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* PM / Runtime: Asyncronous idle|suspend parent devices at removalUlf Hansson2013-04-121-1/+1
| | | | | | | | | | For irq safe devices return the runtime reference for the parent by using the asyncronous runtime PM API. Thus we don't have to wait for it to become idle|suspended. Instead we can move on and handle the next device in queue. Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* pm / runtime: force memory allocation with no I/O during Runtime PM callbcackMing Lei2013-02-231-1/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | Apply the introduced memalloc_noio_save() and memalloc_noio_restore() to force memory allocation with no I/O during runtime_resume/runtime_suspend callback on device with the flag of 'memalloc_noio' set. Signed-off-by: Ming Lei <ming.lei@canonical.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: David Decotigny <david.decotigny@google.com> Cc: Tom Herbert <therbert@google.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Jens Axboe <axboe@kernel.dk> Cc: Minchan Kim <minchan@kernel.org> Cc: Alan Stern <stern@rowland.harvard.edu> Cc: Oliver Neukum <oneukum@suse.de> Cc: Jiri Kosina <jiri.kosina@suse.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Cc: Greg KH <greg@kroah.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* pm / runtime: introduce pm_runtime_set_memalloc_noio()Ming Lei2013-02-231-0/+70
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Introduce the flag memalloc_noio in 'struct dev_pm_info' to help PM core to teach mm not allocating memory with GFP_KERNEL flag for avoiding probable deadlock. As explained in the comment, any GFP_KERNEL allocation inside runtime_resume() or runtime_suspend() on any one of device in the path from one block or network device to the root device in the device tree may cause deadlock, the introduced pm_runtime_set_memalloc_noio() sets or clears the flag on device in the path recursively. Signed-off-by: Ming Lei <ming.lei@canonical.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Alan Stern <stern@rowland.harvard.edu> Cc: Oliver Neukum <oneukum@suse.de> Cc: Jiri Kosina <jiri.kosina@suse.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Cc: Greg KH <greg@kroah.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: "David S. Miller" <davem@davemloft.net> Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: David Decotigny <david.decotigny@google.com> Cc: Tom Herbert <therbert@google.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* PM / Runtime: let rpm_resume() succeed if RPM_ACTIVE, even when disabled, v2Kevin Hilman2012-09-221-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There are several drivers where the return value of pm_runtime_get_sync() is used to decide whether or not it is safe to access hardware and that don't provide .suspend() callbacks for system suspend (but may use late/noirq callbacks.) If such a driver happens to call pm_runtime_get_sync() during system suspend, after the core has disabled runtime PM, it will get the error code and will decide that the hardware should not be accessed, although this may be a wrong conclusion, depending on the state of the device when runtime PM was disabled. Drivers might work around this problem by using a test like: ret = pm_runtime_get_sync(dev); if (!ret || (ret == -EACCES && driver_private_data(dev)->suspended)) { /* access hardware */ } where driver_private_data(dev)->suspended is a flag set by the driver's .suspend() method (that would have to be added for this purpose). However, that potentially would need to be done by multiple drivers which means quite a lot of duplicated code and bloat. To avoid that we can use the observation that the core sets dev->power.is_suspended before disabling runtime PM and use that instead of the driver's private flag. Still, potentially many drivers would need to repeat that same check in quite a few places, so it's better to let the core do it. Then we can be a bit smarter and check whether or not runtime PM was disabled by the core only (disable_depth == 1) or by someone else in addition to the core (disable_depth > 1). In the former case rpm_resume() can return 1 if the runtime PM status is RPM_ACTIVE, because it means the device was active when the core disabled runtime PM. In the latter case it should still return -EACCES, because it isn't clear why runtime PM has been disabled. Tested on AM3730/Beagle-xM where a wakeup IRQ firing during the late suspend phase triggers runtime PM activity in the I2C driver since the wakeup IRQ is on an I2C-connected PMIC. [rjw: Modified whitespace to follow the file's convention.] Signed-off-by: Kevin Hilman <khilman@ti.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
