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path: root/include/linux/pm.h
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2011-12-26Merge branch 'pm-runtime' into pm-for-linusRafael J. Wysocki1-0/+2
* pm-runtime: PM / Runtime: Use device PM QoS constraints (v2)
2011-12-22PM: Drop generic_subsys_pm_opsRafael J. Wysocki1-13/+0
Since the PM core is now going to execute driver callbacks directly if the corresponding subsystem callbacks are not present, forward-only subsystem callbacks (i.e. such that only execute the corresponding driver callbacks) are not necessary any more. Thus it is possible to remove generic_subsys_pm_ops, because the only callback in there that is not forward-only, .runtime_idle, is not really used by the only user of generic_subsys_pm_ops, which is vio_bus_type. However, the generic callback routines themselves cannot be removed from generic_ops.c, because they are used individually by a number of subsystems. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-12-02PM / Runtime: Use device PM QoS constraints (v2)Rafael J. Wysocki1-0/+2
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 <rjw@sisk.pl>
2011-11-29PM: Update comments describing device power management callbacksRafael J. Wysocki1-95/+134
The comments describing device power management callbacks in include/pm.h are outdated and somewhat confusing, so make them reflect the reality more accurately. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-11-18PM Sleep: Do not extend wakeup paths to devices with ignore_children setRafael J. Wysocki1-1/+1
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 <rjw@sisk.pl> Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-10-22Merge branch 'pm-domains' into pm-for-linusRafael J. Wysocki1-0/+1
* pm-domains: ARM: mach-shmobile: sh7372 A4R support (v4) ARM: mach-shmobile: sh7372 A3SP support (v4) PM / Sleep: Mark devices involved in wakeup signaling during suspend
2011-10-22PM / Sleep: Mark devices involved in wakeup signaling during suspendRafael J. Wysocki1-0/+1
The generic PM domains code in drivers/base/power/domain.c has to avoid powering off domains that provide power to wakeup devices during system suspend. Currently, however, this only works for wakeup devices directly belonging to the given domain and not for their children (or the children of their children and so on). Thus, if there's a wakeup device whose parent belongs to a power domain handled by the generic PM domains code, the domain will be powered off during system suspend preventing the device from signaling wakeup. To address this problem introduce a device flag, power.wakeup_path, that will be set during system suspend for all wakeup devices, their parents, the parents of their parents and so on. This way, all wakeup paths in the device hierarchy will be marked and the generic PM domains code will only need to avoid powering off domains containing devices whose power.wakeup_path is set. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-10-08Merge branch 'pm-qos' into pm-for-linusRafael J. Wysocki1-0/+3
* pm-qos: PM / QoS: Update Documentation for the pm_qos and dev_pm_qos frameworks PM / QoS: Add function dev_pm_qos_read_value() (v3) PM QoS: Add global notification mechanism for device constraints PM QoS: Implement per-device PM QoS constraints PM QoS: Generalize and export constraints management code PM QoS: Reorganize data structs PM QoS: Code reorganization PM QoS: Minor clean-ups PM QoS: Move and rename the implementation files
2011-10-08Merge branch 'pm-domains' into pm-for-linusRafael J. Wysocki1-1/+19
* pm-domains: PM / Domains: Split device PM domain data into base and need_restore ARM: mach-shmobile: sh7372 sleep warning fixes ARM: mach-shmobile: sh7372 A3SM support ARM: mach-shmobile: sh7372 generic suspend/resume support PM / Domains: Preliminary support for devices with power.irq_safe set PM: Move clock-related definitions and headers to separate file PM / Domains: Use power.sybsys_data to reduce overhead PM: Reference counting of power.subsys_data PM: Introduce struct pm_subsys_data ARM / shmobile: Make A3RV be a subdomain of A4LC on SH7372 PM / Domains: Rename argument of pm_genpd_add_subdomain() PM / Domains: Rename GPD_STATE_WAIT_PARENT to GPD_STATE_WAIT_MASTER PM / Domains: Allow generic PM domains to have multiple masters PM / Domains: Add "wait for parent" status for generic PM domains PM / Domains: Make pm_genpd_poweron() always survive parent removal PM / Domains: Do not take parent locks to modify subdomain counters PM / Domains: Implement subdomain counters as atomic fields
2011-10-04PM / QoS: Add function dev_pm_qos_read_value() (v3)Rafael J. Wysocki1-8/+2
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 <rjw@sisk.pl>
2011-09-26PM / Domains: Split device PM domain data into base and need_restoreRafael J. Wysocki1-2/+1
