[RFC][PATCH] PM / Wakeup: Introduce wakeup source objects and event statistics (was: Re: Wakeup-events implementation)

[Rafael J. Wysocki]

Hi,

Below is a patch that adds some statistics to the previously merged
pm_wakeup_event()/pm_stay_awake()/pm_relax() code.  It also makes it possible
to use wakeup sources that are not directly associated with devices.

It adds functions for manipulating wakeup source objects and reworks the
device wakeup enabling/disabling to use the new functions.  The list of wakeup
sources is only used for updating the "hit count" statistics for now (this is
the number of times the wakeup source was active when the PM core checked), but
I'm planning to add a /proc file listing all wakeup sources, including the ones
that are not attached to device objects.

It appears to work with the PCI wakeup code added previously, but that's only
one case.  I'm also not sure if it builds withoug CONFIG_PM_SLEEP.  [BTW, I'm
not sure it atomic_inc() and atomic_dec() imply a memory barrier in general.
That seems to be the case on x86, but I don't know about other architectures.]

Please have a look and let me know what you think.

Thanks,
Rafael


---
 drivers/base/power/main.c    |    3 
 drivers/base/power/power.h   |    1 
 drivers/base/power/runtime.c |    2 
 drivers/base/power/sysfs.c   |  121 +++++++++
 drivers/base/power/wakeup.c  |  532 ++++++++++++++++++++++++++++++++++++-------
 include/linux/pm.h           |   16 -
 include/linux/pm_wakeup.h    |  114 +++++++--
 include/linux/suspend.h      |    4 
 kernel/power/main.c          |    8 
 9 files changed, 673 insertions(+), 128 deletions(-)

Index: linux-2.6/include/linux/pm_wakeup.h
===================================================================
--- linux-2.6.orig/include/linux/pm_wakeup.h
+++ linux-2.6/include/linux/pm_wakeup.h
@@ -2,6 +2,7 @@
  *  pm_wakeup.h - Power management wakeup interface
  *
  *  Copyright (C) 2008 Alan Stern
+ *  Copyright (C) 2010 Rafael J. Wysocki, Novell Inc.
  *
  *  This program is free software; you can redistribute it and/or modify
  *  it under the terms of the GNU General Public License as published by
@@ -27,18 +28,27 @@
 
 #include <linux/types.h>
 
-#ifdef CONFIG_PM
+struct wakeup_source {
+	char 			*name;
+	struct list_head	entry;
+	spinlock_t		lock;
+	struct timer_list	timer;
+	unsigned long		timer_expires;
+	ktime_t total_time;
+	ktime_t max_time;
+	ktime_t last_time;
+	unsigned long		event_count;
+	unsigned long		active_count;
+	unsigned long		relax_count;
+	unsigned long		hit_count;
+	unsigned int		active:1;
+};
 
-/* Changes to device_may_wakeup take effect on the next pm state change.
- *
- * By default, most devices should leave wakeup disabled.  The exceptions
- * are devices that everyone expects to be wakeup sources: keyboards,
- * power buttons, possibly network interfaces, etc.
+#ifdef CONFIG_PM_SLEEP
+
+/*
+ * Changes to device_may_wakeup take effect on the next pm state change.
  */
-static inline void device_init_wakeup(struct device *dev, bool val)
-{
-	dev->power.can_wakeup = dev->power.should_wakeup = val;
-}
 
 static inline void device_set_wakeup_capable(struct device *dev, bool capable)
 {
@@ -50,23 +60,32 @@ static inline bool device_can_wakeup(str
 	return dev->power.can_wakeup;
 }
 
-static inline void device_set_wakeup_enable(struct device *dev, bool enable)
-{
-	dev->power.should_wakeup = enable;
-}
+
 
 static inline bool device_may_wakeup(struct device *dev)
 {
-	return dev->power.can_wakeup && dev->power.should_wakeup;
+	return dev->power.can_wakeup && !!dev->power.wakeup;
 }
 
-#else /* !CONFIG_PM */
+/* drivers/base/power/wakeup.c */
+extern struct wakeup_source *wakeup_source_create(const char *name);
+extern void wakeup_source_destroy(struct wakeup_source *ws);
+extern void wakeup_source_register(struct wakeup_source *ws);
+extern void wakeup_source_unregister(struct wakeup_source *ws);
+extern struct wakeup_source *wakeup_source_add(const char *name);
+extern void wakeup_source_remove(struct wakeup_source *ws);
+extern int device_wakeup_enable(struct device *dev);
+extern int device_wakeup_disable(struct device *dev);
+extern int device_init_wakeup(struct device *dev, bool val);
+extern int device_set_wakeup_enable(struct device *dev, bool enable);
+extern void __pm_stay_awake(struct wakeup_source *ws);
+extern void pm_stay_awake(struct device *dev);
+extern void __pm_relax(struct wakeup_source *ws);
+extern void pm_relax(struct device *dev);
+extern void __pm_wakeup_event(struct wakeup_source *ws, unsigned int msec);
+extern void pm_wakeup_event(struct device *dev, unsigned int msec);
 
