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1100 lines
28 KiB
1100 lines
28 KiB
/*
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* drivers/base/power/runtime.c - Helper functions for device run-time PM
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*
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* Copyright (c) 2009 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc.
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*
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* This file is released under the GPLv2.
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*/
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#include <linux/sched.h>
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#include <linux/pm_runtime.h>
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#include <linux/jiffies.h>
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static int __pm_runtime_resume(struct device *dev, bool from_wq);
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static int __pm_request_idle(struct device *dev);
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static int __pm_request_resume(struct device *dev);
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/**
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* pm_runtime_deactivate_timer - Deactivate given device's suspend timer.
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* @dev: Device to handle.
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*/
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static void pm_runtime_deactivate_timer(struct device *dev)
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{
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if (dev->power.timer_expires > 0) {
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del_timer(&dev->power.suspend_timer);
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dev->power.timer_expires = 0;
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}
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}
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/**
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* pm_runtime_cancel_pending - Deactivate suspend timer and cancel requests.
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* @dev: Device to handle.
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*/
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static void pm_runtime_cancel_pending(struct device *dev)
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{
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pm_runtime_deactivate_timer(dev);
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/*
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* In case there's a request pending, make sure its work function will
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* return without doing anything.
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*/
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dev->power.request = RPM_REQ_NONE;
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}
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/**
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* __pm_runtime_idle - Notify device bus type if the device can be suspended.
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* @dev: Device to notify the bus type about.
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*
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* This function must be called under dev->power.lock with interrupts disabled.
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*/
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static int __pm_runtime_idle(struct device *dev)
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__releases(&dev->power.lock) __acquires(&dev->power.lock)
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{
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int retval = 0;
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if (dev->power.runtime_error)
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retval = -EINVAL;
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else if (dev->power.idle_notification)
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retval = -EINPROGRESS;
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else if (atomic_read(&dev->power.usage_count) > 0
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|| dev->power.disable_depth > 0
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|| dev->power.runtime_status != RPM_ACTIVE)
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retval = -EAGAIN;
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else if (!pm_children_suspended(dev))
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retval = -EBUSY;
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if (retval)
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goto out;
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if (dev->power.request_pending) {
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/*
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* If an idle notification request is pending, cancel it. Any
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* other pending request takes precedence over us.
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*/
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if (dev->power.request == RPM_REQ_IDLE) {
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dev->power.request = RPM_REQ_NONE;
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} else if (dev->power.request != RPM_REQ_NONE) {
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retval = -EAGAIN;
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goto out;
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}
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}
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dev->power.idle_notification = true;
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if (dev->bus && dev->bus->pm && dev->bus->pm->runtime_idle) {
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spin_unlock_irq(&dev->power.lock);
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dev->bus->pm->runtime_idle(dev);
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spin_lock_irq(&dev->power.lock);
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} else if (dev->type && dev->type->pm && dev->type->pm->runtime_idle) {
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spin_unlock_irq(&dev->power.lock);
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dev->type->pm->runtime_idle(dev);
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spin_lock_irq(&dev->power.lock);
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} else if (dev->class && dev->class->pm
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&& dev->class->pm->runtime_idle) {
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spin_unlock_irq(&dev->power.lock);
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dev->class->pm->runtime_idle(dev);
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spin_lock_irq(&dev->power.lock);
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}
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dev->power.idle_notification = false;
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wake_up_all(&dev->power.wait_queue);
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out:
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return retval;
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}
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/**
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* pm_runtime_idle - Notify device bus type if the device can be suspended.
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* @dev: Device to notify the bus type about.
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*/
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int pm_runtime_idle(struct device *dev)
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{
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int retval;
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spin_lock_irq(&dev->power.lock);
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retval = __pm_runtime_idle(dev);
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spin_unlock_irq(&dev->power.lock);
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return retval;
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}
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EXPORT_SYMBOL_GPL(pm_runtime_idle);
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/**
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* __pm_runtime_suspend - Carry out run-time suspend of given device.
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* @dev: Device to suspend.
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* @from_wq: If set, the function has been called via pm_wq.
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*
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* Check if the device can be suspended and run the ->runtime_suspend() callback
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* provided by its bus type. If another suspend has been started earlier, wait
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* for it to finish. If an idle notification or suspend request is pending or
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* scheduled, cancel it.
