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Merge tag 'pm-for-3.4' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

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Pull power management updates for 3.4 from Rafael Wysocki:
 "Assorted extensions and fixes including:

  * Introduction of early/late suspend/hibernation device callbacks.
  * Generic PM domains extensions and fixes.
  * devfreq updates from Axel Lin and MyungJoo Ham.
  * Device PM QoS updates.
  * Fixes of concurrency problems with wakeup sources.
  * System suspend and hibernation fixes."

* tag 'pm-for-3.4' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (43 commits)
  PM / Domains: Check domain status during hibernation restore of devices
  PM / devfreq: add relation of recommended frequency.
  PM / shmobile: Make MTU2 driver use pm_genpd_dev_always_on()
  PM / shmobile: Make CMT driver use pm_genpd_dev_always_on()
  PM / shmobile: Make TMU driver use pm_genpd_dev_always_on()
  PM / Domains: Introduce "always on" device flag
  PM / Domains: Fix hibernation restore of devices, v2
  PM / Domains: Fix handling of wakeup devices during system resume
  sh_mmcif / PM: Use PM QoS latency constraint
  tmio_mmc / PM: Use PM QoS latency constraint
  PM / QoS: Make it possible to expose PM QoS latency constraints
  PM / Sleep: JBD and JBD2 missing set_freezable()
  PM / Domains: Fix include for PM_GENERIC_DOMAINS=n case
  PM / Freezer: Remove references to TIF_FREEZE in comments
  PM / Sleep: Add more wakeup source initialization routines
  PM / Hibernate: Enable usermodehelpers in hibernate() error path
  PM / Sleep: Make __pm_stay_awake() delete wakeup source timers
  PM / Sleep: Fix race conditions related to wakeup source timer function
  PM / Sleep: Fix possible infinite loop during wakeup source destruction
  PM / Hibernate: print physical addresses consistently with other parts of kernel
  ...
This commit is contained in:
Linus Torvalds
2012-03-21 10:15:51 -07:00
parent 9f3938346a 98e8bdafeb
commit c7c66c0cb0
53 changed files with 1462 additions and 621 deletions
Download Patch File Download Diff File Expand all files Collapse all files

18
Documentation/ABI/testing/sysfs-devices-power
View File

@ -165,3 +165,21 @@ Description:
Not all drivers support this attribute. If it isn't supported,
attempts to read or write it will yield I/O errors.
What: /sys/devices/.../power/pm_qos_latency_us
Date: March 2012
Contact: Rafael J. Wysocki <rjw@sisk.pl>
Description:
The /sys/devices/.../power/pm_qos_resume_latency_us attribute
contains the PM QoS resume latency limit for the given device,
which is the maximum allowed time it can take to resume the
device, after it has been suspended at run time, from a resume
request to the moment the device will be ready to process I/O,
in microseconds. If it is equal to 0, however, this means that
the PM QoS resume latency may be arbitrary.
Not all drivers support this attribute. If it isn't supported,
it is not present.
This attribute has no effect on system-wide suspend/resume and
hibernation.

21
Documentation/devicetree/bindings/arm/exynos/power_domain.txt Normal file
View File

@ -0,0 +1,21 @@
* Samsung Exynos Power Domains
Exynos processors include support for multiple power domains which are used
to gate power to one or more peripherals on the processor.
Required Properties:
- compatiable: should be one of the following.
* samsung,exynos4210-pd - for exynos4210 type power domain.
- reg: physical base address of the controller and length of memory mapped
region.
Optional Properties:
- samsung,exynos4210-pd-off: Specifies that the power domain is in turned-off
state during boot and remains to be turned-off until explicitly turned-on.
Example:
lcd0: power-domain-lcd0 {
compatible = "samsung,exynos4210-pd";
reg = <0x10023C00 0x10>;
};