-/* For some reason the following routines work even without CONFIG_PM */
-static inline void device_init_wakeup(struct device *dev, bool val)
-{
-	dev->power.can_wakeup = val;
-}
+#else /* !CONFIG_PM_SLEEP */
 
 static inline void device_set_wakeup_capable(struct device *dev, bool capable)
 {
@@ -78,15 +97,60 @@ static inline bool device_can_wakeup(str
 	return dev->power.can_wakeup;
 }
 
-static inline void device_set_wakeup_enable(struct device *dev, bool enable)
+static inline bool device_may_wakeup(struct device *dev)
 {
+	return false;
 }
 
-static inline bool device_may_wakeup(struct device *dev)
+static inline struct wakeup_source *wakeup_source_create(char *name)
 {
-	return false;
+	return NULL;
+}
+
+static inline void wakeup_source_destroy(struct wakeup_source *ws) {}
+
+static inline void wakeup_source_register(struct wakeup_source *ws) {}
+
+static inline void wakeup_source_unregister(struct wakeup_source *ws) {}
+
+static inline struct wakeup_source *wakeup_source_add(char *name)
+{
+	return NULL;
 }
 
-#endif /* !CONFIG_PM */
+static inline void wakeup_source_remove(struct wakeup_source *ws) {}
+
+static inline int device_wakeup_enable(struct device *dev)
+{
+	return -EINVAL;
+}
+
+static inline int device_wakeup_disable(struct device *dev) {}
+
+static inline int device_init_wakeup(struct device *dev, bool val)
+{
+	dev->power.can_wakeup = val;
+	return val ? -EINVAL : 0;
+}
+
+
+static inline int device_set_wakeup_enable(struct device *dev, bool enable)
+{
+	return -EINVAL;
+}
+
+static inline void __pm_stay_awake(struct wakeup_source *ws) {}
+
+static inline void pm_stay_awake(struct device *dev) {}
+
+static inline void __pm_relax(struct wakeup_source *ws) {}
+
+static inline void pm_relax(struct device *dev) {}
+
+static inline void __pm_wakeup_event(struct wakeup_source *ws, unsigned int msec) {}
+
+static inline void pm_wakeup_event(struct device *dev, unsigned int msec) {}
+
+#endif /* !CONFIG_PM_SLEEP */
 
 #endif /* _LINUX_PM_WAKEUP_H */
Index: linux-2.6/include/linux/pm.h
===================================================================
--- linux-2.6.orig/include/linux/pm.h
+++ linux-2.6/include/linux/pm.h
@@ -448,23 +448,24 @@ enum rpm_request {
 	RPM_REQ_RESUME,
 };
 
+struct wakeup_source;
+
 struct dev_pm_info {
 	pm_message_t		power_state;
 	unsigned int		can_wakeup:1;
-	unsigned int		should_wakeup:1;
 	unsigned		async_suspend:1;
 	enum dpm_state		status;		/* Owned by the PM core */
+	spinlock_t		lock;
 #ifdef CONFIG_PM_SLEEP
 	struct list_head	entry;
 	struct completion	completion;
-	unsigned long		wakeup_count;
+	struct wakeup_source	*wakeup;
 #endif
 #ifdef CONFIG_PM_RUNTIME
 	struct timer_list	suspend_timer;
 	unsigned long		timer_expires;
 	struct work_struct	work;
 	wait_queue_head_t	wait_queue;
-	spinlock_t		lock;
 	atomic_t		usage_count;
 	atomic_t		child_count;
 	unsigned int		disable_depth:3;
@@ -559,11 +560,6 @@ extern void __suspend_report_result(cons
 	} while (0)
 
 extern void device_pm_wait_for_dev(struct device *sub, struct device *dev);
-
-/* drivers/base/power/wakeup.c */
-extern void pm_wakeup_event(struct device *dev, unsigned int msec);
-extern void pm_stay_awake(struct device *dev);
-extern void pm_relax(void);
 #else /* !CONFIG_PM_SLEEP */
 
 #define device_pm_lock() do {} while (0)
@@ -577,10 +573,6 @@ static inline int dpm_suspend_start(pm_m
 #define suspend_report_result(fn, ret)		do {} while (0)
 
 static inline void device_pm_wait_for_dev(struct device *a, struct device *b) {}
-
-static inline void pm_wakeup_event(struct device *dev, unsigned int msec) {}
-static inline void pm_stay_awake(struct device *dev) {}
-static inline void pm_relax(void) {}
 #endif /* !CONFIG_PM_SLEEP */
 
 /* How to reorder dpm_list after device_move() */
Index: linux-2.6/drivers/base/power/wakeup.c
===================================================================
--- linux-2.6.orig/drivers/base/power/wakeup.c
+++ linux-2.6/drivers/base/power/wakeup.c
@@ -11,7 +11,10 @@
 #include <linux/sched.h>
 #include <linux/capability.h>
 #include <linux/suspend.h>
-#include <linux/pm.h>
+
+#include "power.h"
+
+#define TIMEOUT		100
 
 /*
  * If set, the suspend/hibernate code will abort transitions to a sleep state
@@ -20,18 +23,251 @@
 bool events_check_enabled;
 
