diff options
| -rw-r--r-- | drivers/base/power/main.c | 66 | ||||
| -rw-r--r-- | include/linux/pm.h | 36 | ||||
| -rw-r--r-- | include/linux/pm_runtime.h | 6 |
3 files changed, 85 insertions, 23 deletions
diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c index 86d5e4fb5b98..343ffad59377 100644 --- a/drivers/base/power/main.c +++ b/drivers/base/power/main.c @@ -479,7 +479,7 @@ static int device_resume_noirq(struct device *dev, pm_message_t state, bool asyn TRACE_DEVICE(dev); TRACE_RESUME(0); - if (dev->power.syscore) + if (dev->power.syscore || dev->power.direct_complete) goto Out; if (!dev->power.is_noirq_suspended) @@ -605,7 +605,7 @@ static int device_resume_early(struct device *dev, pm_message_t state, bool asyn TRACE_DEVICE(dev); TRACE_RESUME(0); - if (dev->power.syscore) + if (dev->power.syscore || dev->power.direct_complete) goto Out; if (!dev->power.is_late_suspended) @@ -735,6 +735,12 @@ static int device_resume(struct device *dev, pm_message_t state, bool async) if (dev->power.syscore) goto Complete; + if (dev->power.direct_complete) { + /* Match the pm_runtime_disable() in __device_suspend(). */ + pm_runtime_enable(dev); + goto Complete; + } + dpm_wait(dev->parent, async); dpm_watchdog_set(&wd, dev); device_lock(dev); @@ -1007,7 +1013,7 @@ static int __device_suspend_noirq(struct device *dev, pm_message_t state, bool a goto Complete; } - if (dev->power.syscore) + if (dev->power.syscore || dev->power.direct_complete) goto Complete; dpm_wait_for_children(dev, async); @@ -1146,7 +1152,7 @@ static int __device_suspend_late(struct device *dev, pm_message_t state, bool as goto Complete; } - if (dev->power.syscore) + if (dev->power.syscore || dev->power.direct_complete) goto Complete; dpm_wait_for_children(dev, async); @@ -1332,6 +1338,17 @@ static int __device_suspend(struct device *dev, pm_message_t state, bool async) if (dev->power.syscore) goto Complete; + if (dev->power.direct_complete) { + if (pm_runtime_status_suspended(dev)) { + pm_runtime_disable(dev); + if (pm_runtime_suspended_if_enabled(dev)) + goto Complete; + + pm_runtime_enable(dev); + } + dev->power.direct_complete = false; + } + dpm_watchdog_set(&wd, dev); device_lock(dev); @@ -1382,10 +1399,19 @@ static int __device_suspend(struct device *dev, pm_message_t state, bool async) End: if (!error) { + struct device *parent = dev->parent; + dev->power.is_suspended = true; - if (dev->power.wakeup_path - && dev->parent && !dev->parent->power.ignore_children) - dev->parent->power.wakeup_path = true; + if (parent) { + spin_lock_irq(&parent->power.lock); + + dev->parent->power.direct_complete = false; + if (dev->power.wakeup_path + && !dev->parent->power.ignore_children) + dev->parent->power.wakeup_path = true; + + spin_unlock_irq(&parent->power.lock); + } } device_unlock(dev); @@ -1487,7 +1513,7 @@ static int device_prepare(struct device *dev, pm_message_t state) { int (*callback)(struct device *) = NULL; char *info = NULL; - int error = 0; + int ret = 0; if (dev->power.syscore) return 0; @@ -1523,17 +1549,27 @@ static int device_prepare(struct device *dev, pm_message_t state) callback = dev->driver->pm->prepare; } - if (callback) { - error = callback(dev); - suspend_report_result(callback, error); - } + if (callback) + ret = callback(dev); device_unlock(dev); - if (error) + if (ret < 0) { + suspend_report_result(callback, ret); pm_runtime_put(dev); - - return error; + return ret; + } + /* + * A positive return value from ->prepare() means "this device appears + * to be runtime-suspended and its state is fine, so if it really is + * runtime-suspended, you can leave it in that state provided that you + * will do the same thing with all of its descendants". This only + * applies to suspend transitions, however. + */ + spin_lock_irq(&dev->power.lock); + dev->power.direct_complete = ret > 0 && state.event == PM_EVENT_SUSPEND; + spin_unlock_irq(&dev->power.lock); + return 0; } /** diff --git a/include/linux/pm.h b/include/linux/pm.h index d915d0345fa1..72c0fe098a27 100644 --- a/include/linux/pm.h +++ b/include/linux/pm.h @@ -93,13 +93,23 @@ typedef struct pm_message { * been registered) to recover from the race condition. * This method is executed for all kinds of suspend transitions and is * followed by one of the suspend callbacks: @suspend(), @freeze(), or - * @poweroff(). The PM core executes subsystem-level @prepare() for all - * devices