The struct pm_domain_data data type is defined in such a way that adding new fields specific to the generic PM domains code will require include/linux/pm.h to be modified. As a result, data types used only by the generic PM domains code will be defined in two headers, although they all should be defined in pm_domain.h and pm.h will need to include more headers, which won't be very nice. For this reason change the definition of struct pm_subsys_data so that its domain_data member is a pointer, which will allow struct pm_domain_data to be subclassed by various PM domains implementations. Remove the need_restore member from struct pm_domain_data and make the generic PM domains code subclass it by adding the need_restore member to the new data type. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-08-25PM QoS: Implement per-device PM QoS constraintsJean Pihet1-0/+9
Implement the per-device PM QoS constraints by creating a device PM QoS API, which calls the PM QoS constraints management core code. The per-device latency constraints data strctures are stored in the device dev_pm_info struct. The device PM code calls the init and destroy of the per-device constraints data struct in order to support the dynamic insertion and removal of the devices in the system. To minimize the data usage by the per-device constraints, the data struct is only allocated at the first call to dev_pm_qos_add_request. The data is later free'd when the device is removed from the system. A global mutex protects the constraints users from the data being allocated and free'd. Signed-off-by: Jean Pihet <j-pihet@ti.com> Reviewed-by: Kevin Hilman <khilman@ti.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-08-25PM / Domains: Use power.sybsys_data to reduce overheadRafael J. Wysocki1-0/+9
Currently pm_genpd_runtime_resume() has to walk the list of devices from the device's PM domain to find the corresponding device list object containing the need_restore field to check if the driver's .runtime_resume() callback should be executed for the device. This is suboptimal and can be simplified by using power.sybsys_data to store device information used by the generic PM domains code. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-08-25PM: Reference counting of power.subsys_dataRafael J. Wysocki1-0/+3
Since the power.subsys_data device field will be used by multiple filesystems, introduce a reference counting mechanism for it to avoid freeing it prematurely or changing its value at a wrong time. Make the PM clocks management code that currently is the only user of power.subsys_data use the new reference counting. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-08-25PM: Introduce struct pm_subsys_dataRafael J. Wysocki1-1/+8
Introduce struct pm_subsys_data that may be subclassed by subsystems to store subsystem-specific information related to the device. Move the clock management fields accessed through the power.subsys_data pointer in struct device to the new strucutre. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-08-20PM / Runtime: Add macro to test for runtime PM eventsAlan Stern1-0/+2
This patch (as1482) adds a macro for testing whether or not a pm_message value represents an autosuspend or autoresume (i.e., a runtime PM) event. Encapsulating this notion seems preferable to open-coding the test all over the place. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Acked-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-07-02PM: Introduce generic "noirq" callback routines for subsystems (v2)Rafael J. Wysocki1-0/+6
Introduce generic "noirq" power management callback routines for subsystems in addition to the "regular" generic PM callback routines. The new routines will be used, among other things, for implementing system-wide PM transitions support for generic PM domains. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-07-02PM: subsys_data in struct dev_pm_info need not depend on RM_RUNTIMERafael J. Wysocki1-1/+1
The subsys_data field of struct dev_pm_info, introduced by commit 1d2b71f61b6a10216274e27b717becf9ae101fc7 (PM / Runtime: Add subsystem data field to struct dev_pm_info), is going to be used even if CONFIG_PM_RUNTIME is not set, so move it from under the #ifdef. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-07-02PM / Domains: Rename struct dev_power_domain to struct dev_pm_domainRafael J. Wysocki1-1/+1
The naming convention used by commit 7538e3db6e015e890825fbd9f86599b (PM: Add support for device power domains), which introduced the struct dev_power_domain type for representing device power domains, evidently confuses some developers who tend to think that objects of this type must correspond to "power domains" as defined by hardware, which is not the case. Namely, at the kernel level, a struct dev_power_domain object can represent arbitrary set of devices that are mutually dependent power management-wise and need not belong to one hardware power domain. To avoid that confusion, rename struct dev_power_domain to struct dev_pm_domain and rename the related pointers in struct device and struct pm_clk_notifier_block from pwr_domain to pm_domain. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Kevin Hilman <khilman@ti.com>
2011-06-22PM: Fix async resume following suspend failureAlan Stern1-0/+1
