pm_runtime_suspend(struct device *dev, bool from_wq) +static int rpm_suspend(struct device *dev, int rpmflags) __releases(&dev->power.lock) __acquires(&dev->power.lock) { + int (*callback)(struct device *); struct device *parent = NULL; - bool notify = false; - int retval = 0; + int retval; - dev_dbg(dev, "__pm_runtime_suspend()%s!\n", - from_wq ? " from workqueue" : ""); + trace_rpm_suspend(dev, rpmflags); repeat: - if (dev->power.runtime_error) { - retval = -EINVAL; - goto out; - } + retval = rpm_check_suspend_allowed(dev); - /* Pending resume requests take precedence over us. */ - if (dev->power.request_pending - && dev->power.request == RPM_REQ_RESUME) { + if (retval < 0) + ; /* Conditions are wrong. */ + + /* Synchronous suspends are not allowed in the RPM_RESUMING state. */ + else if (dev->power.runtime_status == RPM_RESUMING && + !(rpmflags & RPM_ASYNC)) retval = -EAGAIN; + if (retval) goto out; + + /* If the autosuspend_delay time hasn't expired yet, reschedule. */ + if ((rpmflags & RPM_AUTO) + && dev->power.runtime_status != RPM_SUSPENDING) { + unsigned long expires = pm_runtime_autosuspend_expiration(dev); + + if (expires != 0) { + /* Pending requests need to be canceled. */ + dev->power.request = RPM_REQ_NONE; + + /* + * Optimization: If the timer is already running and is + * set to expire at or before the autosuspend delay, + * avoid the overhead of resetting it. Just let it + * expire; pm_suspend_timer_fn() will take care of the + * rest. + */ + if (!(dev->power.timer_expires && time_before_eq( + dev->power.timer_expires, expires))) { + dev->power.timer_expires = expires; + mod_timer(&dev->power.suspend_timer, expires); + } + dev->power.timer_autosuspends = 1; + goto out; + } } /* Other scheduled or pending requests need to be canceled. */ pm_runtime_cancel_pending(dev); - if (dev->power.runtime_status == RPM_SUSPENDED) - retval = 1; - else if (dev->power.runtime_status == RPM_RESUMING - || dev->power.disable_depth > 0 - || atomic_read(&dev->power.usage_count) > 0) - retval = -EAGAIN; - else if (!pm_children_suspended(dev)) - retval = -EBUSY; - if (retval) - goto out; - if (dev->power.runtime_status == RPM_SUSPENDING) { DEFINE_WAIT(wait); - if (from_wq) { + if (rpmflags & (RPM_ASYNC | RPM_NOWAIT)) { retval = -EINPROGRESS; goto out; } + if (dev->power.irq_safe) { + spin_unlock(&dev->power.lock); + + cpu_relax(); + + spin_lock(&dev->power.lock); + goto repeat; + } + /* Wait for the other suspend running in parallel with us. */ for (;;) { prepare_to_wait(&dev->power.wait_queue, &wait, @@ -197,141 +501,157 @@ int __pm_runtime_suspend(struct device *dev, bool from_wq) goto repeat; } - dev->power.runtime_status = RPM_SUSPENDING; - dev->power.deferred_resume = false; - - if (dev->bus && dev->bus->pm && dev->bus->pm->runtime_suspend) { - spin_unlock_irq(&dev->power.lock); + if (dev->power.no_callbacks) + goto no_callback; /* Assume success. */ - retval = dev->bus->pm->runtime_suspend(dev); - - spin_lock_irq(&dev->power.lock); - dev->power.runtime_error = retval; - } else if (dev->type && dev->type->pm - && dev->type->pm->runtime_suspend) { - spin_unlock_irq(&dev->power.lock); - - retval = dev->type->pm->runtime_suspend(dev); - - spin_lock_irq(&dev->power.lock); - dev->power.runtime_error = retval; - } else if (dev->class && dev->class->pm - && dev->class->pm->runtime_suspend) { - spin_unlock_irq(&dev->power.lock); + /* Carry out an asynchronous or a synchronous suspend. */ + if (rpmflags & RPM_ASYNC) { + dev->power.request = (rpmflags & RPM_AUTO) ? + RPM_REQ_AUTOSUSPEND : RPM_REQ_SUSPEND; + if (!dev->power.request_pending) { + dev->power.request_pending = true; + queue_work(pm_wq, &dev->power.work); + } + goto out; + } - retval = dev->class->pm->runtime_suspend(dev); + __update_runtime_status(dev, RPM_SUSPENDING); - spin_lock_irq(&dev->power.lock); - dev->power.runtime_error = retval; - } else { - retval = -ENOSYS; - } + callback = rpm_get_suspend_cb(dev); - if (retval) { - dev->power.runtime_status = RPM_ACTIVE; - pm_runtime_cancel_pending(dev); + retval = rpm_callback(callback, dev); + if (retval) + goto fail; - if (retval == -EAGAIN || retval == -EBUSY) { - notify = true; - dev->power.runtime_error = 0; - } - } else { - dev->power.runtime_status = RPM_SUSPENDED; + no_callback: + __update_runtime_status(dev, RPM_SUSPENDED); + pm_runtime_deactivate_timer(dev); - if (dev->parent) { - parent = dev->parent; - atomic_add_unless(&parent->power.child_count, -1, 0); - } + if (dev->parent) { + parent = dev->parent; + atomic_add_unless(&parent->power.child_count, -1, 0); } wake_up_all(&dev->power.wait_queue); if (dev->power.deferred_resume) { - __pm_runtime_resume(dev, false); + dev->power.deferred_resume = false; + rpm_resume(dev, 0); retval = -EAGAIN; goto out; } - if (notify) - __pm_runtime_idle(dev); - - if (parent && !parent->power.ignore_children) { - spin_unlock_irq(&dev->power.lock); + /* Maybe the parent is now able to suspend. */ + if (parent && !parent->power.ignore_children && !dev->power.irq_safe) { + spin_unlock(&dev->power.lock); - pm_request_idle(parent); + spin_lock(&parent->power.lock); + rpm_idle(parent, RPM_ASYNC); + spin_unlock(&parent->power.lock); - spin_lock_irq(&dev->power.lock); + spin_lock(&dev->power.lock); } out: - dev_dbg(dev, "__pm_runtime_suspend() returns %d!