* PM / Runtime: Check device PM QoS setting before "no callbacks" checkRafael J. Wysocki2012-08-171-6/+2
| | | | | | | | | | | | | If __dev_pm_qos_read_value(dev) returns a negative value, rpm_suspend() should return -EPERM for dev even if its power.no_callbacks flag is set. For this to happen, the device's power.no_callbacks flag has to be checked after the PM QoS check, so move the PM QoS check to rpm_check_suspend_allowed() (this will make it cover idle notifications as well as runtime suspend too). Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Alan Stern <stern@rowland.harvard.edu> Cc: stable@vger.kernel.org
* PM / Runtime: Clear power.deferred_resume on success in rpm_suspend()Rafael J. Wysocki2012-08-171-1/+1
| | | | | | | | | | | | | | | | | | | | The power.deferred_resume can only be set if the runtime PM status of device is RPM_SUSPENDING and it should be cleared after its status has been changed, regardless of whether or not the runtime suspend has been successful. However, it only is cleared on suspend failure, while it may remain set on successful suspend and is happily leaked to rpm_resume() executed in that case. That shouldn't happen, so if power.deferred_resume is set in rpm_suspend() after the status has been changed to RPM_SUSPENDED, clear it before calling rpm_resume(). Then, it doesn't need to be cleared before changing the status to RPM_SUSPENDING any more, because it's always cleared after the status has been changed to either RPM_SUSPENDED (on success) or RPM_ACTIVE (on failure). Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Alan Stern <stern@rowland.harvard.edu> Cc: stable@vger.kernel.org
* PM / Runtime: Fix rpm_resume() return value for power.no_callbacks setRafael J. Wysocki2012-08-171-1/+2
| | | | | | | | | | | | | | | | For devices whose power.no_callbacks flag is set, rpm_resume() should return 1 if the device's parent is already active, so that the callers of pm_runtime_get() don't think that they have to wait for the device to resume (asynchronously) in that case (the core won't queue up an asynchronous resume in that case, so there's nothing to wait for anyway). Modify the code accordingly (and make sure that an idle notification will be queued up on success, even if 1 is to be returned). Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Alan Stern <stern@rowland.harvard.edu> Cc: stable@vger.kernel.org
* PM / Runtime: Remove device fields related to suspend time, v2Rafael J. Wysocki2012-05-011-101/+2
| | | | | | | | | | | | After the previous changes in default_stop_ok() and default_power_down_ok() for PM domains, there are two fields in struct dev_pm_info that aren't necessary any more, suspend_time and max_time_suspended_ns. Remove those fields along with all of the code that accesses them, which simplifies the runtime PM framework quite a bit. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
* PM / Runtime: don't forget to wake up waitqueue on failureAlan Stern2012-03-261-1/+2
| | | | | | | | | | | | | | | | This patch (as1535) fixes a bug in the runtime PM core. When a runtime suspend attempt completes, whether successfully or not, the device's power.wait_queue is supposed to be signalled. But this doesn't happen in the failure pathway of rpm_suspend() when another autosuspend attempt is rescheduled. As a result, a task can get stuck indefinitely on the wait queue (I have seen this happen in testing). The patch fixes the problem by moving the wake_up_all() call up near the start of the failure code. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> CC: <stable@vger.kernel.org> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
* Merge branch 'pm-runtime' into pm-for-linusRafael J. Wysocki2011-12-251-20/+128
|\ | | | | | | | | * pm-runtime: PM / Runtime: Use device PM QoS constraints (v2)
| * PM / Runtime: Use device PM QoS constraints (v2)Rafael J. Wysocki2011-12-011-20/+128