The PM core doesn't handle suspend failures correctly when it comes to asynchronously suspended devices. These devices are moved onto the dpm_suspended_list as soon as the corresponding async thread is started up, and they remain on the list even if they fail to suspend or the sleep transition is cancelled before they get suspended. As a result, when the PM core unwinds the transition, it tries to resume the devices even though they were never suspended. This patch (as1474) fixes the problem by adding a new "is_suspended" flag to dev_pm_info. Devices are resumed only if the flag is set. [rjw: * Moved the dev->power.is_suspended check into device_resume(), because we need to complete dev->power.completion and clear dev->power.is_prepared too for devices whose dev->power.is_suspended flags are unset. * Fixed __device_suspend() to avoid setting dev->power.is_suspended if async_error is different from zero.] Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Cc: stable@kernel.org
2011-06-22PM: Rename dev_pm_info.in_suspend to is_preparedAlan Stern1-1/+1
This patch (as1473) renames the "in_suspend" field in struct dev_pm_info to "is_prepared", in preparation for an upcoming change. The new name is more descriptive of what the field really means. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Cc: stable@kernel.org
2011-05-18PM: Introduce generic prepare and complete callbacks for subsystemsRafael J. Wysocki1-7/+19
Introduce generic .prepare() and .complete() power management callbacks, currently missing, that can be used by subsystems and power domains and export them. Provide NULL definitions of all the generic system sleep callbacks for CONFIG_PM_SLEEP unset. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-05-18PM: Allow drivers to allocate memory from .prepare() callbacks safelyRafael J. Wysocki1-0/+4
If device drivers allocate substantial amounts of memory (above 1 MB) in their hibernate .freeze() callbacks (or in their legacy suspend callbcks during hibernation), the subsequent creation of hibernate image may fail due to the lack of memory. This is the case, because the drivers' .freeze() callbacks are executed after the hibernate memory preallocation has been carried out and the preallocated amount of memory may be too small to cover the new driver allocations. Unfortunately, the drivers' .prepare() callbacks also are executed after the hibernate memory preallocation has completed, so they are not suitable for allocating additional memory either. Thus the only way a driver can safely allocate memory during hibernation is to use a hibernate/suspend notifier. However, the notifiers are called before the freezing of user space and the drivers wanting to use them for allocating additional memory may not know how much memory needs to be allocated at that point. To let device drivers overcome this difficulty rework the hibernation sequence so that the memory preallocation is carried out after the drivers' .prepare() callbacks have been executed, so that the .prepare() callbacks can be used for allocating additional memory to be used by the drivers' .freeze() callbacks. Update documentation to match the new behavior of the code. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-05-18Merge branch 'power-domains' into for-linusRafael J. Wysocki1-0/+1
* power-domains: PM: Fix build issue in clock_ops.c for CONFIG_PM_RUNTIME unset PM: Revert "driver core: platform_bus: allow runtime override of dev_pm_ops" OMAP1 / PM: Use generic clock manipulation routines for runtime PM PM / Runtime: Generic clock manipulation rountines for runtime PM (v6) PM / Runtime: Add subsystem data field to struct dev_pm_info OMAP2+ / PM: move runtime PM implementation to use device power domains PM / Platform: Use generic runtime PM callbacks directly shmobile: Use power domains for platform runtime PM PM: Export platform bus type's default PM callbacks PM: Make power domain callbacks take precedence over subsystem ones
2011-05-11PM: Remove sysdev suspend, resume and shutdown operationsRafael J. Wysocki1-8/+0
Since suspend, resume and shutdown operations in struct sysdev_class and struct sysdev_driver are not used any more, remove them. Also drop sysdev_suspend(), sysdev_resume() and sysdev_shutdown() used for executing those operations and modify all of their users accordingly. This reduces kernel code size quite a bit and reduces its complexity. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-04-29PM / Runtime: Add subsystem data field to struct dev_pm_infoRafael J. Wysocki1-0/+1
Some subsystems need to attach PM-related data to struct device and they need to use devres for this purpose. For their convenience and to make code more straightforward, add a new field called subsys_data to struct dev_pm_info and let subsystems use it for attaching PM-related information to devices. Convert the ARM shmobile platform to using the new field. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-03-24Introduce ARCH_NO_SYSDEV_OPS config option (v2)Rafael J. Wysocki1-2/+8
