<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/Documentation/power, branch v3.0-rc2</title>
<subtitle>Linux kernel source tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/'/>
<entry>
<title>regulator: Remove supply_regulator_dev from machine configuration</title>
<updated>2011-05-27T09:34:37+00:00</updated>
<author>
<name>Mark Brown</name>
<email>broonie@opensource.wolfsonmicro.com</email>
</author>
<published>2011-05-08T21:30:18+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=492c826b9facefa84995f4dea917e301b5ee0884'/>
<id>492c826b9facefa84995f4dea917e301b5ee0884</id>
<content type='text'>
supply_regulator_dev (using a struct pointer) has been deprecated in favour
of supply_regulator (using a regulator name) for quite a few releases
now with a warning generated if it is used and there are no current in tree
users so just remove the code.

Signed-off-by: Mark Brown &lt;broonie@opensource.wolfsonmicro.com&gt;
Signed-off-by: Liam Girdwood &lt;lrg@slimlogic.co.uk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
supply_regulator_dev (using a struct pointer) has been deprecated in favour
of supply_regulator (using a regulator name) for quite a few releases
now with a warning generated if it is used and there are no current in tree
users so just remove the code.

Signed-off-by: Mark Brown &lt;broonie@opensource.wolfsonmicro.com&gt;
Signed-off-by: Liam Girdwood &lt;lrg@slimlogic.co.uk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>PM: Allow drivers to allocate memory from .prepare() callbacks safely</title>
<updated>2011-05-17T21:26:00+00:00</updated>
<author>
<name>Rafael J. Wysocki</name>
<email>rjw@sisk.pl</email>
</author>
<published>2011-05-17T21:26:00+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=91e7c75ba93c48a82670d630b9daac92ff70095d'/>
<id>91e7c75ba93c48a82670d630b9daac92ff70095d</id>
<content type='text'>
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 &lt;rjw@sisk.pl&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
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 &lt;rjw@sisk.pl&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Fix common misspellings</title>
<updated>2011-03-31T14:26:23+00:00</updated>
<author>
<name>Lucas De Marchi</name>
<email>lucas.demarchi@profusion.mobi</email>
</author>
<published>2011-03-31T01:57:33+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=25985edcedea6396277003854657b5f3cb31a628'/>
<id>25985edcedea6396277003854657b5f3cb31a628</id>
<content type='text'>
Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi &lt;lucas.demarchi@profusion.mobi&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi &lt;lucas.demarchi@profusion.mobi&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>PM: Documentation/power/states.txt: fix repetition</title>
<updated>2011-03-14T23:43:17+00:00</updated>
<author>
<name>Alexandre Courbot</name>
<email>gnurou@gmail.com</email>
</author>
<published>2011-02-24T19:48:56+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=a8b7228cdce9937ebc302a28db8599035e7b3c86'/>
<id>a8b7228cdce9937ebc302a28db8599035e7b3c86</id>
<content type='text'>
Remove repetition of "called swsusp".

Signed-off-by: Alexandre Courbot &lt;gnurou@gmail.com&gt;
Signed-off-by: Rafael J. Wysocki &lt;rjw@sisk.pl&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Remove repetition of "called swsusp".

Signed-off-by: Alexandre Courbot &lt;gnurou@gmail.com&gt;
Signed-off-by: Rafael J. Wysocki &lt;rjw@sisk.pl&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>PM: Make system-wide PM and runtime PM treat subsystems consistently</title>
<updated>2011-03-14T23:43:17+00:00</updated>
<author>
<name>Rafael J. Wysocki</name>
<email>rjw@sisk.pl</email>
</author>
<published>2011-02-18T22:20:21+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=9659cc0678b954f187290c6e8b247a673c5d37e1'/>
<id>9659cc0678b954f187290c6e8b247a673c5d37e1</id>
<content type='text'>
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-&gt;type is not NULL)
    and its pm pointer is not NULL, the callbacks from dev-&gt;type-&gt;pm
    will be used.
(2) If dev-&gt;type is NULL or dev-&gt;type-&gt;pm is NULL, but the device's
    class is defined (eg. dev-&gt;class is not NULL) and its pm pointer
    is not NULL, the callbacks from dev-&gt;class-&gt;pm will be used.
(3) If dev-&gt;type is NULL or dev-&gt;type-&gt;pm is NULL and dev-&gt;class is
    NULL or dev-&gt;class-&gt;pm is NULL, the callbacks from dev-&gt;bus-&gt;pm
    will be used provided that both dev-&gt;bus and dev-&gt;bus-&gt;pm are
    not NULL.

