diff options
Diffstat (limited to 'drivers/base/power/runtime.c')
-rw-r--r-- | drivers/base/power/runtime.c | 131 |
1 files changed, 56 insertions, 75 deletions
diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c index 7bcf80fa9ada..8bef3cb2424d 100644 --- a/drivers/base/power/runtime.c +++ b/drivers/base/power/runtime.c @@ -134,11 +134,11 @@ unsigned long pm_runtime_autosuspend_expiration(struct device *dev) if (!dev->power.use_autosuspend) goto out; - autosuspend_delay = ACCESS_ONCE(dev->power.autosuspend_delay); + autosuspend_delay = READ_ONCE(dev->power.autosuspend_delay); if (autosuspend_delay < 0) goto out; - last_busy = ACCESS_ONCE(dev->power.last_busy); + last_busy = READ_ONCE(dev->power.last_busy); elapsed = jiffies - last_busy; if (elapsed < 0) goto out; /* jiffies has wrapped around. */ @@ -253,7 +253,7 @@ static int rpm_check_suspend_allowed(struct device *dev) || (dev->power.request_pending && dev->power.request == RPM_REQ_RESUME)) retval = -EAGAIN; - else if (__dev_pm_qos_read_value(dev) < 0) + else if (__dev_pm_qos_read_value(dev) == 0) retval = -EPERM; else if (dev->power.runtime_status == RPM_SUSPENDED) retval = 1; @@ -276,7 +276,8 @@ static int rpm_get_suppliers(struct device *dev) continue; retval = pm_runtime_get_sync(link->supplier); - if (retval < 0) { + /* Ignore suppliers with disabled runtime PM. */ + if (retval < 0 && retval != -EACCES) { pm_runtime_put_noidle(link->supplier); return retval; } @@ -894,9 +895,9 @@ static void pm_runtime_work(struct work_struct *work) * * Check if the time is right and queue a suspend request. */ -static void pm_suspend_timer_fn(unsigned long data) +static void pm_suspend_timer_fn(struct timer_list *t) { - struct device *dev = (struct device *)data; + struct device *dev = from_timer(dev, t, power.suspend_timer); unsigned long flags; unsigned long expires; @@ -1101,29 +1102,13 @@ int __pm_runtime_set_status(struct device *dev, unsigned int status) goto out; } - if (dev->power.runtime_status == status) + if (dev->power.runtime_status == status || !parent) goto out_set; if (status == RPM_SUSPENDED) { - /* - * It is invalid to suspend a device with an active child, - * unless it has been set to ignore its children. - */ - if (!dev->power.ignore_children && - atomic_read(&dev->power.child_count)) { - dev_err(dev, "runtime PM trying to suspend device but active child\n"); - error = -EBUSY; - goto out; - } - - if (parent) { - atomic_add_unless(&parent->power.child_count, -1, 0); - notify_parent = !parent->power.ignore_children; - } - goto out_set; - } - - if (parent) { + atomic_add_unless(&parent->power.child_count, -1, 0); + notify_parent = !parent->power.ignore_children; + } else { spin_lock_nested(&parent->power.lock, SINGLE_DEPTH_NESTING); /* @@ -1307,6 +1292,13 @@ void pm_runtime_enable(struct device *dev) else dev_warn(dev, "Unbalanced %s!\n", __func__); + WARN(!dev->power.disable_depth && + dev->power.runtime_status == RPM_SUSPENDED && + !dev->power.ignore_children && + atomic_read(&dev->power.child_count) > 0, + "Enabling runtime PM for inactive device (%s) with active children\n", + dev_name(dev)); + spin_unlock_irqrestore(&dev->power.lock, flags); } EXPORT_SYMBOL_GPL(pm_runtime_enable); @@ -1499,8 +1491,7 @@ void pm_runtime_init(struct device *dev) INIT_WORK(&dev->power.work, pm_runtime_work); dev->power.timer_expires = 0; - setup_timer(&dev->power.suspend_timer, pm_suspend_timer_fn, - (unsigned long)dev); + timer_setup(&dev->power.suspend_timer, pm_suspend_timer_fn, 0); init_waitqueue_head(&dev->power.wait_queue); } @@ -1622,22 +1613,34 @@ void pm_runtime_drop_link(struct device *dev) spin_unlock_irq(&dev->power.lock); } +static bool pm_runtime_need_not_resume(struct device *dev) +{ + return atomic_read(&dev->power.usage_count) <= 1 && + (atomic_read(&dev->power.child_count) == 0 || + dev->power.ignore_children); +} + /** * pm_runtime_force_suspend - Force a device into suspend state if needed. * @dev: Device to suspend. * * Disable runtime PM so we safely can check the device's runtime PM status and - * if it is active, invoke it's .runtime_suspend callback to bring it into - * suspend state. Keep runtime PM disabled to preserve the state unless we - * encounter