diff options
| -rw-r--r-- | Documentation/power/devices.txt | 5 | ||||
| -rw-r--r-- | drivers/base/core.c | 6 | ||||
| -rw-r--r-- | drivers/base/power/main.c | 57 | ||||
| -rw-r--r-- | drivers/base/power/power.h | 23 | ||||
| -rw-r--r-- | include/linux/pm.h | 1 |
5 files changed, 40 insertions, 52 deletions
diff --git a/Documentation/power/devices.txt b/Documentation/power/devices.txt index 461e4f1dbec..421e7d00ffd 100644 --- a/Documentation/power/devices.txt +++ b/Documentation/power/devices.txt @@ -196,6 +196,11 @@ its parent; and can't be removed or suspended after that parent. The policy is that the device tree should match hardware bus topology. (Or at least the control bus, for devices which use multiple busses.) +In particular, this means that a device registration may fail if the parent of +the device is suspending (ie. has been chosen by the PM core as the next +device to suspend) or has already suspended, as well as after all of the other +devices have been suspended. Device drivers must be prepared to cope with such +situations. Suspending Devices diff --git a/drivers/base/core.c b/drivers/base/core.c index 24198ad0197..79848e6c5db 100644 --- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -820,7 +820,11 @@ int device_add(struct device *dev) error = dpm_sysfs_add(dev); if (error) goto PMError; - device_pm_add(dev); + error = device_pm_add(dev); + if (error) { + dpm_sysfs_remove(dev); + goto PMError; + } error = bus_add_device(dev); if (error) goto BusError; diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c index 26de2c0fda8..0e3991a437c 100644 --- a/drivers/base/power/main.c +++ b/drivers/base/power/main.c @@ -54,7 +54,8 @@ static LIST_HEAD(dpm_destroy); static DEFINE_MUTEX(dpm_list_mtx); -static DECLARE_RWSEM(pm_sleep_rwsem); +/* 'true' if all devices have been suspended, protected by dpm_list_mtx */ +static bool all_sleeping; int (*platform_enable_wakeup)(struct device *dev, int is_on); @@ -62,14 +63,28 @@ int (*platform_enable_wakeup)(struct device *dev, int is_on); * device_pm_add - add a device to the list of active devices * @dev: Device to be added to the list */ -void device_pm_add(struct device *dev) +int device_pm_add(struct device *dev) { + int error = 0; + pr_debug("PM: Adding info for %s:%s\n", dev->bus ? dev->bus->name : "No Bus", kobject_name(&dev->kobj)); mutex_lock(&dpm_list_mtx); - list_add_tail(&dev->power.entry, &dpm_active); + if ((dev->parent && dev->parent->power.sleeping) || all_sleeping) { + if (dev->parent->power.sleeping) + dev_warn(dev, + "parent %s is sleeping, will not add\n", + dev->parent->bus_id); + else + dev_warn(dev, "devices are sleeping, will not add\n"); + WARN_ON(true); + error = -EBUSY; + } else { + list_add_tail(&dev->power.entry, &dpm_active); + } mutex_unlock(&dpm_list_mtx); + return error; } /** @@ -107,32 +122,6 @@ void device_pm_schedule_removal(struct device *dev) } EXPORT_SYMBOL_GPL(device_pm_schedule_removal); -/** - * pm_sleep_lock - mutual exclusion for registration and suspend - * - * Returns 0 if no suspend is underway and device registration - * may proceed, otherwise -EBUSY. - */ -int pm_sleep_lock(void) -{ - if (down_read_trylock(&pm_sleep_rwsem)) - return 0; - - return -EBUSY; -} - -/** - * pm_sleep_unlock - mutual exclusion for registration and suspend - * - * This routine undoes the effect of device_pm_add_lock - * when a device's registration is complete. - */ -void pm_sleep_unlock(void) -{ - up_read(&pm_sleep_rwsem); -} - - /*------------------------- Resume routines -------------------------*/ /** @@ -242,11 +231,13 @@ static int resume_device(struct device *dev) static void dpm_resume(void) { mutex_lock(&dpm_list_mtx); + all_sleeping = false; while(!list_empty(&dpm_off)) { struct list_head *entry = dpm_off.next; struct device *dev = to_device(entry); list_move_tail(entry, &dpm_active); + dev->power.sleeping = false; mutex_unlock(&dpm_list_mtx); resume_device(dev); mutex_lock(&dpm_list_mtx); @@ -285,7 +276,6 @@ void device_resume(void) might_sleep(); dpm_resume(); unregister_dropped_devices(); - up_write(&pm_sleep_rwsem); } EXPORT_SYMBOL_GPL(device_resume); @@ -421,6 +411,9 @@ static int dpm_suspend(pm_message_t state) struct list_head *entry = dpm_active.prev; struct device *dev = to_device(entry); + WARN_ON(dev->parent && dev->parent->power.sleeping); + + dev->power.sleeping = true; mutex_unlock(&dpm_list_mtx); error = suspend_device(dev, state); mutex_lock(&dpm_list_mtx); @@ -432,11 +425,14 @@ static int dpm_suspend(pm_message_t state) (error == -EAGAIN ? " (please convert to suspend_late)" : "")); + dev->power.sleeping = false; break; } if (!list_empty(&dev->power.entry)) list_move(&dev->power.entry, &dpm_off); } + if (!error) + all_sleeping = true; mutex_unlock(&dpm_list_mtx); return error; @@ -454,7 +450,6 @@ int device_suspend(pm_message_t state) int error; might_sleep(); - down_write(&pm_sleep_rwsem); error = dpm_suspend(state); if (error) device_resume(); diff --git a/drivers/base/power/power.h b/drivers/base/power/power.h index e32d3bdb92c..a6894f2a4b9 100644 --- a/drivers/base/power/power.h +++ b/drivers/base/power/power.h @@ -11,30 +11,13 @@ static inline struct device *to_device(struct list_head *entry) return container_of(entry, struct device, power.entry); } -extern void device_pm_add(struct device *); +extern int device_pm_add(struct device *); extern void device_pm_remove(struct device *); -extern int pm_sleep_lock(void); -extern void pm_sleep_unlock(void); #else /* CONFIG_PM_SLEEP */ - -static inline void device_pm_add(struct device *dev) -{ -} - -static inline void device_pm_remove(struct device *dev) -{ -} - -static inline int pm_sleep_lock(void) -{ - return 0; -} - -static inline void pm_sleep_unlock(void) -{ -} +static inline int device_pm_add(struct device *dev) { return 0; } +static inline void device_pm_remove(struct device *dev) {} #endif diff --git a/include/linux/pm.h b/include/linux/pm.h index 015b735811b..e6b9f29e27d 100644 --- a/include/linux/pm.h +++ b/include/linux/pm.h @@ -183,6 +183,7 @@ typedef struct pm_message { struct dev_pm_info { pm_message_t power_state; unsigned can_wakeup:1; + bool sleeping:1; /* Owned by the PM core */ #ifdef CONFIG_PM_SLEEP unsigned should_wakeup:1; struct list_head entry; |