linux-toradex.git/drivers/base/power, branch v2.6.34.8

power: support _noirq actions on device types and classes

2010-03-24T10:00:02+00:00

The new-style dev_pm_ops provide callbacks for both IRQs enabled
and disabled. However, the _noirq variants were only called for
buses registered with a device, not for classes and types.

In order to properly use dev_pm_ops in class pcmcia_socket_class,
support _noirq actions also on classes and types.

Signed-off-by: Dominik Brodowski 
Acked-by: Rafael J. Wysocki

Driver core: create lock/unlock functions for struct device

2010-03-08T01:04:52+00:00

In the future, we are going to be changing the lock type for struct
device (once we get the lockdep infrastructure properly worked out)  To
make that changeover easier, and to possibly burry the lock in a
different part of struct device, let's create some functions to lock and
unlock a device so that no out-of-core code needs to be changed in the
future.

This patch creates the device_lock/unlock/trylock() functions, and
converts all in-tree users to them.

Cc: Thomas Gleixner 
Cc: Jean Delvare 
Cc: Dave Young 
Cc: Ming Lei 
Cc: Jiri Kosina 
Cc: Phil Carmody 
Cc: Arjan van de Ven 
Cc: Cornelia Huck 
Cc: Rafael J. Wysocki 
Cc: Pavel Machek 
Cc: Len Brown 
Cc: Magnus Damm 
Cc: Alan Stern 
Cc: Randy Dunlap 
Cc: Stefan Richter 
Cc: David Brownell 
Cc: Vegard Nossum 
Cc: Jesse Barnes 
Cc: Alex Chiang 
Cc: Kenji Kaneshige 
Cc: Andrew Morton 
Cc: Andrew Patterson 
Cc: Yu Zhao 
Cc: Dominik Brodowski 
Cc: Samuel Ortiz 
Cc: Wolfram Sang 
Cc: CHENG Renquan 
Cc: Oliver Neukum 
Cc: Frans Pop 
Cc: David Vrabel 
Cc: Kay Sievers 
Cc: Sarah Sharp 
Signed-off-by: Greg Kroah-Hartman

PM: Provide generic subsystem-level callbacks

2010-03-06T20:28:37+00:00

There are subsystems whose power management callbacks only need to
invoke the callbacks provided by device drivers.  Still, their system
sleep PM callbacks should play well with the runtime PM callbacks,
so that devices suspended at run time can be left in that state for
a system sleep transition.

Provide a set of generic PM callbacks for such subsystems and
define convenience macros for populating dev_pm_ops structures.

Signed-off-by: Rafael J. Wysocki

PM: Allow device drivers to use dpm_wait()

2010-02-26T19:39:11+00:00

There are some dependencies between devices (in particular, between
EHCI USB controllers and their OHCI/UHCI siblings) which are not
reflected by the structure of the device tree.  With synchronous
suspend and resume these dependencies are taken into accout
automatically, because the devices in question are always registered
in the right order, but to meet these constraints with asynchronous
suspend and resume the drivers of these devices will need to use
dpm_wait() in their suspend/resume routines, so introduce a helper
function allowing them to do that.

Signed-off-by: Rafael J. Wysocki

PM: Start asynchronous resume threads upfront

2010-02-26T19:39:11+00:00

It has been shown by testing that total device resume time can be
reduced significantly (by as much as 50% or more) if the async
threads executing some devices' resume routines are all started
before the main resume thread starts to handle the "synchronous"
devices.

This is a consequence of the fact that the slowest devices tend to be
located at the end of dpm_list, so their resume routines are started
very late.  Consequently, they have to wait for all the preceding
"synchronous" devices before their resume routines can be started
by the main resume thread, even if they are "asynchronous".  By
starting their async threads upfront we effectively move those
devices towards the beginning of dpm_list, without breaking their
ordering with respect to their parents and children.  As a result,
their resume routines are started much earlier and we are able to
save much more device resume time this way.

Signed-off-by: Rafael J. Wysocki

PM: Add facility for advanced testing of async suspend/resume

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

Add configuration switch CONFIG_PM_ADVANCED_DEBUG for compiling in
extra PM debugging/testing code allowing one to access some
PM-related attributes of devices from the user space via sysfs.

If CONFIG_PM_ADVANCED_DEBUG is set, add sysfs attribute power/async
for every device allowing the user space to access the device's
power.async_suspend flag and modify it, if desired.

Signed-off-by: Rafael J. Wysocki

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: Asynchronous suspend and resume of devices

2010-02-26T19:39:09+00:00

Theoretically, the total time of system sleep transitions (suspend
to RAM, hibernation) can be reduced by running suspend and resume
callbacks of device drivers in parallel with each other.  However,
there are dependencies between devices such that we're not allowed
to suspend the parent of a device before suspending the device
itself.  Analogously, we're not allowed to resume a device before
resuming its parent.

The most straightforward way to take these dependencies into accout
is to start the async threads used for suspending and resuming
devices at the core level, so that async_schedule() is called for
each suspend and resume callback supposed to be executed
asynchronously.

For this purpose, introduce a new device flag, power.async_suspend,
used to mark the devices whose suspend and resume callbacks are to be
executed asynchronously (ie. in parallel with the main suspend/resume
thread and possibly in parallel with each other) and helper function
device_enable_async_suspend() allowing one to set power.async_suspend
for given device (power.async_suspend is unset by default for all
devices).  For each device with the power.async_suspend flag set the
PM core will use async_schedule() to execute its suspend and resume
callbacks.

The async threads started for different devices as a result of
calling async_schedule() are synchronized with each other and with
the main suspend/resume thread with the help of completions, in the
following way:
(1) There is a completion, power.completion, for each device object.
(2) Each device's completion is reset before calling async_schedule()
    for the device or, in the case of devices with the
    power.async_suspend flags unset, before executing the device's
    suspend and resume callbacks.
(3) During suspend, right before running the bus type, device type
    and device class suspend callbacks for the device, the PM core
    waits for the completions of all the device's children to be
    completed.
(4) During resume, right before running the bus type, device type and
    device class resume callbacks for the device, the PM core waits
    for the completion of the device's parent to be completed.
(5) The PM core completes power.completion for each device right
    after the bus type, device type and device class suspend (or
    resume) callbacks executed for the device have returned.

Signed-off-by: Rafael J. Wysocki

PM: Add parent information to timing messages

2010-02-26T19:39:09+00:00

Add parent information to the messages printed by the suspend/resume
core when initcall_debug is set.

Signed-off-by: Rafael J. Wysocki

PM / Runtime: Add sysfs switch for disabling device run-time PM

2010-02-26T19:39:08+00:00

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 
Acked-by: Alan Stern