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*
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* This function must be called under dev->power.lock with interrupts disabled.
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*/
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int __pm_runtime_suspend(struct device *dev, bool from_wq)
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__releases(&dev->power.lock) __acquires(&dev->power.lock)
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{
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struct device *parent = NULL;
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bool notify = false;
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int retval = 0;
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dev_dbg(dev, "__pm_runtime_suspend()%s!\n",
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from_wq ? " from workqueue" : "");
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repeat:
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if (dev->power.runtime_error) {
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retval = -EINVAL;
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goto out;
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}
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/* Pending resume requests take precedence over us. */
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if (dev->power.request_pending
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&& dev->power.request == RPM_REQ_RESUME) {
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retval = -EAGAIN;
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goto out;
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}
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/* Other scheduled or pending requests need to be canceled. */
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pm_runtime_cancel_pending(dev);
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if (dev->power.runtime_status == RPM_SUSPENDED)
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retval = 1;
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else if (dev->power.runtime_status == RPM_RESUMING
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|| dev->power.disable_depth > 0
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|| atomic_read(&dev->power.usage_count) > 0)
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retval = -EAGAIN;
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else if (!pm_children_suspended(dev))
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retval = -EBUSY;
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if (retval)
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goto out;
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if (dev->power.runtime_status == RPM_SUSPENDING) {
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DEFINE_WAIT(wait);
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if (from_wq) {
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retval = -EINPROGRESS;
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goto out;
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}
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/* Wait for the other suspend running in parallel with us. */
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for (;;) {
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prepare_to_wait(&dev->power.wait_queue, &wait,
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TASK_UNINTERRUPTIBLE);
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if (dev->power.runtime_status != RPM_SUSPENDING)
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break;
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spin_unlock_irq(&dev->power.lock);
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schedule();
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spin_lock_irq(&dev->power.lock);
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}
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finish_wait(&dev->power.wait_queue, &wait);
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goto repeat;
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}
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dev->power.runtime_status = RPM_SUSPENDING;
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dev->power.deferred_resume = false;
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if (dev->bus && dev->bus->pm && dev->bus->pm->runtime_suspend) {
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spin_unlock_irq(&dev->power.lock);
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retval = dev->bus->pm->runtime_suspend(dev);
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spin_lock_irq(&dev->power.lock);
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dev->power.runtime_error = retval;
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} else if (dev->type && dev->type->pm
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&& dev->type->pm->runtime_suspend) {
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spin_unlock_irq(&dev->power.lock);
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retval = dev->type->pm->runtime_suspend(dev);
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spin_lock_irq(&dev->power.lock);
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dev->power.runtime_error = retval;
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} else if (dev->class && dev->class->pm
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&& dev->class->pm->runtime_suspend) {
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spin_unlock_irq(&dev->power.lock);
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retval = dev->class->pm->runtime_suspend(dev);
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spin_lock_irq(&dev->power.lock);
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dev->power.runtime_error = retval;
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} else {
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retval = -ENOSYS;
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}
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if (retval) {
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dev->power.runtime_status = RPM_ACTIVE;
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if (retval == -EAGAIN || retval == -EBUSY) {
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if (dev->power.timer_expires == 0)
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notify = true;
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dev->power.runtime_error = 0;
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} else {
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pm_runtime_cancel_pending(dev);
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}
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} else {
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dev->power.runtime_status = RPM_SUSPENDED;
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pm_runtime_deactivate_timer(dev);
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if (dev->parent) {
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parent = dev->parent;
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atomic_add_unless(&parent->power.child_count, -1, 0);
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}
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}
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wake_up_all(&dev->power.wait_queue);
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if (dev->power.deferred_resume) {
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__pm_runtime_resume(dev, false);
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retval = -EAGAIN;
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goto out;
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}
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if (notify)
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__pm_runtime_idle(dev);
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if (parent && !parent->power.ignore_children) {
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spin_unlock_irq(&dev->power.lock);
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pm_request_idle(parent);
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spin_lock_irq(&dev->power.lock);
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}
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out:
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dev_dbg(dev, "__pm_runtime_suspend() returns %d!\n", retval);
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return retval;
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}
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/**
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* pm_runtime_suspend - Carry out run-time suspend of given device.
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* @dev: Device to suspend.