 /* The counter of registered wakeup events. */
-static unsigned long event_count;
+static atomic_t event_count = ATOMIC_INIT(0);
 /* A preserved old value of event_count. */
-static unsigned long saved_event_count;
+static unsigned int saved_count;
 /* The counter of wakeup events being processed. */
-static unsigned long events_in_progress;
+static atomic_t events_in_progress = ATOMIC_INIT(0);
 
 static DEFINE_SPINLOCK(events_lock);
 
 static void pm_wakeup_timer_fn(unsigned long data);
 
-static DEFINE_TIMER(events_timer, pm_wakeup_timer_fn, 0, 0);
-static unsigned long events_timer_expires;
+static LIST_HEAD(wakeup_sources);
+
+/**
+ * wakeup_source_create - Create a struct wakeup_source object.
+ * @name: Name of the new wakeup source.
+ */
+struct wakeup_source *wakeup_source_create(const char *name)
+{
+	struct wakeup_source *ws;
+
+	ws = kzalloc(sizeof(*ws), GFP_KERNEL);
+	if (!ws)
+		return NULL;
+
+	if (name) {
+		int len = strlen(name);
+		char *s = kzalloc(len + 1, GFP_KERNEL);
+		if (s) {
+			strncpy(s, name, len);
+			ws->name = s;
+		}
+	}
+
+	return ws;
+}
+EXPORT_SYMBOL_GPL(wakeup_source_create);
+
+/**
+ * wakeup_source_destroy - Destroy a struct wakeup_source object.
+ * @ws: Wakeup source to destroy.
+ */
+void wakeup_source_destroy(struct wakeup_source *ws)
+{
+	if (!ws)
+		return;
+
+	spin_lock_irq(&ws->lock);
+	while (ws->active) {
+		spin_unlock_irq(&ws->lock);
+
+		schedule_timeout_interruptible(msecs_to_jiffies(TIMEOUT));
+
+		spin_lock_irq(&ws->lock);
+	}
+	spin_unlock_irq(&ws->lock);
+
+	if (ws->name)
+		kfree(ws->name);
+	kfree(ws);
+}
+EXPORT_SYMBOL_GPL(wakeup_source_destroy);
+
+/**
+ * wakeup_source_register - Add given object to the list of wakeup sources.
+ * @ws: Wakeup source object to register.
+ */
+void wakeup_source_register(struct wakeup_source *ws)
+{
+	if (WARN_ON(!ws))
+		return;
+
+	spin_lock_init(&ws->lock);
+	setup_timer(&ws->timer, pm_wakeup_timer_fn, (unsigned long)ws);
+	ws->active = false;
+
+	spin_lock_irq(&events_lock);
+	list_add_rcu(&ws->entry, &wakeup_sources);
+	spin_unlock_irq(&events_lock);
+	synchronize_rcu();
+}
+EXPORT_SYMBOL_GPL(wakeup_source_register);
+
+/**
+ * wakeup_source_unregister - Remove given object from the wakeup sources list.
+ * @ws: Wakeup source object to unregister.
+ */
+void wakeup_source_unregister(struct wakeup_source *ws)
+{
+	if (WARN_ON(!ws))
+		return;
+
+	spin_lock_irq(&events_lock);
+	list_del_rcu(&ws->entry);
+	spin_unlock_irq(&events_lock);
+	synchronize_rcu();
+}
+EXPORT_SYMBOL_GPL(wakeup_source_unregister);
+
+/**
+ * wakeup_source_add - Create and register a wakeup source object.
+ * @name: Name of the wakeup source to create.
+ */
+struct wakeup_source *wakeup_source_add(const char *name)
+{
+	struct wakeup_source *ws;
+
+	ws = wakeup_source_create(name);
+	if (ws)
+		wakeup_source_register(ws);
+
+	return ws;
+}
+EXPORT_SYMBOL_GPL(wakeup_source_add);
+
+/**
+ * wakeup_source_remove - Unregister and destroy a wakeup source object.
+ * @ws: Wakeup source object to handle.
+ */
+void wakeup_source_remove(struct wakeup_source *ws)
+{
+	wakeup_source_unregister(ws);
+	wakeup_source_destroy(ws);
+}
+EXPORT_SYMBOL_GPL(wakeup_source_remove);
+
+/**
+ * device_wakeup_attach - Attach a wakeup source object to a device object.
+ * @dev: Device to handle.
+ * @ws: Wakeup source object to attach to @dev.
+ *
+ * This causes @dev to be treated as a wakeup device.
+ */
+static int device_wakeup_attach(struct device *dev, struct wakeup_source *ws)
+{
+	spin_lock_irq(&dev->power.lock);
+	if (dev->power.wakeup) {
+		spin_unlock_irq(&dev->power.lock);
+		return -EEXIST;
+	}
+	dev->power.wakeup = ws;
+	spin_unlock_irq(&dev->power.lock);
+	return 0;
+}
+
+/**
+ * device_wakeup_enable - Enable given device to be a wakeup source.
+ * @dev: Device to handle.
+ *
+ * Create a wakeup source object, register it and attach it to @dev.
+ */
+int device_wakeup_enable(struct device *dev)
+{
+	struct wakeup_source *ws;
+	int ret;
+
+	if (!dev || !dev->power.can_wakeup)
+		return -EINVAL;
+
+	ws = wakeup_source_add(dev_name(dev));
+	if (!ws)
+		return -ENOMEM;
+
+	ret = device_wakeup_attach(dev, ws);
+	if (ret)
+		wakeup_source_remove(ws);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(device_wakeup_enable);
+
+/**
+ * device_wakeup_detach - Detach a device's wakeup source object from it.
+ * @dev: Device to detach the wakeup source object from.
+ *
+ * After it returns, @dev will not be treated as a wakeup device any more.
+ */
+static struct wakeup_source *device_wakeup_detach(struct device *dev)
+{
+	struct wakeup_source *ws;
+
+	spin_lock_irq(&dev->power.lock);
+	ws = dev->power.wakeup;
+	dev->power.wakeup = NULL;
+	spin_unlock_irq(&dev->power.lock);
+	return ws;
+}
+
+/**
+ * device_wakeup_disable - Do not regard a device as a wakeup source any more.
+ * @dev: Device to handle.
+ *
+ * Detach the @dev's wakeup source object from it, unregister this wakeup source
+ * object and destroy it.
+ */
+int device_wakeup_disable(struct device *dev)
+{
+	struct wakeup_source *ws;
+
+	if (!dev || !dev->power.can_wakeup)
+		return -EINVAL;
+
+	ws = device_wakeup_detach(dev);
+	if (ws)
+		wakeup_source_remove(ws);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(device_wakeup_disable);
+
+/**
+ * device_init_wakeup - Device wakeup initialization.
+ * @dev: Device to handle.
+ * @enable: Whether or not to enable @dev as a wakeup device.
+ *
+ * By default, most devices should leave wakeup disabled.  The exceptions are
+ * devices that everyone expects to be wakeup sources: keyboards, power buttons,
+ * possibly network interfaces, etc.
+ */
+int device_init_wakeup(struct device *dev, bool enable)
+{
+	int ret = 0;
+
+	if (enable) {
+		device_set_wakeup_capable(dev, true);
+		ret = device_wakeup_enable(dev);
+	} else {
+		device_set_wakeup_capable(dev, false);
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(device_init_wakeup);
+
+/**
+ * device_set_wakeup_enable - Enable or disable a device to wake up the system.
+ * @dev: Device to handle.
+ */
+int device_set_wakeup_enable(struct device *dev, bool enable)
+{
+	if (!dev || !dev->power.can_wakeup)
+		return -EINVAL;
+
+	return enable ? device_wakeup_enable(dev) : device_wakeup_disable(dev);
+}
+EXPORT_SYMBOL_GPL(device_set_wakeup_enable);
 
