summaryrefslogtreecommitdiffstats
path: root/drivers/base/power (follow)
Commit message (Collapse)AuthorAgeFilesLines
* PM: Limit race conditions between runtime PM and system sleep (v2)Rafael J. Wysocki2011-07-061-12/+23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | One of the roles of the PM core is to prevent different PM callbacks executed for the same device object from racing with each other. Unfortunately, after commit e8665002477f0278f84f898145b1f141ba26ee26 (PM: Allow pm_runtime_suspend() to succeed during system suspend) runtime PM callbacks may be executed concurrently with system suspend/resume callbacks for the same device. The main reason for commit e8665002477f0278f84f898145b1f141ba26ee26 was that some subsystems and device drivers wanted to use runtime PM helpers, pm_runtime_suspend() and pm_runtime_put_sync() in particular, for carrying out the suspend of devices in their .suspend() callbacks. However, as it's been determined recently, there are multiple reasons not to do so, inlcuding: * The caller really doesn't control the runtime PM usage counters, because user space can access them through sysfs and effectively block runtime PM. That means using pm_runtime_suspend() or pm_runtime_get_sync() to suspend devices during system suspend may or may not work. * If a driver calls pm_runtime_suspend() from its .suspend() callback, it causes the subsystem's .runtime_suspend() callback to be executed, which leads to the call sequence: subsys->suspend(dev) driver->suspend(dev) pm_runtime_suspend(dev) subsys->runtime_suspend(dev) recursive from the subsystem's point of view. For some subsystems that may actually work (e.g. the platform bus type), but for some it will fail in a rather spectacular fashion (e.g. PCI). In each case it means a layering violation. * Both the subsystem and the driver can provide .suspend_noirq() callbacks for system suspend that can do whatever the .runtime_suspend() callbacks do just fine, so it really isn't necessary to call pm_runtime_suspend() during system suspend. * The runtime PM's handling of wakeup devices is usually different from the system suspend's one, so .runtime_suspend() may simply be inappropriate for system suspend. * System suspend is supposed to work even if CONFIG_PM_RUNTIME is unset. * The runtime PM workqueue is frozen before system suspend, so if whatever the driver is going to do during system suspend depends on it, that simply won't work. Still, there is a good reason to allow pm_runtime_resume() to succeed during system suspend and resume (for instance, some subsystems and device drivers may legitimately use it to ensure that their devices are in full-power states before suspending them). Moreover, there is no reason to prevent runtime PM callbacks from being executed in parallel with the system suspend/resume .prepare() and .complete() callbacks and the code removed by commit e8665002477f0278f84f898145b1f141ba26ee26 went too far in this respect. On the other hand, runtime PM callbacks, including .runtime_resume(), must not be executed during system suspend's "late" stage of suspending devices and during system resume's "early" device resume stage. Taking all of the above into consideration, make the PM core acquire a runtime PM reference to every device and resume it if there's a runtime PM resume request pending right before executing the subsystem-level .suspend() callback for it. Make the PM core drop references to all devices right after executing the subsystem-level .resume() callbacks for them. Additionally, make the PM core disable the runtime PM framework for all devices during system suspend, after executing the subsystem-level .suspend() callbacks for them, and enable the runtime PM framework for all devices during system resume, right before executing the subsystem-level .resume() callbacks for them. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Kevin Hilman <khilman@ti.com>
* 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: Rename clock management functionsRafael J. Wysocki2011-07-021-94/+94
| | | | | | | | | | | The common PM clock management functions may be used for system suspend/resume as well as for runtime PM, so rename them accordingly. Modify kerneldoc comments describing these functions and kernel messages printed by them, so that they refer to power management in general rather that to runtime PM. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Reviewed-by: Kevin Hilman <khilman@ti.com>
* PM: Allow the clocks management code to be used during system suspendRafael J. Wysocki2011-07-021-1/+59
| | | | | | | | | | | | | | | | | | The common clocks management code in drivers/base/power/clock_ops.c is going to be used during system-wide power transitions as well as for runtime PM, so it shouldn't depend on CONFIG_PM_RUNTIME. However, the suspend/resume functions provided by it for CONFIG_PM_RUNTIME unset, to be used during system-wide power transitions, should not behave in the same way as their counterparts defined for CONFIG_PM_RUNTIME set, because in that case the clocks are managed differently at run time. The names of the functions still contain the word "runtime" after this change, but that is going to be modified by a separate patch later. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Reviewed-by: Kevin Hilman <khilman@ti.com>
