From aa8e54b559479d0cb7eb632ba443b8cacd20cd4b Mon Sep 17 00:00:00 2001 From: Tomeu Vizoso Date: Thu, 7 Jan 2016 16:46:14 +0100 Subject: PM / sleep: Go direct_complete if driver has no callbacks If a suitable prepare callback cannot be found for a given device and its driver has no PM callbacks at all, assume that it can go direct to complete when the system goes to sleep. The reason for this is that there's lots of devices in a system that do no PM at all and there's no reason for them to prevent their ancestors to do direct_complete if they can support it. Signed-off-by: Tomeu Vizoso Reviewed-by: Ulf Hansson Signed-off-by: Rafael J. Wysocki --- drivers/base/power/main.c | 35 +++++++++++++++++++++++++++++++++++ 1 file changed, 35 insertions(+) (limited to 'drivers/base/power/main.c') diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c index 9d626ac08d9c..6e7c3ccea24b 100644 --- a/drivers/base/power/main.c +++ b/drivers/base/power/main.c @@ -125,6 +125,7 @@ void device_pm_add(struct device *dev) { pr_debug("PM: Adding info for %s:%s\n", dev->bus ? dev->bus->name : "No Bus", dev_name(dev)); + device_pm_check_callbacks(dev); mutex_lock(&dpm_list_mtx); if (dev->parent && dev->parent->power.is_prepared) dev_warn(dev, "parent %s should not be sleeping\n", @@ -147,6 +148,7 @@ void device_pm_remove(struct device *dev) mutex_unlock(&dpm_list_mtx); device_wakeup_disable(dev); pm_runtime_remove(dev); + device_pm_check_callbacks(dev); } /** @@ -1572,6 +1574,11 @@ static int device_prepare(struct device *dev, pm_message_t state) dev->power.wakeup_path = device_may_wakeup(dev); + if (dev->power.no_pm_callbacks) { + ret = 1; /* Let device go direct_complete */ + goto unlock; + } + if (dev->pm_domain) { info = "preparing power domain "; callback = dev->pm_domain->ops.prepare; @@ -1594,6 +1601,7 @@ static int device_prepare(struct device *dev, pm_message_t state) if (callback) ret = callback(dev); +unlock: device_unlock(dev); if (ret < 0) { @@ -1736,3 +1744,30 @@ void dpm_for_each_dev(void *data, void (*fn)(struct device *, void *)) device_pm_unlock(); } EXPORT_SYMBOL_GPL(dpm_for_each_dev); + +static bool pm_ops_is_empty(const struct dev_pm_ops *ops) +{ + if (!ops) + return true; + + return !ops->prepare && + !ops->suspend && + !ops->suspend_late && + !ops->suspend_noirq && + !ops->resume_noirq && + !ops->resume_early && + !ops->resume && + !ops->complete; +} + +void device_pm_check_callbacks(struct device *dev) +{ + spin_lock_irq(&dev->power.lock); + dev->power.no_pm_callbacks = + (!dev->bus || pm_ops_is_empty(dev->bus->pm)) && + (!dev->class || pm_ops_is_empty(dev->class->pm)) && + (!dev->type || pm_ops_is_empty(dev->type->pm)) && + (!dev->pm_domain || pm_ops_is_empty(&dev->pm_domain->ops)) && + (!dev->driver || pm_ops_is_empty(dev->driver->pm)); + spin_unlock_irq(&dev->power.lock); +} -- cgit v1.2.3