\n", retval); + trace_rpm_return_int(dev, _THIS_IP_, retval); return retval; -} -/** - * pm_runtime_suspend - Carry out run-time suspend of given device. - * @dev: Device to suspend. - */ -int pm_runtime_suspend(struct device *dev) -{ - int retval; + fail: + __update_runtime_status(dev, RPM_ACTIVE); + dev->power.deferred_resume = false; + wake_up_all(&dev->power.wait_queue); - spin_lock_irq(&dev->power.lock); - retval = __pm_runtime_suspend(dev, false); - spin_unlock_irq(&dev->power.lock); + if (retval == -EAGAIN || retval == -EBUSY) { + dev->power.runtime_error = 0; - return retval; + /* + * If the callback routine failed an autosuspend, and + * if the last_busy time has been updated so that there + * is a new autosuspend expiration time, automatically + * reschedule another autosuspend. + */ + if ((rpmflags & RPM_AUTO) && + pm_runtime_autosuspend_expiration(dev) != 0) + goto repeat; + } else { + pm_runtime_cancel_pending(dev); + } + goto out; } -EXPORT_SYMBOL_GPL(pm_runtime_suspend); /** - * __pm_runtime_resume - Carry out run-time resume of given device. + * rpm_resume - Carry out runtime resume of given device. * @dev: Device to resume. - * @from_wq: If set, the function has been called via pm_wq. + * @rpmflags: Flag bits. * - * Check if the device can be woken up and run the ->runtime_resume() callback - * provided by its bus type. If another resume has been started earlier, wait - * for it to finish. If there's a suspend running in parallel with this - * function, wait for it to finish and resume the device. Cancel any scheduled - * or pending requests. + * Check if the device's runtime PM status allows it to be resumed. Cancel + * any scheduled or pending requests. If another resume has been started + * earlier, either return immediately or wait for it to finish, depending on the + * RPM_NOWAIT and RPM_ASYNC flags. Similarly, if there's a suspend running in + * parallel with this function, either tell the other process to resume after + * suspending (deferred_resume) or wait for it to finish. If the RPM_ASYNC + * flag is set then queue a resume request; otherwise run the + * ->runtime_resume() callback directly. Queue an idle notification for the + * device if the resume succeeded. * * This function must be called under dev->power.lock with interrupts disabled. */ -int __pm_runtime_resume(struct device *dev, bool from_wq) +static int rpm_resume(struct device *dev, int rpmflags) __releases(&dev->power.lock) __acquires(&dev->power.lock) { + int (*callback)(struct device *); struct device *parent = NULL; int retval = 0; - dev_dbg(dev, "__pm_runtime_resume()%s!\n", - from_wq ? " from workqueue" : ""); + trace_rpm_resume(dev, rpmflags); repeat: - if (dev->power.runtime_error) { + if (dev->power.runtime_error) retval = -EINVAL; + else if (dev->power.disable_depth == 1 && dev->power.is_suspended + && dev->power.runtime_status == RPM_ACTIVE) + retval = 1; + else if (dev->power.disable_depth > 0) + retval = -EACCES; + if (retval) goto out; - } - pm_runtime_cancel_pending(dev); + /* + * Other scheduled or pending requests need to be canceled. Small + * optimization: If an autosuspend timer is running, leave it running + * rather than cancelling it now only to restart it again in the near + * future. + */ + dev->power.request = RPM_REQ_NONE; + if (!dev->power.timer_autosuspends) + pm_runtime_deactivate_timer(dev); - if (dev->power.runtime_status == RPM_ACTIVE) + if (dev->power.runtime_status == RPM_ACTIVE) { retval = 1; - else if (dev->power.disable_depth > 0) - retval = -EAGAIN; - if (retval) goto out; + } if (dev->power.runtime_status == RPM_RESUMING || dev->power.runtime_status == RPM_SUSPENDING) { DEFINE_WAIT(wait); - if (from_wq) { + if (rpmflags & (RPM_ASYNC | RPM_NOWAIT)) { if (dev->power.runtime_status == RPM_SUSPENDING) dev->power.deferred_resume = true; - retval = -EINPROGRESS; + else + retval = -EINPROGRESS; goto out; } + if (dev->power.irq_safe) { + spin_unlock(&dev->power.lock); + + cpu_relax(); + + spin_lock(&dev->power.lock); + goto repeat; + } + /* Wait for the