* PM / Domains: Wakeup devices support for system sleep transitionsRafael J. Wysocki2011-07-021-0/+8
| | | | | | | | | | | | | | | | | | | | | | | | There is the problem how to handle devices set up to wake up the system from sleep states during system-wide power transitions. In some cases, those devices can be turned off entirely, because the wakeup signals will be generated on their behalf anyway. In some other cases, they will generate wakeup signals if their clocks are stopped, but only if power is not removed from them. Finally, in some cases, they can only generate wakeup signals if power is not removed from them and their clocks are enabled. To allow platform-specific code to decide whether or not to put wakeup devices (and their PM domains) into low-power state during system-wide transitions, such as system suspend, introduce a new generic PM domain callback, .active_wakeup(), that will be used during the "noirq" phase of system suspend and hibernation (after image creation) to decide what to do with wakeup devices. Specifically, if this callback is present and returns "true", the generic PM domain code will not execute .stop_device() for the given wakeup device and its PM domain won't be powered off. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Kevin Hilman <khilman@ti.com>
* PM / Domains: System-wide transitions support for generic domains (v5)Rafael J. Wysocki2011-07-021-15/+536
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Make generic PM domains support system-wide power transitions (system suspend and hibernation). Add suspend, resume, freeze, thaw, poweroff and restore callbacks to be associated with struct generic_pm_domain objects and make pm_genpd_init() use them as appropriate. The new callbacks do nothing for devices belonging to power domains that were powered down at run time (before the transition). For the other devices the action carried out depends on the type of the transition. During system suspend the power domain .suspend() callback executes pm_generic_suspend() for the device, while the PM domain .suspend_noirq() callback runs pm_generic_suspend_noirq() for it, stops it and eventually removes power from the PM domain it belongs to (after all devices in the domain have been stopped and its subdomains have been powered off). During system resume the PM domain .resume_noirq() callback restores power to the PM domain (when executed for it first time), starts the device and executes pm_generic_resume_noirq() for it, while the .resume() callback executes pm_generic_resume() for the device. Finally, the .complete() callback executes pm_runtime_idle() for the device which should put it back into the suspended state if its runtime PM usage count is equal to zero at that time. The actions carried out during hibernation and resume from it are analogous to the ones described above. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Reviewed-by: Kevin Hilman <khilman@ti.com>
* PM / Domains: Move code from under #ifdef CONFIG_PM_RUNTIME (v2)Rafael J. Wysocki2011-07-021-55/+65
| | | | | | | | | There is some code in drivers/base/power/domain.c that will be useful for both runtime PM and system-wide power transitions, so make it depend on CONFIG_PM instead of CONFIG_PM_RUNTIME. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Reviewed-by: Kevin Hilman <khilman@ti.com>
* PM: Introduce generic "noirq" callback routines for subsystems (v2)Rafael J. Wysocki2011-07-021-15/+83
| | | | | | | | | | Introduce generic "noirq" power management callback routines for subsystems in addition to the "regular" generic PM callback routines. The new routines will be used, among other things, for implementing system-wide PM transitions support for generic PM domains. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
* PM / Domains: Support for generic I/O PM domains (v8)Rafael J. Wysocki2011-07-022-0/+495
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Introduce common headers, helper functions and callbacks allowing platforms to use simple generic power domains for runtime power management. Introduce struct generic_pm_domain to be used for representing power domains that each contain a number of devices and may be parent domains or subdomains with respect to other power domains. Among other things, this structure includes callbacks to be provided by platforms for performing specific tasks related to power management (i.e. ->stop_device() may disable a device's clocks, while ->start_device() may enable them, ->power_off() is supposed to remove power from the entire power domain and ->power_on() is supposed to restore it). Introduce functions that can be used as power domain runtime PM callbacks, pm_genpd_runtime_suspend() and pm_genpd_runtime_resume(), as well as helper functions for the initialization of a power domain represented by a struct generic_power_domain object, adding a device to or removing a device from it and adding or removing subdomains. Introduce configuration option CONFIG_PM_GENERIC_DOMAINS to be selected by the platforms that want to use the new code. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Greg Kroah-Hartman <gregkh@suse.de> Reviewed-by: Kevin Hilman <khilman@ti.com>