93
Documentation/power/devices.txt
View File

@ -96,6 +96,12 @@ struct dev_pm_ops {
int (*thaw)(struct device *dev);
int (*poweroff)(struct device *dev);
int (*restore)(struct device *dev);
int (*suspend_late)(struct device *dev);
int (*resume_early)(struct device *dev);
int (*freeze_late)(struct device *dev);
int (*thaw_early)(struct device *dev);
int (*poweroff_late)(struct device *dev);
int (*restore_early)(struct device *dev);
int (*suspend_noirq)(struct device *dev);
int (*resume_noirq)(struct device *dev);
int (*freeze_noirq)(struct device *dev);
@ -305,7 +311,7 @@ Entering System Suspend
-----------------------
When the system goes into the standby or memory sleep state, the phases are:
prepare, suspend, suspend_noirq.
prepare, suspend, suspend_late, suspend_noirq.
1. The prepare phase is meant to prevent races by preventing new devices
from being registered; the PM core would never know that all the
@ -324,7 +330,12 @@ When the system goes into the standby or memory sleep state, the phases are:
appropriate low-power state, depending on the bus type the device is on,
and they may enable wakeup events.
3. The suspend_noirq phase occurs after IRQ handlers have been disabled,
3 For a number of devices it is convenient to split suspend into the
"quiesce device" and "save device state" phases, in which cases
suspend_late is meant to do the latter. It is always executed after
runtime power management has been disabled for all devices.
4. The suspend_noirq phase occurs after IRQ handlers have been disabled,
which means that the driver's interrupt handler will not be called while
the callback method is running. The methods should save the values of
the device's registers that weren't saved previously and finally put the
@ -359,7 +370,7 @@ Leaving System Suspend
----------------------
When resuming from standby or memory sleep, the phases are:
resume_noirq, resume, complete.
resume_noirq, resume_early, resume, complete.
1. The resume_noirq callback methods should perform any actions needed
before the driver's interrupt handlers are invoked. This generally
@ -375,14 +386,18 @@ When resuming from standby or memory sleep, the phases are:
device driver's ->pm.resume_noirq() method to perform device-specific
actions.
2. The resume methods should bring the the device back to its operating
2. The resume_early methods should prepare devices for the execution of
the resume methods. This generally involves undoing the actions of the
preceding suspend_late phase.
3 The resume methods should bring the the device back to its operating
state, so that it can perform normal I/O. This generally involves
undoing the actions of the suspend phase.
3. The complete phase uses only a bus callback. The method should undo the
actions of the prepare phase. Note, however, that new children may be
registered below the device as soon as the resume callbacks occur; it's
not necessary to wait until the complete phase.
4. The complete phase should undo the actions of the prepare phase. Note,
however, that new children may be registered below the device as soon as
the resume callbacks occur; it's not necessary to wait until the
complete phase.
At the end of these phases, drivers should be as functional as they were before
suspending: I/O can be performed using DMA and IRQs, and the relevant clocks are
@ -429,8 +444,8 @@ an image of the system memory while everything is stable, reactivate all
devices (thaw), write the image to permanent storage, and finally shut down the
system (poweroff). The phases used to accomplish this are:
prepare, freeze, freeze_noirq, thaw_noirq, thaw, complete,
prepare, poweroff, poweroff_noirq
prepare, freeze, freeze_late, freeze_noirq, thaw_noirq, thaw_early,
thaw, complete, prepare, poweroff, poweroff_late, poweroff_noirq
1. The prepare phase is discussed in the "Entering System Suspend" section
above.
@ -441,7 +456,11 @@ system (poweroff). The phases used to accomplish this are:
save time it's best not to do so. Also, the device should not be
prepared to generate wakeup events.
3. The freeze_noirq phase is analogous to the suspend_noirq phase discussed
3. The freeze_late phase is analogous to the suspend_late phase described
above, except that the device should not be put in a low-power state and
should not be allowed to generate wakeup events by it.
4. The freeze_noirq phase is analogous to the suspend_noirq phase discussed
above, except again that the device should not be put in a low-power
state and should not be allowed to generate wakeup events.
@ -449,15 +468,19 @@ At this point the system image is created. All devices should be inactive and
the contents of memory should remain undisturbed while this happens, so that the
image forms an atomic snapshot of the system state.
4. The thaw_noirq phase is analogous to the resume_noirq phase discussed
5. The thaw_noirq phase is analogous to the resume_noirq phase discussed
above. The main difference is that its methods can assume the device is
in the same state as at the end of the freeze_noirq phase.