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*/
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int pm_runtime_suspend(struct device *dev)
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{
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int retval;
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spin_lock_irq(&dev->power.lock);
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retval = __pm_runtime_suspend(dev, false);
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spin_unlock_irq(&dev->power.lock);
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return retval;
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}
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EXPORT_SYMBOL_GPL(pm_runtime_suspend);
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/**
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* __pm_runtime_resume - Carry out run-time resume of given device.
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* @dev: Device to resume.
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* @from_wq: If set, the function has been called via pm_wq.
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*
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* Check if the device can be woken up and run the ->runtime_resume() callback
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* provided by its bus type. If another resume has been started earlier, wait
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* for it to finish. If there's a suspend running in parallel with this
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* function, wait for it to finish and resume the device. Cancel any scheduled
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* or pending requests.
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*
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* This function must be called under dev->power.lock with interrupts disabled.
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*/
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int __pm_runtime_resume(struct device *dev, bool from_wq)
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__releases(&dev->power.lock) __acquires(&dev->power.lock)
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{
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struct device *parent = NULL;
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int retval = 0;
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dev_dbg(dev, "__pm_runtime_resume()%s!\n",
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from_wq ? " from workqueue" : "");
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repeat:
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if (dev->power.runtime_error) {
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retval = -EINVAL;
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goto out;
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}
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pm_runtime_cancel_pending(dev);
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if (dev->power.runtime_status == RPM_ACTIVE)
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retval = 1;
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else if (dev->power.disable_depth > 0)
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retval = -EAGAIN;
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if (retval)
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goto out;
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if (dev->power.runtime_status == RPM_RESUMING
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|| dev->power.runtime_status == RPM_SUSPENDING) {
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DEFINE_WAIT(wait);
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if (from_wq) {
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if (dev->power.runtime_status == RPM_SUSPENDING)
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dev->power.deferred_resume = true;
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retval = -EINPROGRESS;
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goto out;
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}
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/* Wait for the operation carried out in parallel with us. */
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for (;;) {
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prepare_to_wait(&dev->power.wait_queue, &wait,
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TASK_UNINTERRUPTIBLE);
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if (dev->power.runtime_status != RPM_RESUMING
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&& dev->power.runtime_status != RPM_SUSPENDING)
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break;
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spin_unlock_irq(&dev->power.lock);
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schedule();
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spin_lock_irq(&dev->power.lock);
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}
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finish_wait(&dev->power.wait_queue, &wait);
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goto repeat;
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}
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if (!parent && dev->parent) {
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/*
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* Increment the parent's resume counter and resume it if
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* necessary.
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*/
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parent = dev->parent;
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spin_unlock(&dev->power.lock);
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pm_runtime_get_noresume(parent);
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spin_lock(&parent->power.lock);
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/*
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* We can resume if the parent's run-time PM is disabled or it
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* is set to ignore children.
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*/
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if (!parent->power.disable_depth
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&& !parent->power.ignore_children) {
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__pm_runtime_resume(parent, false);
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if (parent->power.runtime_status != RPM_ACTIVE)
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retval = -EBUSY;
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}
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spin_unlock(&parent->power.lock);
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spin_lock(&dev->power.lock);
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if (retval)
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goto out;
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goto repeat;
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}
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dev->power.runtime_status = RPM_RESUMING;
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if (dev->bus && dev->bus->pm && dev->bus->pm->runtime_resume) {
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spin_unlock_irq(&dev->power.lock);
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retval = dev->bus->pm->runtime_resume(dev);
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spin_lock_irq(&dev->power.lock);
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dev->power.runtime_error = retval;
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} else if (dev->type && dev->type->pm
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&& dev->type->pm->runtime_resume) {
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spin_unlock_irq(&dev->power.lock);
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retval = dev->type->pm->runtime_resume(dev);
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spin_lock_irq(&dev->power.lock);
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dev->power.runtime_error = retval;
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} else if (dev->class && dev->class->pm
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&& dev->class->pm->runtime_resume) {
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spin_unlock_irq(&dev->power.lock);
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retval = dev->class->pm->runtime_resume(dev);
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spin_lock_irq(&dev->power.lock);
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dev->power.runtime_error = retval;
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} else {
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retval = -ENOSYS;
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}
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if (retval) {
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dev->power.runtime_status = RPM_SUSPENDED;
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pm_runtime_cancel_pending(dev);
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} else {
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dev->power.runtime_status = RPM_ACTIVE;
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if (parent)
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atomic_inc(&parent->power.child_count);
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}
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wake_up_all(&dev->power.wait_queue);
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if (!retval)
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__pm_request_idle(dev);
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out:
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if (parent) {
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spin_unlock_irq(&dev->power.lock);
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pm_runtime_put(parent);
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spin_lock_irq(&dev->power.lock);
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}
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dev_dbg(dev, "__pm_runtime_resume() returns %d!\n", retval);
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return retval;
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}
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/**
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* pm_runtime_resume - Carry out run-time resume of given device.