errors. + * if it is active, invoke its ->runtime_suspend callback to suspend it and + * change its runtime PM status field to RPM_SUSPENDED. Also, if the device's + * usage and children counters don't indicate that the device was in use before + * the system-wide transition under way, decrement its parent's children counter + * (if there is a parent). Keep runtime PM disabled to preserve the state + * unless we encounter errors. * * Typically this function may be invoked from a system suspend callback to make - * sure the device is put into low power state. + * sure the device is put into low power state and it should only be used during + * system-wide PM transitions to sleep states. It assumes that the analogous + * pm_runtime_force_resume() will be used to resume the device. */ int pm_runtime_force_suspend(struct device *dev) { int (*callback)(struct device *); - int ret = 0; + int ret; pm_runtime_disable(dev); if (pm_runtime_status_suspended(dev)) @@ -1645,27 +1648,23 @@ int pm_runtime_force_suspend(struct device *dev) callback = RPM_GET_CALLBACK(dev, runtime_suspend); - if (!callback) { - ret = -ENOSYS; - goto err; - } - - ret = callback(dev); + ret = callback ? callback(dev) : 0; if (ret) goto err; /* - * Increase the runtime PM usage count for the device's parent, in case - * when we find the device being used when system suspend was invoked. - * This informs pm_runtime_force_resume() to resume the parent - * immediately, which is needed to be able to resume its children, - * when not deferring the resume to be managed via runtime PM. + * If the device can stay in suspend after the system-wide transition + * to the working state that will follow, drop the children counter of + * its parent, but set its status to RPM_SUSPENDED anyway in case this + * function will be called again for it in the meantime. */ - if (dev->parent && atomic_read(&dev->power.usage_count) > 1) - pm_runtime_get_noresume(dev->parent); + if (pm_runtime_need_not_resume(dev)) + pm_runtime_set_suspended(dev); + else + __update_runtime_status(dev, RPM_SUSPENDED); - pm_runtime_set_suspended(dev); return 0; + err: pm_runtime_enable(dev); return ret; @@ -1678,13 +1677,9 @@ EXPORT_SYMBOL_GPL(pm_runtime_force_suspend); * * Prior invoking this function we expect the user to have brought the device * into low power state by a call to pm_runtime_force_suspend(). Here we reverse - * those actions and brings the device into full power, if it is expected to be - * used on system resume. To distinguish that, we check whether the runtime PM - * usage count is greater than 1 (the PM core increases the usage count in the - * system PM prepare phase), as that indicates a real user (such as a subsystem, - * driver, userspace, etc.) is using it. If that is the case, the device is - * expected to be used on system resume as well, so then we resume it. In the - * other case, we defer the resume to be managed via runtime PM. + * those actions and bring the device into full power, if it is expected to be + * used on system resume. In the other case, we defer the resume to be managed + * via runtime PM. * * Typically this function may be invoked from a system resume callback. */ @@ -1693,32 +1688,18 @@ int pm_runtime_force_resume(struct device *dev) int (*callback)(struct device *); int ret = 0; - callback = RPM_GET_CALLBACK(dev, runtime_resume); - - if (!callback) { - ret = -ENOSYS; - goto out; - } - - if (!pm_runtime_status_suspended(dev)) + if (!pm_runtime_status_suspended(dev) || pm_runtime_need_not_resume(dev)) goto out; /* - * Decrease the parent's runtime PM usage count, if we increased it - * during system suspend in pm_runtime_force_suspend(). - */ - if (atomic_read(&dev->power.usage_count) > 1) { - if (dev->parent) - pm_runtime_put_noidle(dev->parent); - } else { - goto out; - } + * The value of the parent's children counter is correct already, so + * just update the status of the device. + */ + __update_runtime_status(dev, RPM_ACTIVE); - ret = pm_runtime_set_active(dev); - if (ret) - goto out; + callback = RPM_GET_CALLBACK(dev, runtime_resume); - ret = callback(dev); + ret = callback ? callback(dev) : 0; if (ret) { pm_runtime_set_suspended(dev); goto out; |