operation carried out in parallel with us. */ for (;;) { prepare_to_wait(&dev->power.wait_queue, &wait, @@ -350,24 +670,56 @@ int __pm_runtime_resume(struct device *dev, bool from_wq) goto repeat; } + /* + * See if we can skip waking up the parent. This is safe only if + * power.no_callbacks is set, because otherwise we don't know whether + * the resume will actually succeed. + */ + if (dev->power.no_callbacks && !parent && dev->parent) { + spin_lock_nested(&dev->parent->power.lock, SINGLE_DEPTH_NESTING); + if (dev->parent->power.disable_depth > 0 + || dev->parent->power.ignore_children + || dev->parent->power.runtime_status == RPM_ACTIVE) { + atomic_inc(&dev->parent->power.child_count); + spin_unlock(&dev->parent->power.lock); + retval = 1; + goto no_callback; /* Assume success. */ + } + spin_unlock(&dev->parent->power.lock); + } + + /* Carry out an asynchronous or a synchronous resume. */ + if (rpmflags & RPM_ASYNC) { + dev->power.request = RPM_REQ_RESUME; + if (!dev->power.request_pending) { + dev->power.request_pending = true; + queue_work(pm_wq, &dev->power.work); + } + retval = 0; + goto out; + } + if (!parent && dev->parent) { /* - * Increment the parent's resume counter and resume it if - * necessary. + * Increment the parent's usage counter and resume it if + * necessary. Not needed if dev is irq-safe; then the + * parent is permanently resumed. */ parent = dev->parent; + if (dev->power.irq_safe) + goto skip_parent; spin_unlock(&dev->power.lock); pm_runtime_get_noresume(parent); spin_lock(&parent->power.lock); /* - * We can resume if the parent's run-time PM is disabled or it + * We can resume if the parent's runtime PM is disabled or it * is set to ignore children. */ if (!parent->power.disable_depth && !parent->power.ignore_children) { - __pm_runtime_resume(parent, false); + rpm_resume(parent, 0); if (parent->power.runtime_status != RPM_ACTIVE) retval = -EBUSY; } @@ -378,51 +730,32 @@ int __pm_runtime_resume(struct device *dev, bool from_wq) goto out; goto repeat; } + skip_parent: - dev->power.runtime_status = RPM_RESUMING; + if (dev->power.no_callbacks) + goto no_callback; /* Assume success. */ - if (dev->bus && dev->bus->pm && dev->bus->pm->runtime_resume) { - spin_unlock_irq(&dev->power.lock); - - retval = dev->bus->pm->runtime_resume(dev); - - spin_lock_irq(&dev->power.lock); - dev->power.runtime_error = retval; - } else if (dev->type && dev->type->pm - && dev->type->pm->runtime_resume) { - spin_unlock_irq(&dev->power.lock); - - retval = dev->type->pm->runtime_resume(dev); - - spin_lock_irq(&dev->power.lock); - dev->power.runtime_error = retval; - } else if (dev->class && dev->class->pm - && dev->class->pm->runtime_resume) { - spin_unlock_irq(&dev->power.lock); - - retval = dev->class->pm->runtime_resume(dev); + __update_runtime_status(dev, RPM_RESUMING); - spin_lock_irq(&dev->power.lock); - dev->power.runtime_error = retval; - } else { - retval = -ENOSYS; - } + callback = rpm_get_resume_cb(dev); + retval = rpm_callback(callback, dev); if (retval) { - dev->power.runtime_status = RPM_SUSPENDED; + __update_runtime_status(dev, RPM_SUSPENDED); pm_runtime_cancel_pending(dev); } else { - dev->power.runtime_status = RPM_ACTIVE; + no_callback: + __update_runtime_status(dev, RPM_ACTIVE); if (parent) atomic_inc(&parent->power.child_count); } wake_up_all(&dev->power.wait_queue); - if (!retval) - __pm_request_idle(dev); + if (retval >= 0) + rpm_idle(dev, RPM_ASYNC); out: - if (parent) { + if (parent && !dev->power.irq_safe) { spin_unlock_irq(&dev->power.lock); pm_runtime_put(parent); @@ -430,33 +763,17 @@ int __pm_runtime_resume(struct device *dev, bool from_wq) spin_lock_irq(&dev->power.lock); } - dev_dbg(dev, "__pm_runtime_resume() returns %d!\n", retval); + trace_rpm_return_int(dev, _THIS_IP_, retval); return retval; } /** - * pm_runtime_resume - Carry out run-time resume of given device. - * @dev: Device to suspend. - */ -int pm_runtime_resume(struct device *dev) -{ - int retval; - - spin_lock_irq(&dev->power.lock); - retval = __pm_runtime_resume(dev, false); - spin_unlock_irq(&dev->power.lock); - - return retval; -} -EXPORT_SYMBOL_GPL(pm_runtime_resume); - -/** - * pm_runtime_work - Universal run-time PM work function. + * pm_runtime_work - Universal runtime PM work function. * @work: Work structure used for scheduling the execution of this function. * * Use @work to get the device object the work is to be done for, determine what - * is to be done and execute the appropriate run-time PM function. + * is to be done and execute the appropriate runtime PM function. */ static void pm_runtime_work(struct work_struct *work) { @@ -476,13 +793,16 @@ static void pm_runtime_work(struct