5. The thaw phase is analogous to the resume phase discussed above. Its
6. The thaw_early phase is analogous to the resume_early phase described
above. Its methods should undo the actions of the preceding
freeze_late, if necessary.
7. The thaw phase is analogous to the resume phase discussed above. Its
methods should bring the device back to an operating state, so that it
can be used for saving the image if necessary.
6. The complete phase is discussed in the "Leaving System Suspend" section
8. The complete phase is discussed in the "Leaving System Suspend" section
above.
At this point the system image is saved, and the devices then need to be
@ -465,16 +488,19 @@ prepared for the upcoming system shutdown. This is much like suspending them
before putting the system into the standby or memory sleep state, and the phases
are similar.
7. The prepare phase is discussed above.
9. The prepare phase is discussed above.
8. The poweroff phase is analogous to the suspend phase.
10. The poweroff phase is analogous to the suspend phase.
9. The poweroff_noirq phase is analogous to the suspend_noirq phase.
11. The poweroff_late phase is analogous to the suspend_late phase.
The poweroff and poweroff_noirq callbacks should do essentially the same things
as the suspend and suspend_noirq callbacks. The only notable difference is that
they need not store the device register values, because the registers should
already have been stored during the freeze or freeze_noirq phases.
12. The poweroff_noirq phase is analogous to the suspend_noirq phase.
The poweroff, poweroff_late and poweroff_noirq callbacks should do essentially
the same things as the suspend, suspend_late and suspend_noirq callbacks,
respectively. The only notable difference is that they need not store the
device register values, because the registers should already have been stored
during the freeze, freeze_late or freeze_noirq phases.
Leaving Hibernation
@ -518,22 +544,25 @@ To achieve this, the image kernel must restore the devices' pre-hibernation
functionality. The operation is much like waking up from the memory sleep
state, although it involves different phases:
restore_noirq, restore, complete
restore_noirq, restore_early, restore, complete
1. The restore_noirq phase is analogous to the resume_noirq phase.
2. The restore phase is analogous to the resume phase.
2. The restore_early phase is analogous to the resume_early phase.
3. The complete phase is discussed above.
3. The restore phase is analogous to the resume phase.
The main difference from resume[_noirq] is that restore[_noirq] must assume the
device has been accessed and reconfigured by the boot loader or the boot kernel.
Consequently the state of the device may be different from the state remembered
from the freeze and freeze_noirq phases. The device may even need to be reset
and completely re-initialized. In many cases this difference doesn't matter, so
the resume[_noirq] and restore[_norq] method pointers can be set to the same
routines. Nevertheless, different callback pointers are used in case there is a
situation where it actually matters.
4. The complete phase is discussed above.
The main difference from resume[_early|_noirq] is that restore[_early|_noirq]
must assume the device has been accessed and reconfigured by the boot loader or
the boot kernel. Consequently the state of the device may be different from the
state remembered from the freeze, freeze_late and freeze_noirq phases. The
device may even need to be reset and completely re-initialized. In many cases
this difference doesn't matter, so the resume[_early|_noirq] and
restore[_early|_norq] method pointers can be set to the same routines.
Nevertheless, different callback pointers are used in case there is a situation
where it actually does matter.
Device Power Management Domains

21
Documentation/power/freezing-of-tasks.txt
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@ -63,6 +63,27 @@ devices have been reinitialized, the function thaw_processes() is called in
order to clear the PF_FROZEN flag for each frozen task. Then, the tasks that
have been frozen leave __refrigerator() and continue running.
Rationale behind the functions dealing with freezing and thawing of tasks:
-------------------------------------------------------------------------
freeze_processes():
- freezes only userspace tasks
freeze_kernel_threads():
- freezes all tasks (including kernel threads) because we can't freeze
kernel threads without freezing userspace tasks
thaw_kernel_threads():
- thaws only kernel threads; this is particularly useful if we need to do
anything special in between thawing of kernel threads and thawing of
userspace tasks, or if we want to postpone the thawing of userspace tasks
thaw_processes():
- thaws all tasks (including kernel threads) because we can't thaw userspace
tasks without thawing kernel threads
III. Which kernel threads are freezable?
Kernel threads are not freezable by default. However, a kernel thread may clear