diff options
| -rw-r--r-- | Documentation/ABI/testing/sysfs-devices-power | 79 | ||||
| -rw-r--r-- | Documentation/ABI/testing/sysfs-power | 13 | ||||
| -rw-r--r-- | drivers/base/power/main.c | 132 | ||||
| -rw-r--r-- | drivers/base/power/power.h | 6 | ||||
| -rw-r--r-- | drivers/base/power/runtime.c | 45 | ||||
| -rw-r--r-- | drivers/base/power/sysfs.c | 100 | ||||
| -rw-r--r-- | include/linux/device.h | 17 | ||||
| -rw-r--r-- | include/linux/pm.h | 4 | ||||
| -rw-r--r-- | include/linux/pm_runtime.h | 4 | ||||
| -rw-r--r-- | include/linux/resume-trace.h | 7 | ||||
| -rw-r--r-- | kernel/power/Kconfig | 14 | ||||
| -rw-r--r-- | kernel/power/main.c | 31 |
12 files changed, 437 insertions, 15 deletions
diff --git a/Documentation/ABI/testing/sysfs-devices-power b/Documentation/ABI/testing/sysfs-devices-power new file mode 100644 index 000000000000..6123c523bfd7 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-devices-power @@ -0,0 +1,79 @@ +What: /sys/devices/.../power/ +Date: January 2009 +Contact: Rafael J. Wysocki <rjw@sisk.pl> +Description: + The /sys/devices/.../power directory contains attributes + allowing the user space to check and modify some power + management related properties of given device. + +What: /sys/devices/.../power/wakeup +Date: January 2009 +Contact: Rafael J. Wysocki <rjw@sisk.pl> +Description: + The /sys/devices/.../power/wakeup attribute allows the user + space to check if the device is enabled to wake up the system + from sleep states, such as the memory sleep state (suspend to + RAM) and hibernation (suspend to disk), and to enable or disable + it to do that as desired. + + Some devices support "wakeup" events, which are hardware signals + used to activate the system from a sleep state. Such devices + have one of the following two values for the sysfs power/wakeup + file: + + + "enabled\n" to issue the events; + + "disabled\n" not to do so; + + In that cases the user space can change the setting represented + by the contents of this file by writing either "enabled", or + "disabled" to it. + + For the devices that are not capable of generating system wakeup + events this file contains "\n". In that cases the user space + cannot modify the contents of this file and the device cannot be + enabled to wake up the system. + +What: /sys/devices/.../power/control +Date: January 2009 +Contact: Rafael J. Wysocki <rjw@sisk.pl> +Description: + The /sys/devices/.../power/control attribute allows the user + space to control the run-time power management of the device. + + All devices have one of the following two values for the + power/control file: + + + "auto\n" to allow the device to be power managed at run time; + + "on\n" to prevent the device from being power managed; + + The default for all devices is "auto", which means that they may + be subject to automatic power management, depending on their + drivers. Changing this attribute to "on" prevents the driver + from power managing the device at run time. Doing that while + the device is suspended causes it to be woken up. + +What: /sys/devices/.../power/async +Date: January 2009 +Contact: Rafael J. Wysocki <rjw@sisk.pl> +Description: + The /sys/devices/.../async attribute allows the user space to + enable or diasble the device's suspend and resume callbacks to + be executed asynchronously (ie. in separate threads, in parallel + with the main suspend/resume thread) during system-wide power + transitions (eg. suspend to RAM, hibernation). + + All devices have one of the following two values for the + power/async file: + + + "enabled\n" to permit the asynchronous suspend/resume; + + "disabled\n" to forbid it; + + The value of this attribute may be changed by writing either + "enabled", or "disabled" to it. + + It generally is unsafe to permit the asynchronous suspend/resume + of a device unless it is certain that all of the PM dependencies + of the device are known to the PM core. However, for some + devices this attribute is set to "enabled" by bus type code or + device drivers and in that cases it should be safe to leave the + default value. diff --git a/Documentation/ABI/testing/sysfs-power b/Documentation/ABI/testing/sysfs-power index dcff4d0623ad..d6a801f45b48 100644 --- a/Documentation/ABI/testing/sysfs-power +++ b/Documentation/ABI/testing/sysfs-power @@ -101,3 +101,16 @@ Description: CAUTION: Using it will cause your machine's real-time (CMOS) clock to be set to a random invalid time after a resume. + +What: /sys/power/pm_async +Date: January 2009 +Contact: Rafael J. Wysocki <rjw@sisk.pl> +Description: + The /sys/power/pm_async file controls the switch allowing the + user space to enable or disable asynchronous suspend and resume + of devices. If enabled, this feature will cause some device + drivers' suspend and resume callbacks to be executed in parallel + with each other and with the main suspend thread. It is enabled + if this file contains "1", which is the default. It may be + disabled by writing "0" to this file, in which case all devices + will be suspended and resumed synchronously. diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c index a5142bddef41..6efef9fb23a1 100644 --- a/drivers/base/power/main.c +++ b/drivers/base/power/main.c @@ -25,6 +25,7 @@ #include <linux/resume-trace.h> #include <linux/interrupt.h> #include <linux/sched.h> +#include <linux/async.h> #include "../base.h" #include "power.h" @@ -42,6 +43,7 @@ LIST_HEAD(dpm_list); static DEFINE_MUTEX(dpm_list_mtx); +static pm_message_t pm_transition; /* * Set once the preparation of devices for a PM transition has started, reset @@ -56,6 +58,7 @@ static bool transition_started; void device_pm_init(struct device *dev) { dev->power.status = DPM_ON; + init_completion(&dev->power.completion); pm_runtime_init(dev); } @@ -111,6 +114,7 @@ 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)); + complete_all(&dev->power.completion); mutex_lock(&dpm_list_mtx); list_del_init(&dev->power.entry); mutex_unlock(&dpm_list_mtx); @@ -188,6 +192,31 @@ static void initcall_debug_report(struct device *dev, ktime_t calltime, } /** + * dpm_wait - Wait for a PM operation to complete. + * @dev: Device to wait for. + * @async: If unset, wait only if the device's power.async_suspend flag is set. + */ +static void dpm_wait(struct device *dev, bool async) +{ + if (!dev) + return; + + if (async || (pm_async_enabled && dev->power.async_suspend)) + wait_for_completion(&dev->power.completion); +} + +static int dpm_wait_fn(struct device *dev, void *async_ptr) +{ + dpm_wait(dev, *((bool *)async_ptr)); + return 0; +} + +static void dpm_wait_for_children(struct device *dev, bool async) +{ + device_for_each_child(dev, &async, dpm_wait_fn); +} + +/** * pm_op - Execute the PM operation appropriate for given PM event. * @dev: Device to handle. * @ops: PM operations to choose from. @@ -271,8 +300,9 @@ static int pm_noirq_op(struct device *dev, ktime_t calltime, delta, rettime; if (initcall_debug) { - pr_info("calling %s_i+ @ %i\n", - dev_name(dev), task_pid_nr(current)); + pr_info("calling %s+ @ %i, parent: %s\n", + dev_name(dev), task_pid_nr(current), + dev->parent ? dev_name(dev->parent) : "none"); calltime = ktime_get(); } @@ -468,16 +498,20 @@ static int legacy_resume(struct device *dev, int (*cb)(struct device *dev)) * device_resume - Execute "resume" callbacks for given device. * @dev: Device to handle. * @state: PM transition of the system being carried out. + * @async: If true, the device is being resumed asynchronously. */ -static int device_resume(struct device *dev, pm_message_t state) +static int device_resume(struct device *dev, pm_message_t state, bool async) { int error = 0; TRACE_DEVICE(dev); TRACE_RESUME(0); + dpm_wait(dev->parent, async); down(&dev->sem); + dev->power.status = DPM_RESUMING; + if (dev->bus) { if (dev->bus->pm) { pm_dev_dbg(dev, state, ""); @@ -510,11 +544,29 @@ static int device_resume(struct device *dev, pm_message_t state) } End: up(&dev->sem); + complete_all(&dev->power.completion); TRACE_RESUME(error); return error; } +static void async_resume(void *data, async_cookie_t cookie) +{ + struct device *dev = (struct device *)data; + int