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path: root/include/linux/pm_qos.h
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2012-10-24PM / QoS: Make it possible to expose PM QoS device flags to user spaceRafael J. Wysocki1-0/+26
Define two device PM QoS flags, PM_QOS_FLAG_NO_POWER_OFF and PM_QOS_FLAG_REMOTE_WAKEUP, and introduce routines dev_pm_qos_expose_flags() and dev_pm_qos_hide_flags() allowing the caller to expose those two flags to user space or to hide them from it, respectively. After the flags have been exposed, user space will see two additional sysfs attributes, pm_qos_no_power_off and pm_qos_remote_wakeup, under the device's /sys/devices/.../power/ directory. Then, writing 1 to one of them will update the PM QoS flags request owned by user space so that the corresponding flag is requested to be set. In turn, writing 0 to one of them will cause the corresponding flag in the user space's request to be cleared (however, the owners of the other PM QoS flags requests for the same device may still request the flag to be set and it may be effectively set even if user space doesn't request that). Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Jean Pihet <j-pihet@ti.com> Acked-by: mark gross <markgross@thegnar.org>
2012-10-23PM / QoS: Introduce PM QoS device flags supportRafael J. Wysocki1-1/+25
Modify the device PM QoS core code to support PM QoS flags requests. First, add a new field of type struct pm_qos_flags called "flags" to struct dev_pm_qos for representing the list of PM QoS flags requests for the given device. Accordingly, add a new "type" field to struct dev_pm_qos_request (along with an enum for representing request types) and a new member called "flr" to its data union for representig flags requests. Second, modify dev_pm_qos_add_request(), dev_pm_qos_update_request(), the internal routine apply_constraint() used by them and their existing callers to cover flags requests as well as latency requests. In particular, dev_pm_qos_add_request() gets a new argument called "type" for specifying the type of a request to be added. Finally, introduce two routines, __dev_pm_qos_flags() and dev_pm_qos_flags(), allowing their callers to check which PM QoS flags have been requested for the given device (the caller is supposed to pass the mask of flags to check as the routine's second argument and examine its return value for the result). Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Jean Pihet <j-pihet@ti.com> Reviewed-by: mark gross <markgross@thegnar.org>
2012-10-23PM / QoS: Prepare struct dev_pm_qos_request for more request typesRafael J. Wysocki1-1/+3
The subsequent patches will use struct dev_pm_qos_request for representing both latency requests and flags requests. To make that easier, put the node member of struct dev_pm_qos_request (under the name "pnode") into a union called "data" that will represent the request's value and list node depending on its type. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Jean Pihet <j-pihet@ti.com> Reviewed-by: mark gross <markgross@thegnar.org>
2012-10-23PM / QoS: Introduce request and constraint data types for PM QoS flagsRafael J. Wysocki1-2/+15
Introduce struct pm_qos_flags_request and struct pm_qos_flags representing PM QoS flags request type and PM QoS flags constraint type, respectively. With these definitions the data structures will be arranged so that the list member of a struct pm_qos_flags object will contain the head of a list of struct pm_qos_flags_request objects representing all of the "flags" requests present for the given device. Then, the effective_flags member of a struct pm_qos_flags object will contain the bitwise OR of the flags members of all the struct pm_qos_flags_request objects in the list. Additionally, introduce helper function pm_qos_update_flags() allowing the caller to manage the list of struct pm_qos_flags_request pointed to by the list member of struct pm_qos_flags. The flags are of type s32 so that the request's "value" field is always of the same type regardless of what kind of request it is (latency requests already have value fields of type s32). Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Jean Pihet <j-pihet@ti.com> Acked-by: mark gross <markgross@thegnar.org>