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* @dev: Device to suspend.
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*/
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int pm_runtime_resume(struct device *dev)
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{
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int retval;
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spin_lock_irq(&dev->power.lock);
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retval = __pm_runtime_resume(dev, false);
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spin_unlock_irq(&dev->power.lock);
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return retval;
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}
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EXPORT_SYMBOL_GPL(pm_runtime_resume);
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/**
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* pm_runtime_work - Universal run-time PM work function.
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* @work: Work structure used for scheduling the execution of this function.
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*
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* Use @work to get the device object the work is to be done for, determine what
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* is to be done and execute the appropriate run-time PM function.
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*/
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static void pm_runtime_work(struct work_struct *work)
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{
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struct device *dev = container_of(work, struct device, power.work);
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enum rpm_request req;
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spin_lock_irq(&dev->power.lock);
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if (!dev->power.request_pending)
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goto out;
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req = dev->power.request;
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dev->power.request = RPM_REQ_NONE;
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dev->power.request_pending = false;
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switch (req) {
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case RPM_REQ_NONE:
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break;
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case RPM_REQ_IDLE:
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__pm_runtime_idle(dev);
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break;
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case RPM_REQ_SUSPEND:
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__pm_runtime_suspend(dev, true);
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break;
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case RPM_REQ_RESUME:
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__pm_runtime_resume(dev, true);
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break;
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}
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out:
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spin_unlock_irq(&dev->power.lock);
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}
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/**
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* __pm_request_idle - Submit an idle notification request for given device.
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* @dev: Device to handle.
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*
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* Check if the device's run-time PM status is correct for suspending the device
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* and queue up a request to run __pm_runtime_idle() for it.
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*
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* This function must be called under dev->power.lock with interrupts disabled.
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*/
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static int __pm_request_idle(struct device *dev)
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{
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int retval = 0;
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if (dev->power.runtime_error)
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retval = -EINVAL;
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else if (atomic_read(&dev->power.usage_count) > 0
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|| dev->power.disable_depth > 0
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|| dev->power.runtime_status == RPM_SUSPENDED
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|| dev->power.runtime_status == RPM_SUSPENDING)
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retval = -EAGAIN;
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else if (!pm_children_suspended(dev))
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retval = -EBUSY;
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if (retval)
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return retval;
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if (dev->power.request_pending) {
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/* Any requests other then RPM_REQ_IDLE take precedence. */
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if (dev->power.request == RPM_REQ_NONE)
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dev->power.request = RPM_REQ_IDLE;
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else if (dev->power.request != RPM_REQ_IDLE)
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retval = -EAGAIN;
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return retval;
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}
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dev->power.request = RPM_REQ_IDLE;
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dev->power.request_pending = true;
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queue_work(pm_wq, &dev->power.work);
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return retval;
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}
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/**
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* pm_request_idle - Submit an idle notification request for given device.
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* @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.
|
|
*/
|
|
static void pm_suspend_timer_fn(unsigned long data)
|
|
{
|
|
struct device *dev = (struct device *)data;
|
|
unsigned long flags;
|
|
unsigned long expires;
|
|
|
|
spin_lock_irqsave(&dev->power.lock, flags);
|
|
|
|
expires = dev->power.timer_expires;
|
|
/* 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);
|
|
}
|
|
|
|
spin_unlock_irqrestore(&dev->power.lock, flags);
|
|
}
|
|
|
|
/**
|
|
* pm_schedule_suspend - Set up a timer to submit a suspend request in future.
|
|
* @dev: Device to suspend.
|
|
* @delay: Time to wait before submitting a suspend request, in milliseconds.
