From 8b258cc8ac229aa7d5dcb7cc34cb35d9124498ac Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Thu, 17 Nov 2011 21:39:33 +0100 Subject: PM Sleep: Do not extend wakeup paths to devices with ignore_children set Commit 4ca46ff3e0d8c234cb40ebb6457653b59584426c (PM / Sleep: Mark devices involved in wakeup signaling during suspend) introduced the power.wakeup_path field in struct dev_pm_info to mark devices whose children are enabled to wake up the system from sleep states, so that power domains containing the parents that provide their children with wakeup power and/or relay their wakeup signals are not turned off. Unfortunately, that introduced a PM regression on SH7372 whose power consumption in the system "memory sleep" state increased as a result of it, because it prevented the power domain containing the I2C controller from being turned off when some children of that controller were enabled to wake up the system, although the controller was not necessary for them to signal wakeup. To fix this issue use the observation that devices whose power.ignore_children flag is set for runtime PM should be treated analogously during system suspend. Namely, they shouldn't be included in wakeup paths going through their children. Since the SH7372 I2C controller's power.ignore_children flag is set, doing so will restore the previous behavior of that SOC. Signed-off-by: Rafael J. Wysocki Acked-by: Greg Kroah-Hartman --- include/linux/pm_runtime.h | 6 ------ 1 file changed, 6 deletions(-) (limited to 'include/linux/pm_runtime.h') diff --git a/include/linux/pm_runtime.h b/include/linux/pm_runtime.h index d8d903619642..d3085e72a0ee 100644 --- a/include/linux/pm_runtime.h +++ b/include/linux/pm_runtime.h @@ -52,11 +52,6 @@ static inline bool pm_children_suspended(struct device *dev) || !atomic_read(&dev->power.child_count); } -static inline void pm_suspend_ignore_children(struct device *dev, bool enable) -{ - dev->power.ignore_children = enable; -} - static inline void pm_runtime_get_noresume(struct device *dev) { atomic_inc(&dev->power.usage_count); @@ -130,7 +125,6 @@ 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) {} static inline void pm_runtime_get_noresume(struct device *dev) {} static inline void pm_runtime_put_noidle(struct device *dev) {} static inline bool device_run_wake(struct device *dev) { return false; } -- cgit v1.3 From 00dc9ad18d707f36b2fb4af98fd2cf0548d2b258 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Thu, 1 Dec 2011 00:01:31 +0100 Subject: PM / Runtime: Use device PM QoS constraints (v2) Make the runtime PM core use device PM QoS constraints to check if it is allowed to suspend a given device, so that an error code is returned if the device's own PM QoS constraint is negative or one of its children has already been suspended for too long. If this is not the case, the maximum estimated time the device is allowed to be suspended, computed as the minimum of the device's PM QoS constraint and the PM QoS constraints of its children (reduced by the difference between the current time and their suspend times) is stored in a new device's PM field power.max_time_suspended_ns that can be used by the device's subsystem or PM domain to decide whether or not to put the device into lower-power (and presumably higher-latency) states later (if the constraint is 0, which means "no constraint", the power.max_time_suspended_ns is set to -1). Additionally, the time of execution of the subsystem-level .runtime_suspend() callback for the device is recorded in the new power.suspend_time field for later use by the device's subsystem or PM domain along with power.max_time_suspended_ns (it also is used by the core code when the device's parent is suspended). Introduce a new helper function, pm_runtime_update_max_time_suspended(), allowing subsystems and PM domains (or device drivers) to update the power.max_time_suspended_ns field, for example after changing the power state of a suspended device. Signed-off-by: Rafael J. Wysocki --- drivers/base/power/qos.c | 24 ++++--- drivers/base/power/runtime.c | 148 +++++++++++++++++++++++++++++++++++++------ include/linux/pm.h | 2 + include/linux/pm_qos.h | 3 + include/linux/pm_runtime.h | 5 ++ 5 files changed, 154 insertions(+), 28 deletions(-) (limited to 'include/linux/pm_runtime.h') diff --git a/drivers/base/power/qos.c b/drivers/base/power/qos.c index 86de6c50fc41..03f4bd069ca8 100644 --- a/drivers/base/power/qos.c +++ b/drivers/base/power/qos.c @@ -47,21 +47,29 @@ static DEFINE_MUTEX(dev_pm_qos_mtx); static