ACPI: PM: Add acpi_device_fix_up_power_children() function

In some cases it is necessary to fix-up the power-state of an ACPI
device's children without touching the ACPI device itself add
a new acpi_device_fix_up_power_children() function for this.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Cc: 6.6+ <stable@vger.kernel.org> # 6.6+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

PCI/ACPI: Account for _S0W of the target bridge in acpi_pci_bridge_d3()

It is questionable to allow a PCI bridge to go into D3 if it has _S0W
returning D2 or a shallower power state, so modify acpi_pci_bridge_d3(() to
always take the return value of _S0W for the target bridge into account.
That is, make it return 'false' if _S0W returns D2 or a shallower power
state for the target bridge regardless of its ancestor Root Port
properties. Of course, this also causes 'false' to be returned if the Root
Port itself is the target and its _S0W returns D2 or a shallower power
state.

However, still allow bridges without _S0W that are power-manageable via
ACPI to enter D3 to retain the current code behavior in that case.

This fixes problems where a hotplug notification is missed because a bridge
is in D3. That means hot-added devices such as USB4 docks (and the devices
they contain) and Thunderbolt 3 devices may not work.

Link: https://lore.kernel.org/linux-pci/20221031223356.32570-1-mario.limonciello@amd.com/
Link: https://lore.kernel.org/r/12155458.O9o76ZdvQC@kreacher
Reported-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

ACPI: PM: Take wake IRQ into consideration when entering suspend-to-idle

This change adds support for ACPI devices that use ExclusiveAndWake or
SharedAndWake in their _CRS GpioInt definition (instead of using _PRW),
and also provide power resources. Previously the ACPI subsystem had no
idea if the device had a wake capable interrupt armed. This resulted
in the ACPI device PM system placing the device into D3Cold, and thus
cutting power to the device. With this change we will now query the
_S0W method to figure out the appropriate wake capable D-state.

Signed-off-by: Raul E Rangel <rrangel@chromium.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI: PM: Fix NULL argument handling in acpi_device_get/set_power()

In principle, it should be valid to pass NULL as the ACPI device
pointer to acpi_device_get_power() and acpi_device_set_power() and they
both are expected to return -EINVAL in that case, but that has been
broken recently by commit 62fcb99bdf10 ("ACPI: Drop parent field from
struct acpi_device") which has caused the ACPI device pointer to be
dereferenced in these functions before the NULL check.

Fix that and while at it make acpi_device_set_power() only use the
parent field if the target ACPI device object's ignore_parent flag
in not set.

Fixes: 62fcb99bdf10 ("ACPI: Drop parent field from struct acpi_device")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI: Drop parent field from struct acpi_device

The parent field in struct acpi_device is, in fact, redundant,
because the dev.parent field in it effectively points to the same
object and it is used by the driver core.

Accordingly, the parent field can be dropped from struct acpi_device
and for this purpose define acpi_dev_parent() to retrieve a parent
struct acpi_device pointer from the dev.parent field in struct
acpi_device. Next, update all of the users of the parent field
in struct acpi_device to use acpi_dev_parent() instead of it and
drop it.

While at it, drop the ACPI_IS_ROOT_DEVICE() macro that is only used
in one place in a confusing way.

No intentional functional impact.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Mark Brown <broonie@kernel.org>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Wei Liu <wei.liu@kernel.org>
Reviewed-by: Punit Agrawal <punit.agrawal@bytedance.com>

ACPI: PM: Fix acpi_dev_state_d0() kerneldoc

The documentation for acpi_dev_state_d0() referred to
Documentation/firmware-guide/acpi/low-power-probe.rst that does not exist,
the right file name is Documentation/firmware-guide/acpi/non-d0-probe.rst.
Fix this.

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
[ rjw: Subject edits ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI: Rename acpi_bus_get/put_acpi_device()

Because acpi_bus_get_acpi_device() is completely analogous to
acpi_fetch_acpi_dev(), rename it to acpi_get_acpi_dev() and
add a kerneldoc comment to it.

Accordingly, rename acpi_bus_put_acpi_device() to acpi_put_acpi_dev()
and update all of the users of these two functions.

