On Thursday 11 June 2009, Oliver Neukum wrote:
> Am Donnerstag, 11. Juni 2009 00:01:20 schrieb Rafael J. Wysocki:
> > We have queued up resume requests for the device's parent, its parent etc.,
> > the topmost one goes first. The workqueue is singlethread, so
> > pm_autoresume() is going to be run for all parents before the device
> > itself, so if that were the only resume mechanism, it would be enough to
> > check if the parent is RPM_ACTIVE.
>
> A (IDLE)
> / \
> B (SUSPENDED) C (SUSPENDED)
>
> Suppose C is to be resumed. This means first in case of A the request
> to suspend would be cancelled. Here you drop the locks:
>
> + && (dev->parent->power.runtime_status == RPM_IDLE
> + || dev->parent->power.runtime_status == RPM_SUSPENDING
> + || dev->parent->power.runtime_status == RPM_SUSPENDED)) {
> + spin_unlock_irqrestore(&dev->power.lock, flags);
> + spin_unlock_irqrestore(&dev->parent->power.lock, parent_flags);
> +
> + /* We have to resume the parent first. */
> + pm_request_resume(dev->parent);
>
> But after pm_request_resume() returns there's no means to make sure
> nothing alters it back to RPM_SUSPENDED. The workqueue doesn't help
> you because you've scheduled nothing by that time. The suspension will
> work because C is still in RPM_SUSPENDED.
That exactly is the bug I told you about in one of the previous messages. :-)
The solution I used in the current version of the patch (appended) is to have
separate bits for RPM_WAKE and RPM_SUSPENDED (and for the other status
constants), so that they both can be set at a time.
Well, there probably still are some bugs lurking in it ...
Best,
Rafael
---
drivers/base/power/Makefile | 1
drivers/base/power/main.c | 2
drivers/base/power/runtime.c | 415 +++++++++++++++++++++++++++++++++++++++++++
include/linux/pm.h | 82 ++++++++
include/linux/pm_runtime.h | 50 +++++
kernel/power/Kconfig | 14 +
kernel/power/main.c | 17 +
7 files changed, 578 insertions(+), 3 deletions(-)
Index: linux-2.6/kernel/power/Kconfig
===================================================================
--- linux-2.6.orig/kernel/power/Kconfig
+++ linux-2.6/kernel/power/Kconfig
@@ -208,3 +208,17 @@ config APM_EMULATION
random kernel OOPSes or reboots that don't seem to be related to
anything, try disabling/enabling this option (or disabling/enabling
APM in your BIOS).
+
+config PM_RUNTIME
+ bool "Run-time PM core functionality"
+ depends on PM
+ ---help---
+ Enable functionality allowing I/O devices to be put into energy-saving
+ (low power) states at run time (or autosuspended) after a specified
+ period of inactivity and woken up in response to a hardware-generated
+ wake-up event or a driver's request.
+
+ Hardware support is generally required for this functionality to work
+ and the bus type drivers of the buses the devices are on are
+ responsibile for the actual handling of the autosuspend requests and
+ wake-up events.
Index: linux-2.6/kernel/power/main.c
===================================================================
--- linux-2.6.orig/kernel/power/main.c
+++ linux-2.6/kernel/power/main.c
@@ -11,6 +11,7 @@
#include <linux/kobject.h>
#include <linux/string.h>
#include <linux/resume-trace.h>
+#include <linux/workqueue.h>
#include "power.h"
@@ -217,8 +218,24 @@ static struct attribute_group attr_group
.attrs = g,
};
+#ifdef CONFIG_PM_RUNTIME
+struct workqueue_struct *pm_wq;
+
+static int __init pm_start_workqueue(void)
+{
+ pm_wq = create_freezeable_workqueue("pm");
+
+ return pm_wq ? 0 : -ENOMEM;
+}
+#else
+static inline int pm_start_workqueue(void) { return 0; }
+#endif
+
static int __init pm_init(void)
{
+ int error = pm_start_workqueue();
+ if (error)
+ return error;
power_kobj = kobject_create_and_add("power", NULL);
if (!power_kobj)
return -ENOMEM;
Index: linux-2.6/include/linux/pm.h
===================================================================
--- linux-2.6.orig/include/linux/pm.h
+++ linux-2.6/include/linux/pm.h
@@ -22,6 +22,9 @@
#define _LINUX_PM_H
#include <linux/list.h>
+#include <linux/workqueue.h>
+#include <linux/spinlock.h>
+#include <linux/completion.h>
/*
* Callbacks for platform drivers to implement.