Introduce Kconfig option allowing architectures where sysdev operations used during system suspend, resume and shutdown have been completely replaced with struct sycore_ops operations to avoid building sysdev code that will never be used. Make callbacks in struct sys_device and struct sysdev_driver depend on ARCH_NO_SYSDEV_OPS to allows us to verify if all of the references have been actually removed from the code the given architecture depends on. Make x86 select ARCH_NO_SYSDEV_OPS. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-03-15PM: Add support for device power domainsRafael J. Wysocki1-0/+8
The platform bus type is often used to handle Systems-on-a-Chip (SoC) where all devices are represented by objects of type struct platform_device. In those cases the same "platform" device driver may be used with multiple different system configurations, but the actions needed to put the devices it handles into a low-power state and back into the full-power state may depend on the design of the given SoC. The driver, however, cannot possibly include all the information necessary for the power management of its device on all the systems it is used with. Moreover, the device hierarchy in its current form also is not suitable for representing this kind of information. The patch below attempts to address this problem by introducing objects of type struct dev_power_domain that can be used for representing power domains within a SoC. Every struct dev_power_domain object provides a sets of device power management callbacks that can be used to perform what's needed for device power management in addition to the operations carried out by the device's driver and subsystem. Namely, if a struct dev_power_domain object is pointed to by the pwr_domain field in a struct device, the callbacks provided by its ops member will be executed in addition to the corresponding callbacks provided by the device's subsystem and driver during all power transitions. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Tested-and-acked-by: Kevin Hilman <khilman@ti.com>
2011-03-15PM: Drop pm_flags that is not necessaryRafael J. Wysocki1-9/+0
The variable pm_flags is used to prevent APM from being enabled along with ACPI, which would lead to problems. However, acpi_init() is always called before apm_init() and after acpi_init() has returned, it is known whether or not ACPI will be used. Namely, if acpi_disabled is not set after acpi_init() has returned, this means that ACPI is enabled. Thus, it is sufficient to check acpi_disabled in apm_init() to prevent APM from being enabled in parallel with ACPI. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Len Brown <len.brown@intel.com>
2011-03-15PM: Remove CONFIG_PM_OPSRafael J. Wysocki1-1/+1
After redefining CONFIG_PM to depend on (CONFIG_PM_SLEEP || CONFIG_PM_RUNTIME) the CONFIG_PM_OPS option is redundant and can be replaced with CONFIG_PM. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-02-24PM: Make ACPI wakeup from S5 work again when CONFIG_PM_SLEEP is unsetRafael J. Wysocki1-0/+2
Commit 074037e (PM / Wakeup: Introduce wakeup source objects and event statistics (v3)) caused ACPI wakeup to only work if CONFIG_PM_SLEEP is set, but it also worked for CONFIG_PM_SLEEP unset before. This can be fixed by making device_set_wakeup_enable(), device_init_wakeup() and device_may_wakeup() work in the same way as before commit 074037e when CONFIG_PM_SLEEP is unset. Reported-and-tested-by: Justin Maggard <jmaggard10@gmail.com> Cc: stable@kernel.org Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2010-12-24PM: Prototype the pm_generic_ operationsMark Brown1-0/+7
The pm_generic_ operations are all exported but are not prototyped in any header file for direct use. Do so. [rjw: Added extern.] Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2010-12-24PM: Replace the device power.status field with a bit fieldRafael J. Wysocki1-41/+2
The device power.status field is too complicated for its purpose (storing the information about whether or not the device is in the "active" state from the PM core's point of view), so replace it with a bit field and modify all of its users accordingly. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2010-12-24PM / Runtime: Add synchronous runtime interface for interrupt handlers (v3)Alan Stern1-0/+1
This patch (as1431c) makes the synchronous runtime-PM interface suitable for use in interrupt handlers. Subsystems can call the new pm_runtime_irq_safe() function to tell the PM core that a device's runtime_suspend and runtime_resume callbacks should be invoked with interrupts disabled and the spinlock held. This permits the pm_runtime_get_sync() and the new pm_runtime_put_sync_suspend() routines to be called from within interrupt handlers. When a device is declared irq-safe in this way, the PM core increments the parent's usage count, so the parent will never be runtime suspended. This prevents difficult situations in which an irq-safe device can't resume because it is forced to wait for its non-irq-safe parent. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2010-10-17PM / Runtime: Implement autosuspend supportAlan Stern1-0/+8