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Make the runtime PM core use device PM QoS constraints to check if it is allowed to suspend a given device, so that an error code is returned if the device's own PM QoS constraint is negative or one of its children has already been suspended for too long. If this is not the case, the maximum estimated time the device is allowed to be suspended, computed as the minimum of the device's PM QoS constraint and the PM QoS constraints of its children (reduced by the difference between the current time and their suspend times) is stored in a new device's PM field power.max_time_suspended_ns that can be used by the device's subsystem or PM domain to decide whether or not to put the device into lower-power (and presumably higher-latency) states later (if the constraint is 0, which means "no constraint", the power.max_time_suspended_ns is set to -1). Additionally, the time of execution of the subsystem-level .runtime_suspend() callback for the device is recorded in the new power.suspend_time field for later use by the device's subsystem or PM domain along with power.max_time_suspended_ns (it also is used by the core code when the device's parent is suspended). Introduce a new helper function, pm_runtime_update_max_time_suspended(), allowing subsystems and PM domains (or device drivers) to update the power.max_time_suspended_ns field, for example after changing the power state of a suspended device. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
* | PM: Run the driver callback directly if the subsystem one is not thereRafael J. Wysocki2011-12-211-0/+9
|/ | | | | | | | | | | | | | | | | | | | | Make the PM core execute driver PM callbacks directly if the corresponding subsystem callbacks are not present. There are three reasons for doing that. First, it reflects the behavior of drivers/base/dd.c:really_probe() that runs the driver's .probe() callback directly if the bus type's one is not defined, so this change will remove one arbitrary difference between the PM core and the remaining parts of the driver core. Second, it will allow some subsystems, whose PM callbacks don't do anything except for executing driver callbacks, to be simplified quite a bit by removing those "forward-only" callbacks. Finally, it will allow us to remove one level of indirection in the system suspend and resume code paths where it is not necessary, which is going to lead to less debug noise with initcall_debug passed in the kernel command line (messages won't be printed for driverless devices whose subsystems don't provide PM callbacks among other things). Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
* Merge branch 'modsplit-Oct31_2011' of ↵Linus Torvalds2011-11-061-0/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux * 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux: (230 commits) Revert "tracing: Include module.h in define_trace.h" irq: don't put module.h into irq.h for tracking irqgen modules. bluetooth: macroize two small inlines to avoid module.h ip_vs.h: fix implicit use of module_get/module_put from module.h nf_conntrack.h: fix up fallout from implicit moduleparam.h presence include: replace linux/module.h with "struct module" wherever possible include: convert various register fcns to macros to avoid include chaining crypto.h: remove unused crypto_tfm_alg_modname() inline uwb.h: fix implicit use of asm/page.h for PAGE_SIZE pm_runtime.h: explicitly requires notifier.h linux/dmaengine.h: fix implicit use of bitmap.h and asm/page.h miscdevice.h: fix up implicit use of lists and types stop_machine.h: fix implicit use of smp.h for smp_processor_id of: fix implicit use of errno.h in include/linux/of.h of_platform.h: delete needless include <linux/module.h> acpi: remove module.h include from platform/aclinux.h miscdevice.h: delete unnecessary inclusion of module.h device_cgroup.h: delete needless include <linux/module.h> net: sch_generic remove redundant use of <linux/module.h> net: inet_timewait_sock doesnt need <linux/module.h> ... Fix up trivial conflicts (other header files, and removal of the ab3550 mfd driver) in - drivers/media/dvb/frontends/dibx000_common.c - drivers/media/video/{mt9m111.c,ov6650.c} - drivers/mfd/ab3550-core.c - include/linux/dmaengine.h
| * drivers/base: Add export.h for EXPORT_SYMBOL/THIS_MODULE as required.Paul Gortmaker2011-10-311-0/+1
| | | | | | | | | | | | | | | | | | | | Most of these files were implicitly getting EXPORT_SYMBOL via device.h which was including module.h, but that path will be broken soon. [ with input from Stephen Rothwell <sfr@canb.auug.org.au> ] Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
* | PM / Runtime: Automatically retry failed autosuspendsAlan Stern2011-11-041-2/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Originally, the runtime PM core would send an idle notification whenever a suspend attempt failed. The idle callback routine could then schedule a delayed suspend for some time later. However this behavior was changed by commit f71648d73c1650b8b4aceb3856bebbde6daa3b86 (PM / Runtime: Remove idle notification after failing suspend). No notifications were sent, and there was no clear mechanism to retry failed suspends. This caused problems for the usbhid driver, because it fails autosuspend attempts as long as a key is being held down. Therefore this patch (as1492) adds a mechanism for retrying failed autosuspends. If the callback routine updates the last_busy field so that the next autosuspend expiration time is in the future, the autosuspend will automatically be rescheduled. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Tested-by: Henrik Rydberg <rydberg@euromail.se> Cc: <stable@kernel.org> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