@@ -165,6 +168,15 @@ typedef struct pm_message {
* It is allowed to unregister devices while the above callbacks are being
* executed. However, it is not allowed to unregister a device from within any
* of its own callbacks.
+ *
+ * There also are two callbacks related to run-time power management of devices:
+ *
+ * @autosuspend: Save the device registers and put it into an energy-saving (low
+ * power) state at run-time, enable wake-up events as appropriate.
+ *
+ * @autoresume: Put the device into the full power state and restore its
+ * registers (if applicable) at run time, in response to a wake-up event
+ * generated by hardware or at a request of software.
*/
struct dev_pm_ops {
@@ -182,6 +194,10 @@ struct dev_pm_ops {
int (*thaw_noirq)(struct device *dev);
int (*poweroff_noirq)(struct device *dev);
int (*restore_noirq)(struct device *dev);
+#ifdef CONFIG_PM_RUNTIME
+ int (*runtime_suspend)(struct device *dev);
+ int (*runtime_resume)(struct device *dev);
+#endif
};
/**
@@ -315,14 +331,74 @@ enum dpm_state {
DPM_OFF_IRQ,
};
+/**
+ * Device run-time power management state.
+ *
+ * These state labels are used internally by the PM core to indicate the current
+ * status of a device with respect to the PM core operations. They do not
+ * reflect the actual power state of the device or its status as seen by the
+ * driver.
+ *
+ * RPM_ACTIVE Device is fully operational, no run-time PM requests are
+ * pending for it.
+ *
+ * RPM_IDLE It has been requested that the device be suspended.
+ * Suspend request has been put into the run-time PM
+ * workqueue and it's pending execution.
+ *
+ * RPM_SUSPENDING Device bus type's ->runtime_suspend() callback is being
+ * executed.
+ *
+ * RPM_SUSPENDED Device bus type's ->runtime_suspend() callback has
+ * completed successfully. The device is regarded as
+ * suspended.
+ *
+ * RPM_WAKE It has been requested that the device be woken up.
+ * Resume request has been put into the run-time PM
+ * workqueue and it's pending execution.
+ *
+ * RPM_RESUMING Device bus type's ->runtime_resume() callback is being
+ * executed.
+ *
+ * RPM_ERROR Represents a condition from which the PM core cannot
+ * recover by itself. If the device's run-time PM status
+ * field has this value, all of the run-time PM operations
+ * carried out for the device by the core will fail, until
+ * the status field is changed to either RPM_ACTIVE or
+ * RPM_SUSPENDED (it is not valid to use the other values
+ * in such a situation) by the device's driver or bus type.
+ * This happens when the device bus type's
+ * ->runtime_suspend() or ->runtime_resume() callback
+ * returns error code different from -EAGAIN or -EBUSY.
+ */
+
+#define RPM_ACTIVE 0
+#define RPM_IDLE 0x01
+#define RPM_SUSPENDING 0x02
+#define RPM_SUSPENDED 0x04
+#define RPM_WAKE 0x08
+#define RPM_RESUMING 0x10
+
+#define RPM_IN_SUSPEND (RPM_SUSPENDING | RPM_SUSPENDED)
+#define RPM_INACTIVE (RPM_IDLE | RPM_IN_SUSPEND)
+#define RPM_ERROR (-1)
+
struct dev_pm_info {
pm_message_t power_state;
- unsigned can_wakeup:1;
- unsigned should_wakeup:1;
+ unsigned int can_wakeup:1;
+ unsigned int should_wakeup:1;
enum dpm_state status; /* Owned by the PM core */
-#ifdef CONFIG_PM_SLEEP
+#ifdef CONFIG_PM_SLEEP
struct list_head entry;
#endif
+#ifdef CONFIG_PM_RUNTIME
+ struct delayed_work suspend_work;
+ struct work_struct resume_work;
+ struct completion work_done;
+ unsigned int suspend_aborted:1;
+ unsigned int runtime_status:5;
+ spinlock_t lock;
+#endif
};
/*
Index: linux-2.6/drivers/base/power/Makefile
===================================================================
--- linux-2.6.orig/drivers/base/power/Makefile
+++ linux-2.6/drivers/base/power/Makefile
@@ -1,5 +1,6 @@
obj-$(CONFIG_PM) += sysfs.o
obj-$(CONFIG_PM_SLEEP) += main.o
+obj-$(CONFIG_PM_RUNTIME) += runtime.o
obj-$(CONFIG_PM_TRACE_RTC) += trace.o
ccflags-$(CONFIG_DEBUG_DRIVER) := -DDEBUG
Index: linux-2.6/drivers/base/power/runtime.c
===================================================================
--- /dev/null
+++ linux-2.6/drivers/base/power/runtime.c
@@ -0,0 +1,415 @@
+/*
+ * drivers/base/power/runtime.c - Helper functions for device run-time PM
+ *
+ * Copyright (c) 2009 Rafael J. Wysocki <rjw@xxxxxxx>, Novell Inc.
