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2011-01-25PM / Runtime: Don't enable interrupts while running in_interruptAlan Stern1-3/+6
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 git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivialLinus Torvalds1-1/+1
* '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. Wysocki1-1/+1
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. Wysocki1-16/+9
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. Wysocki1-22/+3
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. Wysocki1-12/+5
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. Wysocki1-27/+17
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. Wysocki1-34/+19
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. Wysocki1-1/+1
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. Wysocki1-0/+5
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. Wysocki2-11/+11
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. Wysocki1-4/+7
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 Stern1-9/+38
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 Koskinen1-2/+2
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 Kosina1-4/+30
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. Wysocki1-4/+30
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-König1-1/+1
"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 Winchester1-1/+1
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 Lei1-1/+1
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. Wysocki1-0/+85
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 Menon2-0/+629
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 Hogan1-0/+31
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 Hogan1-1/+4
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. Wysocki1-9/+2
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. Wysocki1-68/+54
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 Stern2-7/+219
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 Stern3-8/+103
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 Stern1-110/+64
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 Stern1-235/+140
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 Stern1-36/+39
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 Stern1-39/+38
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. Wysocki1-6/+9
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. Wysocki5-83/+573
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 Cernekee1-1/+1
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-Cohen1-2/+2
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 Cross1-0/+1
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 Ven2-7/+77
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 Stern1-20/+33
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. Wysocki1-19/+37
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>
2010-07-19PM: Make it possible to avoid races between wakeup and system sleepRafael J. Wysocki4-1/+246
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>
2010-05-10PM / Runtime: Add sysfs debug filesDominik Brodowski1-3/+62
Add a few sysfs files relating to runtime power management for advanced debug purposes: runtime_enabled: is runtime PM enabled for this device? States are "enabled", "disabled", "forbidden" or a combination of the latter two. runtime_status: what state is the device in currently? E.g., it reports "suspended" for runtime-suspended devices, and "active" for active devices. NOTE: if runtime_enabled returns "disabled", the value of this file may not reflect its physical state. runtime_usage: the runtime PM usage count of a device runtime_active_kids: the runtime PM children usage count of a device, or 0 if the ignore_children flag is set. Also, CONFIG_PM_SLEEP_ADVANCED_DEBUG is not defined in any Kconfig file, so replace it with CONFIG_PM_ADVANCED_DEBUG. Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net> Acked-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2010-05-10PM: Allow runtime_suspend methods to call pm_schedule_suspend()Alan Stern1-5/+5
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>
2010-03-24power: support _noirq actions on device types and classesDominik Brodowski1-0/+31
The new-style dev_pm_ops provide callbacks for both IRQs enabled and disabled. However, the _noirq variants were only called for buses registered with a device, not for classes and types. In order to properly use dev_pm_ops in class pcmcia_socket_class, support _noirq actions also on classes and types. Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net> Acked-by: Rafael J. Wysocki <rjw@sisk.pl>
2010-03-07Driver core: create lock/unlock functions for struct deviceGreg Kroah-Hartman1-10/+10
In the future, we are going to be changing the lock type for struct device (once we get the lockdep infrastructure properly worked out) To make that changeover easier, and to possibly burry the lock in a different part of struct device, let's create some functions to lock and unlock a device so that no out-of-core code needs to be changed in the future. This patch creates the device_lock/unlock/trylock() functions, and converts all in-tree users to them. Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Jean Delvare <khali@linux-fr.org> Cc: Dave Young <hidave.darkstar@gmail.com> Cc: Ming Lei <tom.leiming@gmail.com> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Phil Carmody <ext-phil.2.carmody@nokia.com> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Cornelia Huck <cornelia.huck@de.ibm.com> Cc: Rafael J. Wysocki <rjw@sisk.pl> Cc: Pavel Machek <pavel@ucw.cz> Cc: Len Brown <len.brown@intel.com> Cc: Magnus Damm <damm@igel.co.jp> Cc: Alan Stern <stern@rowland.harvard.edu> Cc: Randy Dunlap <randy.dunlap@oracle.com> Cc: Stefan Richter <stefanr@s5r6.in-berlin.de> Cc: David Brownell <dbrownell@users.sourceforge.net> Cc: Vegard Nossum <vegard.nossum@gmail.com> Cc: Jesse Barnes <jbarnes@virtuousgeek.org> Cc: Alex Chiang <achiang@hp.com> Cc: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andrew Patterson <andrew.patterson@hp.com> Cc: Yu Zhao <yu.zhao@intel.com> Cc: Dominik Brodowski <linux@dominikbrodowski.net> Cc: Samuel Ortiz <sameo@linux.intel.com> Cc: Wolfram Sang <w.sang@pengutronix.de> Cc: CHENG Renquan <rqcheng@smu.edu.sg> Cc: Oliver Neukum <oliver@neukum.org> Cc: Frans Pop <elendil@planet.nl> Cc: David Vrabel <david.vrabel@csr.com> Cc: Kay Sievers <kay.sievers@vrfy.org> Cc: Sarah Sharp <sarah.a.sharp@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-03-06PM: Provide generic subsystem-level callbacksRafael J. Wysocki2-0/+234
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/+11
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: Start asynchronous resume threads upfrontRafael J. Wysocki1-19/+24
It has been shown by testing that total device resume time can be reduced significantly (by as much as 50% or more) if the async threads executing some devices' resume routines are all started before the main resume thread starts to handle the "synchronous" devices. This is a consequence of the fact that the slowest devices tend to be located at the end of dpm_list, so their resume routines are started very late. Consequently, they have to wait for all the preceding "synchronous" devices before their resume routines can be started by the main resume thread, even if they are "asynchronous". By starting their async threads upfront we effectively move those devices towards the beginning of dpm_list, without breaking their ordering with respect to their parents and children. As a result, their resume routines are started much earlier and we are able to save much more device resume time this way. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2010-02-26PM: Add facility for advanced testing of async suspend/resumeRafael J. Wysocki1-0/+49
Add configuration switch CONFIG_PM_ADVANCED_DEBUG for compiling in extra PM debugging/testing code allowing one to access some PM-related attributes of devices from the user space via sysfs. If CONFIG_PM_ADVANCED_DEBUG is set, add sysfs attribute power/async for every device allowing the user space to access the device's power.async_suspend flag and modify it, if desired. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2010-02-26PM: Add a switch for disabling/enabling asynchronous suspend/resumeRafael J. Wysocki2-6/+7
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>
2010-02-26PM: Asynchronous suspend and resume of devicesRafael J. Wysocki1-6/+109
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>