PM: Remove pm_parent from struct dev_pm_info

The pm_parent member of struct dev_pm_info (defined in include/linux/pm.h) is
only used to check if the device's parent is in the right state while the
device is being suspended or resumed.  However, this can be done just as well
with the help of the parent pointer in struct device, so pm_parent can be
removed along with some code that handles it.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

3 files changed, 10 insertions, 34 deletions

diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c
index 7b3cc3c..eb9f38d 100644
--- a/drivers/base/power/main.c
+++ b/drivers/base/power/main.c
@@ -33,28 +33,7 @@ DEFINE_MUTEX(dpm_list_mtx);
 
 int (*platform_enable_wakeup)(struct device *dev, int is_on);
 
-
-/**
- *	device_pm_set_parent - Specify power dependency.
- *	@dev:		Device who needs power.
- *	@parent:	Device that supplies power.
- *
- *	This function is used to manually describe a power-dependency
- *	relationship. It may be used to specify a transversal relationship
- *	(where the power supplier is not the physical (or electrical)
- *	ancestor of a specific device.
- *	The effect of this is that the supplier will not be powered down
- *	before the power dependent.
- */
-
-void device_pm_set_parent(struct device * dev, struct device * parent)
-{
-	put_device(dev->power.pm_parent);
-	dev->power.pm_parent = get_device(parent);
-}
-EXPORT_SYMBOL_GPL(device_pm_set_parent);
-
-int device_pm_add(struct device * dev)
+int device_pm_add(struct device *dev)
 {
 	int error;
 
@@ -63,21 +42,20 @@ int device_pm_add(struct device * dev)
 		 kobject_name(&dev->kobj));
 	mutex_lock(&dpm_list_mtx);
 	list_add_tail(&dev->power.entry, &dpm_active);
-	device_pm_set_parent(dev, dev->parent);
-	if ((error = dpm_sysfs_add(dev)))
+	error = dpm_sysfs_add(dev);
+	if (error)
 		list_del(&dev->power.entry);
 	mutex_unlock(&dpm_list_mtx);
 	return error;
 }
 
-void device_pm_remove(struct device * dev)
+void device_pm_remove(struct device *dev)
 {
 	pr_debug("PM: Removing info for %s:%s\n",
 		 dev->bus ? dev->bus->name : "No Bus",
 		 kobject_name(&dev->kobj));
 	mutex_lock(&dpm_list_mtx);
 	dpm_sysfs_remove(dev);
-	put_device(dev->power.pm_parent);
 	list_del_init(&dev->power.entry);
 	mutex_unlock(&dpm_list_mtx);
 }
diff --git a/drivers/base/power/resume.c b/drivers/base/power/resume.c
index f6cfea4..99679e7 100644
--- a/drivers/base/power/resume.c
+++ b/drivers/base/power/resume.c
@@ -29,12 +29,11 @@ int resume_device(struct device * dev)
 
 	down(&dev->sem);
 
-	if (dev->power.pm_parent
-			&& dev->power.pm_parent->power.power_state.event) {
+	if (dev->parent && dev->parent->power.power_state.event) {
 		dev_err(dev, "PM: resume from %d, parent %s still %d\n",
 			dev->power.power_state.event,
-			dev->power.pm_parent->bus_id,
-			dev->power.pm_parent->power.power_state.event);
+			dev->parent->bus_id,
+			dev->parent->power.power_state.event);
 	}
 
 	if (dev->bus && dev->bus->resume) {
diff --git a/drivers/base/power/suspend.c b/drivers/base/power/suspend.c
index 9d6701c..19fae88 100644
--- a/drivers/base/power/suspend.c
+++ b/drivers/base/power/suspend.c
@@ -55,13 +55,12 @@ int suspend_device(struct device * dev, pm_message_t state)
 		dev_dbg(dev, "PM: suspend %d-->%d\n",
 			dev->power.power_state.event, state.event);
 	}
-	if (dev->power.pm_parent
-			&& dev->power.pm_parent->power.power_state.event) {
+	if (dev->parent && dev->parent->power.power_state.event) {
 		dev_err(dev,
 			"PM: suspend %d->%d, parent %s already %d\n",
 			dev->power.power_state.event, state.event,
-			dev->power.pm_parent->bus_id,
-			dev->power.pm_parent->power.power_state.event);
+			dev->parent->bus_id,
+			dev->parent->power.power_state.event);
 	}
 
 	dev->power.prev_state = dev->power.power_state;