work_struct *work) case RPM_REQ_NONE: break; case RPM_REQ_IDLE: - __pm_runtime_idle(dev); + rpm_idle(dev, RPM_NOWAIT); break; case RPM_REQ_SUSPEND: - __pm_runtime_suspend(dev, true); + rpm_suspend(dev, RPM_NOWAIT); + break; + case RPM_REQ_AUTOSUSPEND: + rpm_suspend(dev, RPM_NOWAIT | RPM_AUTO); break; case RPM_REQ_RESUME: - __pm_runtime_resume(dev, true); + rpm_resume(dev, RPM_NOWAIT); break; } @@ -491,117 +811,10 @@ static void pm_runtime_work(struct work_struct *work) } /** - * __pm_request_idle - Submit an idle notification request for given device. - * @dev: Device to handle. - * - * Check if the device's run-time PM status is correct for suspending the device - * and queue up a request to run __pm_runtime_idle() for it. - * - * This function must be called under dev->power.lock with interrupts disabled. - */ -static int __pm_request_idle(struct device *dev) -{ - int retval = 0; - - if (dev->power.runtime_error) - retval = -EINVAL; - else if (atomic_read(&dev->power.usage_count) > 0 - || dev->power.disable_depth > 0 - || dev->power.runtime_status == RPM_SUSPENDED - || dev->power.runtime_status == RPM_SUSPENDING) - retval = -EAGAIN; - else if (!pm_children_suspended(dev)) - retval = -EBUSY; - if (retval) - return retval; - - if (dev->power.request_pending) { - /* Any requests other then RPM_REQ_IDLE take precedence. */ - if (dev->power.request == RPM_REQ_NONE) - dev->power.request = RPM_REQ_IDLE; - else if (dev->power.request != RPM_REQ_IDLE) - retval = -EAGAIN; - return retval; - } - - dev->power.request = RPM_REQ_IDLE; - dev->power.request_pending = true; - queue_work(pm_wq, &dev->power.work); - - return retval; -} - -/** - * pm_request_idle - Submit an idle notification request for given device. - * @dev: Device to handle. - */ -int pm_request_idle(struct device *dev) -{ - unsigned long flags; - int retval; - - spin_lock_irqsave(&dev->power.lock, flags); - retval = __pm_request_idle(dev); - spin_unlock_irqrestore(&dev->power.lock, flags); - - return retval; -} -EXPORT_SYMBOL_GPL(pm_request_idle); - -/** - * __pm_request_suspend - Submit a suspend request for given device. - * @dev: Device to suspend. - * - * This function must be called under dev->power.lock with interrupts disabled. - */ -static int __pm_request_suspend(struct device *dev) -{ - int retval = 0; - - if (dev->power.runtime_error) - return -EINVAL; - - if (dev->power.runtime_status == RPM_SUSPENDED) - retval = 1; - else if (atomic_read(&dev->power.usage_count) > 0 - || dev->power.disable_depth > 0) - retval = -EAGAIN; - else if (dev->power.runtime_status == RPM_SUSPENDING) - retval = -EINPROGRESS; - else if (!pm_children_suspended(dev)) - retval = -EBUSY; - if (retval < 0) - return retval; - - pm_runtime_deactivate_timer(dev); - - if (dev->power.request_pending) { - /* - * Pending resume requests take precedence over us, but we can - * overtake any other pending request. - */ - if (dev->power.request == RPM_REQ_RESUME) - retval = -EAGAIN; - else if (dev->power.request != RPM_REQ_SUSPEND) - dev->power.request = retval ? - RPM_REQ_NONE : RPM_REQ_SUSPEND; - return retval; - } else if (retval) { - return retval; - } - - dev->power.request = RPM_REQ_SUSPEND; - dev->power.request_pending = true; - queue_work(pm_wq, &dev->power.work); - - return 0; -} - -/** * pm_suspend_timer_fn - Timer function for pm_schedule_suspend(). * @data: Device pointer passed by pm_schedule_suspend(). * - * Check if the time is right and execute __pm_request_suspend() in that case. + * Check if the time is right and queue a suspend request. */ static void pm_suspend_timer_fn(unsigned long data) { @@ -615,7 +828,8 @@ static void pm_suspend_timer_fn(unsigned long data) /* If 'expire' is after 'jiffies' we've been called too early. */ if (expires > 0 && !time_after(expires, jiffies)) { dev->power.timer_expires = 0; - __pm_request_suspend(dev); + rpm_suspend(dev, dev->power.timer_autosuspends ? + (RPM_ASYNC | RPM_AUTO) : RPM_ASYNC); } spin_unlock_irqrestore(&dev->power.lock, flags); @@ -629,49 +843,25 @@ static void pm_suspend_timer_fn(unsigned long data) int pm_schedule_suspend(struct device *dev, unsigned int delay) { unsigned long flags; - int retval = 0; + int retval; spin_lock_irqsave(&dev->power.lock, flags); - if (dev->power.runtime_error) { - retval = -EINVAL; - goto out; - } - if (!delay) { - retval = __pm_request_suspend(dev); + retval = rpm_suspend(dev, RPM_ASYNC); goto out; } - pm_runtime_deactivate_timer(dev); - - if (dev->power.request_pending) { - /* - * Pending resume requests take precedence over us, but any - * other pending requests have to be canceled. - */ - if (dev->power.request == RPM_REQ_RESUME) { - retval = -EAGAIN; - goto