Two functions defined in device_pm.c, acpi_dev_pm_add_dependent()
and acpi_dev_pm_remove_dependent(), have no callers and may be
dropped, so drop them.

Moreover, they are the only functions adding entries to and removing
entries from the power_dependent list in struct acpi_device, so drop
that list too.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The state information can be useful to know what the problem is when
an error message about a device can not being set to a higher power
state than its parent appeared, so this patch adds such state
information for both the target state of the device and the current
state of its parent.
Signed-off-by: NAaron Lu <aaron.lu@intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Now that acpi_device_set_power() checks whether or not the given
device is power manageable, it is not necessary to do this check in
acpi_bus_set_power() any more, so remove it.
Signed-off-by: NAaron Lu <aaron.lu@intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Modify acpi_device_set_power() so that diagnostic messages printed by
it to the kernel log always contain the name of the device concerned
to make it possible to identify the device that triggered the message
if need be.

Also replace printk(KERN_WARNING ) with dev_warn() everywhere in that
function.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: NAaron Lu <aaron.lu@intel.com>

Make acpi_device_set_power() check if the given device is power
manageable before checking if the given power state is valid for that
device.  Otherwise it will print that "Device does not support" that
power state into the kernel log, which may not make sense for some
power states (D0 and D3cold are supported by all devices by
definition).
Tested-by: NYinghai Lu <yinghai@kernel.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The role of acpi_bus_update_power() is to update the given ACPI
device object's power.state field to reflect the current physical
state of the device (as inferred from the configuration of power
resources and _PSC, if available).  For this purpose it calls
acpi_device_set_power() that should update the power resources'
reference counters and set power.state as appropriate.  However,
that doesn't work if the "new" state is D1, D2 or D3hot and the
the current value of power.state means D3cold, because in that
case acpi_device_set_power() will refuse to transition the device
from D3cold to non-D0.

To address this problem, make acpi_bus_update_power() call
acpi_power_transition() directly to update the power resources'
reference counters and only use acpi_device_set_power() to put
the device into D0 if the current physical state of it cannot
be determined.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: 3.9+ <stable@vger.kernel.org>

After commit fa1675b5 (ACPI / PM: Rework and clean up
acpi_dev_pm_get_state()) a NULL pointer dereference will take place
if NULL is passed to acpi_pm_device_sleep_state() as the second
argument.

Fix that by avoiding to use the pointer that may be NULL until
it's necessary to store a return value at the location pointed to
by it (if not NULL).
Reported-and-tested-by: NAaron Lu <aaron.lu@intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Commit 7cd8407d (ACPI / PM: Do not execute _PS0 for devices without
_PSC during initialization) introduced a regression on some systems
with Intel Lynxpoint Low-Power Subsystem (LPSS) where some devices
need to be powered up during initialization, but their device objects
in the ACPI namespace have _PS0 and _PS3 only (without _PSC or power
resources).

To work around this problem, make the ACPI LPSS driver power up
devices it knows about by using a new helper function
acpi_device_fix_up_power() that does all of the necessary
sanity checks and calls acpi_dev_pm_explicit_set() to put the
device into D0.
Reported-and-tested-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The acpi_dev_pm_get_state() function defined in device_pm.c is quite
convoluted, which isn't really necessary, and it doesn't validate the
values returned by the ACPI methods executed by it appropriately.

To address these shortcomings modify it in the following way.

 (1) Make its return value only mean whether or not it succeeded and
     pass the device power states determined by it through pointers.

 (2) Drop the d_max_in argument, used by only one of its callers,
     from it, and move the code related to d_max_in into that caller,
     acpi_pm_device_sleep_state().

 (3) Make it always check the return value of acpi_evaluate_integer()
     and handle failures as appropriate.  Moreover, make it check if
     the values returned by the executed ACPI methods are not out of
     range.

 (4) Make it check if the values returned by the executed ACPI
     methods represent valid power states of the given device and
     handle situations in which that's not the case gracefully.

Also update the kerneldoc comments of acpi_dev_pm_get_state() and
acpi_pm_device_sleep_state() to reflect the code changes.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The two symbols ACPI_STATE_D3 and ACPI_STATE_D3_COLD actually
represent the same number (4), but ACPI_STATE_D3 is slightly
ambigugous, because it may not be clear that it really means D3cold
and not D3hot at first sight.