error; + + error = device_resume(dev, pm_transition, true); + if (error) + pm_dev_err(dev, pm_transition, " async", error); + put_device(dev); +} + +static bool is_async(struct device *dev) +{ + return dev->power.async_suspend && pm_async_enabled + && !pm_trace_is_enabled(); +} + /** * dpm_resume - Execute "resume" callbacks for non-sysdev devices. * @state: PM transition of the system being carried out. @@ -525,21 +577,33 @@ static int device_resume(struct device *dev, pm_message_t state) static void dpm_resume(pm_message_t state) { struct list_head list; + struct device *dev; ktime_t starttime = ktime_get(); INIT_LIST_HEAD(&list); mutex_lock(&dpm_list_mtx); - while (!list_empty(&dpm_list)) { - struct device *dev = to_device(dpm_list.next); + pm_transition = state; + + list_for_each_entry(dev, &dpm_list, power.entry) { + if (dev->power.status < DPM_OFF) + continue; + INIT_COMPLETION(dev->power.completion); + if (is_async(dev)) { + get_device(dev); + async_schedule(async_resume, dev); + } + } + + while (!list_empty(&dpm_list)) { + dev = to_device(dpm_list.next); get_device(dev); - if (dev->power.status >= DPM_OFF) { + if (dev->power.status >= DPM_OFF && !is_async(dev)) { int error; - dev->power.status = DPM_RESUMING; mutex_unlock(&dpm_list_mtx); - error = device_resume(dev, state); + error = device_resume(dev, state, false); mutex_lock(&dpm_list_mtx); if (error) @@ -554,6 +618,7 @@ static void dpm_resume(pm_message_t state) } list_splice(&list, &dpm_list); mutex_unlock(&dpm_list_mtx); + async_synchronize_full(); dpm_show_time(starttime, state, NULL); } @@ -731,17 +796,24 @@ static int legacy_suspend(struct device *dev, pm_message_t state, return error; } +static int async_error; + /** * device_suspend - Execute "suspend" callbacks for given device. * @dev: Device to handle. * @state: PM transition of the system being carried out. + * @async: If true, the device is being suspended asynchronously. */ -static int device_suspend(struct device *dev, pm_message_t state) +static int __device_suspend(struct device *dev, pm_message_t state, bool async) { int error = 0; + dpm_wait_for_children(dev, async); down(&dev->sem); + if (async_error) + goto End; + if (dev->class) { if (dev->class->pm) { pm_dev_dbg(dev, state, "class "); @@ -772,12 +844,44 @@ static int device_suspend(struct device *dev, pm_message_t state) error = legacy_suspend(dev, state, dev->bus->suspend); } } + + if (!error) + dev->power.status = DPM_OFF; + End: up(&dev->sem); + complete_all(&dev->power.completion); return error; } +static void async_suspend(void *data, async_cookie_t cookie) +{ + struct device *dev = (struct device *)data; + int error; + + error = __device_suspend(dev, pm_transition, true); + if (error) { + pm_dev_err(dev, pm_transition, " async", error); + async_error = error; + } + + put_device(dev); +} + +static int device_suspend(struct device *dev) +{ + INIT_COMPLETION(dev->power.completion); + + if (pm_async_enabled && dev->power.async_suspend) { + get_device(dev); + async_schedule(async_suspend, dev); + return 0; + } + + return __device_suspend(dev, pm_transition, false); +} + /** * dpm_suspend - Execute "suspend" callbacks for all non-sysdev devices. * @state: PM transition of the system being carried out. @@ -790,13 +894,15 @@ static int dpm_suspend(pm_message_t state) INIT_LIST_HEAD(&list); mutex_lock(&dpm_list_mtx); + pm_transition = state; + async_error = 0; while (!list_empty(&dpm_list)) { struct device *dev = to_device(dpm_list.prev); get_device(dev); mutex_unlock(&dpm_list_mtx); - error = device_suspend(dev, state); + error = device_suspend(dev); mutex_lock(&dpm_list_mtx); if (error) { @@ -804,13 +910,17 @@ static int dpm_suspend(pm_message_t state) put_device(dev); break; } - dev->power.status = DPM_OFF; if (!list_empty(&dev->power.entry)) list_move(&dev->power.entry, &list); put_device(dev); + if (async_error) + break; } list_splice(&list, dpm_list.prev); mutex_unlock(&dpm_list_mtx); + async_synchronize_full(); + if (!error) + error = async_error; if (!error) dpm_show_time(starttime, state, NULL); return error; diff --git a/drivers/base/power/power.h b/drivers/base/power/power.h index b8fa1aa5225a..c0bd03c83b9c 100644 --- a/drivers/base/power/power.h +++ b/drivers/base/power/power.h @@ -12,10 +12,10 @@ static inline void pm_runtime_remove(struct device *dev) {} #ifdef CONFIG_PM_SLEEP -/* - * main.c - */ +/* kernel/power/main.c */ +extern int pm_async_enabled; +/* drivers/base/power/main.c */ extern struct list_head dpm_list; /* The active device list */ static inline struct device *to_device(struct list_head *entry) diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c index f8b044e8aef7..626dd147b75f 100644 --- a/drivers/base/power/runtime.c +++ b/drivers/base/power/runtime.c @@ -1011,6 +1011,50 @@ void pm_runtime_enable(struct device *dev) EXPORT_SYMBOL_GPL(pm_runtime_enable); /** + * pm_runtime_forbid - Block run-time PM of a device. + * @dev: Device to handle. + * + * Increase the device's usage count and clear its power.runtime_auto flag, + * so that it cannot be suspended at run time until pm_runtime_allow() is called + * for it. + */ +void pm_runtime_forbid(struct device *dev) +{ + spin_lock_irq(&dev->power.lock); + if (!dev->power.runtime_auto) + goto out; + + dev->power.runtime_auto = false; + atomic_inc(&dev->power.usage_count); + __pm_runtime_resume(dev, false); + + out: + spin_unlock_irq(&dev->power.lock); +} +EXPORT_SYMBOL_GPL(pm_runtime_forbid); + +/** + * pm_runtime_allow - Unblock run-time PM of a device. + * @dev: Device to handle. + * + * Decrease the device's usage count and set its power.runtime_auto flag. + */ +void pm_runtime_allow(struct device *dev) +{ + spin_lock_irq(&dev->power.lock); + if (dev->power.runtime_auto) + goto out; + + dev->power.runtime_auto = true; + if (atomic_dec_and_test(&dev->power.usage_count)) + __pm_runtime_idle(dev); + + out: + spin_unlock_irq(&dev->power.lock); +} +EXPORT_SYMBOL_GPL(pm_runtime_allow); + +/** * pm_runtime_init - Initialize run-time PM fields in given device object. * @dev: Device object to initialize. */ @@ -1028,6 +1072,7 @@ void pm_runtime_init(struct device *dev) atomic_set(&dev->power.child_count, 0); pm_suspend_ignore_children(dev, false); + dev->power.runtime_auto = true; dev->power.request_pending = false; dev->power.request = RPM_REQ_NONE; diff --git a/drivers/base/power/sysfs.c b/drivers/base/power/sysfs.c index 596aeecfdffe..86fd9373447e 100644 --- a/drivers/base/power/sysfs.c +++ b/drivers/base/power/sysfs.c @@ -4,9 +4,25 @@ #include <linux/device.h> #include <linux/string.h> +#include <linux/pm_runtime.h> #include "power.h" /* + * control - Report/change current runtime PM setting of the device + * + * Runtime power management of a device can be blocked with the help of + * this attribute. All devices have one of the following two values for + * the power/control file: + * + * + "auto\n" to allow the device to be power managed at run time; + * + "on\n" to prevent the device from being power managed at run time; + * + * The default for all devices is "auto", which means that devices may be + * subject to automatic power management, depending on their drivers. + * Changing this attribute to "on" prevents the driver from power managing + * the device at run time. Doing that while the device is suspended causes + * it to be woken up. + * * wakeup - Report/change current wakeup option for device * * Some devices support "wakeup" events, which are hardware signals @@ -38,11 +54,61 @@ * wakeup events internally (unless they are disabled), keeping * their hardware in low power modes whenever they're unused. This * saves runtime power, without requiring system-wide sleep states. + * + * async - Report/change current async suspend setting for the device + * + * Asynchronous suspend and resume of the device during system-wide power + * state transitions can be enabled by writing "enabled" to this file. + * Analogously, if "disabled" is written to this file, the device will be + * suspended and resumed synchronously. + * + * All devices have one of the following two values for power/async: + * + * + "enabled\n" to permit the asynchronous