+ *
+ * This file is released under the GPLv2.
+ */
+
+#include <linux/pm_runtime.h>
+
+/**
+ * pm_runtime_reset - Clear all of the device run-time PM flags.
+ * @dev: Device object to clear the flags for.
+ */
+static void pm_runtime_reset(struct device *dev)
+{
+ dev->power.suspend_aborted = false;
+ dev->power.runtime_status = RPM_ACTIVE;
+}
+
+/**
+ * pm_device_suspended - Check if given device has been suspended at run time.
+ * @dev: Device to check.
+ * @data: Ignored.
+ *
+ * Returns 0 if the device has been suspended and it hasn't been requested to
+ * resume or -EBUSY otherwise.
+ */
+static int pm_device_suspended(struct device *dev, void *data)
+{
+ return dev->power.runtime_status == RPM_SUSPENDED ? 0 : -EBUSY;
+}
+
+/**
+ * pm_check_children - Check if all children of a device have been suspended.
+ * @dev: Device to check.
+ *
+ * Returns 0 if all children of the device have been suspended or -EBUSY
+ * otherwise.
+ */
+static int pm_check_children(struct device *dev)
+{
+ return device_for_each_child(dev, NULL, pm_device_suspended);
+}
+
+/**
+ * pm_runtime_suspend - Run a device bus type's runtime_suspend() callback.
+ * @work: Work structure used for scheduling the execution of this function.
+ *
+ * Use @work to get the device object the suspend has been scheduled for,
+ * check if the suspend request hasn't been cancelled and run the
+ * ->runtime_suspend() callback provided by the device's bus type driver.
+ * Update the run-time PM flags in the device object to reflect the current
+ * status of the device.
+ */
+static void pm_runtime_suspend(struct work_struct *work)
+{
+ struct delayed_work *dw = to_delayed_work(work);
+ struct device *dev = suspend_work_to_device(dw);
+ int error = 0;
+
+ spin_lock(&dev->power.lock);
+
+ if (dev->power.suspend_aborted) {
+ dev->power.runtime_status = RPM_ACTIVE;
+ goto out;
+ } else if (dev->power.runtime_status != RPM_IDLE) {
+ goto out;
+ } else if (pm_check_children(dev)) {
+ /*
+ * We can only suspend the device if all of its children have
+ * been suspended.
+ */
+ goto out;
+ }
+
+ dev->power.runtime_status = RPM_SUSPENDING;
+ init_completion(&dev->power.work_done);
+
+ spin_unlock(&dev->power.lock);
+
+ if (dev && dev->bus && dev->bus->pm && dev->bus->pm->runtime_suspend)
+ error = dev->bus->pm->runtime_suspend(dev);
+
+ spin_lock(&dev->power.lock);
+
+ /*
+ * Resume request might have been queued in the meantime, in which case
+ * the RPM_WAKE bit is also set in runtime_status.
+ */
+ dev->power.runtime_status &= ~RPM_SUSPENDING;
+ switch (error) {
+ case 0:
+ dev->power.runtime_status |= RPM_SUSPENDED;
+ break;
+ case -EAGAIN:
+ case -EBUSY:
+ dev->power.runtime_status = RPM_ACTIVE;
+ break;
+ default:
+ dev->power.runtime_status = RPM_ERROR;
+ }
+ complete(&dev->power.work_done);
+
+ out:
+ spin_unlock(&dev->power.lock);
+}
+
+/**
+ * pm_request_suspend - Schedule run-time suspend of given device.
+ * @dev: Device to suspend.
+ * @delay: Time to wait before attempting to suspend the device.