Remove that ambiguity from drivers/acpi/device_pm.c by making it
use ACPI_STATE_D3_COLD everywhere instead of ACPI_STATE_D3.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

There is a name clash between function acpi_device_power_state()
defined in drivers/acpi/device_pm.c and structure type
acpi_device_power_state defined in include/acpi/acpi_bus.h, which
may be resolved by renaming the function.  Additionally, that
funtion may be made static, because it is not used anywhere outside
of the file it is defined in.

Rename acpi_device_power_state() to acpi_dev_pm_get_state(), which
better reflects its purpose, and make it static.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Commit b3785492 (ACPI / PM: Do not power manage devices in unknown
initial states) added code to force devices without _PSC, but having
_PS0 defined in the ACPI namespace, into ACPI power state D0 by
executing _PS0 for them.  That turned out to break Toshiba P870-303,
however, so revert that code.

References: https://bugzilla.kernel.org/show_bug.cgi?id=58201Reported-and-tested-by: NJerome Cantenot <jerome.cantenot@gmail.com>
Tracked-down-by: NLan Tianyu <tianyu.lan@intel.com>
Cc: 3.9+ <stable@vger.kernel.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The "runtime idle" helper routine, rpm_idle(), currently ignores
return values from .runtime_idle() callbacks executed by it.
However, it turns out that many subsystems use
pm_generic_runtime_idle() which checks the return value of the
driver's callback and executes pm_runtime_suspend() for the device
unless that value is not 0.  If that logic is moved to rpm_idle()
instead, pm_generic_runtime_idle() can be dropped and its users
will not need any .runtime_idle() callbacks any more.

Moreover, the PCI, SCSI, and SATA subsystems' .runtime_idle()
routines, pci_pm_runtime_idle(), scsi_runtime_idle(), and
ata_port_runtime_idle(), respectively, as well as a few drivers'
ones may be simplified if rpm_idle() calls rpm_suspend() after 0 has
been returned by the .runtime_idle() callback executed by it.

To reduce overall code bloat, make the changes described above.
Tested-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Tested-by: NKevin Hilman <khilman@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: NKevin Hilman <khilman@linaro.org>
Reviewed-by: NUlf Hansson <ulf.hansson@linaro.org>
Acked-by: NAlan Stern <stern@rowland.harvard.edu>

Currently, drivers/acpi/device_pm.c depends on CONFIG_PM and all of
the functions defined in there are replaced with static inline stubs
if that option is unset.  However, CONFIG_PM means, roughly, "runtime
PM or suspend/hibernation support" and some of those functions are
useful regardless of that.  For example, they are used by the ACPI
fan driver for controlling fans and acpi_device_set_power() is called
during device removal.  Moreover, device initialization may depend on
setting device power states properly.

For these reasons, make the routines manipulating ACPI device power
states defined in drivers/acpi/device_pm.c available for CONFIG_PM
unset too.
Reported-by: NZhang Rui <rui.zhang@intel.com>
Reported-and-tested-by: NMichel Lespinasse <walken@google.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: 3.9+ <stable@vger.kernel.org>

Theoretically, in some situations acpi_device_get_power() may return
an incorrect result, because the settings of the power resources
depended on by the device may indicate a power state shallower than
the actual power state of the device.

Say that two devices, A and B, depend on two power resources, X and
Y, in such a way that _PR0 for both A and B list both X and Y and
_PR3 for both A and B list power resource Y alone.  Also suppose
that _PS0 and _PS3 are present for both A and B.  Then, if devices
A and B are initially in D0, power resources X and Y are initially
"on" and their reference counters are equal to 2.  To put device A
into power state D3hot the kernel will decrement the reference
counter of power resource X, but that power resource won't be turned
off, because it is still in use by device B (its reference counter is
equal to 1).  Next, _PS3 will be executed for device A.  Afterward
the configuration of the power resources will indicate that device
A is in power state D0 (both X and Y are "on"), but in fact it is
in D3hot (because _PS3 has been executed for it).

In that situation, if acpi_device_get_power() is called to get the
power state of device A, it will first execute _PSC for it which
should return 3.  That will cause acpi_device_get_power() to run
acpi_power_get_inferred_state() for device A and the resultant power
state will be D0, which is incorrect.

To fix that change acpi_device_get_power() to first execute
acpi_power_get_inferred_state() for the given device (if it
depends on power resources) and to evaluate _PSC for it subsequently,
so that the result inferred from the power resources configuration
can be amended by the _PSC return value.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: NAaron Lu <aaron.lu@intel.com>

If _PS0 is defined for an ACPI device node, but _PSC isn't and
the device node doesn't use power resources for power management,
acpi_bus_update_power() will fail to update the power state of it,
because acpi_device_get_power() returns ACPI_STATE_UNKNOWN in that
case.

