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
@@ -431,26 +431,18 @@ static ssize_t async_store(struct device
 static DEVICE_ATTR(async, 0644, async_show, async_store);
 #endif /* CONFIG_PM_ADVANCED_DEBUG */
 
-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
+static struct attribute *power_attrs[] = {
 #ifdef CONFIG_PM_ADVANCED_DEBUG
+#ifdef CONFIG_PM_SLEEP
 	&dev_attr_async.attr,
+#endif
 #ifdef CONFIG_PM_RUNTIME
 	&dev_attr_runtime_status.attr,
 	&dev_attr_runtime_usage.attr,
 	&dev_attr_runtime_active_kids.attr,
 	&dev_attr_runtime_enabled.attr,
 #endif
-#endif
+#endif /* CONFIG_PM_ADVANCED_DEBUG */
 	NULL,
 };
 static struct attribute_group pm_attr_group = {
@@ -458,9 +450,26 @@ static struct attribute_group pm_attr_gr
 	.attrs	= power_attrs,
 };
 
-#ifdef CONFIG_PM_RUNTIME
+static struct attribute *wakeup_attrs[] = {
+#ifdef CONFIG_PM_SLEEP
+	&dev_attr_wakeup.attr,
+	&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
+	NULL,
+};
+static struct attribute_group pm_wakeup_attr_group = {
+	.name	= power_group_name,
+	.attrs	= wakeup_attrs,
+};
 
 static struct attribute *runtime_attrs[] = {
+#ifdef CONFIG_PM_RUNTIME
 #ifndef CONFIG_PM_ADVANCED_DEBUG
 	&dev_attr_runtime_status.attr,
 #endif
@@ -468,6 +477,7 @@ static struct attribute *runtime_attrs[]
 	&dev_attr_runtime_suspended_time.attr,
 	&dev_attr_runtime_active_time.attr,
 	&dev_attr_autosuspend_delay_ms.attr,
+#endif /* CONFIG_PM_RUNTIME */
 	NULL,
 };
 static struct attribute_group pm_runtime_attr_group = {
@@ -480,35 +490,49 @@ int dpm_sysfs_add(struct device *dev)
 	int rc;
 
 	rc = sysfs_create_group(&dev->kobj, &pm_attr_group);
-	if (rc == 0 && !dev->power.no_callbacks) {
+	if (rc)
+		return rc;
+
+	if (pm_runtime_callbacks_present(dev)) {
 		rc = sysfs_merge_group(&dev->kobj, &pm_runtime_attr_group);
 		if (rc)
-			sysfs_remove_group(&dev->kobj, &pm_attr_group);
+			goto err_out;
+	}
+
+	if (device_can_wakeup(dev)) {
+		rc = sysfs_merge_group(&dev->kobj, &pm_wakeup_attr_group);
+		if (rc) {
+			if (pm_runtime_callbacks_present(dev))
+				sysfs_unmerge_group(&dev->kobj,
+						    &pm_runtime_attr_group);
+			goto err_out;
+		}
 	}
+	return 0;
+
+ err_out:
+	sysfs_remove_group(&dev->kobj, &pm_attr_group);
 	return rc;
 }
 
-void rpm_sysfs_remove(struct device *dev)
+int wakeup_sysfs_add(struct device *dev)
 {
-	sysfs_unmerge_group(&dev->kobj, &pm_runtime_attr_group);
+	return sysfs_merge_group(&dev->kobj, &pm_wakeup_attr_group);
 }
 
-void dpm_sysfs_remove(struct device *dev)
+void wakeup_sysfs_remove(struct device *dev)
 {
-	rpm_sysfs_remove(dev);
-	sysfs_remove_group(&dev->kobj, &pm_attr_group);
+	sysfs_unmerge_group(&dev->kobj, &pm_wakeup_attr_group);
 }
 
-#else /* CONFIG_PM_RUNTIME */
-
-int dpm_sysfs_add(struct device * dev)
+void rpm_sysfs_remove(struct device *dev)
 {
-	return sysfs_create_group(&dev->kobj, &pm_attr_group);
+	sysfs_unmerge_group(&dev->kobj, &pm_runtime_attr_group);
 }
 
-void dpm_sysfs_remove(struct device * dev)
+void dpm_sysfs_remove(struct device *dev)
 {
+	rpm_sysfs_remove(dev);
+	sysfs_unmerge_group(&dev->kobj, &pm_wakeup_attr_group);
 	sysfs_remove_group(&dev->kobj, &pm_attr_group);
 }
-
-#endif
Index: linux-2.6/include/linux/pm_runtime.h
===================================================================
--- linux-2.6.orig/include/linux/pm_runtime.h
+++ linux-2.6/include/linux/pm_runtime.h
@@ -87,6 +87,11 @@ static inline bool pm_runtime_enabled(st
 	return !dev->power.disable_depth;
 }
 
