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Commit ffa6a705 authored by Cornelia Huck's avatar Cornelia Huck Committed by Greg Kroah-Hartman
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Driver core: Fix device_move() vs. dpm list ordering, v2 



dpm_list currently relies on the fact that child devices will
be registered after their parents to get a correct suspend
order. Using device_move() however destroys this assumption, as
an already registered device may be moved under a newly registered
one.

This patch adds a new argument to device_move(), allowing callers
to specify how dpm_list should be adapted.

Signed-off-by: default avatarCornelia Huck <cornelia.huck@de.ibm.com>
Acked-by: default avatarAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 60530afe

drivers/base/core.c

+18 −1
Original line number Diff line number Diff line
@@ -1561,8 +1561,10 @@ static int device_move_class_links(struct device *dev, 
 * device_move - moves a device to a new parent

 * @dev: the pointer to the struct device to be moved

 * @new_parent: the new parent of the device (can by NULL)

 * @dpm_order: how to reorder the dpm_list

 */

int device_move(struct device *dev, struct device *new_parent)

int device_move(struct device *dev, struct device *new_parent,

		enum dpm_order dpm_order)

{

	int error;

	struct device *old_parent;
@@ -1572,6 +1574,7 @@ int device_move(struct device *dev, struct device *new_parent) 
	if (!dev)

		return -EINVAL;



	device_pm_lock();

	new_parent = get_device(new_parent);

	new_parent_kobj = get_device_parent(dev, new_parent);
@@ -1613,9 +1616,23 @@ int device_move(struct device *dev, struct device *new_parent) 
		put_device(new_parent);

		goto out;

	}

	switch (dpm_order) {

	case DPM_ORDER_NONE:

		break;

	case DPM_ORDER_DEV_AFTER_PARENT:

		device_pm_move_after(dev, new_parent);

		break;

	case DPM_ORDER_PARENT_BEFORE_DEV:

		device_pm_move_before(new_parent, dev);

		break;

	case DPM_ORDER_DEV_LAST:

		device_pm_move_last(dev);

		break;

	}

out_put:

	put_device(old_parent);

out:

	device_pm_unlock();

	put_device(dev);

	return error;

}

drivers/base/power/main.c

+44 −0
Original line number Diff line number Diff line
@@ -106,6 +106,50 @@ void device_pm_remove(struct device *dev) 
	mutex_unlock(&dpm_list_mtx);

}



/**

 *	device_pm_move_before - move device in dpm_list

 *	@deva:  Device to move in dpm_list

 *	@devb:  Device @deva should come before

 */

void device_pm_move_before(struct device *deva, struct device *devb)

{

	pr_debug("PM: Moving %s:%s before %s:%s\n",

		 deva->bus ? deva->bus->name : "No Bus",

		 kobject_name(&deva->kobj),

		 devb->bus ? devb->bus->name : "No Bus",

		 kobject_name(&devb->kobj));

	/* Delete deva from dpm_list and reinsert before devb. */

	list_move_tail(&deva->power.entry, &devb->power.entry);

}



/**

 *	device_pm_move_after - move device in dpm_list

 *	@deva:  Device to move in dpm_list

 *	@devb:  Device @deva should come after

 */

void device_pm_move_after(struct device *deva, struct device *devb)

{

	pr_debug("PM: Moving %s:%s after %s:%s\n",

		 deva->bus ? deva->bus->name : "No Bus",

		 kobject_name(&deva->kobj),

		 devb->bus ? devb->bus->name : "No Bus",

		 kobject_name(&devb->kobj));

	/* Delete deva from dpm_list and reinsert after devb. */

	list_move(&deva->power.entry, &devb->power.entry);

}



/**

 * 	device_pm_move_last - move device to end of dpm_list

 * 	@dev:   Device to move in dpm_list

 */

void device_pm_move_last(struct device *dev)

{

	pr_debug("PM: Moving %s:%s to end of list\n",

		 dev->bus ? dev->bus->name : "No Bus",

		 kobject_name(&dev->kobj));

	list_move_tail(&dev->power.entry, &dpm_list);