To handle that situation make acpi_bus_update_power() follow
acpi_bus_init_power() and try to force the given device node into
power state D0.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

In general, for ACPI device power management to work, the initial
power states of devices must be known (otherwise, we wouldn't be able
to keep track of power resources, for example).  Hence, if it is
impossible to determine the initial ACPI power states of some
devices, they can't be regarded as power-manageable using ACPI.

For this reason, modify acpi_bus_get_power_flags() to clear the
power_manageable flag if acpi_bus_init_power() fails and add some
extra fallback code to acpi_bus_init_power() to cover broken
BIOSes that provide _PS0/_PS3 without _PSC for some devices.

Verified to work on my HP nx6325 that has this problem.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: NPeter Wu <lekensteyn@gmail.com>

acpi_bus_get_device() returns int not acpi_status.

The patch change not to apply ACPI_FAILURE() to the return value of
acpi_bus_get_device().
Signed-off-by: NYasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

When a transition to the D3cold power state is requested,
acpi_device_set_power() first carries out a transition to D3hot and
then turns off the device's power resources.  However, it fails to
update the device's power.state field appropriately and D3hot is
stored in it as a result.

Fix this, but make sure that the device's power state will be
D3hot if its power resources cannot be turned off in the final
step.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Make acpi_power_state_string() return "D3cold" as the string
representation of ACPI power state D3cold instead of "D3" returned
currently, which is confusing.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The ACPI specitication (ACPI 5, Sections 7.2.8 - 7.2.11) requires
that the _PSn (n = 0..3) method, if present, be executed after the
power resources for the given device power state have been set
appropriately.  However, acpi_device_set_power() does that only
if the new power state is going to be higher-power (lower-number)
than the power state the device is in already.  Otherwise, the
ordering is reverse to protect against situations in which _PSn
might access device registers unavailable after configuring the
power resources for power state Dn (D3 meaning D3hot).

Such situations are very unlikely to happen, though, and _PSn may
actually be implemented with the assumption that power resources
have been configured for power state Dn in advance, so change the
code to follow the specification literally.

This change was previously porposed in a different form by Lv Zheng.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

To reduce code duplication between acpi_device_set_power() and
acpi_bus_init_power(), introduce a new helper function for executing
ACPI devices' _PSn (n = 0..3) methods, acpi_dev_pm_explicit_set().
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The ACPI specification requires the _PSC method to be present under
a device object if its power state cannot be inferred from the states
of power resources used by it (ACPI 5, Section 7.6.2).  However, it
also requires that (for power states D0-D2 and D3hot) if the _PSn
(n = 0, 1, 2, 3) method is present under the device object, it also
must be executed after the power resources have been set
appropriately for the device to go into power state Dn (D3 means
D3hot in this case).  Thus it is not clear from the specification
whether or not the _PSn method should be executed if the initial
configuraion of power resources used by the device indicates power
state Dn and the _PSC method is not present.

The current implementation of acpi_bus_init_power() is based on the
assumption that it should not be necessary to execute _PSn in the
above situation, but experience shows that in fact that assumption
need not be satisfied.  For this reason, make acpi_bus_init_power()
always execute _PSn if the initial configuration of device power
resources indicates power state Dn.
Reported-and-tested-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

It is there probably due to an accident, get rid of it so that the format
is consistent across the file.
Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Move ACPI device power management functions from drivers/acpi/bus.c
to drivers/acpi/device_pm.c.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Commit 0090def6 (ACPI: Add interface to register/unregister device
to/from power resources) made it possible to indicate to the ACPI
core that if the given device depends on any power resources, then
it should be resumed as soon as all of the power resources required
by it to transition to the D0 power state have been turned on.

Unfortunately, however, this was a mistake, because all devices
depending on power resources should be treated this way (i.e. they
should be resumed when all power resources required by their D0
state have been turned on) and for the majority of those devices
the ACPI core can figure out by itself which (physical) devices
depend on what power resources.

For this reason, replace the code added by commit 0090def6 with a
new, much more straightforward, mechanism that will be used
internally by the ACPI core and remove all references to that code
from kernel subsystems using ACPI.