out; - } - dev->power.request = RPM_REQ_NONE; - } - - if (dev->power.runtime_status == RPM_SUSPENDED) - retval = 1; - else if (dev->power.runtime_status == RPM_SUSPENDING) - retval = -EINPROGRESS; - else if (atomic_read(&dev->power.usage_count) > 0 - || dev->power.disable_depth > 0) - retval = -EAGAIN; - else if (!pm_children_suspended(dev)) - retval = -EBUSY; + retval = rpm_check_suspend_allowed(dev); if (retval) goto out; + /* Other scheduled or pending requests need to be canceled. */ + pm_runtime_cancel_pending(dev); + dev->power.timer_expires = jiffies + msecs_to_jiffies(delay); - if (!dev->power.timer_expires) - dev->power.timer_expires = 1; + dev->power.timer_expires += !dev->power.timer_expires; + dev->power.timer_autosuspends = 0; mod_timer(&dev->power.suspend_timer, dev->power.timer_expires); out: @@ -682,110 +872,104 @@ int pm_schedule_suspend(struct device *dev, unsigned int delay) EXPORT_SYMBOL_GPL(pm_schedule_suspend); /** - * pm_request_resume - Submit a resume request for given device. - * @dev: Device to resume. + * __pm_runtime_idle - Entry point for runtime idle operations. + * @dev: Device to send idle notification for. + * @rpmflags: Flag bits. * - * This function must be called under dev->power.lock with interrupts disabled. + * If the RPM_GET_PUT flag is set, decrement the device's usage count and + * return immediately if it is larger than zero. Then carry out an idle + * notification, either synchronous or asynchronous. + * + * This routine may be called in atomic context if the RPM_ASYNC flag is set, + * or if pm_runtime_irq_safe() has been called. */ -static int __pm_request_resume(struct device *dev) +int __pm_runtime_idle(struct device *dev, int rpmflags) { - int retval = 0; - - if (dev->power.runtime_error) - return -EINVAL; - - if (dev->power.runtime_status == RPM_ACTIVE) - retval = 1; - else if (dev->power.runtime_status == RPM_RESUMING) - retval = -EINPROGRESS; - else if (dev->power.disable_depth > 0) - retval = -EAGAIN; - if (retval < 0) - return retval; + unsigned long flags; + int retval; - pm_runtime_deactivate_timer(dev); + might_sleep_if(!(rpmflags & RPM_ASYNC) && !dev->power.irq_safe); - if (dev->power.runtime_status == RPM_SUSPENDING) { - dev->power.deferred_resume = true; - return retval; - } - if (dev->power.request_pending) { - /* If non-resume request is pending, we can overtake it. */ - dev->power.request = retval ? RPM_REQ_NONE : RPM_REQ_RESUME; - return retval; + if (rpmflags & RPM_GET_PUT) { + if (!atomic_dec_and_test(&dev->power.usage_count)) + return 0; } - if (retval) - return retval; - dev->power.request = RPM_REQ_RESUME; - dev->power.request_pending = true; - queue_work(pm_wq, &dev->power.work); + spin_lock_irqsave(&dev->power.lock, flags); + retval = rpm_idle(dev, rpmflags); + spin_unlock_irqrestore(&dev->power.lock, flags); return retval; } +EXPORT_SYMBOL_GPL(__pm_runtime_idle); /** - * pm_request_resume - Submit a resume request for given device. - * @dev: Device to resume. + * __pm_runtime_suspend - Entry point for runtime put/suspend operations. + * @dev: Device to suspend. + * @rpmflags: Flag bits. + * + * If the RPM_GET_PUT flag is set, decrement the device's usage count and + * return immediately if it is larger than zero. Then carry out a suspend, + * either synchronous or asynchronous. + * + * This routine may be called in atomic context if the RPM_ASYNC flag is set, + * or if pm_runtime_irq_safe() has been called. */ -int pm_request_resume(struct device *dev) +int __pm_runtime_suspend(struct device *dev, int rpmflags) { unsigned long flags; int retval; + might_sleep_if(!(rpmflags & RPM_ASYNC) && !dev->power.irq_safe); + + if (rpmflags & RPM_GET_PUT) { + if (!atomic_dec_and_test(&dev->power.usage_count)) + return 0; + } + spin_lock_irqsave(&dev->power.lock, flags); - retval = __pm_request_resume(dev); + retval = rpm_suspend(dev, rpmflags); spin_unlock_irqrestore(&dev->power.lock, flags); return retval; } -EXPORT_SYMBOL_GPL(pm_request_resume); +EXPORT_SYMBOL_GPL(__pm_runtime_suspend); /** - * __pm_runtime_get - Reference count a device and wake it up, if necessary. - * @dev: Device to handle. - * @sync: If set and the device is suspended, resume it synchronously. + * __pm_runtime_resume - Entry point for runtime resume operations. + * @dev: Device to resume. + * @rpmflags: Flag bits. + * + * If the RPM_GET_PUT flag is set, increment the device's usage count. Then + * carry out a resume, either synchronous or asynchronous. * - * Increment the usage count of the device and resume it or submit a resume - * request for it, depending on the value of @sync. + * This routine may be called in atomic context if the RPM_ASYNC flag is set, + * or if pm_runtime_irq_safe() has been called. */ -int __pm_runtime_get(struct device *dev, bool sync) +int __pm_runtime_resume(struct device *dev, int rpmflags) { + unsigned long flags; int retval; - atomic_inc(&dev->power.usage_count); - retval = sync ? pm_runtime_resume(dev) : pm_request_resume(dev); + might_sleep_if(!