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path: root/drivers/base/power/runtime.c
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2011-03-31Fix common misspellingsLucas De Marchi
Fixes generated by 'codespell' and manually reviewed. Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
2011-03-15PM: Make system-wide PM and runtime PM treat subsystems consistentlyRafael J. Wysocki
The code handling system-wide power transitions (eg. suspend-to-RAM) can in theory execute callbacks provided by the device's bus type, device type and class in each phase of the power transition. In turn, the runtime PM core code only calls one of those callbacks at a time, preferring bus type callbacks to device type or class callbacks and device type callbacks to class callbacks. It seems reasonable to make them both behave in the same way in that respect. Moreover, even though a device may belong to two subsystems (eg. bus type and device class) simultaneously, in practice power management callbacks for system-wide power transitions are always provided by only one of them (ie. if the bus type callbacks are defined, the device class ones are not and vice versa). Thus it is possible to modify the code handling system-wide power transitions so that it follows the core runtime PM code (ie. treats the subsystem callbacks as mutually exclusive). On the other hand, the core runtime PM code will choose to execute, for example, a runtime suspend callback provided by the device type even if the bus type's struct dev_pm_ops object exists, but the runtime_suspend pointer in it happens to be NULL. This is confusing, because it may lead to the execution of callbacks from different subsystems during different operations (eg. the bus type suspend callback may be executed during runtime suspend of the device, while the device type callback will be executed during system suspend). Make all of the power management code treat subsystem callbacks in a consistent way, such that: (1) If the device's type is defined (eg. dev->type is not NULL) and its pm pointer is not NULL, the callbacks from dev->type->pm will be used. (2) If dev->type is NULL or dev->type->pm is NULL, but the device's class is defined (eg. dev->class is not NULL) and its pm pointer is not NULL, the callbacks from dev->class->pm will be used. (3) If dev->type is NULL or dev->type->pm is NULL and dev->class is NULL or dev->class->pm is NULL, the callbacks from dev->bus->pm will be used provided that both dev->bus and dev->bus->pm are not NULL. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Kevin Hilman <khilman@ti.com> Reasoning-sounds-sane-to: Grant Likely <grant.likely@secretlab.ca> Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-03-15PM: Add support for device power domainsRafael J. Wysocki
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>
2011-01-25PM / Runtime: Don't enable interrupts while running in_interruptAlan Stern
This patch (as1445) fixes a bug in the runtime PM core left over from the addition of the no_callbacks flag. If this flag is set then it is possible for rpm_suspend() to be called in_interrupt, so when releasing spinlocks it's important not to re-enable interrupts. To avoid an unnecessary save-and-restore of the interrupt flag, the patch also inlines a pm_request_idle() call. This fixes Bugzilla #27482. (The offending code was added in 2.6.37, so it's not necessary to apply this to any earlier stable kernels.) Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Reported-by: tim blechmann <tim@klingt.org> CC: <stable@kernel.org> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2010-12-24PM / Runtime: Add synchronous runtime interface for interrupt handlers (v3)Alan Stern
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>
2010-10-29PM / Runtime: Fix typo in status comparison causing warningKevin Winchester
GCC version 4.5.1 gives the following warning: drivers/base/power/runtime.c: In function ‘rpm_check_suspend_allowed’: drivers/base/power/runtime.c:146:25: warning: comparison between ‘enum dpm_state’ and ‘enum rpm_status’ which seems to be a typo in that dev->power.runtime_status should be compared instead of dev->power.status. Signed-off-by: Kevin Winchester <kjwinchester@gmail.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2010-10-22PM / Runtime: fix recursive locking warning of lockdep from rpm_resume()Ming Lei
For device with no_callbacks flag set, its power lock and its parent's power lock may be held nestedly in rpm_resume, so we should take spin_lock_nested(lock, SINGLE_DEPTH_NESTING) to acquire parent power lock to avoid lockdep warning. Signed-off-by: Ming Lei <tom.leiming@gmail.com> Acked-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2010-10-17PM / Runtime: Remove idle notification after failing suspendRafael J. Wysocki
If runtime suspend of a device fails returning -EAGAIN or -EBUSY, which means that it's safe to try to suspend it again, the PM core runs the runtime idle helper function for it. Unfortunately this may lead to problems, for example for PCI devices whose drivers don't implement the ->runtime_idle() callback, because in that case the PCI bus type's ->runtime_idle() always calls pm_runtime_suspend() for the given device. Then, if there's an automatic idle notification after the driver's ->runtime_suspend() returning -EAGAIN or -EBUSY, it will make the suspend happen again possibly causing a busy loop to appear. To avoid that, remove the idle notification after failing runtime suspend of a device altogether and let the callers of pm_runtime_suspend() repeat the operation if need be. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Alan Stern <stern@rowland.harvard.edu>