For the cases when there are (physical) devices that should be
resumed whenever a not directly related ACPI device node goes into
D0 as a result of power resources configuration changes, like in
the SATA case, add two new routines, acpi_dev_pm_add_dependent()
and acpi_dev_pm_remove_dependent(), allowing subsystems to manage
such dependencies.  Convert the SATA subsystem to use the new
functions accordingly.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Since the return value of acpi_bus_get_device() is not of type
acpi_status, ACPI_SUCCESS() should not be used for checking its
return value.  Fix that.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: NMika Westerberg <mika.westerberg@linux.intel.com>

Currently, the ACPI wakeup capability of PCI devices is set up
in two different places, partially in acpi_pci_bind() where
runtime wakeup is initialized and partially in
platform_pci_wakeup_init(), where system wakeup is initialized.
The cleanup is only done in acpi_pci_unbind() and it only covers
runtime wakeup.

Use the new .setup() and .cleanup() callbacks in struct acpi_bus_type
to consolidate that code and do the setup and the cleanup each in one
place.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: NYinghai Lu <yinghai@kernel.org>
Acked-by: NToshi Kani <toshi.kani@hp.com>

Make it possible to ask the routines used for adding/removing devices
to/from the general ACPI PM domain, acpi_dev_pm_attach() and
acpi_dev_pm_detach(), respectively, to change the power states of
devices so that they are put into the full-power state automatically
by acpi_dev_pm_attach() and into the lowest-power state available
automatically by acpi_dev_pm_detach().
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Tested-by: NMika Westerberg <mika.westerberg@linux.intel.com>

Some bus types don't support power management natively, but generally
there may be device nodes in ACPI tables corresponding to the devices
whose bus types they are (under ACPI 5 those bus types may be SPI,
I2C and platform).  If that is the case, standard ACPI power
management may be applied to those devices, although currently the
kernel has no means for that.

For this reason, provide a set of routines that may be used as power
management callbacks for such devices.  This may be done in three
different ways.

 (1) Device drivers handling the devices in question may run
     acpi_dev_pm_attach() in their .probe() routines, which (on
     success) will cause the devices to be added to the general ACPI
     PM domain and ACPI power management will be used for them going
     forward.  Then, acpi_dev_pm_detach() may be used to remove the
     devices from the general ACPI PM domain if ACPI power management
     is not necessary for them any more.

 (2) The devices' subsystems may use acpi_subsys_runtime_suspend(),
     acpi_subsys_runtime_resume(), acpi_subsys_prepare(),
     acpi_subsys_suspend_late(), acpi_subsys_resume_early() as their
     power management callbacks in the same way as the general ACPI
     PM domain does that.

 (3) The devices' drivers may execute acpi_dev_suspend_late(),
     acpi_dev_resume_early(), acpi_dev_runtime_suspend(),
     acpi_dev_runtime_resume() from their power management callbacks
     as appropriate, if that's absolutely necessary, but it is not
     recommended to do that, because such drivers may not work
     without ACPI support as a result.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Introduce helper function returning the target sleep state of the
system and use it to move the remaining device power management
functions from sleep.c to device_pm.c.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Two device wakeup management routines in device_pm.c and sleep.c,
acpi_pm_device_run_wake() and acpi_pm_device_sleep_wake(), take a
device pointer argument and use it to obtain the ACPI handle of the
corresponding ACPI namespace node.  That handle is then used to get
the address of the struct acpi_device object corresponding to the
struct device passed as the argument.

Unfortunately, that last operation may be costly, because it involves
taking the global ACPI namespace mutex, so it shouldn't be carried
out too often.  However, the callers of those routines usually call
them in a row with acpi_pm_device_sleep_state() which also takes that
mutex for the same reason, so it would be more efficient if they ran
acpi_bus_get_device() themselves to obtain a pointer to the struct
acpi_device object in question and then passed that pointer to the
appropriate PM routines.

To make that possible, split each of the PM routines mentioned above
in two parts, one taking a struct acpi_device pointer argument and
the other implementing the current interface for compatibility.

Additionally, change acpi_pm_device_run_wake() to actually return
an error code if there is an error while setting up runtime remote
wakeup for the device.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The ACPI function for setting up devices to do runtime remote
wakeup is now located in drivers/acpi/sleep.c, but
drivers/acpi/device_pm.c is a more logical place for it, so move it
there.

No functional changes should result from this modification.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The ACPI function for choosing device power state is now located
in drivers/acpi/sleep.c, but drivers/acpi/device_pm.c is a more
logical place for it, so move it there.

However, instead of moving the function entirely, move its core only
under a different name and with a different list of arguments, so
that it is more flexible, and leave a wrapper around it in the
original location.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI routines for adding and removing device wakeup notifiers are
currently defined in a PCI-specific file, but they will be necessary
for non-PCI devices too, so move them to a separate file under
drivers/acpi and rename them to indicate their ACPI origins.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>