BLOCKING_NOTIFIER_HEAD(dev_pm_notifiers); /** - * dev_pm_qos_read_value - Get PM QoS constraint for a given device. + * __dev_pm_qos_read_value - Get PM QoS constraint for a given device. + * @dev: Device to get the PM QoS constraint value for. + * + * This routine must be called with dev->power.lock held. + */ +s32 __dev_pm_qos_read_value(struct device *dev) +{ + struct pm_qos_constraints *c = dev->power.constraints; + + return c ? pm_qos_read_value(c) : 0; +} + +/** + * dev_pm_qos_read_value - Get PM QoS constraint for a given device (locked). * @dev: Device to get the PM QoS constraint value for. */ s32 dev_pm_qos_read_value(struct device *dev) { - struct pm_qos_constraints *c; unsigned long flags; - s32 ret = 0; + s32 ret; spin_lock_irqsave(&dev->power.lock, flags); - - c = dev->power.constraints; - if (c) - ret = pm_qos_read_value(c); - + ret = __dev_pm_qos_read_value(dev); spin_unlock_irqrestore(&dev->power.lock, flags); return ret; diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c index 8c78443bca8f..068f7ed1f009 100644 --- a/drivers/base/power/runtime.c +++ b/drivers/base/power/runtime.c @@ -279,6 +279,47 @@ static int rpm_callback(int (*cb)(struct device *), struct device *dev) return retval != -EACCES ? retval : -EIO; } +struct rpm_qos_data { + ktime_t time_now; + s64 constraint_ns; +}; + +/** + * rpm_update_qos_constraint - Update a given PM QoS constraint data. + * @dev: Device whose timing data to use. + * @data: PM QoS constraint data to update. + * + * Use the suspend timing data of @dev to update PM QoS constraint data pointed + * to by @data. + */ +static int rpm_update_qos_constraint(struct device *dev, void *data) +{ + struct rpm_qos_data *qos = data; + unsigned long flags; + s64 delta_ns; + int ret = 0; + + spin_lock_irqsave(&dev->power.lock, flags); + + if (dev->power.max_time_suspended_ns < 0) + goto out; + + delta_ns = dev->power.max_time_suspended_ns - + ktime_to_ns(ktime_sub(qos->time_now, dev->power.suspend_time)); + if (delta_ns <= 0) { + ret = -EBUSY; + goto out; + } + + if (qos->constraint_ns > delta_ns || qos->constraint_ns == 0) + qos->constraint_ns = delta_ns; + + out: + spin_unlock_irqrestore(&dev->power.lock, flags); + + return ret; +} + /** * rpm_suspend - Carry out runtime suspend of given device. * @dev: Device to suspend. @@ -305,6 +346,7 @@ static int rpm_suspend(struct device *dev, int rpmflags) { int (*callback)(struct device *); struct device *parent = NULL; + struct rpm_qos_data qos; int retval; trace_rpm_suspend(dev, rpmflags); @@ -400,8 +442,38 @@ static int rpm_suspend(struct device *dev, int rpmflags) goto out; } + qos.constraint_ns = __dev_pm_qos_read_value(dev); + if (qos.constraint_ns < 0) { + /* Negative constraint means "never suspend". */ + retval = -EPERM; + goto out; + } + qos.constraint_ns *= NSEC_PER_USEC; + qos.time_now = ktime_get(); + __update_runtime_status(dev, RPM_SUSPENDING); + if (!dev->power.ignore_children) { + if (dev->power.irq_safe) + spin_unlock(&dev->power.lock); + else + spin_unlock_irq(&dev->power.lock); + + retval = device_for_each_child(dev, &qos, + rpm_update_qos_constraint); + + if (dev->power.irq_safe) + spin_lock(&dev->power.lock); + else + spin_lock_irq(&dev->power.lock); + + if (retval) + goto fail; + } + + dev->power.suspend_time = qos.time_now; + dev->power.max_time_suspended_ns = qos.constraint_ns ? : -1; + if (dev->pm_domain) callback = dev->pm_domain->ops.runtime_suspend; else if (dev->type && dev->type->pm) @@ -414,27 +486,9 @@ static int rpm_suspend(struct device *dev, int rpmflags) callback = NULL; retval = rpm_callback(callback, dev); - if (retval) { - __update_runtime_status(dev, RPM_ACTIVE); - dev->power.deferred_resume = false; - if (retval == -EAGAIN || retval == -EBUSY) { - dev->power.runtime_error = 0; + if (retval) + goto fail; - /* - * If the callback routine failed an autosuspend, and - * if the last_busy time has been updated so that there - * is a new autosuspend expiration time, automatically - * reschedule another autosuspend. - */ - if ((rpmflags & RPM_AUTO) && - pm_runtime_autosuspend_expiration(dev) != 0) - goto repeat; - } else { - pm_runtime_cancel_pending(dev); - } - wake_up_all(&dev->power.wait_queue); - goto out; - } no_callback: __update_runtime_status(dev, RPM_SUSPENDED); pm_runtime_deactivate_timer(dev); @@ -466,6 +520,29 @@ static int rpm_suspend(struct device *dev, int rpmflags) trace_rpm_return_int(dev, _THIS_IP_, retval); return retval; + + fail: + __update_runtime_status(dev, RPM_ACTIVE); + dev->power.suspend_time = ktime_set(0, 0); + dev->power.max_time_suspended_ns = -1; + dev->power.deferred_resume = false; + if (retval == -EAGAIN || retval == -EBUSY) { + dev->power.runtime_error = 0; + + /* + * If the callback routine failed an autosuspend, and + * if the last_busy time has been updated so that there + * is a new autosuspend expiration time, automatically + * reschedule another autosuspend. + */ + if ((rpmflags & RPM_AUTO) && + pm_runtime_autosuspend_expiration(dev) != 0) + goto repeat; + } else { + pm_runtime_cancel_pending(dev); + } + wake_up_all(&dev->power.wait_queue); + goto out; } /** @@ -620,6 +697,9 @@ static int rpm_resume(struct device *dev, int rpmflags) if (dev->power.no_callbacks) goto no_callback; /* Assume success. */ + dev->power.suspend_time = ktime_set(0, 0); + dev->power.max_time_suspended_ns = -1; + __update_runtime_status(dev, RPM_RESUMING); if (dev->pm_domain) @@ -1279,6 +1359,9 @@ void pm_runtime_init(struct device *dev) setup_timer(&dev->power.suspend_timer, pm_suspend_timer_fn, (unsigned long)dev); + dev->power.suspend_time = ktime_set(0, 0); + dev->power.max_time_suspended_ns = -1; + init_waitqueue_head(&dev->power.wait_queue); } @@ -1296,3 +1379,28 @@ void pm_runtime_remove(struct device *dev) if (dev->power.irq_safe && dev->parent) pm_runtime_put_sync(dev->parent); } + +/** + * pm_runtime_update_max_time_suspended - Update device's suspend time data. + * @dev: Device to handle. + * @delta_ns: Value to subtract from the device's max_time_suspended_ns field. + * + * Update the device's power.max_time_suspended_ns field by subtracting + * @delta_ns from it. The resulting value of power.max_time_suspended_ns is + * never negative. + */ +void pm_runtime_update_max_time_suspended(struct device *dev, s64 delta_ns) +{ + unsigned long flags; + + spin_lock_irqsave(&dev->power.lock, flags); + + if (delta_ns > 0 && dev->power.max_time_suspended_ns > 0) { + if (dev->power.max_time_suspended_ns > delta_ns) + dev->power.max_time_suspended_ns -= delta_ns; + else + dev->power.max_time_suspended_ns = 0; + } + + spin_unlock_irqrestore(&dev->power.lock, flags); +} diff --git a/include/linux/pm.h b/include/linux/pm.h index 3f3ed83a9aa5..a7676efa6831 100644 --- a/include/linux/pm.h +++ b/include/linux/pm.h @@ -521,6 +521,8 @@ struct dev_pm_info { unsigned long active_jiffies; unsigned long suspended_jiffies; unsigned long accounting_timestamp; + ktime_t suspend_time; + s64 max_time_suspended_ns; #endif struct pm_subsys_data *subsys_data; /* Owned by the subsystem. */ struct pm_qos_constraints *constraints; diff --git a/include/linux/pm_qos.h b/include/linux/pm_qos.h index 83b0ea302a80..775a3236343d 100644 --- a/include/linux/pm_qos.h +++ b/include/linux/pm_qos.h @@ -78,6 +78,7 @@ int pm_qos_remove_notifier(int pm_qos_class, struct notifier_block *notifier); int pm_qos_request_active(struct pm_qos_request *req); s32 pm_qos_read_value(struct pm_qos_constraints *c); +s32 __dev_pm_qos_read_value(struct device *dev); s32 dev_pm_qos_read_value(struct device *dev); int dev_pm_qos_add_request(struct device *dev, struct dev_pm_qos_request *req, s32 value); @@ -119,6 +120,8 @@ static inline int pm_qos_request_active(struct pm_qos_request *req) static inline s32 pm_qos_read_value(struct pm_qos_constraints *c) { return 0; } +static inline s32 __dev_pm_qos_read_value(struct device *dev) + { return 0; } static inline s32 dev_pm_qos_read_value(struct device *dev) { return 0; } static inline int dev_pm_qos_add_request(struct device *dev, diff --git a/include/linux/pm_runtime.h b/include/linux/pm_runtime.h index d3085e72a0ee..609daae7a014 100644 --- a/include/linux/pm_runtime.h +++ b/include/linux/pm_runtime.h @@ -45,6 +45,8 @@ extern void pm_runtime_irq_safe(struct device *dev); extern void __pm_runtime_use_autosuspend(struct device *dev, bool use); extern void pm_runtime_set_autosuspend_delay(struct device *dev, int delay); extern unsigned long pm_runtime_autosuspend_expiration(struct device *dev); +extern void pm_runtime_update_max_time_suspended(struct device *dev, + s64 delta_ns); static inline bool pm_children_suspended(struct device *dev) { @@ -148,6 +150,9 @@ static inline void pm_runtime_set_autosuspend_delay(struct device *dev, static inline unsigned long pm_runtime_autosuspend_expiration( struct device *dev) { return 0; } +static inline void pm_runtime_update_max_time_suspended(struct device *dev, + s64 delta_ns) {} + #endif /* !CONFIG_PM_RUNTIME */ static inline int pm_runtime_idle(struct device *dev) -- cgit v1.3