before starting to invoke suspend callbacks for any of them, so - * generally devices may be assumed to be functional or to respond to - * runtime resume requests while @prepare() is being executed. However, - * device drivers may NOT assume anything about the availability of user - * space at that time and it is NOT valid to request firmware from within - * @prepare() (it's too late to do that). It also is NOT valid to allocate + * @poweroff(). If the transition is a suspend to memory or standby (that + * is, not related to hibernation), the return value of @prepare() may be + * used to indicate to the PM core to leave the device in runtime suspend + * if applicable. Namely, if @prepare() returns a positive number, the PM + * core will understand that as a declaration that the device appears to be + * runtime-suspended and it may be left in that state during the entire + * transition and during the subsequent resume if all of its descendants + * are left in runtime suspend too. If that happens, @complete() will be + * executed directly after @prepare() and it must ensure the proper + * functioning of the device after the system resume. + * The PM core executes subsystem-level @prepare() for all devices before + * starting to invoke suspend callbacks for any of them, so generally + * devices may be assumed to be functional or to respond to runtime resume + * requests while @prepare() is being executed. However, device drivers + * may NOT assume anything about the availability of user space at that + * time and it is NOT valid to request firmware from within @prepare() + * (it's too late to do that). It also is NOT valid to allocate * substantial amounts of memory from @prepare() in the GFP_KERNEL mode. * [To work around these limitations, drivers may register suspend and * hibernation notifiers to be executed before the freezing of tasks.] @@ -112,7 +122,16 @@ typedef struct pm_message { * of the other devices that the PM core has unsuccessfully attempted to * suspend earlier). * The PM core executes subsystem-level @complete() after it has executed - * the appropriate resume callbacks for all devices. + * the appropriate resume callbacks for all devices. If the corresponding + * @prepare() at the beginning of the suspend transition returned a + * positive number and the device was left in runtime suspend (without + * executing any suspend and resume callbacks for it), @complete() will be + * the only callback executed for the device during resume. In that case, + * @complete() must be prepared to do whatever is necessary to ensure the + * proper functioning of the device after the system resume. To this end, + * @complete() can check the power.direct_complete flag of the device to + * learn whether (unset) or not (set) the previous suspend and resume + * callbacks have been executed for it. * * @suspend: Executed before putting the system into a sleep state in which the * contents of main memory are preserved. The exact action to perform @@ -546,6 +565,7 @@ struct dev_pm_info { bool is_late_suspended:1; bool ignore_children:1; bool early_init:1; /* Owned by the PM core */ + bool direct_complete:1; /* Owned by the PM core */ spinlock_t lock; #ifdef CONFIG_PM_SLEEP struct list_head entry; diff --git a/include/linux/pm_runtime.h b/include/linux/pm_runtime.h index 2a5897a4afbc..43fd6716f662 100644 --- a/include/linux/pm_runtime.h +++ b/include/linux/pm_runtime.h @@ -101,6 +101,11 @@ static inline bool pm_runtime_status_suspended(struct device *dev) return dev->power.runtime_status == RPM_SUSPENDED; } +static inline bool pm_runtime_suspended_if_enabled(struct device *dev) +{ + return pm_runtime_status_suspended(dev) && dev->power.disable_depth == 1; +} + static inline bool pm_runtime_enabled(struct device *dev) { return !dev->power.disable_depth; @@ -150,6 +155,7 @@ static inline void device_set_run_wake(struct device *dev, bool enable) {} static inline bool pm_runtime_suspended(struct device *dev) { return false; } static inline bool pm_runtime_active(struct device *dev) { return true; } static inline bool pm_runtime_status_suspended(struct device *dev) { return false; } +static inline bool pm_runtime_suspended_if_enabled(struct device *dev) { return false; } static inline bool pm_runtime_enabled(struct device *dev) { return false; } static inline void pm_runtime_no_callbacks(struct device *dev) {} |