suspend/resume of the device; + * + "disabled\n" to forbid it; + * + * NOTE: It generally is unsafe to permit the asynchronous suspend/resume + * of a device unless it is certain that all of the PM dependencies of the + * device are known to the PM core. However, for some devices this + * attribute is set to "enabled" by bus type code or device drivers and in + * that cases it should be safe to leave the default value. */ static const char enabled[] = "enabled"; static const char disabled[] = "disabled"; +#ifdef CONFIG_PM_RUNTIME +static const char ctrl_auto[] = "auto"; +static const char ctrl_on[] = "on"; + +static ssize_t control_show(struct device *dev, struct device_attribute *attr, + char *buf) +{ + return sprintf(buf, "%s\n", + dev->power.runtime_auto ? ctrl_auto : ctrl_on); +} + +static ssize_t control_store(struct device * dev, struct device_attribute *attr, + const char * buf, size_t n) +{ + char *cp; + int len = n; + + cp = memchr(buf, '\n', n); + if (cp) + len = cp - buf; + if (len == sizeof ctrl_auto - 1 && strncmp(buf, ctrl_auto, len) == 0) + pm_runtime_allow(dev); + else if (len == sizeof ctrl_on - 1 && strncmp(buf, ctrl_on, len) == 0) + pm_runtime_forbid(dev); + else + return -EINVAL; + return n; +} + +static DEVICE_ATTR(control, 0644, control_show, control_store); +#endif + static ssize_t wake_show(struct device * dev, struct device_attribute *attr, char * buf) { @@ -77,9 +143,43 @@ wake_store(struct device * dev, struct device_attribute *attr, static DEVICE_ATTR(wakeup, 0644, wake_show, wake_store); +#ifdef CONFIG_PM_SLEEP_ADVANCED_DEBUG +static ssize_t async_show(struct device *dev, struct device_attribute *attr, + char *buf) +{ + return sprintf(buf, "%s\n", + device_async_suspend_enabled(dev) ? enabled : disabled); +} + +static ssize_t async_store(struct device *dev, struct device_attribute *attr, + const char *buf, size_t n) +{ + char *cp; + int len = n; + + cp = memchr(buf, '\n', n); + if (cp) + len = cp - buf; + if (len == sizeof enabled - 1 && strncmp(buf, enabled, len) == 0) + device_enable_async_suspend(dev); + else if (len == sizeof disabled - 1 && strncmp(buf, disabled, len) == 0) + device_disable_async_suspend(dev); + else + return -EINVAL; + return n; +} + +static DEVICE_ATTR(async, 0644, async_show, async_store); +#endif /* CONFIG_PM_SLEEP_ADVANCED_DEBUG */ static struct attribute * power_attrs[] = { +#ifdef CONFIG_PM_RUNTIME + &dev_attr_control.attr, +#endif &dev_attr_wakeup.attr, +#ifdef CONFIG_PM_SLEEP_ADVANCED_DEBUG + &dev_attr_async.attr, +#endif NULL, }; static struct attribute_group pm_attr_group = { diff --git a/include/linux/device.h b/include/linux/device.h index a62799f2ab00..b30527db3ac0 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -472,6 +472,23 @@ static inline int device_is_registered(struct device *dev) return dev->kobj.state_in_sysfs; } +static inline void device_enable_async_suspend(struct device *dev) +{ + if (dev->power.status == DPM_ON) + dev->power.async_suspend = true; +} + +static inline void device_disable_async_suspend(struct device *dev) +{ + if (dev->power.status == DPM_ON) + dev->power.async_suspend = false; +} + +static inline bool device_async_suspend_enabled(struct device *dev) +{ + return !!dev->power.async_suspend; +} + void driver_init(void); /* diff --git a/include/linux/pm.h b/include/linux/pm.h index 198b8f9fe05e..9c16cd20fc96 100644 --- a/include/linux/pm.h +++ b/include/linux/pm.h @@ -26,6 +26,7 @@ #include <linux/spinlock.h> #include <linux/wait.h> #include <linux/timer.h> +#include <linux/completion.h> /* * Callbacks for platform drivers to implement. @@ -412,9 +413,11 @@ struct dev_pm_info { pm_message_t power_state; unsigned int can_wakeup:1; unsigned int should_wakeup:1; + unsigned async_suspend:1; enum dpm_state status; /* Owned by the PM core */ #ifdef CONFIG_PM_SLEEP struct list_head entry; + struct completion completion; #endif #ifdef CONFIG_PM_RUNTIME struct timer_list suspend_timer; @@ -430,6 +433,7 @@ struct dev_pm_info { unsigned int request_pending:1; unsigned int deferred_resume:1; unsigned int run_wake:1; + unsigned