* | PM / Runtime: Fix runtime accounting calculation errorvenu byravarasu2011-11-041-4/+1
|/ | | | | | | | | With delta type being int, its value is made zero for all values of now > 0x80000000. Hence fixing it. Signed-off-by: venu byravarasu <vbyravarasu@nvidia.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
* PM / Runtime: Handle .runtime_suspend() failure correctlyMing Lei2011-10-161-12/+13
| | | | | | | | | | | | | | | | | If .runtime_suspend() returns -EAGAIN or -EBUSY, the device should still be in ACTIVE state, so it is not necessary to send an idle notification to its parent. If .runtime_suspend() returns other fatal failure, it doesn't make sense to send idle notification to its parent. Skip parent idle notification when failure is returned from .runtime_suspend() and update comments in rpm_suspend() to reflect that change. [rjw: Modified the subject and changelog slightly.] Signed-off-by: Ming Lei <ming.lei@canonical.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
* PM / Runtime: Fix kerneldoc comment for rpm_suspend()Ming Lei2011-10-161-8/+10
| | | | | | | | | | | | | | | | This patch fix kerneldoc comments for rpm_suspend(): - 'Cancel a pending idle notification' should be put before, also should be changed to 'Cancel a pending idle notification, autosuspend or suspend'. - idle notification for the device after succeeding suspend has been removed, so update the comment accordingly. [rjw: Modified the subject and changelog slightly.] Signed-off-by: Ming Lei <ming.lei@canonical.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
* PM / Runtime: Replace dev_dbg() with trace_rpm_*()Ming Lei2011-09-271-4/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch replaces dev_dbg with trace_rpm_* inside the three important functions: rpm_idle rpm_suspend rpm_resume Trace points have the below advantages compared with dev_dbg: - trace points include much runtime information(such as running cpu, current task, ...) - most of linux distributions may disable "verbose debug" driver debug compile switch, so it is very difficult to report/debug runtime pm related problems from distribution users without this kind of debug information. - for upstream kernel users, enableing the debug switch will produce many useless "rpm_resume" output, and it is very noise. - dev_dbg inside rpm_suspend/rpm_resume may have some effects on runtime pm behaviour of console devicer Signed-off-by: Ming Lei <ming.lei@canonical.com> Acked-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
* PM / Runtime: Don't run callbacks under lock for power.irq_safe setRafael J. Wysocki2011-09-271-22/+46
| | | | | | | | | | | | | | | | | | | | The rpm_suspend() and rpm_resume() routines execute subsystem or PM domain callbacks under power.lock if power.irq_safe is set for the given device. This is inconsistent with that rpm_idle() does after commit 02b2677 (PM / Runtime: Allow _put_sync() from interrupts-disabled context) and is problematic for subsystems and PM domains wanting to use power.lock for synchronization in their runtime PM callbacks. This change requires the code checking if the device's runtime PM status is RPM_SUSPENDING or RPM_RESUMING to be modified too, to take the power.irq_safe set case into account (that code wasn't reachable before with power.irq_safe set, because it's executed with the device's power.lock held). Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Reviewed-by: Ming Lei <tom.leiming@gmail.com> Reviewed-by: Kevin Hilman <khilman@ti.com>
* PM / Runtime: Add might_sleep() to runtime PM functionsColin Cross2011-08-141-3/+12
| | | | | | | | | | | | | | | | | | | | | | | Some of the entry points to pm runtime are not safe to call in atomic context unless pm_runtime_irq_safe() has been called. Inspecting the code, it is not immediately obvious that the functions sleep at all, as they run inside a spin_lock_irqsave, but under some conditions they can drop the lock and turn on irqs. If a driver incorrectly calls the pm_runtime apis, it can cause sleeping and irq processing when it expects to stay in atomic context. Add might_sleep_if to the majority of the __pm_runtime_* entry points to enforce correct usage. Add pm_runtime_put_sync_autosuspend to the list of functions that can be called in atomic context. Signed-off-by: Colin Cross <ccross@android.com> Reviewed-by: Kevin Hilman <khilman@ti.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