Signed-off-by: Rafael J. Wysocki &lt;rjw@sisk.pl&gt;
Acked-by: Kevin Hilman &lt;khilman@ti.com&gt;
Reasoning-sounds-sane-to: Grant Likely &lt;grant.likely@secretlab.ca&gt;
Acked-by: Greg Kroah-Hartman &lt;gregkh@suse.de&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
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-&gt;type is not NULL)
    and its pm pointer is not NULL, the callbacks from dev-&gt;type-&gt;pm
    will be used.
(2) If dev-&gt;type is NULL or dev-&gt;type-&gt;pm is NULL, but the device's
    class is defined (eg. dev-&gt;class is not NULL) and its pm pointer
    is not NULL, the callbacks from dev-&gt;class-&gt;pm will be used.
(3) If dev-&gt;type is NULL or dev-&gt;type-&gt;pm is NULL and dev-&gt;class is
    NULL or dev-&gt;class-&gt;pm is NULL, the callbacks from dev-&gt;bus-&gt;pm
    will be used provided that both dev-&gt;bus and dev-&gt;bus-&gt;pm are
    not NULL.

Signed-off-by: Rafael J. Wysocki &lt;rjw@sisk.pl&gt;
Acked-by: Kevin Hilman &lt;khilman@ti.com&gt;
Reasoning-sounds-sane-to: Grant Likely &lt;grant.likely@secretlab.ca&gt;
Acked-by: Greg Kroah-Hartman &lt;gregkh@suse.de&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>PM: Add support for device power domains</title>
<updated>2011-03-14T23:43:16+00:00</updated>
<author>
<name>Rafael J. Wysocki</name>
<email>rjw@sisk.pl</email>
</author>
<published>2011-02-16T20:53:17+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=7538e3db6e015e890825fbd9f8659952896ddd5b'/>
<id>7538e3db6e015e890825fbd9f8659952896ddd5b</id>
<content type='text'>
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 &lt;rjw@sisk.pl&gt;
Tested-and-acked-by: Kevin Hilman &lt;khilman@ti.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
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 &lt;rjw@sisk.pl&gt;
Tested-and-acked-by: Kevin Hilman &lt;khilman@ti.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>PM: Do not create wakeup sysfs files for devices that cannot wake up</title>
<updated>2011-03-14T23:43:14+00:00</updated>
<author>
<name>Rafael J. Wysocki</name>
<email>rjw@sisk.pl</email>
</author>
<published>2011-02-08T22:26:02+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=cb8f51bdadb7969139c2e39c2defd4cde98c1ea8'/>
<id>cb8f51bdadb7969139c2e39c2defd4cde98c1ea8</id>
<content type='text'>
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 &lt;rjw@sisk.pl&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
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 &lt;rjw@sisk.pl&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>PM: Fix references to basic-pm-debugging.txt in drivers-testing.txt</title>
<updated>2010-12-24T14:02:41+00:00</updated>
<author>
<name>Jon Mason</name>
<email>jon.mason@exar.com</email>
</author>
<published>2010-11-30T23:14:55+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=7ac4dcabdb482d4e74c9d36782d00bc6c4c01619'/>
<id>7ac4dcabdb482d4e74c9d36782d00bc6c4c01619</id>
<content type='text'>
basic-pm-debugging.txt is located in Documentation/power/ not
Documents/power/.  Change the references in
Documentation/power/drivers-testing.txt to reflect the location.

Signed-off-by: Jon Mason &lt;jon.mason@exar.com&gt;
Signed-off-by: Rafael J. Wysocki &lt;rjw@sisk.pl&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
basic-pm-debugging.txt is located in Documentation/power/ not
Documents/power/.  Change the references in
Documentation/power/drivers-testing.txt to reflect the location.