+ */
+void pm_request_suspend(struct device *dev, unsigned long delay)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&dev->power.lock, flags);
+
+ if (dev->power.runtime_status != RPM_ACTIVE)
+ goto out;
+
+ dev->power.runtime_status = RPM_IDLE;
+ dev->power.suspend_aborted = false;
+ queue_delayed_work(pm_wq, &dev->power.suspend_work, delay);
+
+ out:
+ spin_unlock_irqrestore(&dev->power.lock, flags);
+}
+
+/**
+ * pm_cancel_suspend - Cancel a pending suspend request for given device.
+ * @dev: Device to cancel the suspend request for.
+ *
+ * Should be called under pm_lock_device() and only if we are sure that the
+ * ->autosuspend() callback hasn't started to yet.
+ */
+static void pm_cancel_suspend(struct device *dev)
+{
+ dev->power.suspend_aborted = true;
+ cancel_delayed_work(&dev->power.suspend_work);
+ dev->power.runtime_status = RPM_ACTIVE;
+}
+
+/**
+ * pm_runtime_resume - Run a device bus type's runtime_resume() callback.
+ * @work: Work structure used for scheduling the execution of this function.
+ *
+ * Use @work to get the device object the resume has been scheduled for,
+ * check if the device is really suspended and run the ->runtime_resume()
+ * callback provided by the device's bus type driver. Update the run-time PM
+ * flags in the device object to reflect the current status of the device.
+ */
+static void pm_runtime_resume(struct work_struct *work)
+{
+ struct device *dev = resume_work_to_device(work);
+ int error = 0;
+
+ if (dev->parent)
+ spin_lock(&dev->parent->power.lock);
+ spin_lock(&dev->power.lock);
+
+ /*
+ * Since the PM workqueue is singlethread, this function cannot run
+ * in parallel with pm_runtime_suspend(). For this reason it is not
+ * necessary to check if RPM_SUSPENDING is set in runtime_status of the
+ * device.
+ */
+ repeat:
+ if (!(dev->power.runtime_status & RPM_WAKE)) {
+ if (dev->parent)
+ spin_unlock(&dev->parent->power.lock);
+ goto out;
+ } else if (dev->parent
+ && dev->parent->power.runtime_status != RPM_ACTIVE) {
+ /*
+ * Although this function cannot run in parallel with another
+ * instance of itself, it may be running in parallel with the
+ * synchronous resume of another device. In particular, that
+ * may be the device's parent.
+ */
+ if (dev->parent->power.runtime_status & RPM_RESUMING) {
+ spin_unlock(&dev->power.lock);
+ spin_unlock(&dev->parent->power.lock);
+
+ wait_for_completion(&dev->parent->power.work_done);
+
+ spin_lock(&dev->parent->power.lock);
+ spin_lock(&dev->power.lock);
+ }
+ if (dev->parent->power.runtime_status != RPM_ACTIVE) {
+ spin_unlock(&dev->parent->power.lock);
+ goto out;
+ }
+ goto repeat;
+ }
+
+ dev->power.runtime_status = RPM_RESUMING;
+ init_completion(&dev->power.work_done);
+
+ spin_unlock(&dev->power.lock);
+ if (dev->parent)
+ spin_unlock(&dev->parent->power.lock);
+
+ if (dev->bus && dev->bus->pm && dev->bus->pm->runtime_resume)
+ error = dev->bus->pm->runtime_resume(dev);
+
+ spin_lock(&dev->power.lock);
+
+ switch (error) {
+ case 0:
+ dev->power.runtime_status = RPM_ACTIVE;
+ break;
+ case -EAGAIN:
+ case -EBUSY:
+ dev->power.runtime_status = RPM_SUSPENDED;
+ break;
+ default:
+ dev->power.runtime_status = RPM_ERROR;
+ }
+ complete(&dev->power.work_done);
+
+ out:
+ spin_unlock(&dev->power.lock);
+}
+
+/**
+ * pm_request_resume - Schedule run-time resume of given device.
+ * @dev: Device to resume.
+ */
+void pm_request_resume(struct device *dev)
+{
+ unsigned long parent_flags = 0, flags;
+
+ repeat:
+ if (dev->parent)
+ spin_lock_irqsave(&dev->parent->power.lock, parent_flags);
+ spin_lock_irqsave(&dev->power.lock, flags);
+
+ if (dev->power.runtime_status == RPM_IDLE) {
+ /* Autosuspend request is pending, no need to resume. */
+ pm_cancel_suspend(dev);
+ goto out;
+ } else if (!(dev->power.runtime_status & RPM_IN_SUSPEND)) {
+ goto out;
+ } else if (dev->parent
+ && (dev->parent->power.runtime_status & RPM_INACTIVE)) {
+ spin_unlock_irqrestore(&dev->power.lock, flags);
+ spin_unlock_irqrestore(&dev->parent->power.lock, parent_flags);
+
+ /* We have to resume the parent first. */
+ pm_request_resume(dev->parent);
+
+ goto repeat;
+ }
+
+ /*
+ * The device may be suspending at the moment and we can't clear the
+ * RPM_SUSPENDING bit in its runtime_status just yet.