|
|
*/
|
|
int pm_schedule_suspend(struct device *dev, unsigned int delay)
|
|
{
|
|
unsigned long flags;
|
|
int retval = 0;
|
|
|
|
spin_lock_irqsave(&dev->power.lock, flags);
|
|
|
|
if (dev->power.runtime_error) {
|
|
retval = -EINVAL;
|
|
goto out;
|
|
}
|
|
|
|
if (!delay) {
|
|
retval = __pm_request_suspend(dev);
|
|
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 (atomic_read(&dev->power.usage_count) > 0
|
|
|| dev->power.disable_depth > 0)
|
|
retval = -EAGAIN;
|
|
else if (!pm_children_suspended(dev))
|
|
retval = -EBUSY;
|
|
if (retval)
|
|
goto out;
|
|
|
|
dev->power.timer_expires = jiffies + msecs_to_jiffies(delay);
|
|
if (!dev->power.timer_expires)
|
|
dev->power.timer_expires = 1;
|
|
mod_timer(&dev->power.suspend_timer, dev->power.timer_expires);
|
|
|
|
out:
|
|
spin_unlock_irqrestore(&dev->power.lock, flags);
|
|
|
|
return retval;
|
|
}
|
|
EXPORT_SYMBOL_GPL(pm_schedule_suspend);
|
|
|
|
/**
|
|
* pm_request_resume - Submit a resume request for given device.
|
|
* @dev: Device to resume.
|
|
*
|
|
* This function must be called under dev->power.lock with interrupts disabled.
|
|
*/
|
|
static int __pm_request_resume(struct device *dev)
|
|
{
|
|
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;
|
|
|
|
pm_runtime_deactivate_timer(dev);
|
|
|
|
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 (retval)
|
|
return retval;
|
|
|
|
dev->power.request = RPM_REQ_RESUME;
|
|
dev->power.request_pending = true;
|
|
queue_work(pm_wq, &dev->power.work);
|
|
|
|
return retval;
|
|
}
|
|
|
|
/**
|
|
* pm_request_resume - Submit a resume request for given device.
|
|
* @dev: Device to resume.
|
|
*/
|
|
int pm_request_resume(struct device *dev)
|
|
{
|
|
unsigned long flags;
|
|
int retval;
|
|
|
|
spin_lock_irqsave(&dev->power.lock, flags);
|
|
retval = __pm_request_resume(dev);
|
|
spin_unlock_irqrestore(&dev->power.lock, flags);
|
|
|
|
return retval;
|
|
}
|
|
EXPORT_SYMBOL_GPL(pm_request_resume);
|
|
|
|
/**
|
|
* __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.
|
|
*
|
|
* Increment the usage count of the device and resume it or submit a resume
|
|
* request for it, depending on the value of @sync.
|
|
*/
|
|
int __pm_runtime_get(struct device *dev, bool sync)
|
|
{
|
|
int retval;
|
|
|
|
atomic_inc(&dev->power.usage_count);
|
|
retval = sync ? pm_runtime_resume(dev) : pm_request_resume(dev);
|
|
|
|
return retval;
|
|
}
|
|
EXPORT_SYMBOL_GPL(__pm_runtime_get);
|
|
|
|
/**
|
|
* __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);
|
|
|
|
return retval;
|
|
}
|
|
EXPORT_SYMBOL_GPL(__pm_runtime_put);
|
|
|
|
/**
|
|
* __pm_runtime_set_status - Set run-time PM status of a device.
|
|
* @dev: Device to handle.
|
|
* @status: New run-time PM status of the device.
|
|
*
|
|
* If run-time 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
|
|
* parent's power.ignore_children flag is unset, the device's status cannot be
|
|
* set to RPM_ACTIVE, so -EBUSY is returned in that case.
|
|
*
|
|
* If successful, __pm_runtime_set_status() clears the power.runtime_error field
|
|
* and the device parent's counter of unsuspended children is modified to
|
|
* reflect the new status. If the new status is RPM_SUSPENDED, an idle
|
|
* notification request for the parent is submitted.
