Commit ffa6a705 authored by Cornelia Huck's avatar Cornelia Huck Committed by Greg Kroah-Hartman
Browse files

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
......@@ -1561,8 +1561,10 @@ out:
* 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;
}
......
......@@ -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.
......
......@@ -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
......
......@@ -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 "
......
......@@ -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
......
......@@ -400,6 +400,9 @@ extern void __suspend_report_result(const char *function, void *fn, int ret);
#else /* !CONFIG_PM_SLEEP */
#define device_pm_lock() do {} while (0)
#define device_pm_unlock() do {} while (0)
static inline int device_suspend(pm_message_t state)
{
return 0;
......@@ -409,6 +412,14 @@ static inline int device_suspend(pm_message_t state)
#endif /* !CONFIG_PM_SLEEP */
/* How to reorder dpm_list after device_move() */
enum dpm_order {
DPM_ORDER_NONE,
DPM_ORDER_DEV_AFTER_PARENT,
DPM_ORDER_PARENT_BEFORE_DEV,
DPM_ORDER_DEV_LAST,
};
/*
* Global Power Management flags
* Used to keep APM and ACPI from both being active
......
......@@ -140,7 +140,7 @@ static void del_conn(struct work_struct *work)
dev = device_find_child(&conn->dev, NULL, __match_tty);
if (!dev)
break;
device_move(dev, NULL);
device_move(dev, NULL, DPM_ORDER_DEV_LAST);
put_device(dev);
}
......
......@@ -731,7 +731,8 @@ static int rfcomm_tty_open(struct tty_struct *tty, struct file *filp)
remove_wait_queue(&dev->wait, &wait);
if (err == 0)
device_move(dev->tty_dev, rfcomm_get_device(dev));
device_move(dev->tty_dev, rfcomm_get_device(dev),
DPM_ORDER_DEV_AFTER_PARENT);
rfcomm_tty_copy_pending(dev);
......@@ -751,7 +752,7 @@ static void rfcomm_tty_close(struct tty_struct *tty, struct file *filp)
if (atomic_dec_and_test(&dev->opened)) {
if (dev->tty_dev->parent)
device_move(dev->tty_dev, NULL);
device_move(dev->tty_dev, NULL, DPM_ORDER_DEV_LAST);
/* Close DLC and dettach TTY */
rfcomm_dlc_close(dev->dlc, 0);
......
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