This patch (as1427) implements the "autosuspend" facility for runtime PM. A few new fields are added to the dev_pm_info structure and several new PM helper functions are defined, for telling the PM core whether or not a device uses autosuspend, for setting the autosuspend delay, and for marking periods of device activity. Drivers that do not want to use autosuspend can continue using the same helper functions as before; their behavior will not change. In addition, drivers supporting autosuspend can also call the old helper functions to get the old behavior. The details are all explained in Documentation/power/runtime_pm.txt and Documentation/ABI/testing/sysfs-devices-power. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2010-10-17PM / Runtime: Add no_callbacks flagAlan Stern1-0/+7
Some devices, such as USB interfaces, cannot be power-managed independently of their parents, i.e., they cannot be put in low power while the parent remains at full power. This patch (as1425) creates a new "no_callbacks" flag, which tells the PM core not to invoke the runtime-PM callback routines for the such devices but instead to assume that the callbacks always succeed. In addition, the non-debugging runtime-PM sysfs attributes for the devices are removed, since they are pretty much meaningless. The advantage of this scheme comes not so much from avoiding the callbacks themselves, but rather from the fact that without the need for a process context in which to run the callbacks, more work can be done in interrupt context. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2010-10-17PM: Fix potential issue with failing asynchronous suspendRafael J. Wysocki1-2/+5
There is a potential issue with the asynchronous suspend code that a device driver suspending asynchronously may not notice that it should back off. There are two failing scenarions, (1) when the driver is waiting for a driver suspending synchronously to complete and that second driver returns error code, in which case async_error won't be set and the waiting driver will continue suspending and (2) after the driver has called device_pm_wait_for_dev() and the waited for driver returns error code, in which case the caller of device_pm_wait_for_dev() will not know that there was an error and will continue suspending. To fix this issue make __device_suspend() set async_error, so async_suspend() doesn't need to set it any more, and make device_pm_wait_for_dev() return async_error, so that its callers can check whether or not they should continue suspending. No more changes are necessary, since device_pm_wait_for_dev() is not used by any drivers' suspend routines. Reported-by: Colin Cross <ccross@android.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-10-17PM / Wakeup: Introduce wakeup source objects and event statistics (v3)Rafael J. Wysocki1-12/+4
Introduce struct wakeup_source for representing system wakeup sources within the kernel and for collecting statistics related to them. Make the recently introduced helper functions pm_wakeup_event(), pm_stay_awake() and pm_relax() use struct wakeup_source objects internally, so that wakeup statistics associated with wakeup devices can be collected and reported in a consistent way (the definition of pm_relax() is changed, which is harmless, because this function is not called directly by anyone yet). Introduce new wakeup-related sysfs device attributes in /sys/devices/.../power for reporting the device wakeup statistics. Change the global wakeup events counters event_count and events_in_progress into atomic variables, so that it is not necessary to acquire a global spinlock in pm_wakeup_event(), pm_stay_awake() and pm_relax(), which should allow us to avoid lock contention in these functions on SMP systems with many wakeup devices. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-07-19PM / Runtime: Add runtime PM statistics (v3)Arjan van de Ven1-0/+6
In order for PowerTOP to be able to report how well the new runtime PM is working for the various drivers, the kernel needs to export some basic statistics in sysfs. This patch adds two sysfs files in the runtime PM domain that expose the total time a device has been active, and the time a device has been suspended. With this PowerTOP can compute the activity percentage Active %age = 100 * (delta active) / (delta active + delta suspended) and present the information to the user. I've written the PowerTOP code (slated for version 1.12) already, and the output looks like this: Runtime Device Power Management statistics Active Device name 10.0% 06:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8101E/RTL8102E PCI Express Fast Ethernet controller [version 2: fix stat update bugs noticed by Alan Stern] [version 3: rebase to -next and move the sysfs declaration] Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2010-07-19PM: Make it possible to avoid races between wakeup and system sleepRafael J. Wysocki1-0/+10