2012-10-23PM / QoS: Prepare device structure for adding more constraint typesRafael J. Wysocki1-0/+4
Currently struct dev_pm_info contains only one PM QoS constraints pointer reserved for latency requirements. Since one more device constraints type (i.e. flags) will be necessary, introduce a new structure, struct dev_pm_qos, that eventually will contain all of the available device PM QoS constraints and replace the "constraints" pointer in struct dev_pm_info with a pointer to the new structure called "qos". Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Jean Pihet <j-pihet@ti.com>
2012-07-19PM / QoS: Use NULL pointer instead of plain integer in pm_qos.hSachin Kamat1-1/+1
Fix the following sparse warning: include/linux/pm_qos.h:69:28: warning: Using plain integer as NULL pointer Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2012-03-29PM / QoS: add pm_qos_update_request_timeout() APIMyungJoo Ham1-0/+4
The new API, pm_qos_update_request_timeout() is to provide a timeout with pm_qos_update_request. For example, pm_qos_update_request_timeout(req, 100, 1000), means that QoS request on req with value 100 will be active for 1000 microseconds. After 1000 microseconds, the QoS request thru req is reset. If there were another pm_qos_update_request(req, x) during the 1000 us, this new request with value x will override as this is another request on the same req handle. A new request on the same req handle will always override the previous request whether it is the conventional request or it is the new timeout request. Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com> Acked-by: Mark Gross <markgross@thegnar.org> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2012-03-14PM / QoS: Make it possible to expose PM QoS latency constraintsRafael J. Wysocki1-0/+9
A runtime suspend of a device (e.g. an MMC controller) belonging to a power domain or, in a more complicated scenario, a runtime suspend of another device in the same power domain, may cause power to be removed from the entire domain. In that case, the amount of time necessary to runtime-resume the given device (e.g. the MMC controller) is often substantially greater than the time needed to run its driver's runtime resume callback. That may hurt performance in some situations, because user data may need to wait for the device to become operational, so we should make it possible to prevent that from happening. For this reason, introduce a new sysfs attribute for devices, power/pm_qos_resume_latency_us, allowing user space to specify the upper bound of the time necessary to bring the (runtime-suspended) device up after the resume of it has been requested. However, make that attribute appear only for the devices whose drivers declare support for it by calling the (new) dev_pm_qos_expose_latency_limit() helper function with the appropriate initial value of the attribute. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Reviewed-by: Kevin Hilman <khilman@ti.com> Reviewed-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Acked-by: Linus Walleij <linus.walleij@linaro.org>
2012-02-13PM / QoS: unconditionally build the featureJean Pihet1-40/+1
The PM QoS feature originally didn't depend on CONFIG_PM, which was mistakenly changed by commit e8db0be1245de16a6cc6365506abc392c3c212d4 PM QoS: Move and rename the implementation files Later, commit d020283dc694c9ec31b410f522252f7a8397e67d PM / QoS: CPU C-state breakage with PM Qos change partially fixed that by introducing a static inline definition of pm_qos_request(), but that still didn't allow user space to use the PM QoS interface if CONFIG_PM was unset (which had been possible before). For this reason, remove the dependency of PM QoS on CONFIG_PM to make it work (as intended) with CONFIG_PM unset. [rjw: Replaced the original changelog with a new one.] Signed-off-by: Jean Pihet <j-pihet@ti.com> Reported-by: Venkatesh Pallipadi <venki@google.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2012-02-13Merge commit 'pm-fixes-for-3.3-rc3' into pm-qosRafael J. Wysocki1-1/+13
New material in the pm-qos branch depends on recent power management fixes.