 /*
  * The functions below use the observation that each wakeup event starts a
@@ -55,118 +291,252 @@ static unsigned long events_timer_expire
  * knowledge, however, may not be available to it, so it can simply specify time
  * to wait before the system can be suspended and pass it as the second
  * argument of pm_wakeup_event().
+ *
+ * It is valid to call pm_relax() after pm_wakeup_event(), in which case the
+ * "no suspend" period will be ended either by the pm_relax(), or by the timer
+ * function executed when the timer expires, whichever comes first.
  */
 
 /**
+ * wakup_source_activate - Mark given wakeup source as active.
+ * @ws: Wakeup source to handle.
+ *
+ * Update the @ws' statistics and, if @ws has just been activated, notify the PM
+ * core of the event by incrementing the counter of of wakeup events being
+ * processed.
+ */
+static void wakeup_source_activate(struct wakeup_source *ws)
+{
+	ws->active = true;
+	ws->active_count++;
+	ws->timer_expires = jiffies;
+	ws->last_time = ktime_get();
+
+	atomic_inc(&events_in_progress);
+}
+
+/**
+ * __pm_stay_awake - Notify the PM core of a wakeup event.
+ * @ws: Wakeup source object associated with the source of the event.
+ *
+ * It is safe to call this function from interrupt context.
+ */
+void __pm_stay_awake(struct wakeup_source *ws)
+{
+	unsigned long flags;
+
+	if (!ws)
+		return;
+
+	spin_lock_irqsave(&ws->lock, flags);
+	ws->event_count++;
+	if (!ws->active)
+		wakeup_source_activate(ws);
+	spin_unlock_irqrestore(&ws->lock, flags);
+}
+EXPORT_SYMBOL_GPL(__pm_stay_awake);
+
+/**
  * pm_stay_awake - Notify the PM core that a wakeup event is being processed.
  * @dev: Device the wakeup event is related to.
  *
- * Notify the PM core of a wakeup event (signaled by @dev) by incrementing the
- * counter of wakeup events being processed.  If @dev is not NULL, the counter
- * of wakeup events related to @dev is incremented too.
+ * Notify the PM core of a wakeup event (signaled by @dev) by calling
+ * __pm_stay_awake for the @dev's wakeup source object.
  *
  * Call this function after detecting of a wakeup event if pm_relax() is going
  * to be called directly after processing the event (and possibly passing it to
  * user space for further processing).
- *
- * It is safe to call this function from interrupt context.
  */
 void pm_stay_awake(struct device *dev)
 {
 	unsigned long flags;
 
