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path: root/drivers/base/power/power.h
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2013-03-04PM / QoS: Remove device PM QoS sysfs attributes at the right placeRafael J. Wysocki
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 <sasha.levin@oracle.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2012-10-24PM / QoS: Make it possible to expose PM QoS device flags to user spaceRafael J. Wysocki
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 <rafael.j.wysocki@intel.com> Reviewed-by: Jean Pihet <j-pihet@ti.com> Acked-by: mark gross <markgross@thegnar.org>
2012-09-04PM / Runtime: Allow helpers to be called by early platform driversRafael J. Wysocki
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 <rjw@sisk.pl>
2012-09-04PM: Reorganize device PM initializationRafael J. Wysocki
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 <rjw@sisk.pl>
2012-03-13PM / QoS: Make it possible to expose PM QoS latency constraintsRafael J. Wysocki
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 <rjw@sisk.pl> Reviewed-by: Kevin Hilman <khilman@ti.com> Reviewed-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Acked-by: Linus Walleij <linus.walleij@linaro.org>
2011-10-04PM / QoS: Add function dev_pm_qos_read_value() (v3)Rafael J. Wysocki
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>
2011-03-15PM: Do not create wakeup sysfs files for devices that cannot wake upRafael J. Wysocki
Currently, wakeup sysfs attributes are created for all devices, regardless of whether or not they are wakeup-capable. This is excessive and complicates wakeup device identification from user space (i.e. to identify wakeup-capable devices user space has to read /sys/devices/.../power/wakeup for all devices and see if they are not empty). Fix this issue by avoiding to create wakeup sysfs files for devices that cannot wake up the system from sleep states (i.e. whose power.can_wakeup flags are unset during registration) and modify device_set_wakeup_capable() so that it adds (or removes) the relevant sysfs attributes if a device's wakeup capability status is changed. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2010-10-17PM / Runtime: Add no_callbacks flagAlan Stern
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 / Wakeup: Introduce wakeup source objects and event statistics (v3)Rafael J. Wysocki
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>
2010-02-26PM: Add a switch for disabling/enabling asynchronous suspend/resumeRafael J. Wysocki
Add sysfs attribute /sys/power/pm_async allowing the user space to disable/enable asynchronous suspend/resume of devices. 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. Wysocki
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>
2009-03-24Driver core: Fix device_move() vs. dpm list ordering, v2Cornelia Huck
dpm_list currently relies on the fact that child devices will be registered after their parents to get a correct suspend order. Using device_move() however destroys this assumption, as an already registered device may be moved under a newly registered one. This patch adds a new argument to device_move(), allowing callers to specify how dpm_list should be adapted. Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com> Acked-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-08-21PM: don't skip device PM init when CONFIG_PM_SLEEP isn't set and CONFIG_PM ↵Alan Stern
is set This patch (as1124) fixes a couple of bugs in the PM core. The new dev->power.status field should be initialized regardless of whether CONFIG_PM_SLEEP is enabled, and similarly dpm_sysfs_add() should be called whenever CONFIG_PM is enabled. The patch separates out the call to dpm_sysfs_add() from the call to device_pm_add(). As a result device_pm_add() can no longer return an error, so its return type is changed to void. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Tested-by: Romit Dasgupta <romit@ti.com> Acked-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-06-10Introduce new top level suspend and hibernation callbacksRafael J. Wysocki
Introduce 'struct pm_ops' and 'struct pm_ext_ops' ('ext' meaning 'extended') representing suspend and hibernation operations for bus types, device classes, device types and device drivers. Modify the PM core to use 'struct pm_ops' and 'struct pm_ext_ops' objects, if defined, instead of the ->suspend(), ->resume(), ->suspend_late(), and ->resume_early() callbacks (the old callbacks will be considered as legacy and gradually phased out). The main purpose of doing this is to separate suspend (aka S2RAM and standby) callbacks from hibernation callbacks in such a way that the new callbacks won't take arguments and the semantics of each of them will be clearly specified. This has been requested for multiple times by many people, including Linus himself, and the reason is that within the current scheme if ->resume() is called, for example, it's difficult to say why it's been called (ie. is it a resume from RAM or from hibernation or a suspend/hibernation failure etc.?). The second purpose is to make the suspend/hibernation callbacks more flexible so that device drivers can handle more than they can within the current scheme. For example, some drivers may need to prevent new children of the device from being registered before their ->suspend() callbacks are executed or they may want to carry out some operations requiring the availability of some other devices, not directly bound via the parent-child relationship, in order to prepare for the execution of ->suspend(), etc. Ultimately, we'd like to stop using the freezing of tasks for suspend and therefore the drivers' suspend/hibernation code will have to take care of the handling of the user space during suspend/hibernation. That, in turn, would be difficult within the current scheme, without the new ->prepare() and ->complete() callbacks. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2008-04-19PM: Handle device registrations during suspend/resumeRafael J. Wysocki