2012-02-05PM / QoS: CPU C-state breakage with PM Qos changeVenkatesh Pallipadi1-1/+13
Looks like change "PM QoS: Move and rename the implementation files" merged during the 3.2 development cycle made PM QoS depend on CONFIG_PM which depends on (PM_SLEEP || PM_RUNTIME). That breaks CPU C-states with kernels not having these CONFIGs, causing CPUs to spend time in Polling loop idle instead of going into deep C-states, consuming way way more power. This is with either acpi idle or intel idle enabled. Either CONFIG_PM should be enabled with any pm_qos users or the !CONFIG_PM pm_qos_request() should return sane defaults not to break the existing users. Here's is the patch for the latter option. [rjw: Modified the changelog slightly.] Signed-off-by: Venkatesh Pallipadi <venki@google.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Cc: stable@vger.kernel.org
2012-01-29PM / QoS: Simplify PM QoS expansion/mergeAlex Frid1-5/+9
- Replace class ID #define with enumeration - Loop through PM QoS objects during initialization (rather than initializing them one-by-one) Signed-off-by: Alex Frid <afrid@nvidia.com> Reviewed-by: Antti Miettinen <amiettinen@nvidia.com> Reviewed-by: Diwakar Tundlam <dtundlam@nvidia.com> Reviewed-by: Scott Williams <scwilliams@nvidia.com> Reviewed-by: Yu-Huan Hsu <yhsu@nvidia.com> Acked-by: markgross <markgross@thegnar.org> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-12-26Merge branch 'pm-domains' into pm-for-linusRafael J. Wysocki1-0/+5
* pm-domains: PM / shmobile: Allow the A4R domain to be turned off at run time PM / input / touchscreen: Make st1232 use device PM QoS constraints PM / QoS: Introduce dev_pm_qos_add_ancestor_request() PM / shmobile: Remove the stay_on flag from SH7372's PM domains PM / shmobile: Don't include SH7372's INTCS in syscore suspend/resume PM / shmobile: Add support for the sh7372 A4S power domain / sleep mode ARM: S3C64XX: Implement basic power domain support PM / shmobile: Use common always on power domain governor PM / Domains: Provide an always on power domain governor PM / Domains: Fix default system suspend/resume operations PM / Domains: Make it possible to assign names to generic PM domains PM / Domains: fix compilation failure for CONFIG_PM_GENERIC_DOMAINS unset PM / Domains: Automatically update overoptimistic latency information PM / Domains: Add default power off governor function (v4) PM / Domains: Add device stop governor function (v4) PM / Domains: Rework system suspend callback routines (v2) PM / Domains: Introduce "save/restore state" device callbacks PM / Domains: Make it possible to use per-device domain callbacks
2011-12-26PM / QoS: Introduce dev_pm_qos_add_ancestor_request()Rafael J. Wysocki1-0/+5
Some devices, like the I2C controller on SH7372, are not necessary for providing power to their children or forwarding wakeup signals (and generally interrupts) from them. They are only needed by their children when there's some data to transfer, so they may be suspended for the majority of time and resumed on demand, when the children have data to send or receive. For this purpose, however, their power.ignore_children flags have to be set, or the PM core wouldn't allow them to be suspended while their children were active. Unfortunately, in some situations it may take too much time to resume such devices so that they can assist their children in transferring data. For example, if such a device belongs to a PM domain which goes to the "power off" state when that device is suspended, it may take too much time to restore power to the domain in response to the request from one of the device's children. In that case, if the parent's resume time is critical, the domain should stay in the "power on" state, although it still may be desirable to power manage the parent itself (e.g. by manipulating its clock). In general, device PM QoS may be used to address this problem. Namely, if the device's children added PM QoS latency constraints for it, they would be able to prevent it from being put into an overly deep low-power state. However, in some cases the devices needing to be serviced are not the immediate children of a "children-ignoring" device, but its grandchildren or even less direct descendants. In those cases, the entity wanting to add a PM QoS request for a given device's ancestor that ignores its children will have to find it in the first place, so introduce a new helper function that may be used to achieve that. This function, dev_pm_qos_add_ancestor_request(), will search for the first ancestor of the given device whose power.ignore_children flag is set and will add a device PM QoS latency request for that ancestor on behalf of the caller. The request added this way may be removed with the help of dev_pm_qos_remove_request() in the future, like any other device PM QoS latency request. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-12-02PM / Runtime: Use device PM QoS constraints (v2)Rafael J. Wysocki1-0/+3