* PM / Domains: Rename struct dev_power_domain to struct dev_pm_domainRafael J. Wysocki2011-07-023-28/+28
| | | | | | | | | | | | | | | | | | 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 / Runtime: Handle clocks correctly if CONFIG_PM_RUNTIME is unsetRafael J. Wysocki2011-06-211-2/+2
| | | | | | | | | | | | | | | | | Commit 85eb8c8d0b0900c073b0e6f89979ac9c439ade1a (PM / Runtime: Generic clock manipulation rountines for runtime PM (v6)) converted the shmobile platform to using generic code for runtime PM clock management, but it changed the behavior for CONFIG_PM_RUNTIME unset incorrectly. Specifically, for CONFIG_PM_RUNTIME unset pm_runtime_clk_notify() should enable clocks for action equal to BUS_NOTIFY_BIND_DRIVER and it should disable them for action equal to BUS_NOTIFY_UNBOUND_DRIVER (instead of BUS_NOTIFY_ADD_DEVICE and BUS_NOTIFY_DEL_DEVICE, respectively). Make this function behave as appropriate. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Magnus Damm <damm@opensource.se>
* PM: Fix async resume following suspend failureAlan Stern2011-06-211-2/+12
| | | | | | | | | | | | | | | | | | | | | | | | | The PM core doesn't handle suspend failures correctly when it comes to asynchronously suspended devices. These devices are moved onto the dpm_suspended_list as soon as the corresponding async thread is started up, and they remain on the list even if they fail to suspend or the sleep transition is cancelled before they get suspended. As a result, when the PM core unwinds the transition, it tries to resume the devices even though they were never suspended. This patch (as1474) fixes the problem by adding a new "is_suspended" flag to dev_pm_info. Devices are resumed only if the flag is set. [rjw: * Moved the dev->power.is_suspended check into device_resume(), because we need to complete dev->power.completion and clear dev->power.is_prepared too for devices whose dev->power.is_suspended flags are unset. * Fixed __device_suspend() to avoid setting dev->power.is_suspended if async_error is different from zero.] Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Cc: stable@kernel.org
* PM: Rename dev_pm_info.in_suspend to is_preparedAlan Stern2011-06-211-5/+9
| | | | | | | | | | This patch (as1473) renames the "in_suspend" field in struct dev_pm_info to "is_prepared", in preparation for an upcoming change. The new name is more descriptive of what the field really means. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Cc: stable@kernel.org
* PM / Runtime: Fix loops in pm_runtime_clk_notify()Rafael J. Wysocki2011-06-071-8/+8
| | | | | | | | | | | | The loops over connection ID strings in pm_runtime_clk_notify() should actually iterate over the strings and not over the elements of the first of them, so make them behave as appropriate. This fixes a regression introduced by commit 600b776eb39a13a28b090 (OMAP1 / PM: Use generic clock manipulation routines for runtime PM). Reported-and-tested-by: Janusz Krzysztofik <jkrzyszt@tis.icnet.pl> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
* PM: Introduce generic prepare and complete callbacks for subsystemsRafael J. Wysocki2011-05-171-0/+39
| | | | | | | | | Introduce generic .prepare() and .complete() power management callbacks, currently missing, that can be used by subsystems and power domains and export them. Provide NULL definitions of all the generic system sleep callbacks for CONFIG_PM_SLEEP unset. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
* PM: Allow drivers to allocate memory from .prepare() callbacks safelyRafael J. Wysocki2011-05-171-6/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | If device drivers allocate substantial amounts of memory (above 1 MB) in their hibernate .freeze() callbacks (or in their legacy suspend callbcks during hibernation), the subsequent creation of hibernate image may fail due to the lack of memory. This is the case, because the drivers' .freeze() callbacks are executed after the hibernate memory preallocation has been carried out and the preallocated amount of memory may be too small to cover the new driver allocations. Unfortunately, the drivers' .prepare() callbacks also are executed after the hibernate memory preallocation has completed, so they are not suitable for allocating additional memory either. Thus the only way a driver can safely allocate memory during hibernation is to use a hibernate/suspend notifier. However, the notifiers are called before the freezing of user space and the drivers wanting to use them for allocating additional memory may not know how much memory needs to be allocated at that point. To let device drivers overcome this difficulty rework the hibernation sequence so that the memory preallocation is carried out after the drivers' .prepare() callbacks have been executed, so that the .prepare() callbacks can be used for allocating additional memory to be used by the drivers' .freeze() callbacks. Update documentation to match the new behavior of the code. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