* PM / Runtime: Allow _put_sync() from interrupts-disabled contextKevin Hilman2011-08-051-2/+8
| | | | | | | | | | | | | | | | | | | | | | | | | Currently the use of pm_runtime_put_sync() is not safe from interrupts-disabled context because rpm_idle() will release the spinlock and enable interrupts for the idle callbacks. This enables interrupts during a time where interrupts were expected to be disabled, and can have strange side effects on drivers that expected interrupts to be disabled. This is not a bug since the documentation clearly states that only _put_sync_suspend() is safe in IRQ-safe mode. However, pm_runtime_put_sync() could be made safe when in IRQ-safe mode by releasing the spinlock but not re-enabling interrupts, which is what this patch aims to do. Problem was found when using some buggy drivers that set pm_runtime_irq_safe() and used _put_sync() in interrupts-disabled context. Reported-by: Colin Cross <ccross@google.com> Tested-by: Nishanth Menon <nm@ti.com> Signed-off-by: Kevin Hilman <khilman@ti.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
* PM / Runtime: Consistent utilization of deferred_resumeShuoX Liu2011-07-081-1/+1
| | | | | | | dev->power.deferred_resume is used as a bool typically, so change one assignment to false from 0, like other places. Signed-off-by: ShuoX Liu <shuox.liu@intel.com>
* PM / Runtime: Replace "run-time" with "runtime" in documentationRafael J. Wysocki2011-07-061-33/+33
| | | | | | | | The runtime PM documentation and kerneldoc comments sometimes spell "runtime" with a dash (i.e. "run-time"). Replace all of those instances with "runtime" to make the naming consistent. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
* PM / Runtime: Return special error code if runtime PM is disabledRafael J. Wysocki2011-07-021-4/+5
| | | | | | | | | | | | | | | Some callers of pm_runtime_get_sync() and other runtime PM helper functions, scsi_autopm_get_host() and scsi_autopm_get_device() in particular, need to distinguish error codes returned when runtime PM is disabled (i.e. power.disable_depth is nonzero for the given device) from error codes returned in other situations. For this reason, make the runtime PM helper functions return -EACCES when power.disable_depth is nonzero and ensure that this error code won't be returned by them in any other circumstances. Modify scsi_autopm_get_host() and scsi_autopm_get_device() to check the error code returned by pm_runtime_get_sync() and ignore -EACCES. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
* PM / Domains: Rename struct dev_power_domain to struct dev_pm_domainRafael J. Wysocki2011-07-021-6/+6
| | | | | | | | | | | | | | | | | | The naming convention used by commit 7538e3db6e015e890825fbd9f86599b (PM: Add support for device power domains), which introduced the struct dev_power_domain type for representing device power domains, evidently confuses some developers who tend to think that objects of this type must correspond to "power domains" as defined by hardware, which is not the case. Namely, at the kernel level, a struct dev_power_domain object can represent arbitrary set of devices that are mutually dependent power management-wise and need not belong to one hardware power domain. To avoid that confusion, rename struct dev_power_domain to struct dev_pm_domain and rename the related pointers in struct device and struct pm_clk_notifier_block from pwr_domain to pm_domain. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Kevin Hilman <khilman@ti.com>
* PM: Make power domain callbacks take precedence over subsystem onesRafael J. Wysocki2011-04-291-19/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Change the PM core's behavior related to power domains in such a way that, if a power domain is defined for a given device, its callbacks will be executed instead of and not in addition to the device subsystem's PM callbacks. The idea behind the initial implementation of power domains handling by the PM core was that power domain callbacks would be executed in addition to subsystem callbacks, so that it would be possible to extend the subsystem callbacks by using power domains. It turns out, however, that this wouldn't be really convenient in some important situations. For example, there are systems in which power can only be removed from entire power domains. On those systems it is not desirable to execute device drivers' PM callbacks until it is known that power is going to be removed from the devices