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>
2011-10-04PM / QoS: Add function dev_pm_qos_read_value() (v3)Rafael J. Wysocki1-2/+10
To read the current PM QoS value for a given device we need to make sure that the device's power.constraints object won't be removed while we're doing that. For this reason, put the operation under dev->power.lock and acquire the lock around the initialization and removal of power.constraints. Moreover, since we're using the value of power.constraints to determine whether or not the object is present, the power.constraints_state field isn't necessary any more and may be removed. However, dev_pm_qos_add_request() needs to check if the device is being removed from the system before allocating a new PM QoS constraints object for it, so make it use the power.power_state field of struct device for this purpose. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-08-25PM QoS: Add global notification mechanism for device constraintsJean Pihet1-0/+11
Add a global notification chain that gets called upon changes to the aggregated constraint value for any device. The notification callbacks are passing the full constraint request data in order for the callees to have access to it. The current use is for the platform low-level code to access the target device of the constraint. Signed-off-by: Jean Pihet <j-pihet@ti.com> Reviewed-by: Kevin Hilman <khilman@ti.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-08-25PM QoS: Implement per-device PM QoS constraintsJean Pihet1-0/+42
Implement the per-device PM QoS constraints by creating a device PM QoS API, which calls the PM QoS constraints management core code. The per-device latency constraints data strctures are stored in the device dev_pm_info struct. The device PM code calls the init and destroy of the per-device constraints data struct in order to support the dynamic insertion and removal of the devices in the system. To minimize the data usage by the per-device constraints, the data struct is only allocated at the first call to dev_pm_qos_add_request. The data is later free'd when the device is removed from the system. A global mutex protects the constraints users from the data being allocated and free'd. Signed-off-by: Jean Pihet <j-pihet@ti.com> Reviewed-by: Kevin Hilman <khilman@ti.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-08-25PM QoS: Generalize and export constraints management codeJean Pihet1-0/+14
In preparation for the per-device constratins support: - rename update_target to pm_qos_update_target - generalize and export pm_qos_update_target for usage by the upcoming per-device latency constraints framework: * operate on struct pm_qos_constraints for constraints management, * introduce an 'action' parameter for constraints add/update/remove, * the return value indicates if the aggregated constraint value has changed, - update the internal code to operate on struct pm_qos_constraints - add a NULL pointer check in the API functions Signed-off-by: Jean Pihet <j-pihet@ti.com> Reviewed-by: Kevin Hilman <khilman@ti.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-08-25PM QoS: Reorganize data structsJean Pihet1-0/+19
In preparation for the per-device constratins support, re-organize the data strctures: - add a struct pm_qos_constraints which contains the constraints related data - update struct pm_qos_object contents to the PM QoS internal object data. Add a pointer to struct pm_qos_constraints - update the internal code to use the new data structs. Signed-off-by: Jean Pihet <j-pihet@ti.com> Reviewed-by: Kevin Hilman <khilman@ti.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-08-25PM QoS: Minor clean-upsJean Pihet1-11/+11
- Misc fixes to improve code readability: * rename struct pm_qos_request_list to struct pm_qos_request, * rename pm_qos_req parameter to req in internal code, consistenly use req in the API parameters, * update the in-kernel API callers to the new parameters names, * rename of fields names (requests, list, node, constraints) Signed-off-by: Jean Pihet <j-pihet@ti.com> Acked-by: markgross <markgross@thegnar.org> Reviewed-by: Kevin Hilman <khilman@ti.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-08-25PM QoS: Move and rename the implementation filesJean Pihet1-0/+61
The PM QoS implementation files are better named kernel/power/qos.c and include/linux/pm_qos.h. The PM QoS support is compiled under the CONFIG_PM option. Signed-off-by: Jean Pihet <j-pihet@ti.com> Acked-by: markgross <markgross@thegnar.org> Reviewed-by: Kevin Hilman <khilman@ti.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>