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: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: 3.9+ <stable@vger.kernel.org>

* acpi-pm:
  ACPI / PM: Fix possible NULL pointer deref in acpi_pm_device_sleep_state()

* pm-assorted:
  PM / QoS: Add pm_qos and dev_pm_qos to events-power.txt
  PM / QoS: Add dev_pm_qos_request tracepoints
  PM / QoS: Add pm_qos_request tracepoints
  PM / QoS: Add pm_qos_update_target/flags tracepoints
  PM / QoS: Update Documentation/power/pm_qos_interface.txt
  PM / Sleep: Print last wakeup source on failed wakeup_count write
  PM / QoS: correct the valid range of pm_qos_class
  PM / wakeup: Adjust messaging for wake events during suspend
  PM / Runtime: Update .runtime_idle() callback documentation
  PM / Runtime: Rework the "runtime idle" helper routine
  PM / Hibernate: print physical addresses consistently with other parts of kernel

* acpi-pm:
  ACPI / PM: Rework and clean up acpi_dev_pm_get_state()
  ACPI / PM: Replace ACPI_STATE_D3 with ACPI_STATE_D3_COLD in device_pm.c
  ACPI / PM: Rename function acpi_device_power_state() and make it static
  ACPI / PM: acpi_processor_suspend() can be static
  xen / ACPI / sleep: Register an acpi_suspend_lowlevel callback.
  x86 / ACPI / sleep: Provide registration for acpi_suspend_lowlevel.

After commit fa1675b (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: Aaron Lu <aaron.lu@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Commit 7cd8407 (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: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Rafael 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: Rafael 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: Rafael 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: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Commit b378549 (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=58201
Reported-and-tested-by: Jerome Cantenot <jerome.cantenot@gmail.com>
Tracked-down-by: Lan Tianyu <tianyu.lan@intel.com>
Cc: 3.9+ <stable@vger.kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>