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path: root/drivers/base/power
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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 / OPP: opp_find_freq_exact() documentation fixNishanth Menon
opp_find_freq_exact() documentation has is_available instead of available. This also fixes warning with the kernel-doc: scripts/kernel-doc drivers/base/power/opp.c >/dev/null Warning(drivers/base/power/opp.c:246): No description found for parameter 'available' Warning(drivers/base/power/opp.c:246): Excess function parameter 'is_available' description in 'opp_find_freq_exact' Signed-off-by: Nishanth Menon <nm@ti.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
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>
2011-03-15PM: Allow pm_runtime_suspend() to succeed during system suspendRafael J. Wysocki
The dpm_prepare() function increments the runtime PM reference counters of all devices to prevent pm_runtime_suspend() from executing subsystem-level callbacks. However, this was supposed to guard against a specific race condition that cannot happen, because the power management workqueue is freezable, so pm_runtime_suspend() can only be called synchronously during system suspend and we can rely on subsystems and device drivers to avoid doing that unnecessarily. Make dpm_prepare() drop the runtime PM reference to each device after making sure that runtime resume is not pending for it. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Kevin Hilman <khilman@ti.com>
2011-03-15PM: Remove CONFIG_PM_OPSRafael J. Wysocki
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>
2011-03-15PM: 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>
2011-03-15PM: Use appropriate printk() priority level in trace.cMandeep Singh Baines
printk()s without a priority level default to KERN_WARNING. To reduce noise at KERN_WARNING, this patch sets the priority level appriopriately for unleveled printks()s. This should be useful to folks that look at dmesg warnings closely. Changed these messages to pr_info(). Signed-off-by: Mandeep Singh Baines <msb@chromium.org> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-03-15PM / Wakeup: Don't update events_check_enabled in pm_get_wakeup_count()Rafael J. Wysocki
Since pm_save_wakeup_count() has just been changed to clear events_check_enabled unconditionally before checking if there are any new wakeup events registered since the last read from /sys/power/wakeup_count, the detection of wakeup events during suspend may be disabled, after it's been enabled, by writing a "wrong" value back to /sys/power/wakeup_count. For this reason, it is not necessary to update events_check_enabled in pm_get_wakeup_count() any more. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-03-15PM / Wakeup: Make pm_save_wakeup_count() work as documentedRafael J. Wysocki
According to Documentation/ABI/testing/sysfs-power, the /sys/power/wakeup_count interface should only make the kernel react to wakeup events during suspend if the last write to it has been successful. However, if /sys/power/wakeup_count is written to two times in a row, where the first write is successful and the second is not, the kernel will still react to wakeup events during suspend due to a bug in pm_save_wakeup_count(). Fix the bug by making pm_save_wakeup_count() clear events_check_enabled unconditionally before checking if there are any new wakeup events registered since the previous read from /sys/power/wakeup_count. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-03-15PM / Wakeup: Combine atomic counters to avoid reordering issuesRafael J. Wysocki
The memory barrier in wakeup_source_deactivate() is supposed to prevent the callers of pm_wakeup_pending() and pm_get_wakeup_count() from seeing the new value of events_in_progress (0, in particular) and the old value of event_count at the same time. However, if wakeup_source_deactivate() is executed by CPU0 and, for instance, pm_wakeup_pending() is executed by CPU1, where both processors can reorder operations, the memory barrier in wakeup_source_deactivate() doesn't affect CPU1 which can reorder reads. In that case CPU1 may very well decide to fetch event_count before it's modified and events_in_progress after it's been updated, so pm_wakeup_pending() may fail to detect a wakeup event. This issue can be addressed by using a single atomic variable to store both events_in_progress and event_count, so that they can be updated together in a single atomic operation. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
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>
2011-01-13Merge branch 'for-next' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial * 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (43 commits) Documentation/trace/events.txt: Remove obsolete sched_signal_send. writeback: fix global_dirty_limits comment runtime -> real-time ppc: fix comment typo singal -> signal drivers: fix comment typo diable -> disable. m68k: fix comment typo diable -> disable. wireless: comment typo fix diable -> disable. media: comment typo fix diable -> disable. remove doc for obsolete dynamic-printk kernel-parameter remove extraneous 'is' from Documentation/iostats.txt Fix spelling milisec -> ms in snd_ps3 module parameter description Fix spelling mistakes in comments Revert conflicting V4L changes i7core_edac: fix typos in comments mm/rmap.c: fix comment sound, ca0106: Fix assignment to 'channel'. hrtimer: fix a typo in comment init/Kconfig: fix typo anon_inodes: fix wrong function name in comment fix comment typos concerning "consistent" poll: fix a typo in comment ... Fix up trivial conflicts in: - drivers/net/wireless/iwlwifi/iwl-core.c (moved to iwl-legacy.c) - fs/ext4/ext4.h Also fix missed 'diabled' typo in drivers/net/bnx2x/bnx2x.h while at it.