in question, which means that they should be executed by power domain callbacks rather then by subsystem (e.g. bus type) PM callbacks, because subsystems generally have no information about what devices belong to which power domain. Thus, for instance, if the bus type in question is the platform bus type, its PM callbacks generally should not be called in addition to power domain callbacks, because they run device drivers' callbacks unconditionally if defined. While in principle the default subsystem PM callbacks, or a subset of them, may be replaced with different functions, it doesn't seem correct to do so, because that would change the subsystem's behavior with respect to all devices in the system, regardless of whether or not they belong to any power domains. Thus, the only remaining option is to make power domain callbacks take precedence over subsystem callbacks. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Kevin Hilman <khilman@ti.com>
* Fix common misspellingsLucas De Marchi2011-03-311-1/+1
| | | | | | Fixes generated by 'codespell' and manually reviewed. Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
* PM: Make system-wide PM and runtime PM treat subsystems consistentlyRafael J. Wysocki2011-03-151-9/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* PM: Add support for device power domainsRafael J. Wysocki2011-03-151-2/+17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* PM / Runtime: Don't enable interrupts while running in_interruptAlan Stern2011-01-251-3/+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>
* PM / Runtime: Add synchronous runtime interface for interrupt handlers (v3)Alan Stern2010-12-241-9/+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>
* PM / Runtime: Fix typo in status comparison causing warningKevin Winchester2010-10-291-1/+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>
* PM / Runtime: fix recursive locking warning of lockdep from rpm_resume()Ming Lei2010-10-221-1/+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>
* PM / Runtime: Remove idle notification after failing suspendRafael J. Wysocki2010-10-171-9/+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>
* PM / Runtime: Reduce code duplication in core helper functionsRafael J. Wysocki2010-10-171-68/+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>
* PM / Runtime: Implement autosuspend supportAlan Stern2010-10-171-7/+179
| | | | | | | | | | | | | | | | | | | 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>
* PM / Runtime: Add no_callbacks flagAlan Stern2010-10-171-1/+53
| | | | | | | | | | | | | | | | | | | 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>
* PM / Runtime: Combine runtime PM entry pointsAlan Stern2010-10-171-110/+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>
* PM / Runtime: Merge synchronous and async runtime routinesAlan Stern2010-10-171-235/+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>
* PM / Runtime: Replace boolean arguments with bitflagsAlan Stern2010-10-171-36/+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>
* PM / Runtime: Move code in drivers/base/power/runtime.cAlan Stern2010-10-171-39/+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>
* PM / Wakeup: Introduce wakeup source objects and event statistics (v3)Rafael J. Wysocki2010-10-171-2/+0
| | | | | | | | | | | | | | | | | | | | | | 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>
* PM / Runtime: Add runtime PM statistics (v3)Arjan van de Ven2010-07-191-7/+47
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* PM: Allow runtime_suspend methods to call pm_schedule_suspend()Alan Stern2010-05-101-5/+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>
* PM / Runtime: Add sysfs switch for disabling device run-time PMRafael J. Wysocki2010-02-261-0/+45
| | | | | | | | | | | | 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>
* PM / Runtime: Use device type and device class callbacksRafael J. Wysocki2009-12-221-0/+45
| | | | | | | | | | | | | 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>
* PM: allow for usage_count > 0 in pm_runtime_get()Alan Stern2009-12-151-5/+5
| | | | | | | | | | 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>
* PM / Runtime: Remove unnecessary braces in __pm_runtime_set_status()Rafael J. Wysocki2009-12-061-5/+3
| | | | | | | Some braces in __pm_runtime_set_status() are not necessary, so remove them. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
* PM / Runtime: Ensure timer_expires is nonzero in pm_schedule_suspend()Rafael J. Wysocki2009-12-061-0/+2
| | | | | | | | | | | 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>
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