Signed-off-by: Jon Mason &lt;jon.mason@exar.com&gt;
Signed-off-by: Rafael J. Wysocki &lt;rjw@sisk.pl&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>PM / Runtime: Add synchronous runtime interface for interrupt handlers (v3)</title>
<updated>2010-12-24T14:02:41+00:00</updated>
<author>
<name>Alan Stern</name>
<email>stern@rowland.harvard.edu</email>
</author>
<published>2010-11-30T23:14:42+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=c7b61de5b7b17f0df34dc7d2f8b9576f8bd36fce'/>
<id>c7b61de5b7b17f0df34dc7d2f8b9576f8bd36fce</id>
<content type='text'>
This patch (as1431c) makes the synchronous runtime-PM interface
suitable for use in interrupt handlers.  Subsystems can call the new
pm_runtime_irq_safe() function to tell the PM core that a device's
runtime_suspend and runtime_resume callbacks should be invoked with
interrupts disabled and the spinlock held.  This permits the
pm_runtime_get_sync() and the new pm_runtime_put_sync_suspend()
routines to be called from within interrupt handlers.

When a device is declared irq-safe in this way, the PM core increments
the parent's usage count, so the parent will never be runtime
suspended.  This prevents difficult situations in which an irq-safe
device can't resume because it is forced to wait for its non-irq-safe
parent.

Signed-off-by: Alan Stern &lt;stern@rowland.harvard.edu&gt;
Signed-off-by: Rafael J. Wysocki &lt;rjw@sisk.pl&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This patch (as1431c) makes the synchronous runtime-PM interface
suitable for use in interrupt handlers.  Subsystems can call the new
pm_runtime_irq_safe() function to tell the PM core that a device's
runtime_suspend and runtime_resume callbacks should be invoked with
interrupts disabled and the spinlock held.  This permits the
pm_runtime_get_sync() and the new pm_runtime_put_sync_suspend()
routines to be called from within interrupt handlers.

When a device is declared irq-safe in this way, the PM core increments
the parent's usage count, so the parent will never be runtime
suspended.  This prevents difficult situations in which an irq-safe
device can't resume because it is forced to wait for its non-irq-safe
parent.

Signed-off-by: Alan Stern &lt;stern@rowland.harvard.edu&gt;
Signed-off-by: Rafael J. Wysocki &lt;rjw@sisk.pl&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>PM / Runtime: Fix pm_runtime_suspended()</title>
<updated>2010-12-16T16:12:25+00:00</updated>
<author>
<name>Rafael J. Wysocki</name>
<email>rjw@sisk.pl</email>
</author>
<published>2010-12-16T16:11:58+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=f08f5a0add20834d3f3d876dfe08005a5df656db'/>
<id>f08f5a0add20834d3f3d876dfe08005a5df656db</id>
<content type='text'>
There are some situations (e.g. in __pm_generic_call()), where
pm_runtime_suspended() is used to decide whether or not to execute
a device's (system) -&gt;suspend() callback.  The callback is not
executed if pm_runtime_suspended() returns true, but it does so
for devices that don't even support runtime PM, because the
power.disable_depth device field is ignored by it.  This leads to
problems (i.e. devices are not suspened when they should), so rework
pm_runtime_suspended() so that it returns false if the device's
power.disable_depth field is different from zero.

Signed-off-by: Rafael J. Wysocki &lt;rjw@sisk.pl&gt;
Cc: stable@kernel.org
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
There are some situations (e.g. in __pm_generic_call()), where
pm_runtime_suspended() is used to decide whether or not to execute
a device's (system) -&gt;suspend() callback.  The callback is not
executed if pm_runtime_suspended() returns true, but it does so
for devices that don't even support runtime PM, because the
power.disable_depth device field is ignored by it.  This leads to
problems (i.e. devices are not suspened when they should), so rework
pm_runtime_suspended() so that it returns false if the device's
power.disable_depth field is different from zero.

Signed-off-by: Rafael J. Wysocki &lt;rjw@sisk.pl&gt;
Cc: stable@kernel.org
</pre>
</div>
</content>
</entry>
</feed>
