Revert commit eed4d47efe95 (ACPI / sleep: Ignore spurious SCI wakeups
from suspend-to-idle) as it turned out to be premature and triggered
a number of different issues on various systems.

That includes, but is not limited to, premature suspend-to-RAM aborts
on Dell XPS 13 (9343) reported by Dominik.

The issue the commit in question attempted to address is real and
will need to be taken care of going forward, but evidently more work
is needed for this purpose.

Reported-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

The ACPI SCI (System Control Interrupt) is set up as a wakeup IRQ
during suspend-to-idle transitions and, consequently, any events
signaled through it wake up the system from that state.  However,
on some systems some of the events signaled via the ACPI SCI while
suspended to idle should not cause the system to wake up.  In fact,
quite often they should just be discarded.

Arguably, systems should not resume entirely on such events, but in
order to decide which events really should cause the system to resume
and which are spurious, it is necessary to resume up to the point
when ACPI SCIs are actually handled and processed, which is after
executing dpm_resume_noirq() in the system resume path.

For this reasons, add a loop around freeze_enter() in which the
platforms can process events signaled via multiplexed IRQ lines
like the ACPI SCI and add suspend-to-idle hooks that can be
used for this purpose to struct platform_freeze_ops.

In the ACPI case, the ->wake hook is used for checking if the SCI
has triggered while suspended and deferring the interrupt-induced
system wakeup until the events signaled through it are actually
processed sufficiently to decide whether or not the system should
resume.  In turn, the ->sync hook allows all of the relevant event
queues to be flushed so as to prevent events from being missed due
to race conditions.

In addition to that, some ACPI code processing wakeup events needs
to be modified to use the "hard" version of wakeup triggers, so that
it will cause a system resume to happen on device-induced wakeup
events even if the "soft" mechanism to prevent the system from
suspending is not enabled (that also helps to catch device-induced
wakeup events occurring during suspend transitions in progress).

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Drivers that needs acpi_device_fix_up_power(), allow them to be built as
modules by exporting this function.

Cc: <stable@vger.kernel.org> # 4.5+
Tested-by: Laszlo Fiat <laszlo.fiat@gmail.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Adds a function that sets the pointer to dev_pm_domain in struct device
and that warns if the device has already finished probing. The reason
why we want to enforce that is because in the general case that can
cause problems and also that we can simplify code quite a bit if we can
always assume that.

This patch also changes all current code that directly sets the
dev.pm_domain pointer.

Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

There is a concern that if the platform firmware was involved in
the system resume that's being completed,  some devices might have
been reset by it and if those devices had the power.direct_complete
flag set during the preceding suspend transition, they may stay
in a reset-power-on state indefinitely (until they are runtime-resumed
and then suspended again).  That may not be a big deal from the
individual device's perspective, but if the system is an SoC, it may
be prevented from entering deep SoC-wide low-power states on idle
because of that.

The devices that are most likely to be affected by this issue are
PCI devices and ACPI-enumerated devices using the general ACPI PM
domain, so to prevent it from happening for those devices, force a
runtime resume for them if they have their power.direct_complete
flags set and the platform firmware was involved in the resume
transition currently in progress.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

* acpi-pm:
  ACPI / bus: Move duplicate code to a separate new function
  mfd: Add support for Intel Sunrisepoint LPSS devices
  dmaengine: add a driver for Intel integrated DMA 64-bit
  mfd: make mfd_remove_devices() iterate in reverse order
  driver core: implement device_for_each_child_reverse()
  klist: implement klist_prev()
  Driver core: wakeup the parent device before trying probe
  ACPI / PM: Attach ACPI power domain only once
  PM / QoS: Make it possible to expose device latency tolerance to userspace
  ACPI / PM: Update the copyright notice and description of power.c

* acpi-scan:
  ACPI / bus: Move ACPI bus type registration
  ACPI / scan: Move bus operations and notification routines to bus.c
  ACPI / scan: Move device matching code to bus.c
  ACPI / scan: Move sysfs-related device code to a separate file

* acpi-processor:
  PCC: Disable compilation by default
  ACPI: Decouple ACPI idle and ACPI processor drivers
  ACPI: Split out ACPI PSS from ACPI Processor driver
  PCC: Initialize PCC Mailbox earlier at boot
  ACPI / processor: remove leftover __refdata annotations

* acpi-assorted:
  ACPI: fix acpi_debugfs_init prototype
  ACPI: Remove FSF mailing addresses

Commit 20dacb71ad28 ("ACPI / PM: Rework device power management to follow
ACPI 6") changed the device power management to use D3hot if the device
in question does not have _PR3 method even if D3cold was requested by the
caller.

However, if the device has _PR3 device->power.state is also set to D3hot
instead of D3Cold after power resources have been turned off because
device->power.state will be assigned from "state" instead of
"target_state".

Next time the device is transitioned to D0, acpi_power_transition() will
find that the current power state of the device is D3hot instead of D3cold
which causes it to power down all resources required for the current
(wrong) state D3hot.

Below is a simplified ASL example of a real touch panel device which
triggers the problem:

  Scope (TPL1)
  {
      Name (_PR0, Package (1) { \_SB.PCI0.I2C1.PXTC })
      Name (_PR3, Package (1) { \_SB.PCI0.I2C1.PXTC })
      ...
  }

In both D0 and D3hot the same power resource is required. However, when
acpi_power_transition() turns off power resources required for D3hot (as
the device is transitioned to D0) it powers down PXTC which then makes the
device to lose its power.

Fix this by assigning "target_state" to the device power state instead of
"state" that is always D3hot even for devices with valid _PR3.

Fixes: 20dacb71ad28 (ACPI / PM: Rework device power management to follow ACPI 6)
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Some devices, like MFD subdevices, share a single ACPI companion device so
that they are able to access their resources and children. However,
currently all these subdevices are attached to the ACPI power domain and
this might cause that the power methods for the companion device get called
more than once.

In order to solve this we attach the ACPI power domain only to the first
physical device that is bound to the ACPI companion device. In case of MFD
devices, this is the parent MFD device itself.

Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>