|
|
*/
|
|
int __pm_runtime_set_status(struct device *dev, unsigned int status)
|
|
{
|
|
struct device *parent = dev->parent;
|
|
unsigned long flags;
|
|
bool notify_parent = false;
|
|
int error = 0;
|
|
|
|
if (status != RPM_ACTIVE && status != RPM_SUSPENDED)
|
|
return -EINVAL;
|
|
|
|
spin_lock_irqsave(&dev->power.lock, flags);
|
|
|
|
if (!dev->power.runtime_error && !dev->power.disable_depth) {
|
|
error = -EAGAIN;
|
|
goto out;
|
|
}
|
|
|
|
if (dev->power.runtime_status == status)
|
|
goto out_set;
|
|
|
|
if (status == RPM_SUSPENDED) {
|
|
/* It always is possible to set the status to 'suspended'. */
|
|
if (parent) {
|
|
atomic_add_unless(&parent->power.child_count, -1, 0);
|
|
notify_parent = !parent->power.ignore_children;
|
|
}
|
|
goto out_set;
|
|
}
|
|
|
|
if (parent) {
|
|
spin_lock_nested(&parent->power.lock, SINGLE_DEPTH_NESTING);
|
|
|
|
/*
|
|
* It is invalid to put an active child under a parent that is
|
|
* not active, has run-time PM enabled and the
|
|
* 'power.ignore_children' flag unset.
|
|
*/
|
|
if (!parent->power.disable_depth
|
|
&& !parent->power.ignore_children
|
|
&& parent->power.runtime_status != RPM_ACTIVE)
|
|
error = -EBUSY;
|
|
else if (dev->power.runtime_status == RPM_SUSPENDED)
|
|
atomic_inc(&parent->power.child_count);
|
|
|
|
spin_unlock(&parent->power.lock);
|
|
|
|
if (error)
|
|
goto out;
|
|
}
|
|
|
|
out_set:
|
|
dev->power.runtime_status = status;
|
|
dev->power.runtime_error = 0;
|
|
out:
|
|
spin_unlock_irqrestore(&dev->power.lock, flags);
|
|
|
|
if (notify_parent)
|
|
pm_request_idle(parent);
|
|
|
|
return error;
|
|
}
|
|
EXPORT_SYMBOL_GPL(__pm_runtime_set_status);
|
|
|
|
/**
|
|
* __pm_runtime_barrier - Cancel pending requests and wait for completions.
|
|
* @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.
|
|
*
|
|
* Should be called under dev->power.lock with interrupts disabled.
|
|
*/
|
|
static void __pm_runtime_barrier(struct device *dev)
|
|
{
|
|
pm_runtime_deactivate_timer(dev);
|
|
|
|
if (dev->power.request_pending) {
|
|
dev->power.request = RPM_REQ_NONE;
|
|
spin_unlock_irq(&dev->power.lock);
|
|
|
|
cancel_work_sync(&dev->power.work);
|
|
|
|
spin_lock_irq(&dev->power.lock);
|
|
dev->power.request_pending = false;
|
|
}
|
|
|
|
if (dev->power.runtime_status == RPM_SUSPENDING
|
|
|| dev->power.runtime_status == RPM_RESUMING
|
|
|| dev->power.idle_notification) {
|
|
DEFINE_WAIT(wait);
|
|
|
|
/* Suspend, wake-up or idle notification in progress. */
|
|
for (;;) {
|
|
prepare_to_wait(&dev->power.wait_queue, &wait,
|
|
TASK_UNINTERRUPTIBLE);
|
|
if (dev->power.runtime_status != RPM_SUSPENDING
|
|
&& dev->power.runtime_status != RPM_RESUMING
|
|
&& !dev->power.idle_notification)
|
|
break;
|
|
spin_unlock_irq(&dev->power.lock);
|
|
|
|
schedule();
|
|
|
|
spin_lock_irq(&dev->power.lock);
|
|
}
|
|
finish_wait(&dev->power.wait_queue, &wait);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* pm_runtime_barrier - Flush pending requests and wait for completions.
|
|
* @dev: Device to handle.
|
|
*
|
|
* 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
|
|
* progress to complete.