+ */
+ dev->power.runtime_status |= RPM_WAKE;
+ queue_work(pm_wq, &dev->power.resume_work);
+
+ out:
+ spin_unlock_irqrestore(&dev->power.lock, flags);
+ if (dev->parent)
+ spin_unlock_irqrestore(&dev->parent->power.lock, parent_flags);
+}
+
+/**
+ * pm_resume_sync - Resume given device waiting for the operation to complete.
+ * @dev: Device to resume.
+ *
+ * Resume the device synchronously, waiting for the operation to complete. If
+ * autosuspend is in progress while this function is being run, wait for it to
+ * finish before resuming the device. If the autosuspend is scheduled, but it
+ * hasn't started yet, cancel it and we're done.
+ */
+int pm_resume_sync(struct device *dev)
+{
+ int error = 0;
+
+ spin_lock(&dev->power.lock);
+
+ if (dev->power.runtime_status == RPM_ACTIVE) {
+ goto out;
+ } if (dev->power.runtime_status == RPM_IDLE) {
+ /* ->runtime_suspend() hasn't started yet, no need to resume. */
+ pm_cancel_suspend(dev);
+ goto out;
+ }
+
+ if (dev->power.runtime_status & RPM_SUSPENDING) {
+ spin_unlock(&dev->power.lock);
+
+ /*
+ * The ->runtime_suspend() callback is being executed right now,
+ * wait for it to complete.
+ */
+ wait_for_completion(&dev->power.work_done);
+ } else if (dev->power.runtime_status == RPM_SUSPENDED && dev->parent) {
+ spin_unlock(&dev->power.lock);
+
+ /* The device's parent may also be suspended. Resume it. */
+ error = pm_resume_sync(dev->parent);
+ if (error)
+ return error;
+ } else {
+ spin_unlock(&dev->power.lock);
+ }
+
+ if (dev->parent)
+ spin_lock(&dev->parent->power.lock);
+ spin_lock(&dev->power.lock);
+
+ if (dev->power.runtime_status & RPM_WAKE) {
+ /* There's a pending resume request that can be cancelled. */
+ work_clear_pending(&dev->power.resume_work);
+ } else if (dev->power.runtime_status == RPM_RESUMING) {
+ spin_unlock(&dev->power.lock);
+ if (dev->parent)
+ spin_unlock(&dev->parent->power.lock);
+
+ /*
+ * There's another resume running in parallel with us. Wait for
+ * it to complete.
+ */
+ wait_for_completion(&dev->power.work_done);
+
+ return dev->power.runtime_status == RPM_ACTIVE ? 0 : -EAGAIN;
+ } else if (!(dev->power.runtime_status & RPM_SUSPENDED)) {
+ error = -EINVAL;
+ if (dev->parent)
+ spin_unlock(&dev->parent->power.lock);
+ goto out;
+ }
+
+ dev->power.runtime_status = RPM_RESUMING;
+ init_completion(&dev->power.work_done);
+
+ spin_unlock(&dev->power.lock);
+ if (dev->parent)
+ spin_unlock(&dev->parent->power.lock);
+
+ if (dev->bus && dev->bus->pm && dev->bus->pm->runtime_resume)
+ error = dev->bus->pm->runtime_resume(dev);
+
+ spin_lock(&dev->power.lock);
+
+ switch (error) {
+ case 0:
+ dev->power.runtime_status = RPM_ACTIVE;
+ break;
+ case -EAGAIN:
+ case -EBUSY:
+ dev->power.runtime_status = RPM_SUSPENDED;
+ break;
+ default:
+ dev->power.runtime_status = RPM_ERROR;
+ }
+ complete(&dev->power.work_done);
+
+ out:
+ spin_unlock(&dev->power.lock);
+
+ return error;
+}
+
+/**
+ * pm_cancel_autosuspend - Cancel a pending autosuspend request for given device
+ * @dev: Device to handle.
