From ffa6a7054d172a2f57248dff2de600ca795c5656 Mon Sep 17 00:00:00 2001 From: Cornelia Huck Date: Wed, 4 Mar 2009 12:44:00 +0100 Subject: [PATCH] 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: Cornelia Huck Acked-by: Alan Stern Signed-off-by: Greg Kroah-Hartman --- drivers/base/core.c | 19 +++++++++++++++- drivers/base/power/main.c | 44 ++++++++++++++++++++++++++++++++++++++ drivers/base/power/power.h | 8 +++++++ drivers/s390/cio/device.c | 9 ++++---- include/linux/device.h | 3 ++- include/linux/pm.h | 11 ++++++++++ net/bluetooth/hci_sysfs.c | 2 +- net/bluetooth/rfcomm/tty.c | 5 +++-- 8 files changed, 92 insertions(+), 9 deletions(-) diff --git a/drivers/base/core.c b/drivers/base/core.c index 95c67ffd71da..e73c92d13a23 100644 --- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -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; } diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c index 2d14f4ae6c01..e255341682c8 100644 --- a/drivers/base/power/main.c +++ b/drivers/base/power/main.c @@ -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. diff --git a/drivers/base/power/power.h b/drivers/base/power/power.h index 41f51fae042f..c7cb4fc3735c 100644 --- a/drivers/base/power/power.h +++ b/drivers/base/power/power.h @@ -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 diff --git a/drivers/s390/cio/device.c b/drivers/s390/cio/device.c index 611d2e001dd5..e28f8ae53453 100644 --- a/drivers/s390/cio/device.c +++ b/drivers/s390/cio/device.c @@ -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 " diff --git a/include/linux/device.h b/include/linux/device.h index 914c1016dd8f..f98d0cfb4f81 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -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 diff --git a/include/linux/pm.h b/include/linux/pm.h index 24ba5f67b3a3..1d4e2d289821 100644 --- a/include/linux/pm.h +++ b/include/linux/pm.h @@ -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 diff --git a/net/bluetooth/hci_sysfs.c b/net/bluetooth/hci_sysfs.c index 1a1f916be44e..ed82796d4a0f 100644 --- a/net/bluetooth/hci_sysfs.c +++ b/net/bluetooth/hci_sysfs.c @@ -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); } diff --git a/net/bluetooth/rfcomm/tty.c b/net/bluetooth/rfcomm/tty.c index d030c69cb5a3..abdc703a11d2 100644 --- a/net/bluetooth/rfcomm/tty.c +++ b/net/bluetooth/rfcomm/tty.c @@ -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); -- 2.20.1