+static inline bool pm_runtime_callbacks_present(struct device *dev)
+{
+	return !dev->power.no_callbacks;
+}
+
 static inline void pm_runtime_mark_last_busy(struct device *dev)
 {
 	ACCESS_ONCE(dev->power.last_busy) = jiffies;
@@ -133,6 +138,7 @@ static inline int pm_generic_runtime_res
 static inline void pm_runtime_no_callbacks(struct device *dev) {}
 static inline void pm_runtime_irq_safe(struct device *dev) {}
 
+static inline bool pm_runtime_callbacks_present(struct device *dev) { return false; }
 static inline void pm_runtime_mark_last_busy(struct device *dev) {}
 static inline void __pm_runtime_use_autosuspend(struct device *dev,
 						bool use) {}
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
@@ -58,19 +58,18 @@ static inline void device_pm_move_last(s
  * sysfs.c
  */
 
-extern int dpm_sysfs_add(struct device *);
-extern void dpm_sysfs_remove(struct device *);
-extern void rpm_sysfs_remove(struct device *);
+extern int dpm_sysfs_add(struct device *dev);
+extern void dpm_sysfs_remove(struct device *dev);
+extern void rpm_sysfs_remove(struct device *dev);
+extern int wakeup_sysfs_add(struct device *dev);
+extern void wakeup_sysfs_remove(struct device *dev);
 
 #else /* CONFIG_PM */
 
-static inline int dpm_sysfs_add(struct device *dev)
-{
-	return 0;
-}
-
-static inline void dpm_sysfs_remove(struct device *dev)
-{
-}
+static inline int dpm_sysfs_add(struct device *dev) { return 0; }
+static inline void dpm_sysfs_remove(struct device *dev) {}
+static inline void rpm_sysfs_remove(struct device *dev) {}
+static inline int wakeup_sysfs_add(struct device *dev) { return 0; }
+static inline void wakeup_sysfs_remove(struct device *dev) {}
 
 #endif
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
@@ -62,18 +62,11 @@ struct wakeup_source {
  * Changes to device_may_wakeup take effect on the next pm state change.
  */
 
-static inline void device_set_wakeup_capable(struct device *dev, bool capable)
-{
-	dev->power.can_wakeup = capable;
-}
-
 static inline bool device_can_wakeup(struct device *dev)
 {
 	return dev->power.can_wakeup;
 }
 
-
-
 static inline bool device_may_wakeup(struct device *dev)
 {
 	return dev->power.can_wakeup && !!dev->power.wakeup;
@@ -88,6 +81,7 @@ extern struct wakeup_source *wakeup_sour
 extern void wakeup_source_unregister(struct wakeup_source *ws);
 extern int device_wakeup_enable(struct device *dev);
 extern int device_wakeup_disable(struct device *dev);
+extern void device_set_wakeup_capable(struct device *dev, bool capable);
 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);
@@ -144,7 +138,7 @@ static inline int device_wakeup_disable(
 
 static inline int device_init_wakeup(struct device *dev, bool val)
 {
-	dev->power.can_wakeup = val;
+	device_set_wakeup_capable(dev, val);
 	return val ? -EINVAL : 0;
 }
 
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
@@ -242,6 +242,35 @@ int device_wakeup_disable(struct device
 EXPORT_SYMBOL_GPL(device_wakeup_disable);
 
 /**
+ * device_set_wakeup_capable - Set/reset device wakeup capability flag.
+ * @dev: Device to handle.
+ * @capable: Whether or not @dev is capable of waking up the system from sleep.
+ *
+ * If @capable is set, set the @dev's power.can_wakeup flag and add its
+ * wakeup-related attributes to sysfs.  Otherwise, unset the @dev's
+ * power.can_wakeup flag and remove its wakeup-related attributes from sysfs.
+ *
+ * This function may sleep and it can't be called from any context where
+ * sleeping is not allowed.
+ */
+void device_set_wakeup_capable(struct device *dev, bool capable)
+{
+	if (!!dev->power.can_wakeup == !!capable)
+		return;
+
+	if (device_is_registered(dev)) {
+		if (capable) {
+			if (wakeup_sysfs_add(dev))
+				return;
+		} else {
+			wakeup_sysfs_remove(dev);
+		}
+	}
+	dev->power.can_wakeup = capable;
+}
+EXPORT_SYMBOL_GPL(device_set_wakeup_capable);
+
+/**
  * device_init_wakeup - Device wakeup initialization.
  * @dev: Device to handle.
  * @enable: Whether or not to enable @dev as a wakeup device.
Index: linux-2.6/Documentation/power/devices.txt
===================================================================
--- linux-2.6.orig/Documentation/power/devices.txt
+++ linux-2.6/Documentation/power/devices.txt
@@ -159,18 +159,18 @@ matter, and the kernel is responsible fo
 whether or not a wakeup-capable device should issue wakeup events is a policy
 decision, and it is managed by user space through a sysfs attribute: the
 power/wakeup file.  User space can write the strings "enabled" or "disabled" to
-set or clear the should_wakeup flag, respectively.  Reads from the file will
-return the corresponding string if can_wakeup is true, but if can_wakeup is
-false then reads will return an empty string, to indicate that the device
-doesn't support wakeup events.  (But even though the file appears empty, writes
-will still affect the should_wakeup flag.)
+set or clear the "should_wakeup" flag, respectively.  This file is only present
+for wakeup-capable devices (i.e. devices whose "can_wakeup" flags are set)
+and is created (or removed) by device_set_wakeup_capable().  Reads from the
+file will return the corresponding string.
 