Modify the PM core to protect its data structures, specifically the dpm_active list, from being corrupted if a child of the currently suspending device is registered concurrently with its ->suspend() callback. In that case, since the new device (the child) is added to dpm_active after its parent, the PM core will attempt to suspend it after the parent, which is wrong. Introduce a new member of struct dev_pm_info, called 'sleeping', and use it to check if the parent of the device being added to dpm_active has been suspended, in which case the device registration fails. Also, use 'sleeping' for checking if the ordering of devices on dpm_active is correct. Introduce variable 'all_sleeping' that will be set to 'true' once all devices have been suspended and make new device registrations fail until 'all_sleeping' is reset to 'false', in order to avoid having unsuspended devices around while the system is going into a sleep state. Remove pm_sleep_rwsem which is not necessary any more. Special thanks to Alan Stern for discussions and suggestions that lead to the creation of this patch. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-02PM: Export device_pm_schedule_removalRafael J. Wysocki
Move the declaration of device_pm_schedule_removal() to device.h and make it exported, as it will be used directly by some drivers for unregistering device objects during suspend/resume cycles in a safe way. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-01-24driver core: clean up shutdown.cGreg Kroah-Hartman
shutdown.c had some stuff it did not need, including a duplicate extern in the power.h file. This cleans up all of that. Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-01-24PM: Acquire device locks on suspendRafael J. Wysocki
This patch reorganizes the way suspend and resume notifications are sent to drivers. The major changes are that now the PM core acquires every device semaphore before calling the methods, and calls to device_add() during suspends will fail, while calls to device_del() during suspends will block. It also provides a way to safely remove a suspended device with the help of the PM core, by using the device_pm_schedule_removal() callback introduced specifically for this purpose, and updates two drivers (msr and cpuid) that need to use it. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-11-28create /sys/.../power when CONFIG_PM is setDaniel Drake
The CONFIG_SUSPEND changes in 2.6.23 caused a regression under certain configuration conditions (SUSPEND=n, USB_AUTOSUSPEND=y) where all USB device attributes in sysfs (idVendor, idProduct, ...) silently disappeared, causing udev breakage and more. The cause of this is that the /sys/.../power subdirectory is now only created when CONFIG_PM_SLEEP is set, however, it should be created whenever CONFIG_PM is set to handle the above situation. The following patch fixes the regression. Signed-off-by: Daniel Drake <dsd@gentoo.org> Acked-by: Rafael J. Wysocki <rjw@sisk.pl> Cc: Alan Stern <stern@rowland.harvard.edu> Cc: Kay Sievers <kay.sievers@vrfy.org> Cc: stable <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-10-12PM: merge device power-management source filesAlan Stern
This patch (as993) merges the suspend.c and resume.c files in drivers/base/power into main.c, making some public symbols private. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Acked-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-10-12drivers/base/power/: make 2 functions staticAdrian Bunk
suspend_device() and resume_device() can now become static. Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-07-29Introduce CONFIG_SUSPEND for suspend-to-Ram and standbyRafael J. Wysocki
Introduce CONFIG_SUSPEND representing the ability to enter system sleep states, such as the ACPI S3 state, and allow the user to choose SUSPEND and HIBERNATION independently of each other. Make HOTPLUG_CPU be selected automatically if SUSPEND or HIBERNATION has been chosen and the kernel is intended for SMP systems. Also, introduce CONFIG_PM_SLEEP which is automatically selected if CONFIG_SUSPEND or CONFIG_HIBERNATION is set and use it to select the code needed for both suspend and hibernation. The top-level power management headers and the ACPI code related to suspend and hibernation are modified to use the new definitions (the changes in drivers/acpi/sleep/main.c are, mostly, moving code to reduce the number of ifdefs). There are many other files in which CONFIG_PM can be replaced with CONFIG_PM_SLEEP or even with CONFIG_SUSPEND, but they can be updated in the future. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-18PM: remove deprecated dpm_runtime_* routinesAlan Stern
This patch (as933) removes the deprecated dpm_runtime_suspend() and dpm_runtime_resume() routines from the PM core. The only user of those routines is the PCMCIA ds driver; local replacements are added. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> CC: Dominik Brodowski <linux@dominikbrodowski.net> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-07-11Power Management: use mutexes instead of semaphoresMatthias Kaehlcke
The Power Management code uses semaphores as mutexes. Use the mutex API instead of the (binary) semaphores. Signed-off-by: Matthias Kaehlcke <matthias.kaehlcke@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2005-10-28[PATCH] USB: fix pm patches with CONFIG_PM off part 2Andrew Morton
With CONFIG_PM=n: drivers/built-in.o(.text+0x1098c): In function `hub_thread': drivers/usb/core/hub.c:2673: undefined reference to `.dpm_runtime_resume' drivers/built-in.o(.text+0x10998):drivers/usb/core/hub.c:2674: undefined reference to `.dpm_runtime_resume' Please, never ever ever put extern decls into .c files. Use the darn header files :( Cc: David Brownell <david-b@pacbell.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2005-05-17[PATCH] Driver Core: remove driver model detach_stateDavid Brownell
The driver model has a "detach_state" mechanism that: - Has never been used by any in-kernel drive; - Is superfluous, since driver remove() methods can do the same thing; - Became buggy when the suspend() parameter changed semantics and type; - Could self-deadlock when called from certain suspend contexts; - Is effectively wasted documentation, object code, and headspace. This removes that "detach_state" mechanism; net code shrink, as well as a per-device saving in the driver model and sysfs. Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2005-04-16Linux-2.6.12-rc2Linus Torvalds
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!