2010-12-24PM / Runtime: Generic resume shouldn't set RPM_ACTIVE unconditionallyRafael J. Wysocki
The __pm_generic_resume() function changes the given device's runtime PM status to RPM_ACTIVE if its driver's callback returns 0, but it only should do that if the rumtime PM is enabled for the device. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2010-12-24PM: Use dev_name() in core device suspend and resume routinesRafael J. Wysocki
Use dev_name() wherever applicable in drivers/base/power/main.c. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2010-12-24PM: Permit registration of parentless devices during system suspendRafael J. Wysocki
The registration of a new parentless device during system suspend will not lead to any complications affecting the PM core (the device will be effectively seen after the subsequent resume has completed), so remove the code used for detection of such events. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2010-12-24PM: Replace the device power.status field with a bit fieldRafael J. Wysocki
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: Remove redundant checks from core device resume routinesRafael J. Wysocki
Since a separate list of devices is used to link devices that have completed each stage of suspend (or resume), it is not necessary to check dev->power.status in the core device resume routines any more. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2010-12-24PM: Use a different list of devices for each stage of device suspendRafael J. Wysocki
Instead of keeping all devices in the same list during system suspend and resume, regardless of what suspend-resume callbacks have been executed for them already, use separate lists of devices that have had their ->prepare(), ->suspend() and ->suspend_noirq() callbacks executed. This will allow us to simplify the core device suspend and resume routines. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2010-12-24PM: Avoid compiler warning in pm_noirq_op()Rafael J. Wysocki
The compiler complains that calltime may be uninitialized in pm_noirq_op(), so add extra initialization for that variable to avoid the warning. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2010-12-24PM: Use pm_wakeup_pending() in __device_suspend()Rafael J. Wysocki
Before starting to suspend a device in __device_suspend() check if there's a request to abort the power transition and return -EBUSY in that case. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2010-12-24PM / Wakeup: Replace pm_check_wakeup_events() with pm_wakeup_pending()Rafael J. Wysocki
To avoid confusion with the meaning and return value of pm_check_wakeup_events() replace it with pm_wakeup_pending() that will work the other way around (ie. return true when system-wide power transition should be aborted). Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2010-12-24PM: Prevent dpm_prepare() from returning errors unnecessarilyRafael J. Wysocki
Currently dpm_prepare() returns error code if it finds that a device being suspended has a pending runtime resume request. However, it should not do that if the checking for wakeup events is not enabled. On the other hand, if the checking for wakeup events is enabled, it can return error when a wakeup event is detected, regardless of its source. 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>
2010-12-24PM / Runtime: Fix comments to match runtime callback codeAaro Koskinen
Commit 05aa55dddb9ee4045c320661068bea78dad6a6e5 changed routines to succeed if the driver handler is not defined. Comments were not updated. Signed-off-by: Aaro Koskinen <aaro.koskinen@nokia.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2010-12-22Merge branch 'master' into for-nextJiri Kosina
Conflicts: MAINTAINERS arch/arm/mach-omap2/pm24xx.c drivers/scsi/bfa/bfa_fcpim.c Needed to update to apply fixes for which the old branch was too outdated.
2010-11-11PM: Allow devices to be removed during late suspend and early resumeRafael J. Wysocki
Holding dpm_list_mtx across late suspend and early resume of devices is problematic for the PCMCIA subsystem and doesn't allow device objects to be removed by late suspend and early resume driver callbacks. This appears to be overly restrictive, as drivers are generally allowed to remove device objects in other phases of suspend and resume. Therefore rework dpm_{suspend|resume}_noirq() so that they don't have to hold dpm_list_mtx all the time. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2010-11-01tree-wide: fix comment/printk typosUwe Kleine-König
"gadget", "through", "command", "maintain", "maintain", "controller", "address", "between", "initiali[zs]e", "instead", "function", "select", "already", "equal", "access", "management", "hierarchy", "registration", "interest", "relative", "memory", "offset", "already", Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
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>
2010-10-19PM / Wakeup: Show wakeup sources statistics in debugfsRafael J. Wysocki
There may be wakeup sources that aren't associated with any devices and their statistics information won't be available from sysfs. Also, for debugging purposes it is convenient to have all of the wakeup sources statistics available from one place. For these reasons, introduce new file "wakeup_sources" in debugfs containing those statistics. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-10-17PM: Introduce library for device-specific OPPs (v7)Nishanth Menon
