linux-toradex.git/kernel/power/main.c, branch tegra-T30.ER5

PM: Add user-space wake lock api.

2010-09-30T00:49:07+00:00

This adds /sys/power/wake_lock and /sys/power/wake_unlock.
Writing a string to wake_lock creates a wake lock the
first time is sees a string and locks it. Optionally, the
string can be followed by a timeout.
To unlock the wake lock, write the same string to wake_unlock.

Change-Id: I66c6e3fe6487d17f9c2fafde1174042e57d15cd7

PM: Enable early suspend through /sys/power/state

2010-09-30T00:49:07+00:00

If EARLYSUSPEND is enabled then writes to /sys/power/state no longer
blocks, and the kernel will try to enter the requested state every
time no wakelocks are held. Write "on" to resume normal operation.

PM: Make it possible to avoid races between wakeup and system sleep

2010-07-18T23:58:48+00:00

One of the arguments during the suspend blockers discussion was that
the mainline kernel didn't contain any mechanisms making it possible
to avoid races between wakeup and system suspend.

Generally, there are two problems in that area.  First, if a wakeup
event occurs exactly when /sys/power/state is being written to, it
may be delivered to user space right before the freezer kicks in, so
the user space consumer of the event may not be able to process it
before the system is suspended.  Second, if a wakeup event occurs
after user space has been frozen, it is not generally guaranteed that
the ongoing transition of the system into a sleep state will be
aborted.

To address these issues introduce a new global sysfs attribute,
/sys/power/wakeup_count, associated with a running counter of wakeup
events and three helper functions, pm_stay_awake(), pm_relax(), and
pm_wakeup_event(), that may be used by kernel subsystems to control
the behavior of this attribute and to request the PM core to abort
system transitions into a sleep state already in progress.

The /sys/power/wakeup_count file may be read from or written to by
user space.  Reads will always succeed (unless interrupted by a
signal) and return the current value of the wakeup events counter.
Writes, however, will only succeed if the written number is equal to
the current value of the wakeup events counter.  If a write is
successful, it will cause the kernel to save the current value of the
wakeup events counter and to abort the subsequent system transition
into a sleep state if any wakeup events are reported after the write
has returned.

[The assumption is that before writing to /sys/power/state user space
will first read from /sys/power/wakeup_count.  Next, user space
consumers of wakeup events will have a chance to acknowledge or
veto the upcoming system transition to a sleep state.  Finally, if
the transition is allowed to proceed, /sys/power/wakeup_count will
be written to and if that succeeds, /sys/power/state will be written
to as well.  Still, if any wakeup events are reported to the PM core
by kernel subsystems after that point, the transition will be
aborted.]

Additionally, put a wakeup events counter into struct dev_pm_info and
make these per-device wakeup event counters available via sysfs,
so that it's possible to check the activity of various wakeup event
sources within the kernel.

To illustrate how subsystems can use pm_wakeup_event(), make the
low-level PCI runtime PM wakeup-handling code use it.

Signed-off-by: Rafael J. Wysocki 
Acked-by: Jesse Barnes 
Acked-by: Greg Kroah-Hartman 
Acked-by: markgross 
Reviewed-by: Alan Stern

PM: Add a switch for disabling/enabling asynchronous suspend/resume

2010-02-26T19:39:10+00:00

Add sysfs attribute /sys/power/pm_async allowing the user space to
disable/enable asynchronous suspend/resume of devices.

Signed-off-by: Rafael J. Wysocki

PM / Runtime: Export the PM runtime workqueue

2009-12-06T15:17:56+00:00

This patch (as1306) exports the PM runtime workqueue for use by
loadable modules.

Signed-off-by: Alan Stern 
Signed-off-by: Rafael J. Wysocki

PM: Introduce core framework for run-time PM of I/O devices (rev. 17)

2009-08-22T22:04:44+00:00

Introduce a core framework for run-time power management of I/O
devices.  Add device run-time PM fields to 'struct dev_pm_info'
and device run-time PM callbacks to 'struct dev_pm_ops'.  Introduce
a run-time PM workqueue and define some device run-time PM helper
functions at the core level.  Document all these things.

Special thanks to Alan Stern for his help with the design and
multiple detailed reviews of the pereceding versions of this patch
and to Magnus Damm for testing feedback.

Signed-off-by: Rafael J. Wysocki 
Acked-by: Magnus Damm

PM: Separate suspend to RAM functionality from core

2009-06-12T19:32:33+00:00

Move the suspend to RAM and standby code from kernel/power/main.c
to two separate files, kernel/power/suspend.c containing the basic
functions and kernel/power/suspend_test.c containing the automatic
suspend test facility based on the RTC clock alarm.

There are no changes in functionality related to these modifications.

Signed-off-by: Rafael J. Wysocki 
Acked-by: Pavel Machek

PM/Suspend: Do not shrink memory before suspend

2009-06-12T19:32:32+00:00

Remove the shrinking of memory from the suspend-to-RAM code, where
it is not really necessary.

Signed-off-by: Rafael J. Wysocki 
Acked-by: Nigel Cunningham 
Acked-by: Wu Fengguang

PM core: rename suspend and resume functions

2009-06-12T19:32:31+00:00

This patch (as1241) renames a bunch of functions in the PM core.
Rather than go through a boring list of name changes, suffice it to
say that in the end we have a bunch of pairs of functions:

	device_resume_noirq	dpm_resume_noirq
	device_resume		dpm_resume
	device_complete		dpm_complete
	device_suspend_noirq	dpm_suspend_noirq
	device_suspend		dpm_suspend
	device_prepare		dpm_prepare

in which device_X does the X operation on a single device and dpm_X
invokes device_X for all devices in the dpm_list.

In addition, the old dpm_power_up and device_resume_noirq have been
combined into a single function (dpm_resume_noirq).

Lastly, dpm_suspend_start and dpm_resume_end are the renamed versions
of the former top-level device_suspend and device_resume routines.

Signed-off-by: Alan Stern 
Acked-by: Magnus Damm 
Signed-off-by: Rafael J. Wysocki

PM: Rename device_power_down/up()

2009-06-12T19:32:31+00:00

Rename the functions performing "_noirq" dev_pm_ops
operations from device_power_down() and device_power_up()
to device_suspend_noirq() and device_resume_noirq().

The new function names are chosen to show that the functions
are responsible for calling the _noirq() versions to finalize
the suspend/resume operation. The current function names do
not perform power down/up anymore so the names may be misleading.

Global function renames:
- device_power_down() -> device_suspend_noirq()
- device_power_up() -> device_resume_noirq()

Static function renames:
- suspend_device_noirq() -> __device_suspend_noirq()
- resume_device_noirq() -> __device_resume_noirq()

Signed-off-by: Magnus Damm 
Acked-by: Greg Kroah-Hartman 
Acked-by: Len Brown 
Signed-off-by: Rafael J. Wysocki