|
|
*
|
|
* Return value:
|
|
* 1, if there was a resume request pending and the device had to be woken up,
|
|
* 0, otherwise
|
|
*/
|
|
int pm_runtime_barrier(struct device *dev)
|
|
{
|
|
int retval = 0;
|
|
|
|
pm_runtime_get_noresume(dev);
|
|
spin_lock_irq(&dev->power.lock);
|
|
|
|
if (dev->power.request_pending
|
|
&& dev->power.request == RPM_REQ_RESUME) {
|
|
__pm_runtime_resume(dev, false);
|
|
retval = 1;
|
|
}
|
|
|
|
__pm_runtime_barrier(dev);
|
|
|
|
spin_unlock_irq(&dev->power.lock);
|
|
pm_runtime_put_noidle(dev);
|
|
|
|
return retval;
|
|
}
|
|
EXPORT_SYMBOL_GPL(pm_runtime_barrier);
|
|
|
|
/**
|
|
* __pm_runtime_disable - Disable run-time 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
|
|
* operations in progress to complete. The device can be either active or
|
|
* suspended after its run-time 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.
|
|
*/
|
|
void __pm_runtime_disable(struct device *dev, bool check_resume)
|
|
{
|
|
spin_lock_irq(&dev->power.lock);
|
|
|
|
if (dev->power.disable_depth > 0) {
|
|
dev->power.disable_depth++;
|
|
goto out;
|
|
}
|
|
|
|
/*
|
|
* 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
|
|
* shouldn't prevent the device from processing the I/O.
|
|
*/
|
|
if (check_resume && dev->power.request_pending
|
|
&& dev->power.request == RPM_REQ_RESUME) {
|
|
/*
|
|
* Prevent suspends and idle notifications from being carried
|
|
* out after we have woken up the device.
|
|
*/
|
|
pm_runtime_get_noresume(dev);
|
|
|
|
__pm_runtime_resume(dev, false);
|
|
|
|
pm_runtime_put_noidle(dev);
|
|
}
|
|
|
|
if (!dev->power.disable_depth++)
|
|
__pm_runtime_barrier(dev);
|
|
|
|
out:
|
|
spin_unlock_irq(&dev->power.lock);
|
|
}
|
|
EXPORT_SYMBOL_GPL(__pm_runtime_disable);
|
|
|
|
/**
|
|
* pm_runtime_enable - Enable run-time PM of a device.
|
|
* @dev: Device to handle.
|
|
*/
|
|
void pm_runtime_enable(struct device *dev)
|
|
{
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&dev->power.lock, flags);
|
|
|
|
if (dev->power.disable_depth > 0)
|
|
dev->power.disable_depth--;
|
|
else
|
|
dev_warn(dev, "Unbalanced %s!\n", __func__);
|
|
|
|
spin_unlock_irqrestore(&dev->power.lock, flags);
|
|
}
|
|
EXPORT_SYMBOL_GPL(pm_runtime_enable);
|
|
|
|
/**
|
|
* pm_runtime_forbid - Block run-time 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);
|
|
__pm_runtime_resume(dev, false);
|
|
|
|
out:
|
|
spin_unlock_irq(&dev->power.lock);
|
|
}
|
|
EXPORT_SYMBOL_GPL(pm_runtime_forbid);
|
|
|
|
/**
|
|
* pm_runtime_allow - Unblock run-time 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))
|
|
__pm_runtime_idle(dev);
|
|
|
|
out:
|
|
spin_unlock_irq(&dev->power.lock);
|
|
}
|
|
EXPORT_SYMBOL_GPL(pm_runtime_allow);
|
|
|
|
/**
|
|
* pm_runtime_init - Initialize run-time 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;
|
|
|
|
dev->power.disable_depth = 1;
|
|
atomic_set(&dev->power.usage_count, 0);
|
|
|
|
dev->power.runtime_error = 0;
|
|
|
|
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;
|
|
INIT_WORK(&dev->power.work, pm_runtime_work);
|
|
|
|
dev->power.timer_expires = 0;
|
|
setup_timer(&dev->power.suspend_timer, pm_suspend_timer_fn,
|
|
(unsigned long)dev);
|
|
|
|
init_waitqueue_head(&dev->power.wait_queue);
|
|
}
|
|
|
|
/**
|
|
* pm_runtime_remove - Prepare for removing a device from device hierarchy.
|
|
* @dev: Device object being removed from device hierarchy.
|
|
*/
|
|
void pm_runtime_remove(struct device *dev)
|
|
{
|
|
__pm_runtime_disable(dev, false);
|
|
|
|
/* Change the status back to 'suspended' to match the initial status. */
|
|
if (dev->power.runtime_status == RPM_ACTIVE)
|
|
pm_runtime_set_suspended(dev);
|
|
}
|
|
|