linux/drivers/base/power/sysfs.c, branch v4.9

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

2015-07-28T07:50:41Z

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: Drop CONFIG_PM_RUNTIME from the driver core

2014-12-03T23:46:58Z

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 / sysfs: avoid shadowing variables

2014-09-08T13:40:18Z

The global variable "enabled" is shadowed in a number of functions in this file, rename it to "_enabled" to avoid that. For consistency, also rename "disabled" and move them both into the #ifdef where they're needed. Signed-off-by: Johannes Berg Acked-by: Pavel Machek Signed-off-by: Rafael J. Wysocki

PM / QoS: Introcuce latency tolerance device PM QoS type

2014-02-10T23:35:38Z

Add a new latency tolerance device PM QoS type to be use for specifying active state (RPM_ACTIVE) memory access (DMA) latency tolerance requirements for devices. It may be used to prevent hardware from choosing overly aggressive energy-saving operation modes (causing too much latency to appear) for the whole platform. This feature reqiures hardware support, so it only will be available for devices having a new .set_latency_tolerance() callback in struct dev_pm_info populated, in which case the routine pointed to by it should implement whatever is necessary to transfer the effective requirement value to the hardware. Whenever the effective latency tolerance changes for the device, its .set_latency_tolerance() callback will be executed and the effective value will be passed to it. If that value is negative, which means that the list of latency tolerance requirements for the device is empty, the callback is expected to switch the underlying hardware latency tolerance control mechanism to an autonomous mode if available. If that value is PM_QOS_LATENCY_ANY, in turn, and the hardware supports a special "no requirement" setting, the callback is expected to use it. That allows software to prevent the hardware from automatically updating the device's latency tolerance in response to its power state changes (e.g. during transitions from D3cold to D0), which generally may be done in the autonomous latency tolerance control mode. If .set_latency_tolerance() is present for the device, a new pm_qos_latency_tolerance_us attribute will be present in the devivce's power directory in sysfs. Then, user space can use that attribute to specify its latency tolerance requirement for the device, if any. Writing "any" to it means "no requirement, but do not let the hardware control latency tolerance" and writing "auto" to it allows the hardware to be switched to the autonomous mode if there are no other requirements from the kernel side in the device's list. This changeset includes a fix from Mika Westerberg. Signed-off-by: Rafael J. Wysocki

PM / QoS: Rename device resume latency QoS items

2014-02-10T23:35:23Z

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

driver core: replace strict_strto() with kstrto()

2013-07-27T01:02:43Z

The usage of strict_strto*() is not preferred, because strict_strto*() is obsolete. Thus, kstrto*() should be used. Signed-off-by: Jingoo Han Signed-off-by: Greg Kroah-Hartman

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

2013-03-04T13:23:12Z

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

2012-10-24T00:08:18Z

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 / QoS: Prepare struct dev_pm_qos_request for more request types

2012-10-22T23:09:00Z

The subsequent patches will use struct dev_pm_qos_request for representing both latency requests and flags requests. To make that easier, put the node member of struct dev_pm_qos_request (under the name "pnode") into a union called "data" that will represent the request's value and list node depending on its type. Signed-off-by: Rafael J. Wysocki Reviewed-by: Jean Pihet Reviewed-by: mark gross

PM / Sleep: Fix build warning in sysfs.c for CONFIG_PM_SLEEP unset

2012-07-12T20:40:02Z

The power/async device sysfs attribute is only used if both CONFIG_PM_ADVANCED_DEBUG and CONFIG_PM_SLEEP are set, but the code implementing it doesn't depend on CONFIG_PM_SLEEP. As a result, a build warning appears if CONFIG_PM_ADVANCED_DEBUG is set and CONFIG_PM_SLEEP is not set. Fix it by adding a #ifdef CONFIG_PM_SLEEP around the code in question. Signed-off-by: Rafael J. Wysocki