-	spin_lock_irqsave(&events_lock, flags);
-	if (dev)
-		dev->power.wakeup_count++;
+	if (!dev)
+		return;
 
-	events_in_progress++;
-	spin_unlock_irqrestore(&events_lock, flags);
+	spin_lock_irqsave(&dev->power.lock, flags);
+	__pm_stay_awake(dev->power.wakeup);
+	spin_unlock_irqrestore(&dev->power.lock, flags);
 }
+EXPORT_SYMBOL_GPL(pm_stay_awake);
 
 /**
- * pm_relax - Notify the PM core that processing of a wakeup event has ended.
+ * wakup_source_deactivate - Mark given wakeup source as inactive.
+ * @ws: Wakeup source to handle.
  *
- * Notify the PM core that a wakeup event has been processed by decrementing
- * the counter of wakeup events being processed and incrementing the counter
- * of registered wakeup events.
+ * Update the @ws' statistics and notify the PM core that the wakeup source has
+ * become inactive by decrementing the counter of wakeup events being processed
+ * and incrementing the counter of registered wakeup events.
+ */
+static void wakeup_source_deactivate(struct wakeup_source *ws)
+{
+	ktime_t duration;
+	ktime_t now;
+
+	ws->relax_count++;
+	/*
+	 * __pm_relax() may be called directly or from a timer function.
+	 * If it is called directly right after the timer function has been
+	 * started, but before the timer function calls __pm_relax(), it is
+	 * possible that __pm_stay_awake() will be called in the meantime and
+	 * will set ws->active.  Then, ws->active may be cleared immediately
+	 * by the __pm_relax() called from the timer function, but in such a
+	 * case ws->relax_count will be different from ws->active_count.
+	 */
+	if (ws->relax_count != ws->active_count) {
+		ws->relax_count--;
+		return;
+	}
+
+	ws->active = false;
+
+	now = ktime_get();
+	duration = ktime_sub(now, ws->last_time);
+	ws->total_time = ktime_add(ws->total_time, duration);
+	if (ktime_to_ns(duration) > ktime_to_ns(ws->max_time))
+		ws->max_time = duration;
+
+	del_timer(&ws->timer);
+
+	atomic_inc(&event_count);
+	atomic_dec(&events_in_progress);
+}
+
+/**
+ * __pm_relax - Notify the PM core that processing of a wakeup event has ended.
+ * @ws: Wakeup source object associated with the source of the event.
  *
  * Call this function for wakeup events whose processing started with calling
- * pm_stay_awake().
+ * __pm_stay_awake().
  *
  * It is safe to call it from interrupt context.
  */
-void pm_relax(void)
+void __pm_relax(struct wakeup_source *ws)
 {
 	unsigned long flags;
 
-	spin_lock_irqsave(&events_lock, flags);
-	if (events_in_progress) {
-		events_in_progress--;
-		event_count++;
-	}
-	spin_unlock_irqrestore(&events_lock, flags);
+	if (!ws)
+		return;
+
+	spin_lock_irqsave(&ws->lock, flags);
+	if (ws->active)
+		wakeup_source_deactivate(ws);
+	spin_unlock_irqrestore(&ws->lock, flags);
 }
+EXPORT_SYMBOL_GPL(__pm_relax);
+
+/**
+ * pm_relax - Notify the PM core that processing of a wakeup event has ended.
+ * @dev: Device that signaled the event.
+ *
+ * Execute __pm_relax() for the @dev's wakeup source object.
+ */
+void pm_relax(struct device *dev)
+{
+	unsigned long flags;
+
+	if (!dev)
+		return;
+
+	spin_lock_irqsave(&dev->power.lock, flags);
+	__pm_relax(dev->power.wakeup);
+	spin_unlock_irqrestore(&dev->power.lock, flags);
+}
+EXPORT_SYMBOL_GPL(pm_relax);
 
 /**
  * pm_wakeup_timer_fn - Delayed finalization of a wakeup event.
+ * @data: Address of the wakeup source object associated with the event source.
  *
- * Decrease the counter of wakeup events being processed after it was increased
- * by pm_wakeup_event().
+ * Call __pm_relax() for the wakeup source whose address is stored in @data.
  */
 static void pm_wakeup_timer_fn(unsigned long data)
 {
+	__pm_relax((struct wakeup_source *)data);
+}
+
+/**
+ * __pm_wakeup_event - Notify the PM core of a wakeup event.
+ * @ws: Wakeup source object associated with the event source.
+ * @msec: Anticipated event processing time (in milliseconds).
+ *
+ * Notify the PM core of a wakeup event whose source is @ws that will take
+ * approximately @msec milliseconds to be processed by the kernel.  If @ws is
+ * not active, activate it.  If @msec is nonzero, set up the @ws' timer to
+ * execute pm_wakeup_timer_fn() in future.
+ *
+ * It is safe to call this function from interrupt context.
+ */
+void __pm_wakeup_event(struct wakeup_source *ws, unsigned int msec)
+{
 	unsigned long flags;
+	unsigned long expires;
 