SoCs have a standard set of tuples consisting of frequency and voltage pairs that the device will support per voltage domain. These are called Operating Performance Points or OPPs. The actual definitions of OPP varies over silicon versions. For a specific domain, we can have a set of {frequency, voltage} pairs. As the kernel boots and more information is available, a default set of these are activated based on the precise nature of device. Further on operation, based on conditions prevailing in the system (such as temperature), some OPP availability may be temporarily controlled by the SoC frameworks. To implement an OPP, some sort of power management support is necessary hence this library depends on CONFIG_PM. Contributions include: Sanjeev Premi for the initial concept: http://patchwork.kernel.org/patch/50998/ Kevin Hilman for converting original design to device-based. Kevin Hilman and Paul Walmsey for cleaning up many of the function abstractions, improvements and data structure handling. Romit Dasgupta for using enums instead of opp pointers. Thara Gopinath, Eduardo Valentin and Vishwanath BS for fixes and cleanups. Linus Walleij for recommending this layer be made generic for usage in other architectures beyond OMAP and ARM. Mark Brown, Andrew Morton, Rafael J. Wysocki, Paul E. McKenney for valuable improvements. Discussions and comments from: http://marc.info/?l=linux-omap&m=126033945313269&w=2 http://marc.info/?l=linux-omap&m=125482970102327&w=2 http://marc.info/?t=125809247500002&r=1&w=2 http://marc.info/?l=linux-omap&m=126025973426007&w=2 http://marc.info/?t=128152609200064&r=1&w=2 http://marc.info/?t=128468723000002&r=1&w=2 incorporated. v1: http://marc.info/?t=128468723000002&r=1&w=2 Signed-off-by: Nishanth Menon <nm@ti.com> Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2010-10-17PM: Add sysfs attr for rechecking dev hash from PM traceJames Hogan
If the device which fails to resume is part of a loadable kernel module it won't be checked at startup against the magic number stored in the RTC. Add a read-only sysfs attribute /sys/power/pm_trace_dev_match which contains a list of newline separated devices (usually just the one) which currently match the last magic number. This allows the device which is failing to resume to be found after the modules are loaded again. Signed-off-by: James Hogan <james@albanarts.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2010-10-17PM: Lock PM device list mutex in show_dev_hash()James Hogan
Lock the PM device list mutex using device_pm_lock() and device_pm_unlock() around the list iteration in show_dev_hash(). show_dev_hash() was reverse iterating dpm_list without first locking the mutex that the functions in drivers/base/power/main.c lock. I assume this was unintentional since there is no comment suggesting why the lock might not be necessary. Signed-off-by: James Hogan <james@albanarts.com> 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: Fix potential issue with failing asynchronous suspendRafael J. Wysocki
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. 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>
2010-10-17PM: Fix signed/unsigned warning in dpm_show_time()Kevin Cernekee
Seen on MIPS32, gcc 4.4.3, 2.6.36-rc4: drivers/base/power/main.c: In function 'dpm_show_time': drivers/base/power/main.c:415: warning: comparison of distinct pointer types lacks a cast do_div() takes unsigned parameters: uint32_t do_div(uint64_t *n, uint32_t base); Using an unsigned variable for usecs64 should not cause any problems, because calltime >= starttime . Signed-off-by: Kevin Cernekee <cernekee@gmail.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2010-10-17PM / Runtime: Lenient generic runtime pm callbacksOhad Ben-Cohen
Allow drivers, that belong to subsystems which use the generic runtime pm callbacks, not to define runtime pm suspend/resume handlers, by implicitly assuming success in such cases. This is needed to eliminate nop handlers that would otherwise be necessary by drivers which enable runtime pm, but don't need to do anything when their devices are runtime-suspended/resumed. Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com> Acked-by: Kevin Hilman <khilman@deeprootsystems.com> Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2010-09-09PM: Prevent waiting forever on asynchronous resume after failing suspendColin Cross
During suspend, the power.completion is expected to be set when a device has not yet started suspending. Set it on init to fix a corner case where a device is resumed when its parent has never suspended. Consider three drivers, A, B, and C. The parent of A is C, and C has async_suspend set. On boot, C->power.completion is initialized to 0. During the first suspend: suspend_devices_and_enter(...) dpm_resume(...) device_suspend(A) device_suspend(B) returns error, aborts suspend dpm_resume_end(...) dpm_resume(...) device_resume(A) dpm_wait(A->parent == C) wait_for_completion(C->power.completion) The wait_for_completion will never complete, because complete_all(C->power.completion) will only be called from device_suspend(C) or device_resume(C), neither of which is called if suspend is aborted before C. After a successful suspend->resume cycle, where B doesn't abort suspend, C->power.completion is left in the completed state by the call to device_resume(C), and the same call path will work if B aborts suspend. Signed-off-by: Colin Cross <ccross@android.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
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>
2010-07-19PM / Runtime: Make runtime_status attribute not debug-only (v. 2)Alan Stern
This patch (as1404b) makes the runtime_status sysfs attribute available even in the absence of CONFIG_PM_ADVANCED_DEBUG, and it changes the routine to display "unsupported" when runtime PM is disabled for a device. Although not strictly 100% accurate, this will almost always be correct. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Acked-by: Dominik Brodowski <linux@dominikbrodowski.net> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2010-07-19PM: Do not use dynamically allocated objects in pm_wakeup_event()Rafael J. Wysocki
Originally, pm_wakeup_event() uses struct delayed_work objects, allocated with GFP_ATOMIC, to schedule the execution of pm_relax() in future. However, as noted by Alan Stern, it is not necessary to do that, because all pm_wakeup_event() calls can use one static timer that will always be set to expire at the latest time passed to pm_wakeup_event(). The modifications are based on the example code posted by Alan. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>