* PM: Remove CONFIG_PM_VERBOSERafael J. Wysocki2011-05-171-2/+1
| | | | | | | | | | | Now that we have CONFIG_DYNAMIC_DEBUG there is no need for yet another flag causing dev_dbg() and pr_debug() statements in the core PM code to produce output. Moreover, CONFIG_PM_VERBOSE causes so much output to be generated that it's not really useful and almost no one sets it. References: https://bugzilla.kernel.org/show_bug.cgi?id=23182 Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
* Merge branch 'power-domains' into for-linusRafael J. Wysocki2011-05-174-52/+473
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | * power-domains: PM: Fix build issue in clock_ops.c for CONFIG_PM_RUNTIME unset PM: Revert "driver core: platform_bus: allow runtime override of dev_pm_ops" OMAP1 / PM: Use generic clock manipulation routines for runtime PM PM / Runtime: Generic clock manipulation rountines for runtime PM (v6) PM / Runtime: Add subsystem data field to struct dev_pm_info OMAP2+ / PM: move runtime PM implementation to use device power domains PM / Platform: Use generic runtime PM callbacks directly shmobile: Use power domains for platform runtime PM PM: Export platform bus type's default PM callbacks PM: Make power domain callbacks take precedence over subsystem ones
| * PM: Fix build issue in clock_ops.c for CONFIG_PM_RUNTIME unsetRafael J. Wysocki2011-05-161-0/+1
| | | | | | | | | | | | | | Fix a build issue in drivers/base/power/clock_ops.c occuring when CONFIG_PM_RUNTIME is not set. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
| * PM / Runtime: Generic clock manipulation rountines for runtime PM (v6)Rafael J. Wysocki2011-04-302-0/+431
| | | | | | | | | | | | | | | | | | | | | | | | Many different platforms and subsystems may want to disable device clocks during suspend and enable them during resume which is going to be done in a very similar way in all those cases. For this reason, provide generic routines for the manipulation of device clocks during suspend and resume. Convert the ARM shmobile platform to using the new routines. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
| * PM: Make power domain callbacks take precedence over subsystem onesRafael J. Wysocki2011-04-292-52/+41
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | PM / Wakeup: Remove useless synchronize_rcu() callEric Dumazet2011-05-171-1/+0
| | | | | | | | | | | | | | | | | | | | | | wakeup_source_add() adds an item into wakeup_sources list. There is no need to call synchronize_rcu() at this point. Its only needed in wakeup_source_remove() Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
* | PM / Wakeup: Fix build warning related to the "wakeup" sysfs fileRafael J. Wysocki2011-05-171-2/+2
|/ | | | | | | | | The "wakeup" device sysfs file is only created if CONFIG_PM_SLEEP is set, so put it under CONFIG_PM_SLEEP and make a build warning related to it go away. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
* PM / Wakeup: Fix initialization of wakeup-related device sysfs filesRafael J. Wysocki2011-04-262-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | It turns out that some PCI devices are only found to be wakeup-capable during registration, in which case, when device_set_wakeup_capable() is called, device_is_registered() already returns 'true' for the given device, but dpm_sysfs_add() hasn't been called for it yet. This leads to situations in which the device's power.can_wakeup flag is not set as requested because of failing wakeup_sysfs_add() and its wakeup-related sysfs files are not created, although they should be present. This is a post-2.6.38 regression introduced by commit cb8f51bdadb7969139c2e39c2defd4cde98c1 (PM: Do not create wakeup sysfs files for devices that cannot wake up). To work around this problem initialize the device's power.entry field to an empty list head and make device_set_wakeup_capable() check if it is still empty before attempting to add the devices wakeup-related sysfs files with wakeup_sysfs_add(). Namely, if power.entry is still empty at this point, device_pm_add() hasn't been called yet for the device and its wakeup-related files will be created later, so device_set_wakeup_capable() doesn't have to create them. Reported-and-tested-by: Tino Keitel <tino.keitel@tikei.de> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