One of the arguments during the suspend blockers discussion was that the mainline kernel didn't contain any mechanisms making it possible to avoid races between wakeup and system suspend. Generally, there are two problems in that area. First, if a wakeup event occurs exactly when /sys/power/state is being written to, it may be delivered to user space right before the freezer kicks in, so the user space consumer of the event may not be able to process it before the system is suspended. Second, if a wakeup event occurs after user space has been frozen, it is not generally guaranteed that the ongoing transition of the system into a sleep state will be aborted. To address these issues introduce a new global sysfs attribute, /sys/power/wakeup_count, associated with a running counter of wakeup events and three helper functions, pm_stay_awake(), pm_relax(), and pm_wakeup_event(), that may be used by kernel subsystems to control the behavior of this attribute and to request the PM core to abort system transitions into a sleep state already in progress. The /sys/power/wakeup_count file may be read from or written to by user space. Reads will always succeed (unless interrupted by a signal) and return the current value of the wakeup events counter. Writes, however, will only succeed if the written number is equal to the current value of the wakeup events counter. If a write is successful, it will cause the kernel to save the current value of the wakeup events counter and to abort the subsequent system transition into a sleep state if any wakeup events are reported after the write has returned. [The assumption is that before writing to /sys/power/state user space will first read from /sys/power/wakeup_count. Next, user space consumers of wakeup events will have a chance to acknowledge or veto the upcoming system transition to a sleep state. Finally, if the transition is allowed to proceed, /sys/power/wakeup_count will be written to and if that succeeds, /sys/power/state will be written to as well. Still, if any wakeup events are reported to the PM core by kernel subsystems after that point, the transition will be aborted.] Additionally, put a wakeup events counter into struct dev_pm_info and make these per-device wakeup event counters available via sysfs, so that it's possible to check the activity of various wakeup event sources within the kernel. To illustrate how subsystems can use pm_wakeup_event(), make the low-level PCI runtime PM wakeup-handling code use it. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Jesse Barnes <jbarnes@virtuousgeek.org> Acked-by: Greg Kroah-Hartman <gregkh@suse.de> Acked-by: markgross <markgross@thegnar.org> Reviewed-by: Alan Stern <stern@rowland.harvard.edu>
2010-03-06PM: Provide generic subsystem-level callbacksRafael J. Wysocki1-6/+45
There are subsystems whose power management callbacks only need to invoke the callbacks provided by device drivers. Still, their system sleep PM callbacks should play well with the runtime PM callbacks, so that devices suspended at run time can be left in that state for a system sleep transition. Provide a set of generic PM callbacks for such subsystems and define convenience macros for populating dev_pm_ops structures. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2010-02-26PM: Allow device drivers to use dpm_wait()Rafael J. Wysocki1-0/+2
There are some dependencies between devices (in particular, between EHCI USB controllers and their OHCI/UHCI siblings) which are not reflected by the structure of the device tree. With synchronous suspend and resume these dependencies are taken into accout automatically, because the devices in question are always registered in the right order, but to meet these constraints with asynchronous suspend and resume the drivers of these devices will need to use dpm_wait() in their suspend/resume routines, so introduce a helper function allowing them to do that. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2010-02-26PM: Asynchronous suspend and resume of devicesRafael J. Wysocki1-0/+3
Theoretically, the total time of system sleep transitions (suspend to RAM, hibernation) can be reduced by running suspend and resume callbacks of device drivers in parallel with each other. However, there are dependencies between devices such that we're not allowed to suspend the parent of a device before suspending the device itself. Analogously, we're not allowed to resume a device before resuming its parent. The most straightforward way to take these dependencies into accout is to start the async threads used for suspending and resuming devices at the core level, so that async_schedule() is called for each suspend and resume callback supposed to be executed asynchronously. For this purpose, introduce a new device flag, power.async_suspend, used to mark the devices whose suspend and resume callbacks are to be executed asynchronously (ie. in parallel with the main suspend/resume thread and possibly in parallel with each other) and helper function device_enable_async_suspend() allowing one to set power.async_suspend for given device (power.async_suspend is unset by default for all devices). For each device with the power.async_suspend flag set the PM core will use async_schedule() to execute its suspend and resume callbacks. The async threads started for different devices as a result of calling async_schedule() are synchronized with each other and with the main suspend/resume thread with the help of completions, in