linux.git/drivers/acpi/power.c, branch v3.13

ACPI / power: Drop automaitc resume of power resource dependent devices

2013-10-16T21:05:42+00:00

The mechanism causing devices depending on a given power resource
(that is, devices that can be in D0 only if that power resource is
on) to be resumed automatically when the power resource is turned
on (and their "inferred" power state becomes D0 as a result) is
inherently racy and in fact unnecessary.

It is racy, because if the power resource is turned on and then
immediately off, the device resume triggered by the first transition
to "on" may still happen, causing the power resource to be turned
on again.  That again will trigger the "resume of dependent devices"
mechanism, but if the devices in question are not in use, they will
be suspended in the meantime causing the power resource to be turned
off.  However, the "resume of dependent devices" will next resume
them again and so on.  In some cases (USB port PM in particular) that
leads to an endless busy loop of flipping the resource on and off
continuously.

It is needless, because whoever turns a power resource on will most
likely turn it off at some point and the devices that go into "D0"
as a result of turning it on will then go back into D3cold
(generally, the state they were in before).

Moreover, turning on all power resources a device needs to go into
D0 is not sufficient for a full transition into D0 in general.
Namely, _PS0 may need to be executed in addition to that in some
cases.  This means that the whole rationale of the "resume of
dependent devices" mechanism was incorrect to begin with and it's
best to remove it entirely.

Signed-off-by: Rafael J. Wysocki

ACPI / power: Release resource_lock after acpi_power_get_state() return error

2013-10-15T22:26:42+00:00

In acpi_resume_power_resources() resource_lock should be released
when acpi_power_get_state() fails and before passing to next power
resource on the list.

Signed-off-by: Lan Tianyu 
Signed-off-by: Rafael J. Wysocki

Merge branch 'acpi-pm'

2013-08-26T23:28:17+00:00

* acpi-pm:
  ACPI / PM: Add state information to error message in acpi_device_set_power()
  ACPI / PM: Remove redundant power manageable check from acpi_bus_set_power()
  ACPI / PM: Use ACPI_STATE_D3_COLD instead of ACPI_STATE_D3 everywhere
  ACPI / PM: Make messages in acpi_device_set_power() print device names
  ACPI / PM: Only set power states of devices that are power manageable

ACPI / PM: Use ACPI_STATE_D3_COLD instead of ACPI_STATE_D3 everywhere

2013-07-30T12:36:20+00:00

There are several places in the tree where ACPI_STATE_D3 is used
instead of ACPI_STATE_D3_COLD which should be used instead for
clarity.  Modify them all to use ACPI_STATE_D3_COLD as appropriate.

[The definition of ACPI_STATE_D3 itself cannot go away at this point
 as it is part of ACPICA.]

Signed-off-by: Rafael J. Wysocki 
Reviewed-by: Aaron Lu

ACPI: introduce helper function acpi_execute_simple_method()

2013-07-14T23:33:10+00:00

Introduce helper function acpi_execute_simple_method() and use it in
a number of places to simplify code.

[rjw: Changelog]
Signed-off-by: Jiang Liu 
Signed-off-by: Rafael J. Wysocki

ACPI / power: add missing newline to debug messages

2013-07-05T11:30:20+00:00

There are few places in power.c where debug messages have no newline
at the end.  Reading such debug messages from dmesg is not fun, so
fix this by adding the missing newlines.

Signed-off-by: Mika Westerberg 
Cc: All 
Signed-off-by: Rafael J. Wysocki

ACPI / PM: Fix error code path for power resources initialization

2013-06-19T22:47:55+00:00

Commit 781d737 (ACPI: Drop power resources driver) introduced a
bug in the power resources initialization error code path causing
a NULL pointer to be referenced in acpi_release_power_resource()
if there's an error triggering a jump to the 'err' label in
acpi_add_power_resource().  This happens because the list_node
field of struct acpi_power_resource has not been initialized yet
at this point and doing a list_del() on it is a bad idea.

To prevent this problem from occuring, initialize the list_node
field of struct acpi_power_resource upfront.

Reported-by: Mika Westerberg 
Tested-by: Lan Tianyu 
Signed-off-by: Rafael J. Wysocki 
Cc: 3.9+ 
Acked-by: Yasuaki Ishimatsu 
Reviewed-by: Mika Westerberg

Merge branch 'acpi-pm'

2013-04-27T23:54:00+00:00

* acpi-pm:
  ACPI / PM: Expose lists of device wakeup power resources to user space
  ACPI / PM: Fix potential problem in acpi_device_get_power()

ACPI / PM: Expose lists of device wakeup power resources to user space

2013-04-11T20:41:48+00:00

Commit 18a3870 (ACPI / PM: Expose lists of device power resources
to user space) exposed the lists of ACPI power resources associated
with power states of ACPI devices, but it didn't expose the lists
of ACPI wakeup power resources, which also is necessary to get the
full picture of dependencies between ACPI devices and power
resources.

For this reason, for every ACPI device node having a list of ACPI
wakeup power resources associated with it, expose that list to user
space in analogy with commit 18a3870.

Signed-off-by: Rafael J. Wysocki

ACPI: Update PNPID set/free interfaces

2013-03-24T22:49:38+00:00

This patch introduces acpi_set_pnp_ids() and acpi_free_pnp_ids(),
which are updated from acpi_device_set_id() and acpi_free_ids(),
to setup and free acpi_device_pnp for a given acpi_handle.  They
can be called without acpi_device.

Signed-off-by: Toshi Kani 
Signed-off-by: Rafael J. Wysocki