* PM / Hibernate: Introduce CONFIG_HIBERNATE_CALLBACKSRafael J. Wysocki2011-04-111-4/+4
| | | | | | | | | | | | | | | | | | | | | Xen save/restore is going to use hibernate device callbacks for quiescing devices and putting them back to normal operations and it would need to select CONFIG_HIBERNATION for this purpose. However, that also would cause the hibernate interfaces for user space to be enabled, which might confuse user space, because the Xen kernels don't support hibernation. Moreover, it would be wasteful, as it would make the Xen kernels include a substantial amount of code that they would never use. To address this issue introduce new power management Kconfig option CONFIG_HIBERNATE_CALLBACKS, such that it will only select the code that is necessary for the hibernate device callbacks to work and make CONFIG_HIBERNATION select it. Then, Xen save/restore will be able to select CONFIG_HIBERNATE_CALLBACKS without dragging the entire hibernate code along with it. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Tested-by: Shriram Rajagopalan <rshriram@cs.ubc.ca>
* 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 / OPP: opp_find_freq_exact() documentation fixNishanth Menon2011-03-151-1/+1
| | | | | | | | | | | 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>
* PM: Make system-wide PM and runtime PM treat subsystems consistentlyRafael J. Wysocki2011-03-152-95/+73
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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. Wysocki2011-03-152-2/+54
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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: Allow pm_runtime_suspend() to succeed during system suspendRafael J. Wysocki2011-03-151-7/+3
| | | | | | | | | | | | | | | | | 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>
* PM: Remove CONFIG_PM_OPSRafael J. Wysocki2011-03-151-2/+1
| | | | | | | | 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>
* PM: Do not create wakeup sysfs files for devices that cannot wake upRafael J. Wysocki2011-03-153-38/+90
| | | | | | | | | | | | | | | | | 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>
* PM: Use appropriate printk() priority level in trace.cMandeep Singh Baines2011-03-151-3/+3
| | | | | | | | | | | | 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>
* PM / Wakeup: Don't update events_check_enabled in pm_get_wakeup_count()Rafael J. Wysocki2011-03-151-5/+2
| | | | | | | | | | | | | 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>
* PM / Wakeup: Make pm_save_wakeup_count() work as documentedRafael J. Wysocki2011-03-151-6/+6
| | | | | | | | | | | | | | | | | 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>
* PM / Wakeup: Combine atomic counters to avoid reordering issuesRafael J. Wysocki2011-03-151-22/+39
| | | | | | | | | | | | | | | | | | | 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>
* 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>
* Merge branch 'for-next' of ↵Linus Torvalds2011-01-131-1/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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.
| * Merge branch 'master' into for-nextJiri Kosina2010-12-221-4/+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.
| * | tree-wide: fix comment/printk typosUwe Kleine-König2010-11-011-1/+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>
* | | PM / Runtime: Generic resume shouldn't set RPM_ACTIVE unconditionallyRafael J. Wysocki2010-12-241-1/+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>
* | | PM: Use dev_name() in core device suspend and resume routinesRafael J. Wysocki2010-12-241-16/+9
| | | | | | | | | | | | | | | | | | Use dev_name() wherever applicable in drivers/base/power/main.c. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
* | | PM: Permit registration of parentless devices during system suspendRafael J. Wysocki2010-12-241-22/+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>
* | | PM: Replace the device power.status field with a bit fieldRafael J. Wysocki2010-12-241-12/+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>
* | | PM: Remove redundant checks from core device resume routinesRafael J. Wysocki2010-12-241-27/+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>
* | | PM: Use a different list of devices for each stage of device suspendRafael J. Wysocki2010-12-241-34/+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>
* | | PM: Avoid compiler warning in pm_noirq_op()Rafael J. Wysocki2010-12-241-1/+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>
* | | PM: Use pm_wakeup_pending() in __device_suspend()Rafael J. Wysocki2010-12-241-0/+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>
* | | PM / Wakeup: Replace pm_check_wakeup_events() with pm_wakeup_pending()Rafael J. Wysocki2010-12-242-11/+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>
* | | PM: Prevent dpm_prepare() from returning errors unnecessarilyRafael J. Wysocki2010-12-241-4/+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>