the following way: (1) There is a completion, power.completion, for each device object. (2) Each device's completion is reset before calling async_schedule() for the device or, in the case of devices with the power.async_suspend flags unset, before executing the device's suspend and resume callbacks. (3) During suspend, right before running the bus type, device type and device class suspend callbacks for the device, the PM core waits for the completions of all the device's children to be completed. (4) During resume, right before running the bus type, device type and device class resume callbacks for the device, the PM core waits for the completion of the device's parent to be completed. (5) The PM core completes power.completion for each device right after the bus type, device type and device class suspend (or resume) callbacks executed for the device have returned. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2010-02-26PM / Runtime: Add sysfs switch for disabling device run-time PMRafael J. Wysocki1-0/+1
Add new device sysfs attribute, power/control, allowing the user space to block the run-time power management of the devices. If this attribute is set to "on", the driver of the device won't be able to power manage it at run time (without breaking the rules) and the device will always be in the full power state (except when the entire system goes into a sleep state). Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Alan Stern <stern@rowland.harvard.edu>
2009-12-15const: constify remaining dev_pm_opsAlexey Dobriyan1-1/+1
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-06PM: Add flag for devices capable of generating run-time wake-up eventsRafael J. Wysocki1-3/+5
Apparently, there are devices that can wake up the system from sleep states and yet are incapable of generating wake-up events at run time. Thus, introduce a flag indicating if given device is capable of generating run-time wake-up events. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2009-09-14PM: Add convenience macro to make switching to dev_pm_ops less error-proneAlbin Tonnerre1-0/+14
In a number of cases, the .suspend, .freeze, .poweroff and .resume, .thaw, .restore functions are identical. However, they all need to be assigned to avoid regressionsm as the previous code called .suspend resp. .resume in all those cases. SIMPLE_DEV_PM_OPS helps to deal with this case. [rjw: Changed the name of the macro and added the comment explaining its purpose.] Signed-off-by: Albin Tonnerre <albin.tonnerre@free-electrons.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2009-08-23PM: Introduce core framework for run-time PM of I/O devices (rev. 17)Rafael J. Wysocki1-3/+98
Introduce a core framework for run-time power management of I/O devices. Add device run-time PM fields to 'struct dev_pm_info' and device run-time PM callbacks to 'struct dev_pm_ops'. Introduce a run-time PM workqueue and define some device run-time PM helper functions at the core level. Document all these things. Special thanks to Alan Stern for his help with the design and multiple detailed reviews of the pereceding versions of this patch and to Magnus Damm for testing feedback. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Magnus Damm <damm@igel.co.jp>
2009-06-12PM core: rename suspend and resume functionsAlan Stern1-6/+5
This patch (as1241) renames a bunch of functions in the PM core. Rather than go through a boring list of name changes, suffice it to say that in the end we have a bunch of pairs of functions: device_resume_noirq dpm_resume_noirq device_resume dpm_resume device_complete dpm_complete device_suspend_noirq dpm_suspend_noirq device_suspend dpm_suspend device_prepare dpm_prepare in which device_X does the X operation on a single device and dpm_X invokes device_X for all devices in the dpm_list. In addition, the old dpm_power_up and device_resume_noirq have been combined into a single function (dpm_resume_noirq). Lastly, dpm_suspend_start and dpm_resume_end are the renamed versions of the former top-level device_suspend and device_resume routines. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Acked-by: Magnus Damm <damm@igel.co.jp> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2009-06-12PM: Rename device_power_down/up()Magnus Damm1-2/+2
Rename the functions performing "_noirq" dev_pm_ops operations from device_power_down() and device_power_up() to device_suspend_noirq() and device_resume_noirq(). The new function names are chosen to show that the functions are responsible for calling the _noirq() versions to finalize the suspend/resume operation. The current function names do not perform power down/up anymore so the names may be misleading. Global function renames: - device_power_down() -> device_suspend_noirq() - device_power_up() -> device_resume_noirq() Static function renames: - suspend_device_noirq() -> __device_suspend_noirq() - resume_device_noirq() -> __device_resume_noirq() Signed-off-by: Magnus Damm <damm@igel.co.jp> Acked-by: Greg Kroah-Hartman <gregkh@suse.de> Acked-by: Len Brown <lenb@kernel.org> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>