}



/**

 *	pm_op - execute the PM operation appropiate for given PM event

 *	@dev:	Device.

drivers/base/power/power.h

+8 −0
Original line number Diff line number Diff line
@@ -18,11 +18,19 @@ static inline struct device *to_device(struct list_head *entry) 


extern void device_pm_add(struct device *);

extern void device_pm_remove(struct device *);

extern void device_pm_move_before(struct device *, struct device *);

extern void device_pm_move_after(struct device *, struct device *);

extern void device_pm_move_last(struct device *);



#else /* CONFIG_PM_SLEEP */



static inline void device_pm_add(struct device *dev) {}

static inline void device_pm_remove(struct device *dev) {}

static inline void device_pm_move_before(struct device *deva,

					 struct device *devb) {}

static inline void device_pm_move_after(struct device *deva,

					struct device *devb) {}

static inline void device_pm_move_last(struct device *dev) {}



#endif

drivers/s390/cio/device.c

+5 −4
Original line number Diff line number Diff line
@@ -799,7 +799,7 @@ static void sch_attach_disconnected_device(struct subchannel *sch, 
		return;

	other_sch = to_subchannel(cdev->dev.parent);

	/* Note: device_move() changes cdev->dev.parent */

	ret = device_move(&cdev->dev, &sch->dev);

	ret = device_move(&cdev->dev, &sch->dev, DPM_ORDER_PARENT_BEFORE_DEV);

	if (ret) {

		CIO_MSG_EVENT(0, "Moving disconnected device 0.%x.%04x failed "

			      "(ret=%d)!\n", cdev->private->dev_id.ssid,
@@ -830,7 +830,7 @@ static void sch_attach_orphaned_device(struct subchannel *sch, 
	 * Try to move the ccw device to its new subchannel.

	 * Note: device_move() changes cdev->dev.parent

	 */

	ret = device_move(&cdev->dev, &sch->dev);

	ret = device_move(&cdev->dev, &sch->dev, DPM_ORDER_PARENT_BEFORE_DEV);

	if (ret) {

		CIO_MSG_EVENT(0, "Moving device 0.%x.%04x from orphanage "

			      "failed (ret=%d)!\n",
@@ -897,7 +897,8 @@ void ccw_device_move_to_orphanage(struct work_struct *work) 
	 * ccw device can take its place on the subchannel.

	 * Note: device_move() changes cdev->dev.parent

	 */

	ret = device_move(&cdev->dev, &css->pseudo_subchannel->dev);

	ret = device_move(&cdev->dev, &css->pseudo_subchannel->dev,

		DPM_ORDER_NONE);

	if (ret) {

		CIO_MSG_EVENT(0, "Moving device 0.%x.%04x to orphanage failed "

			      "(ret=%d)!\n", cdev->private->dev_id.ssid,
@@ -1129,7 +1130,7 @@ static void ccw_device_move_to_sch(struct work_struct *work) 
	 * Try to move the ccw device to its new subchannel.

	 * Note: device_move() changes cdev->dev.parent

	 */

	rc = device_move(&cdev->dev, &sch->dev);

	rc = device_move(&cdev->dev, &sch->dev, DPM_ORDER_PARENT_BEFORE_DEV);

	mutex_unlock(&sch->reg_mutex);

	if (rc) {

		CIO_MSG_EVENT(0, "Moving device 0.%x.%04x to subchannel "

include/linux/device.h

+2 −1
Original line number Diff line number Diff line
@@ -494,7 +494,8 @@ extern int device_for_each_child(struct device *dev, void *data, 
extern struct device *device_find_child(struct device *dev, void *data,

				int (*match)(struct device *dev, void *data));

extern int device_rename(struct device *dev, char *new_name);

extern int device_move(struct device *dev, struct device *new_parent);

extern int device_move(struct device *dev, struct device *new_parent,

		       enum dpm_order dpm_order);



/*

 * Root device objects for grouping under /sys/devices