int runtime_auto:1; enum rpm_request request; enum rpm_status runtime_status; int runtime_error; diff --git a/include/linux/pm_runtime.h b/include/linux/pm_runtime.h index 370ce0a6fe4a..7d773aac5314 100644 --- a/include/linux/pm_runtime.h +++ b/include/linux/pm_runtime.h @@ -28,6 +28,8 @@ extern int __pm_runtime_set_status(struct device *dev, unsigned int status); extern int pm_runtime_barrier(struct device *dev); extern void pm_runtime_enable(struct device *dev); extern void __pm_runtime_disable(struct device *dev, bool check_resume); +extern void pm_runtime_allow(struct device *dev); +extern void pm_runtime_forbid(struct device *dev); static inline bool pm_children_suspended(struct device *dev) { @@ -78,6 +80,8 @@ static inline int __pm_runtime_set_status(struct device *dev, static inline int pm_runtime_barrier(struct device *dev) { return 0; } static inline void pm_runtime_enable(struct device *dev) {} static inline void __pm_runtime_disable(struct device *dev, bool c) {} +static inline void pm_runtime_allow(struct device *dev) {} +static inline void pm_runtime_forbid(struct device *dev) {} static inline bool pm_children_suspended(struct device *dev) { return false; } static inline void pm_suspend_ignore_children(struct device *dev, bool en) {} diff --git a/include/linux/resume-trace.h b/include/linux/resume-trace.h index c9ba2fdf807d..bc8c3881c729 100644 --- a/include/linux/resume-trace.h +++ b/include/linux/resume-trace.h @@ -6,6 +6,11 @@ extern int pm_trace_enabled; +static inline int pm_trace_is_enabled(void) +{ + return pm_trace_enabled; +} + struct device; extern void set_trace_device(struct device *); extern void generate_resume_trace(const void *tracedata, unsigned int user); @@ -17,6 +22,8 @@ extern void generate_resume_trace(const void *tracedata, unsigned int user); #else +static inline int pm_trace_is_enabled(void) { return 0; } + #define TRACE_DEVICE(dev) do { } while (0) #define TRACE_RESUME(dev) do { } while (0) diff --git a/kernel/power/Kconfig b/kernel/power/Kconfig index 4c9cffcf69c7..5c36ea9d55d2 100644 --- a/kernel/power/Kconfig +++ b/kernel/power/Kconfig @@ -27,6 +27,15 @@ config PM_DEBUG code. This is helpful when debugging and reporting PM bugs, like suspend support. +config PM_ADVANCED_DEBUG + bool "Extra PM attributes in sysfs for low-level debugging/testing" + depends on PM_DEBUG + default n + ---help--- + Add extra sysfs attributes allowing one to access some Power Management + fields of device objects from user space. If you are not a kernel + developer interested in debugging/testing Power Management, say "no". + config PM_VERBOSE bool "Verbose Power Management debugging" depends on PM_DEBUG @@ -85,6 +94,11 @@ config PM_SLEEP depends on SUSPEND || HIBERNATION || XEN_SAVE_RESTORE default y +config PM_SLEEP_ADVANCED_DEBUG + bool + depends on PM_ADVANCED_DEBUG + default n + config SUSPEND bool "Suspend to RAM and standby" depends on PM && ARCH_SUSPEND_POSSIBLE diff --git a/kernel/power/main.c b/kernel/power/main.c index 0998c7139053..b58800b21fc0 100644 --- a/kernel/power/main.c +++ b/kernel/power/main.c @@ -44,6 +44,32 @@ int pm_notifier_call_chain(unsigned long val) == NOTIFY_BAD) ? -EINVAL : 0; } +/* If set, devices may be suspended and resumed asynchronously. */ +int pm_async_enabled = 1; + +static ssize_t pm_async_show(struct kobject *kobj, struct kobj_attribute *attr, + char *buf) +{ + return sprintf(buf, "%d\n", pm_async_enabled); +} + +static ssize_t pm_async_store(struct kobject *kobj, struct kobj_attribute *attr, + const char *buf, size_t n) +{ + unsigned long val; + + if (strict_strtoul(buf, 10, &val)) + return -EINVAL; + + if (val > 1) + return -EINVAL; + + pm_async_enabled = val; + return n; +} + +power_attr(pm_async); + #ifdef CONFIG_PM_DEBUG int pm_test_level = TEST_NONE; @@ -208,9 +234,12 @@ static struct attribute * g[] = { #ifdef CONFIG_PM_TRACE &pm_trace_attr.attr, #endif -#if defined(CONFIG_PM_SLEEP) && defined(CONFIG_PM_DEBUG) +#ifdef CONFIG_PM_SLEEP + &pm_async_attr.attr, +#ifdef CONFIG_PM_DEBUG &pm_test_attr.attr, #endif +#endif NULL, }; |