2010-10-17PM / Runtime: Reduce code duplication in core helper functionsRafael J. Wysocki
Reduce code duplication in rpm_idle(), rpm_suspend() and rpm_resume() by using local pointers to store callback addresses and moving some duplicated code into a separate function. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Reviewed-by: Alan Stern <stern@rowland.harvard.edu>
2010-10-17PM / Runtime: Implement autosuspend supportAlan Stern
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 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 / Runtime: Combine runtime PM entry pointsAlan Stern
This patch (as1424) combines the various public entry points for the runtime PM routines into three simple functions: one for idle, one for suspend, and one for resume. A new bitflag specifies whether or not to increment or decrement the usage_count field. The new entry points are named __pm_runtime_idle, __pm_runtime_suspend, and __pm_runtime_resume, to reflect that they are trampolines. Simultaneously, the corresponding internal routines are renamed to rpm_idle, rpm_suspend, and rpm_resume. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2010-10-17PM / Runtime: Merge synchronous and async runtime routinesAlan Stern
This patch (as1423) merges the asynchronous routines __pm_request_idle(), __pm_request_suspend(), and __pm_request_resume() with their synchronous counterparts. The RPM_ASYNC bitflag argument serves to indicate what sort of operation to perform. In the course of performing this merger, it became apparent that the various functions don't all behave consistenly with regard to error reporting and cancellation of outstanding requests. A new routine, rpm_check_suspend_allowed(), was written to centralize much of the testing, and the other functions were revised to follow a simple algorithm: If the operation is disallowed because of the device's settings or current state, return an error. Cancel pending or scheduled requests of lower priority. Schedule, queue, or perform the desired operation. A few special cases and exceptions are noted in comments. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2010-10-17PM / Runtime: Replace boolean arguments with bitflagsAlan Stern
The "from_wq" argument in __pm_runtime_suspend() and __pm_runtime_resume() supposedly indicates whether or not the function was called by the PM workqueue thread, but in fact it isn't always used this way. It really indicates whether or not the function should return early if the requested operation is already in progress. Along with this badly-named boolean argument, later patches in this series will add several other boolean arguments to these functions and others. Therefore this patch (as1422) begins the conversion process by replacing from_wq with a bitflag argument. The same bitflags are also used in __pm_runtime_get() and __pm_runtime_put(), where they indicate whether or not the operation should be asynchronous. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2010-10-17PM / Runtime: Move code in drivers/base/power/runtime.cAlan Stern
This patch (as1421) moves the PM runtime accounting subroutines up to the beginning of runtime.c, taking them out of the middle of the functions that do the actual work. No operational changes. 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>
2010-07-19PM / Runtime: Add runtime PM statistics (v3)Arjan van de Ven
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>
2010-05-10PM: Allow runtime_suspend methods to call pm_schedule_suspend()Alan Stern
This patch (as1361) changes the runtime PM interface slightly; it allows suspend requests to be scheduled while the runtime_suspend method is running. If the method succeeds then the scheduled request is cancelled, whereas if the method fails then an idle notification is sent only if no request was scheduled. Being able to schedule suspend requests from within a runtime_suspend method is useful for drivers that need to test for idleness and suspend the device all while holding a single spinlock, or for drivers that want to check for idleness by polling. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2010-02-26PM / Runtime: Add sysfs switch for disabling device run-time PMRafael J. Wysocki
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>
2009-12-22PM / Runtime: Use device type and device class callbacksRafael J. Wysocki
The power management of some devices is handled through device types and device classes rather than through bus types. Since these devices may also benefit from using the run-time power management core, extend it so that the device type and device class run-time PM callbacks can be taken into consideration by it if the bus type callback is not defined. Update the run-time PM core documentation to reflect this change. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2009-12-15PM: allow for usage_count > 0 in pm_runtime_get()Alan Stern