(rpmflags & RPM_ASYNC) && !dev->power.irq_safe); - return retval; -} -EXPORT_SYMBOL_GPL(__pm_runtime_get); + if (rpmflags & RPM_GET_PUT) + atomic_inc(&dev->power.usage_count); -/** - * __pm_runtime_put - Decrement the device's usage counter and notify its bus. - * @dev: Device to handle. - * @sync: If the device's bus type is to be notified, do that synchronously. - * - * Decrement the usage count of the device and if it reaches zero, carry out a - * synchronous idle notification or submit an idle notification request for it, - * depending on the value of @sync. - */ -int __pm_runtime_put(struct device *dev, bool sync) -{ - int retval = 0; - - if (atomic_dec_and_test(&dev->power.usage_count)) - retval = sync ? pm_runtime_idle(dev) : pm_request_idle(dev); + spin_lock_irqsave(&dev->power.lock, flags); + retval = rpm_resume(dev, rpmflags); + spin_unlock_irqrestore(&dev->power.lock, flags); return retval; } -EXPORT_SYMBOL_GPL(__pm_runtime_put); +EXPORT_SYMBOL_GPL(__pm_runtime_resume); /** - * __pm_runtime_set_status - Set run-time PM status of a device. + * __pm_runtime_set_status - Set runtime PM status of a device. * @dev: Device to handle. - * @status: New run-time PM status of the device. + * @status: New runtime PM status of the device. * - * If run-time PM of the device is disabled or its power.runtime_error field is + * If runtime PM of the device is disabled or its power.runtime_error field is * different from zero, the status may be changed either to RPM_ACTIVE, or to * RPM_SUSPENDED, as long as that reflects the actual state of the device. * However, if the device has a parent and the parent is not active, and the @@ -831,7 +1015,7 @@ int __pm_runtime_set_status(struct device *dev, unsigned int status) /* * It is invalid to put an active child under a parent that is - * not active, has run-time PM enabled and the + * not active, has runtime PM enabled and the * 'power.ignore_children' flag unset. */ if (!parent->power.disable_depth @@ -848,7 +1032,7 @@ int __pm_runtime_set_status(struct device *dev, unsigned int status) } out_set: - dev->power.runtime_status = status; + __update_runtime_status(dev, status); dev->power.runtime_error = 0; out: spin_unlock_irqrestore(&dev->power.lock, flags); @@ -865,7 +1049,7 @@ EXPORT_SYMBOL_GPL(__pm_runtime_set_status); * @dev: Device to handle. * * Flush all pending requests for the device from pm_wq and wait for all - * run-time PM operations involving the device in progress to complete. + * runtime PM operations involving the device in progress to complete. * * Should be called under dev->power.lock with interrupts disabled. */ @@ -913,7 +1097,7 @@ static void __pm_runtime_barrier(struct device *dev) * Prevent the device from being suspended by incrementing its usage counter and * if there's a pending resume request for the device, wake the device up. * Next, make sure that all pending requests for the device have been flushed - * from pm_wq and wait for all run-time PM operations involving the device in + * from pm_wq and wait for all runtime PM operations involving the device in * progress to complete. * * Return value: @@ -929,7 +1113,7 @@ int pm_runtime_barrier(struct device *dev) if (dev->power.request_pending && dev->power.request == RPM_REQ_RESUME) { - __pm_runtime_resume(dev, false); + rpm_resume(dev, 0); retval = 1; } @@ -943,18 +1127,18 @@ int pm_runtime_barrier(struct device *dev) EXPORT_SYMBOL_GPL(pm_runtime_barrier); /** - * __pm_runtime_disable - Disable run-time PM of a device. + * __pm_runtime_disable - Disable runtime PM of a device. * @dev: Device to handle. * @check_resume: If set, check if there's a resume request for the device. * - * Increment power.disable_depth for the device and if was zero previously, - * cancel all pending run-time PM requests for the device and wait for all + * Increment power.disable_depth for the device and if it was zero previously, + * cancel all pending runtime PM requests for the device and wait for all * operations in progress to complete. The device can be either active or - * suspended after its run-time PM has been disabled. + * suspended after its runtime PM has been disabled. * * If @check_resume is set and there's a resume request pending when * __pm_runtime_disable() is called and power.disable_depth is zero, the - * function will wake up the device