-	spin_lock_irqsave(&events_lock, flags);
-	if (events_timer_expires
-	    && time_before_eq(events_timer_expires, jiffies)) {
-		events_in_progress--;
-		events_timer_expires = 0;
+	if (!ws)
+		return;
+
+	spin_lock_irqsave(&ws->lock, flags);
+
+	ws->event_count++;
+	if (!ws->active)
+		wakeup_source_activate(ws);
+
+	if (!msec) {
+		wakeup_source_deactivate(ws);
+		goto unlock;
 	}
-	spin_unlock_irqrestore(&events_lock, flags);
+
+	expires = jiffies + msecs_to_jiffies(msec);
+	if (!expires)
+		expires = 1;
+
+	if (time_after(expires, ws->timer_expires)) {
+		mod_timer(&ws->timer, expires);
+		ws->timer_expires = expires;
+	}
+
+ unlock:
+	spin_unlock_irqrestore(&ws->lock, flags);
 }
+EXPORT_SYMBOL_GPL(__pm_wakeup_event);
+
 
 /**
  * pm_wakeup_event - Notify the PM core of a wakeup event.
  * @dev: Device the wakeup event is related to.
  * @msec: Anticipated event processing time (in milliseconds).
  *
- * Notify the PM core of a wakeup event (signaled by @dev) that will take
- * approximately @msec milliseconds to be processed by the kernel.  Increment
- * the counter of registered wakeup events and (if @msec is nonzero) set up
- * the wakeup events timer to execute pm_wakeup_timer_fn() in future (if the
- * timer has not been set up already, increment the counter of wakeup events
- * being processed).  If @dev is not NULL, the counter of wakeup events related
- * to @dev is incremented too.
- *
- * It is safe to call this function from interrupt context.
+ * Call __pm_wakeup_event() for the @dev's wakeup source object.
  */
 void pm_wakeup_event(struct device *dev, unsigned int msec)
 {
 	unsigned long flags;
 
-	spin_lock_irqsave(&events_lock, flags);
-	event_count++;
-	if (dev)
-		dev->power.wakeup_count++;
-
-	if (msec) {
-		unsigned long expires;
-
-		expires = jiffies + msecs_to_jiffies(msec);
-		if (!expires)
-			expires = 1;
-
-		if (!events_timer_expires
-		    || time_after(expires, events_timer_expires)) {
-			if (!events_timer_expires)
-				events_in_progress++;
+	if (!dev)
+		return;
 
-			mod_timer(&events_timer, expires);
-			events_timer_expires = expires;
-		}
+	spin_lock_irqsave(&dev->power.lock, flags);
+	__pm_wakeup_event(dev->power.wakeup, msec);
+	spin_unlock_irqrestore(&dev->power.lock, flags);
+}
+EXPORT_SYMBOL_GPL(pm_wakeup_event);
+
+/**
+ * pm_wakeup_update_hit_counts - Update hit counts of all active wakeup sources.
+ */
+static void pm_wakeup_update_hit_counts(void)
+{
+	unsigned long flags;
+	struct wakeup_source *ws;
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(ws, &wakeup_sources, entry) {
+		spin_lock_irqsave(&ws->lock, flags);
+		if (ws->active)
+			ws->hit_count++;
+		spin_unlock_irqrestore(&ws->lock, flags);
 	}
-	spin_unlock_irqrestore(&events_lock, flags);
+	rcu_read_unlock();
 }
 
 /**
@@ -184,10 +554,13 @@ bool pm_check_wakeup_events(void)
 
 	spin_lock_irqsave(&events_lock, flags);
 	if (events_check_enabled) {
-		ret = (event_count == saved_event_count) && !events_in_progress;
+		ret = ((unsigned int)atomic_read(&event_count) == saved_count)
+			&& !atomic_read(&events_in_progress);
 		events_check_enabled = ret;
 	}
 	spin_unlock_irqrestore(&events_lock, flags);
+	if (!ret)
+		pm_wakeup_update_hit_counts();
 	return ret;
 }
 
@@ -202,24 +575,20 @@ bool pm_check_wakeup_events(void)
  * drop down to zero has been interrupted by a signal (and the current number
  * of wakeup events being processed is still nonzero).  Otherwise return true.
  */
-bool pm_get_wakeup_count(unsigned long *count)
+bool pm_get_wakeup_count(unsigned int *count)
 {
 	bool ret;
 
-	spin_lock_irq(&events_lock);
 	if (capable(CAP_SYS_ADMIN))
 		events_check_enabled = false;
 