This patch (as1308c) fixes __pm_runtime_get(). Currently the routine will resume a device if the prior usage count was 0. But this isn't right; thanks to pm_runtime_get_noresume() the usage count can be positive even while the device is suspended. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2009-12-06PM / Runtime: Remove unnecessary braces in __pm_runtime_set_status()Rafael J. Wysocki
Some braces in __pm_runtime_set_status() are not necessary, so remove them. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2009-12-06PM / Runtime: Ensure timer_expires is nonzero in pm_schedule_suspend()Rafael J. Wysocki
The runtime PM core code assumes that dev->power.timer_expires is nonzero when the timer is scheduled, but it may become zero incidentally in pm_schedule_suspend(). Prevent this from happening by bumping dev->power.timer_expires up to 1 if it's 0 before calling mod_timer(). Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Reported-by: Alan Stern <stern@rowland.harvard.edu>
2009-12-06PM / Runtime: Use deferred_resume flag in pm_request_resumeAlan Stern
This patch (as1307) adds a small optimization to __pm_request_resume(). If the device is currently being suspended, there's no need to queue a work routine to resume it. Setting the deferred_resume flag will suffice. (There's also a minor improvement to the function's code layout: An unnecessary "else" is removed.) Also, the patch clarifies the usage of the deferred_resume flag. It is meaningful only while a suspend is in progress, so it should be cleared just before a suspend starts, not just after one ends. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2009-12-06PM / Runtime: Fix lockdep warning in __pm_runtime_set_status()Rafael J. Wysocki
Lockdep complains about taking the parent lock in __pm_runtime_set_status(), so mark it as nested. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Reported-by: Alan Stern <stern@rowland.harvard.edu> Cc: stable@kernel.org
2009-11-29PM: fix irq enable/disable in runtime PM codeAlan Stern
This patch (as1305) fixes a bug in the irq-enable settings and removes some related overhead in the runtime PM code. In __pm_runtime_resume(), within the scope of the original spin_lock_irq(), we know that irqs are disabled. There's no reason to go through a pair of enable/disable cycles when acquiring and releasing the parent's lock. In __pm_runtime_set_status(), irqs are already disabled when the parent's lock is acquired, and they must remain disabled when it is released. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2009-11-03PM: Remove some debug messages producing too much noisePavel Machek
pm_runtime_idle() is somewhat noisy. Remove debug prints. Signed-off-by: Pavel Machek <pavel@ucw.cz> 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>
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>
2006-01-06[PATCH] pcmcia: merge suspend into device modelDominik Brodowski
Merge the suspend and resume methods for 16-bit PCMCIA cards into the device model -- for both runtime power management and suspend to ram/disk. Bugfix in ds.c by Richard Purdie Signed-Off-By: Richard Purdie <rpurdie@rpsys.net> Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
2006-01-04[PATCH] drivers/base/power/runtime.c: #if 0 dpm_set_power_state()Adrian Bunk
This patch #if 0's an unused global function. Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2005-10-28[PATCH] root hub changes (lesser half)David Brownell
This patch collects various small updates related to root hubs, to shrink later patches which build on them. - For root hub suspend/resume support: * Make the existing usb_hcd_resume_root_hub() routine respect pmcore locking, exporting and using the dpm_runtime_resume() method. * Add a new usb_hcd_suspend_root_hub() to pair with that routine. (Essential to make OHCI autosuspend behave again...) * HC_SUSPENDED by itself only refers to the root hub's downstream ports. So let HCDs see root hub URBs unless the parent device is suspended. - Remove an assertion we no longer need (and now, also don't want). - Generic suspend/resume updates to work better with swsusp. * Ignore the FREEZE vs SUSPEND distinction for hardware; trying to use it breaks the swsusp snapshots it's supposed to help (sigh). * On resume, mark devices as resumed right away, but then do nothing else if the device is marked NOTATTACHED. These changes shouldn't be very noticable by themselves. Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> drivers/base/power/runtime.c | 1 drivers/usb/core/hcd.c | 64 ++++++++++++++++++++++++++++++++++++++----- drivers/usb/core/hcd.h | 1 drivers/usb/core/hub.c | 45 ++++++++++++++++++++++++------ drivers/usb/core/usb.c | 20 +++++++++---- drivers/usb/core/usb.h | 1 6 files changed, 111 insertions(+), 21 deletions(-)
2005-09-05[PATCH] swsusp: switch pm_message_t to structPavel Machek
This adds type-checking to pm_message_t, so that people can't confuse it with int or u32. It also allows us to fix "disk yoyo" during suspend (disk spinning down/up/down). [We've tried that before; since that cpufreq problems were fixed and I've tried make allyes config and fixed resulting damage.] Signed-off-by: Pavel Machek <pavel@suse.cz> Signed-off-by: Alexander Nyberg <alexn@telia.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-04-16Linux-2.6.12-rc2v2.6.12-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!