before disabling its run-time PM. + * function will wake up the device before disabling its runtime PM. */ void __pm_runtime_disable(struct device *dev, bool check_resume) { @@ -967,7 +1151,7 @@ void __pm_runtime_disable(struct device *dev, bool check_resume) /* * Wake up the device if there's a resume request pending, because that - * means there probably is some I/O to process and disabling run-time PM + * means there probably is some I/O to process and disabling runtime PM * shouldn't prevent the device from processing the I/O. */ if (check_resume && dev->power.request_pending @@ -978,7 +1162,7 @@ void __pm_runtime_disable(struct device *dev, bool check_resume) */ pm_runtime_get_noresume(dev); - __pm_runtime_resume(dev, false); + rpm_resume(dev, 0); pm_runtime_put_noidle(dev); } @@ -992,7 +1176,7 @@ void __pm_runtime_disable(struct device *dev, bool check_resume) EXPORT_SYMBOL_GPL(__pm_runtime_disable); /** - * pm_runtime_enable - Enable run-time PM of a device. + * pm_runtime_enable - Enable runtime PM of a device. * @dev: Device to handle. */ void pm_runtime_enable(struct device *dev) @@ -1011,13 +1195,174 @@ void pm_runtime_enable(struct device *dev) EXPORT_SYMBOL_GPL(pm_runtime_enable); /** - * pm_runtime_init - Initialize run-time PM fields in given device object. + * pm_runtime_forbid - Block runtime PM of a device. + * @dev: Device to handle. + * + * Increase the device's usage count and clear its power.runtime_auto flag, + * so that it cannot be suspended at run time until pm_runtime_allow() is called + * for it. + */ +void pm_runtime_forbid(struct device *dev) +{ + spin_lock_irq(&dev->power.lock); + if (!dev->power.runtime_auto) + goto out; + + dev->power.runtime_auto = false; + atomic_inc(&dev->power.usage_count); + rpm_resume(dev, 0); + + out: + spin_unlock_irq(&dev->power.lock); +} +EXPORT_SYMBOL_GPL(pm_runtime_forbid); + +/** + * pm_runtime_allow - Unblock runtime PM of a device. + * @dev: Device to handle. + * + * Decrease the device's usage count and set its power.runtime_auto flag. + */ +void pm_runtime_allow(struct device *dev) +{ + spin_lock_irq(&dev->power.lock); + if (dev->power.runtime_auto) + goto out; + + dev->power.runtime_auto = true; + if (atomic_dec_and_test(&dev->power.usage_count)) + rpm_idle(dev, RPM_AUTO); + + out: + spin_unlock_irq(&dev->power.lock); +} +EXPORT_SYMBOL_GPL(pm_runtime_allow); + +/** + * pm_runtime_no_callbacks - Ignore runtime PM callbacks for a device. + * @dev: Device to handle. + * + * Set the power.no_callbacks flag, which tells the PM core that this + * device is power-managed through its parent and has no runtime PM + * callbacks of its own. The runtime sysfs attributes will be removed. + */ +void pm_runtime_no_callbacks(struct device *dev) +{ + spin_lock_irq(&dev->power.lock); + dev->power.no_callbacks = 1; + spin_unlock_irq(&dev->power.lock); + if (device_is_registered(dev)) + rpm_sysfs_remove(dev); +} +EXPORT_SYMBOL_GPL(pm_runtime_no_callbacks); + +/** + * pm_runtime_irq_safe - Leave interrupts disabled during callbacks. + * @dev: Device to handle + * + * Set the power.irq_safe flag, which tells the PM core that the + * ->runtime_suspend() and ->runtime_resume() callbacks for this device should + * always be invoked with the spinlock held and interrupts disabled. It also + * causes the parent's usage counter to be permanently incremented, preventing + * the parent from runtime suspending -- otherwise an irq-safe child might have + * to wait for a non-irq-safe parent. + */ +void pm_runtime_irq_safe(struct device *dev) +{ + if (dev->parent) + pm_runtime_get_sync(dev->parent); + spin_lock_irq(&dev->power.lock); + dev->power.irq_safe = 1; + spin_unlock_irq(&dev->power.lock); +} +EXPORT_SYMBOL_GPL(pm_runtime_irq_safe); + +/** + * update_autosuspend - Handle a change to a device's autosuspend settings. + * @dev: Device to handle. + * @old_delay: The former autosuspend_delay value. + * @old_use: The former use_autosuspend value. + * + * Prevent runtime suspend if the new delay is negative and use_autosuspend is + * set; otherwise allow it. Send an idle notification if suspends are allowed. + * + * This function must be called under dev->power.lock with interrupts disabled. + */ +static void update_autosuspend(struct device *dev, int old_delay, int old_use) +{ + int delay = dev->power.autosuspend_delay; + + /* Should runtime suspend be prevented now? */ + if (dev->power.use_autosuspend && delay < 0) { + + /* If it used to be allowed then prevent it. */ + if (!old_use || old_delay >= 0) { + atomic_inc(&dev->power.usage_count); + rpm_resume(dev, 0); + } + } + + /* Runtime suspend should be allowed now. */ + else { + + /* If it used