 The device_may_wakeup() routine returns true only if both flags are set.
-Drivers should check this routine when putting devices in a low-power state
-during a system sleep transition, to see whether or not to enable the devices'
-wakeup mechanisms.  However for runtime power management, wakeup events should
-be enabled whenever the device and driver both support them, regardless of the
-should_wakeup flag.
+This information is used by subsystems, like the PCI bus type code, to see
+whether or not to enable the devices' wakeup mechanisms.  If device wakeup
+mechanisms are enabled or disabled directly by drivers, they also should use
+device_may_wakeup() to decide what to do during a system sleep transition.
+However for runtime power management, wakeup events should be enabled whenever
+the device and driver both support them, regardless of the should_wakeup flag.
 
 
 /sys/devices/.../power/control files
Index: linux-2.6/Documentation/ABI/testing/sysfs-devices-power
===================================================================
--- linux-2.6.orig/Documentation/ABI/testing/sysfs-devices-power
+++ linux-2.6/Documentation/ABI/testing/sysfs-devices-power
@@ -29,9 +29,8 @@ Description:
 		"disabled" to it.
 
 		For the devices that are not capable of generating system wakeup
-		events this file contains "\n".  In that cases the user space
-		cannot modify the contents of this file and the device cannot be
-		enabled to wake up the system.
+		events this file is not present.  In that case the device cannot
+		be enabled to wake up the system from sleep states.
 
 What:		/sys/devices/.../power/control
 Date:		January 2009
@@ -85,7 +84,7 @@ Description:
 		The /sys/devices/.../wakeup_count attribute contains the number
 		of signaled wakeup events associated with the device.  This
 		attribute is read-only.  If the device is not enabled to wake up
-		the system from sleep states, this attribute is empty.
+		the system from sleep states, this attribute is not present.
 
 What:		/sys/devices/.../power/wakeup_active_count
 Date:		September 2010
@@ -95,7 +94,7 @@ Description:
 		number of times the processing of wakeup events associated with
 		the device was completed (at the kernel level).  This attribute
 		is read-only.  If the device is not enabled to wake up the
-		system from sleep states, this attribute is empty.
+		system from sleep states, this attribute is not present.
 
 What:		/sys/devices/.../power/wakeup_hit_count
 Date:		September 2010
@@ -105,7 +104,8 @@ Description:
 		number of times the processing of a wakeup event associated with
 		the device might prevent the system from entering a sleep state.
 		This attribute is read-only.  If the device is not enabled to
-		wake up the system from sleep states, this attribute is empty.
+		wake up the system from sleep states, this attribute is not
+		present.
 
 What:		/sys/devices/.../power/wakeup_active
 Date:		September 2010
@@ -115,7 +115,7 @@ Description:
 		or 0, depending on whether or not a wakeup event associated with
 		the device is being processed (1).  This attribute is read-only.
 		If the device is not enabled to wake up the system from sleep
-		states, this attribute is empty.
+		states, this attribute is not present.
 
 What:		/sys/devices/.../power/wakeup_total_time_ms
 Date:		September 2010
@@ -125,7 +125,7 @@ Description:
 		the total time of processing wakeup events associated with the
 		device, in milliseconds.  This attribute is read-only.  If the
 		device is not enabled to wake up the system from sleep states,
-		this attribute is empty.
+		this attribute is not present.
 
 What:		/sys/devices/.../power/wakeup_max_time_ms
 Date:		September 2010
@@ -135,7 +135,7 @@ Description:
 		the maximum time of processing a single wakeup event associated
 		with the device, in milliseconds.  This attribute is read-only.
 		If the device is not enabled to wake up the system from sleep
-		states, this attribute is empty.
+		states, this attribute is not present.
 
 What:		/sys/devices/.../power/wakeup_last_time_ms
 Date:		September 2010
@@ -146,7 +146,7 @@ Description:
 		signaling the last wakeup event associated with the device, in
 		milliseconds.  This attribute is read-only.  If the device is
 		not enabled to wake up the system from sleep states, this
-		attribute is empty.
+		attribute is not present.
 
 What:		/sys/devices/.../power/autosuspend_delay_ms
 Date:		September 2010
