talos-op-linux/drivers/base/power/power.h, branch v4.4

PM / QoS: Make it possible to expose device latency tolerance to userspace

2015-07-28T07:50:41+00:00

Typically when a device is created the bus core it belongs to (for example PCI) does not know if the device supports things like latency tolerance. This is left to the driver that binds to the device in question. However, at that time the device has already been created and there is no way to set its dev->power.set_latency_tolerance anymore. So follow what has been done for other PM QoS attributes as well and allow drivers to expose and hide latency tolerance from userspace, if the device supports it. Acked-by: Rafael J. Wysocki Signed-off-by: Mika Westerberg Signed-off-by: Andy Shevchenko Signed-off-by: Lee Jones

PM / Wakeirq: Add automated device wake IRQ handling

2015-05-19T23:56:31+00:00

Turns out we can automate the handling for the device_may_wakeup() quite a bit by using the kernel wakeup source list as suggested by Rafael J. Wysocki . And as some hardware has separate dedicated wake-up interrupt in addition to the IO interrupt, we can automate the handling by adding a generic threaded interrupt handler that just calls the device PM runtime to wake up the device. This allows dropping code from device drivers as we currently are doing it in multiple ways, and often wrong. For most drivers, we should be able to drop the following boilerplate code from runtime_suspend and runtime_resume functions: ... device_init_wakeup(dev, true); ... if (device_may_wakeup(dev)) enable_irq_wake(irq); ... if (device_may_wakeup(dev)) disable_irq_wake(irq); ... device_init_wakeup(dev, false); ... We can replace it with just the following init and exit time code: ... device_init_wakeup(dev, true); dev_pm_set_wake_irq(dev, irq); ... dev_pm_clear_wake_irq(dev); device_init_wakeup(dev, false); ... And for hardware with dedicated wake-up interrupts: ... device_init_wakeup(dev, true); dev_pm_set_dedicated_wake_irq(dev, irq); ... dev_pm_clear_wake_irq(dev); device_init_wakeup(dev, false); ... Signed-off-by: Tony Lindgren Signed-off-by: Rafael J. Wysocki

PM: Drop CONFIG_PM_RUNTIME from the driver core

2014-12-03T23:46:58+00:00

After commit b2b49ccbdd54 (PM: Kconfig: Set PM_RUNTIME if PM_SLEEP is selected) PM_RUNTIME is always set if PM is set, so quite a few depend on CONFIG_PM or even may be dropped entirely in some cases. Replace CONFIG_PM_RUNTIME with CONFIG_PM in the PM core code. Reviewed-by: Ulf Hansson Acked-by: Kevin Hilman Signed-off-by: Rafael J. Wysocki

PM / QoS: Rename device resume latency QoS items

2014-02-10T23:35:23+00:00

Rename symbols, variables, functions and structure fields related do the resume latency device PM QoS type so that it is clear where they belong (in particular, to avoid confusion with the latency tolerance device PM QoS type introduced by a subsequent changeset). Update the PM QoS documentation to better reflect its current state. Signed-off-by: Rafael J. Wysocki

PM / QoS: Remove device PM QoS sysfs attributes at the right place

2013-03-04T13:23:12+00:00

Device PM QoS sysfs attributes, if present during device removal, are removed from within device_pm_remove(), which is too late, since dpm_sysfs_remove() has already removed the whole attribute group they belonged to. However, moving the removal of those attributes to dpm_sysfs_remove() alone is not sufficient, because in theory they still can be re-added right after being removed by it (the device's driver is still bound to it at that point). For this reason, move the entire desctruction of device PM QoS constraints to dpm_sysfs_remove() and make it prevent any new constraints from being added after it has run. Also, move the initialization of the power.qos field in struct device to device_pm_init_common() and drop the no longer needed dev_pm_qos_constraints_init(). Reported-by: Sasha Levin Signed-off-by: Rafael J. Wysocki

PM / QoS: Make it possible to expose PM QoS device flags to user space

2012-10-24T00:08:18+00:00

Define two device PM QoS flags, PM_QOS_FLAG_NO_POWER_OFF and PM_QOS_FLAG_REMOTE_WAKEUP, and introduce routines dev_pm_qos_expose_flags() and dev_pm_qos_hide_flags() allowing the caller to expose those two flags to user space or to hide them from it, respectively. After the flags have been exposed, user space will see two additional sysfs attributes, pm_qos_no_power_off and pm_qos_remote_wakeup, under the device's /sys/devices/.../power/ directory. Then, writing 1 to one of them will update the PM QoS flags request owned by user space so that the corresponding flag is requested to be set. In turn, writing 0 to one of them will cause the corresponding flag in the user space's request to be cleared (however, the owners of the other PM QoS flags requests for the same device may still request the flag to be set and it may be effectively set even if user space doesn't request that). Signed-off-by: Rafael J. Wysocki Reviewed-by: Jean Pihet Acked-by: mark gross

PM / Runtime: Allow helpers to be called by early platform drivers

2012-09-03T23:36:03+00:00

Runtime PM helper functions, like pm_runtime_get_sync(), cannot be called by early platform device drivers, because the devices' power management locks are not initialized at that time. This is quite inconvenient, so modify early_platform_add_devices() to initialize the devices power management locks as appropriate and make sure that they won't be initialized more than once if an early platform device is going to be used as a regular one later. Signed-off-by: Rafael J. Wysocki

PM: Reorganize device PM initialization

2012-09-03T23:36:03+00:00

Make the device power management initialization more straightforward by moving the initialization of common (i.e. used by both runtime PM and system suspend) fields to a separate routine. Signed-off-by: Rafael J. Wysocki

PM / QoS: Make it possible to expose PM QoS latency constraints

2012-03-13T21:37:14+00:00

A runtime suspend of a device (e.g. an MMC controller) belonging to a power domain or, in a more complicated scenario, a runtime suspend of another device in the same power domain, may cause power to be removed from the entire domain. In that case, the amount of time necessary to runtime-resume the given device (e.g. the MMC controller) is often substantially greater than the time needed to run its driver's runtime resume callback. That may hurt performance in some situations, because user data may need to wait for the device to become operational, so we should make it possible to prevent that from happening. For this reason, introduce a new sysfs attribute for devices, power/pm_qos_resume_latency_us, allowing user space to specify the upper bound of the time necessary to bring the (runtime-suspended) device up after the resume of it has been requested. However, make that attribute appear only for the devices whose drivers declare support for it by calling the (new) dev_pm_qos_expose_latency_limit() helper function with the appropriate initial value of the attribute. Signed-off-by: Rafael J. Wysocki Reviewed-by: Kevin Hilman Reviewed-by: Mark Brown Acked-by: Linus Walleij

PM / QoS: Add function dev_pm_qos_read_value() (v3)

2011-10-04T19:54:26+00:00

To read the current PM QoS value for a given device we need to make sure that the device's power.constraints object won't be removed while we're doing that. For this reason, put the operation under dev->power.lock and acquire the lock around the initialization and removal of power.constraints. Moreover, since we're using the value of power.constraints to determine whether or not the object is present, the power.constraints_state field isn't necessary any more and may be removed. However, dev_pm_qos_add_request() needs to check if the device is being removed from the system before allocating a new PM QoS constraints object for it, so make it use the power.power_state field of struct device for this purpose. Signed-off-by: Rafael J. Wysocki