+ *
+ * This routine is only supposed to be called when the run-time PM workqueue is
+ * frozen (i.e. during system-wide suspend or hibernation) when it is guaranteed
+ * that no work items are being executed.
+ */
+void pm_cancel_autosuspend(struct device *dev)
+{
+ spin_lock(&dev->power.lock);
+
+ cancel_delayed_work(&dev->power.suspend_work);
+ pm_runtime_reset(dev);
+
+ spin_unlock(&dev->power.lock);
+}
+
+/**
+ * pm_cancel_autoresume - Cancel a pending autoresume request for given device
+ * @dev: Device to handle.
+ *
+ * This routine is only supposed to be called when the run-time PM workqueue is
+ * frozen (i.e. during system-wide suspend or hibernation) when it is guaranteed
+ * that no work items are being executed.
+ */
+void pm_cancel_autoresume(struct device *dev)
+{
+ spin_lock(&dev->power.lock);
+
+ work_clear_pending(&dev->power.resume_work);
+ pm_runtime_reset(dev);
+
+ spin_unlock(&dev->power.lock);
+}
+
+/**
+ * pm_runtime_init - Initialize run-time PM fields in given device object.
+ * @dev: Device object to handle.
+ */
+void pm_runtime_init(struct device *dev)
+{
+ pm_runtime_reset(dev);
+ spin_lock_init(&dev->power.lock);
+ INIT_DELAYED_WORK(&dev->power.suspend_work, pm_runtime_suspend);
+ INIT_WORK(&dev->power.resume_work, pm_runtime_resume);
+}
Index: linux-2.6/include/linux/pm_runtime.h
===================================================================
--- /dev/null
+++ linux-2.6/include/linux/pm_runtime.h
@@ -0,0 +1,50 @@
+/*
+ * pm_runtime.h - Device run-time power management helper functions.
+ *
+ * Copyright (C) 2009 Rafael J. Wysocki <rjw@xxxxxxx>
+ *
+ * This file is released under the GPLv2.
+ */
+
+#ifndef _LINUX_PM_RUNTIME_H
+#define _LINUX_PM_RUNTIME_H
+
+#include <linux/device.h>
+#include <linux/pm.h>
+
+#ifdef CONFIG_PM_RUNTIME
+extern struct workqueue_struct *pm_wq;
+
+extern void pm_runtime_init(struct device *dev);
+extern void pm_request_suspend(struct device *dev, unsigned long delay);
+extern void pm_request_resume(struct device *dev);
+extern int pm_resume_sync(struct device *dev);
+extern void pm_cancel_autosuspend(struct device *dev);
+extern void pm_cancel_autoresume(struct device *dev);
+
+static inline struct device *suspend_work_to_device(struct delayed_work *work)
+{
+ struct dev_pm_info *dpi;
+
+ dpi = container_of(work, struct dev_pm_info, suspend_work);
+ return container_of(dpi, struct device, power);
+}
+
+static inline struct device *resume_work_to_device(struct work_struct *work)
+{
+ struct dev_pm_info *dpi;
+
+ dpi = container_of(work, struct dev_pm_info, resume_work);
+ return container_of(dpi, struct device, power);
+}
+
+#else /* !CONFIG_PM_RUNTIME */
+static inline void pm_runtime_init(struct device *dev) {}
+static inline void pm_request_suspend(struct device *dev, unsigned long delay);
+static inline void pm_request_resume(struct device *dev) {}
+static inline int pm_resume_sync(struct device *dev) { return -ENOSYS; }
+static inline void pm_cancel_autosuspend(struct device *dev) {}
+static inline void pm_cancel_autoresume(struct device *dev) {}
+#endif /* !CONFIG_PM_RUNTIME */
+
+#endif
Index: linux-2.6/drivers/base/power/main.c
===================================================================
--- linux-2.6.orig/drivers/base/power/main.c
+++ linux-2.6/drivers/base/power/main.c
@@ -21,6 +21,7 @@
#include <linux/kallsyms.h>
#include <linux/mutex.h>
#include <linux/pm.h>
+#include <linux/pm_runtime.h>
#include <linux/resume-trace.h>
#include <linux/rwsem.h>
#include <linux/interrupt.h>
@@ -88,6 +89,7 @@ void device_pm_add(struct device *dev)
}
list_add_tail(&dev->power.entry, &dpm_list);
+ pm_runtime_init(dev);
mutex_unlock(&dpm_list_mtx);
}
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