-	while (events_in_progress && !signal_pending(current)) {
-		spin_unlock_irq(&events_lock);
-
-		schedule_timeout_interruptible(msecs_to_jiffies(100));
-
-		spin_lock_irq(&events_lock);
+	while (atomic_read(&events_in_progress) && !signal_pending(current)) {
+		pm_wakeup_update_hit_counts();
+		schedule_timeout_interruptible(msecs_to_jiffies(TIMEOUT));
 	}
-	*count = event_count;
-	ret = !events_in_progress;
-	spin_unlock_irq(&events_lock);
+
+	ret = !atomic_read(&events_in_progress);
+	*count = atomic_read(&event_count);
 	return ret;
 }
 
@@ -232,16 +601,19 @@ bool pm_get_wakeup_count(unsigned long *
  * old number of registered wakeup events to be used by pm_check_wakeup_events()
  * and return true.  Otherwise return false.
  */
-bool pm_save_wakeup_count(unsigned long count)
+bool pm_save_wakeup_count(unsigned int count)
 {
 	bool ret = false;
 
 	spin_lock_irq(&events_lock);
-	if (count == event_count && !events_in_progress) {
-		saved_event_count = count;
+	if (count == (unsigned int)atomic_read(&event_count)
+	    && !atomic_read(&events_in_progress)) {
+		saved_count = count;
 		events_check_enabled = true;
 		ret = true;
 	}
 	spin_unlock_irq(&events_lock);
+	if (!ret)
+		pm_wakeup_update_hit_counts();
 	return ret;
 }
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
@@ -60,7 +60,8 @@ void device_pm_init(struct device *dev)
 	dev->power.status = DPM_ON;
 	init_completion(&dev->power.completion);
 	complete_all(&dev->power.completion);
-	dev->power.wakeup_count = 0;
+	dev->power.wakeup = NULL;
+	spin_lock_init(&dev->power.lock);
 	pm_runtime_init(dev);
 }
 
Index: linux-2.6/drivers/base/power/power.h
===================================================================
--- linux-2.6.orig/drivers/base/power/power.h
+++ linux-2.6/drivers/base/power/power.h
@@ -34,6 +34,7 @@ extern void device_pm_move_last(struct d
 
 static inline void device_pm_init(struct device *dev)
 {
+	spin_lock_init(&dev->power.lock);
 	pm_runtime_init(dev);
 }
 
Index: linux-2.6/drivers/base/power/runtime.c
===================================================================
--- linux-2.6.orig/drivers/base/power/runtime.c
+++ linux-2.6/drivers/base/power/runtime.c
@@ -1099,8 +1099,6 @@ EXPORT_SYMBOL_GPL(pm_runtime_allow);
  */
 void pm_runtime_init(struct device *dev)
 {
-	spin_lock_init(&dev->power.lock);
-
 	dev->power.runtime_status = RPM_SUSPENDED;
 	dev->power.idle_notification = false;
 
Index: linux-2.6/include/linux/suspend.h
===================================================================
--- linux-2.6.orig/include/linux/suspend.h
+++ linux-2.6/include/linux/suspend.h
@@ -302,8 +302,8 @@ extern int unregister_pm_notifier(struct
 extern bool events_check_enabled;
 
 extern bool pm_check_wakeup_events(void);
-extern bool pm_get_wakeup_count(unsigned long *count);
-extern bool pm_save_wakeup_count(unsigned long count);
+extern bool pm_get_wakeup_count(unsigned int *count);
+extern bool pm_save_wakeup_count(unsigned int count);
 #else /* !CONFIG_PM_SLEEP */
 
 static inline int register_pm_notifier(struct notifier_block *nb)
Index: linux-2.6/kernel/power/main.c
===================================================================
--- linux-2.6.orig/kernel/power/main.c
+++ linux-2.6/kernel/power/main.c
@@ -237,18 +237,18 @@ static ssize_t wakeup_count_show(struct 
 				struct kobj_attribute *attr,
 				char *buf)
 {
-	unsigned long val;
+	unsigned int val;
 
-	return pm_get_wakeup_count(&val) ? sprintf(buf, "%lu\n", val) : -EINTR;
+	return pm_get_wakeup_count(&val) ? sprintf(buf, "%u\n", val) : -EINTR;
 }
 
 static ssize_t wakeup_count_store(struct kobject *kobj,
 				struct kobj_attribute *attr,
 				const char *buf, size_t n)
 {
-	unsigned long val;
+	unsigned int val;
 
-	if (sscanf(buf, "%lu", &val) == 1) {
+	if (sscanf(buf, "%u", &val) == 1) {
 		if (pm_save_wakeup_count(val))
 			return n;
 	}
Index: linux-2.6/drivers/base/power/sysfs.c
===================================================================
--- linux-2.6.orig/drivers/base/power/sysfs.c
+++ linux-2.6/drivers/base/power/sysfs.c
@@ -210,11 +210,122 @@ static DEVICE_ATTR(wakeup, 0644, wake_sh
 static ssize_t wakeup_count_show(struct device *dev,
 				struct device_attribute *attr, char *buf)
 {
-	return sprintf(buf, "%lu\n", dev->power.wakeup_count);
+	unsigned long count = 0;
+	bool enabled = false;
+
+	spin_lock_irq(&dev->power.lock);
+	if (dev->power.wakeup) {
+		count = dev->power.wakeup->event_count;
+		enabled = true;
+	}
+	spin_unlock_irq(&dev->power.lock);
+	return enabled ? sprintf(buf, "%lu\n", count) : sprintf(buf, "\n");
 }
 