to be prevented then allow it. */ + if (old_use && old_delay < 0) + atomic_dec(&dev->power.usage_count); + + /* Maybe we can autosuspend now. */ + rpm_idle(dev, RPM_AUTO); + } +} + +/** + * pm_runtime_set_autosuspend_delay - Set a device's autosuspend_delay value. + * @dev: Device to handle. + * @delay: Value of the new delay in milliseconds. + * + * Set the device's power.autosuspend_delay value. If it changes to negative + * and the power.use_autosuspend flag is set, prevent runtime suspends. If it + * changes the other way, allow runtime suspends. + */ +void pm_runtime_set_autosuspend_delay(struct device *dev, int delay) +{ + int old_delay, old_use; + + spin_lock_irq(&dev->power.lock); + old_delay = dev->power.autosuspend_delay; + old_use = dev->power.use_autosuspend; + dev->power.autosuspend_delay = delay; + update_autosuspend(dev, old_delay, old_use); + spin_unlock_irq(&dev->power.lock); +} +EXPORT_SYMBOL_GPL(pm_runtime_set_autosuspend_delay); + +/** + * __pm_runtime_use_autosuspend - Set a device's use_autosuspend flag. + * @dev: Device to handle. + * @use: New value for use_autosuspend. + * + * Set the device's power.use_autosuspend flag, and allow or prevent runtime + * suspends as needed. + */ +void __pm_runtime_use_autosuspend(struct device *dev, bool use) +{ + int old_delay, old_use; + + spin_lock_irq(&dev->power.lock); + old_delay = dev->power.autosuspend_delay; + old_use = dev->power.use_autosuspend; + dev->power.use_autosuspend = use; + update_autosuspend(dev, old_delay, old_use); + spin_unlock_irq(&dev->power.lock); +} +EXPORT_SYMBOL_GPL(__pm_runtime_use_autosuspend); + +/** + * pm_runtime_init - Initialize runtime PM fields in given device object. * @dev: Device object to initialize. */ void pm_runtime_init(struct device *dev) { - spin_lock_init(&dev->power.lock); - dev->power.runtime_status = RPM_SUSPENDED; dev->power.idle_notification = false; @@ -1028,10 +1373,12 @@ void pm_runtime_init(struct device *dev) atomic_set(&dev->power.child_count, 0); pm_suspend_ignore_children(dev, false); + dev->power.runtime_auto = true; dev->power.request_pending = false; dev->power.request = RPM_REQ_NONE; dev->power.deferred_resume = false; + dev->power.accounting_timestamp = jiffies; INIT_WORK(&dev->power.work, pm_runtime_work); dev->power.timer_expires = 0; @@ -1052,4 +1399,89 @@ void pm_runtime_remove(struct device *dev) /* Change the status back to 'suspended' to match the initial status. */ if (dev->power.runtime_status == RPM_ACTIVE) pm_runtime_set_suspended(dev); + if (dev->power.irq_safe && dev->parent) + pm_runtime_put(dev->parent); +} +#endif + +/** + * pm_runtime_force_suspend - Force a device into suspend state if needed. + * @dev: Device to suspend. + * + * Disable runtime PM so we safely can check the device's runtime PM status and + * if it is active, invoke it's .runtime_suspend callback to bring it into + * suspend state. Keep runtime PM disabled to preserve the state unless we + * encounter errors. + * + * Typically this function may be invoked from a system suspend callback to make + * sure the device is put into low power state. + */ +int pm_runtime_force_suspend(struct device *dev) +{ + int (*callback)(struct device *); + int ret = 0; + + pm_runtime_disable(dev); + + /* + * Note that pm_runtime_status_suspended() returns false while + * !CONFIG_PM_RUNTIME, which means the device will be put into low + * power state. + */ + if (pm_runtime_status_suspended(dev)) + return 0; + + callback = rpm_get_suspend_cb(dev); + + if (!callback) { + ret = -ENOSYS; + goto err; + } + + ret = callback(dev); + if (ret) + goto err; + + pm_runtime_set_suspended(dev); + return 0; +err: + pm_runtime_enable(dev); + return ret; +} +EXPORT_SYMBOL_GPL(pm_runtime_force_suspend); + +/** + * pm_runtime_force_resume - Force a device into resume state. + * @dev: Device to resume. + * + * Prior invoking this function we expect the user to have brought the device + * into low power state by a call to pm_runtime_force_suspend(). Here we reverse + * those actions and brings the device into full power. We update the runtime PM + * status and re-enables runtime PM. + * + * Typically this function may be invoked from a system resume callback to make + * sure the device is put into full power state. + */ +int pm_runtime_force_resume(struct device *dev) +{ + int (*callback)(struct device *); + int ret = 0; + + callback = rpm_get_resume_cb(dev); + + if (!callback) { + ret = -ENOSYS; + goto out; + } + + ret = callback(dev); + if (ret) + goto out; + + pm_runtime_set_active(dev); + pm_runtime_mark_last_busy(dev); +out: + pm_runtime_enable(dev); + return ret; } +EXPORT_SYMBOL_GPL(pm_runtime_force_resume); |