 static DEVICE_ATTR(wakeup_count, 0444, wakeup_count_show, NULL);
-#endif
+
+static ssize_t wakeup_active_count_show(struct device *dev,
+				struct device_attribute *attr, char *buf)
+{
+	unsigned long count = 0;
+	bool enabled = false;
+
+	spin_lock_irq(&dev->power.lock);
+	if (dev->power.wakeup) {
+		count = dev->power.wakeup->active_count;
+		enabled = true;
+	}
+	spin_unlock_irq(&dev->power.lock);
+	return enabled ? sprintf(buf, "%lu\n", count) : sprintf(buf, "\n");
+}
+
+static DEVICE_ATTR(wakeup_active_count, 0444, wakeup_active_count_show, NULL);
+
+static ssize_t wakeup_hit_count_show(struct device *dev,
+				struct device_attribute *attr, char *buf)
+{
+	unsigned long count = 0;
+	bool enabled = false;
+
+	spin_lock_irq(&dev->power.lock);
+	if (dev->power.wakeup) {
+		count = dev->power.wakeup->hit_count;
+		enabled = true;
+	}
+	spin_unlock_irq(&dev->power.lock);
+	return enabled ? sprintf(buf, "%lu\n", count) : sprintf(buf, "\n");
+}
+
+static DEVICE_ATTR(wakeup_hit_count, 0444, wakeup_hit_count_show, NULL);
+
+static ssize_t wakeup_active_show(struct device *dev,
+				struct device_attribute *attr, char *buf)
+{
+	unsigned int active = 0;
+	bool enabled = false;
+
+	spin_lock_irq(&dev->power.lock);
+	if (dev->power.wakeup) {
+		active = dev->power.wakeup->active;
+		enabled = true;
+	}
+	spin_unlock_irq(&dev->power.lock);
+	return enabled ? sprintf(buf, "%u\n", active) : sprintf(buf, "\n");
+}
+
+static DEVICE_ATTR(wakeup_active, 0444, wakeup_active_show, NULL);
+
+static ssize_t wakeup_total_time_show(struct device *dev,
+				struct device_attribute *attr, char *buf)
+{
+	s64 msec = 0;
+	bool enabled = false;
+
+	spin_lock_irq(&dev->power.lock);
+	if (dev->power.wakeup) {
+		msec = ktime_to_ms(dev->power.wakeup->total_time);
+		enabled = true;
+	}
+	spin_unlock_irq(&dev->power.lock);
+	return enabled ? sprintf(buf, "%lld\n", msec) : sprintf(buf, "\n");
+}
+
+static DEVICE_ATTR(wakeup_total_time_ms, 0444, wakeup_total_time_show, NULL);
+
+static ssize_t wakeup_max_time_show(struct device *dev,
+				struct device_attribute *attr, char *buf)
+{
+	s64 msec = 0;
+	bool enabled = false;
+
+	spin_lock_irq(&dev->power.lock);
+	if (dev->power.wakeup) {
+		msec = ktime_to_ms(dev->power.wakeup->max_time);
+		enabled = true;
+	}
+	spin_unlock_irq(&dev->power.lock);
+	return enabled ? sprintf(buf, "%lld\n", msec) : sprintf(buf, "\n");
+}
+
+static DEVICE_ATTR(wakeup_max_time_ms, 0444, wakeup_max_time_show, NULL);
+
+static ssize_t wakeup_last_time_show(struct device *dev,
+				struct device_attribute *attr, char *buf)
+{
+	s64 msec = 0;
+	bool enabled = false;
+
+	spin_lock_irq(&dev->power.lock);
+	if (dev->power.wakeup) {
+		msec = ktime_to_ms(dev->power.wakeup->last_time);
+		enabled = true;
+	}
+	spin_unlock_irq(&dev->power.lock);
+	return enabled ? sprintf(buf, "%lld\n", msec) : sprintf(buf, "\n");
+}
+
+static DEVICE_ATTR(wakeup_last_time_ms, 0444, wakeup_last_time_show, NULL);
+#endif /* CONFIG_PM_SLEEP */
 
 #ifdef CONFIG_PM_ADVANCED_DEBUG
 #ifdef CONFIG_PM_RUNTIME
@@ -288,6 +399,12 @@ static struct attribute * power_attrs[] 
 	&dev_attr_wakeup.attr,
 #ifdef CONFIG_PM_SLEEP
 	&dev_attr_wakeup_count.attr,
+	&dev_attr_wakeup_active_count.attr,
+	&dev_attr_wakeup_hit_count.attr,
+	&dev_attr_wakeup_active.attr,
+	&dev_attr_wakeup_total_time_ms.attr,
+	&dev_attr_wakeup_max_time_ms.attr,
+	&dev_attr_wakeup_last_time_ms.attr,
 #endif
 #ifdef CONFIG_PM_ADVANCED_DEBUG
 	&dev_attr_async.attr,
--
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