While at it, move the acpi_fetch_acpi_dev() header next to the
acpi_get_acpi_dev() header in the header file holding them.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Punit Agrawal <punit.agrawal@bytedance.com>

ACPI / MMC: PM: Unify fixing up device power

Introduce acpi_device_fix_up_power_extended() for fixing up power of
a device having an ACPI companion in a manner that takes the device's
children into account and make the MMC code use it in two places
instead of walking the list of the device ACPI companion's children
directly.

This will help to eliminate the children list head from struct
acpi_device as it is redundant and it is used in questionable ways
in some places (in particular, locking is needed for walking the
list pointed to it safely, but it is often missing).

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>

ACPI: bus: Avoid non-ACPI device objects in walks over children

When walking the children of an ACPI device, take extra care to avoid
using to_acpi_device() on the ones that are not ACPI devices, because
that may lead to out-of-bounds access and memory corruption.

While at it, make the function passed to acpi_dev_for_each_child()
take a struct acpi_device pointer argument (instead of a struct device
one), so it is more straightforward to use.

Fixes: b7dd6298db81 ("ACPI: PM: Introduce acpi_dev_power_up_children_with_adr()")
Reported-by: kernel test robot <oliver.sang@intel.com>
BugLink: https://lore.kernel.org/lkml/20220420064725.GB16310@xsang-OptiPlex-9020/
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>

ACPI: PM: Always print final debug message in acpi_device_set_power()

acpi_device_set_power() prints debug messages regarding its outcome
(whether or not the power state has been changed and how) in all
cases except when the device whose power state is being changed to D0
is in that power state already.

Make acpi_device_set_power() print a final debug message in that case
too and while at it, fix the indentation of the "end" label in this
function.

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

ACPI: PM: Introduce acpi_dev_power_up_children_with_adr()

Introduce a function powering up all of the children of a given ACPI
device object that are power-manageable and hold valid _ADR ACPI
objects so as to make it possible to prepare the corresponding
"physical" devices for enumeration carried out by a bus type driver,
like PCI.

This function will be used in a subsequent change set.

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

ACPI: PM: Unify debug messages in acpi_device_set_power()

Convert all of the debug messages printed by acpi_device_set_power()
to acpi_handle_debug() and adjust them slightly for consistency with
acpi_device_get_power() and other acpi_device_set_power() debug
messages.

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

ACPI: PM: Change pr_fmt() in device_pm.c

All messages printed by functions in this file either contain
the "ACPI" or "acpi" string regardless of the format, or they don't
need to contain it at all.

In the former case, the "ACPI:" string added by the format is
redundant, so drop it from there.

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

ACPI: PM: Convert debug message in acpi_device_get_power()

Convert the debug message printed by acpi_device_get_power() to
acpi_handle_debug(), because that function is also called when
the ACPI device object name has not been set yet and the dev_dbg()
message printed by it at that time is not useful.

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

ACPI: Use acpi_fetch_acpi_dev() instead of acpi_bus_get_device()

Modify the ACPI code to use acpi_fetch_acpi_dev() instead of
acpi_bus_get_device() where applicable.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>

ACPI: Add a convenience function to tell a device is in D0 state

Add a convenience function to tell whether a device is in D0 state,
primarily for use in drivers' probe or remove functions on busses where
the custom is to power on the device for the duration of both.

Returns false on non-ACPI systems.

Suggested-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Tomasz Figa <tfiga@chromium.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI: Add quirks for AMD Renoir/Lucienne CPUs to force the D3 hint

AMD systems from Renoir and Lucienne require that the NVME controller
is put into D3 over a Modern Standby / suspend-to-idle
cycle. This is "typically" accomplished using the `StorageD3Enable`
property in the _DSD, but this property was introduced after many
of these systems launched and most OEM systems don't have it in
their BIOS.

On AMD Renoir without these drives going into D3 over suspend-to-idle
the resume will fail with the NVME controller being reset and a trace
like this in the kernel logs:
```
[ 83.556118] nvme nvme0: I/O 161 QID 2 timeout, aborting
[ 83.556178] nvme nvme0: I/O 162 QID 2 timeout, aborting
[ 83.556187] nvme nvme0: I/O 163 QID 2 timeout, aborting
[ 83.556196] nvme nvme0: I/O 164 QID 2 timeout, aborting
[ 95.332114] nvme nvme0: I/O 25 QID 0 timeout, reset controller
[ 95.332843] nvme nvme0: Abort status: 0x371
[ 95.332852] nvme nvme0: Abort status: 0x371
[ 95.332856] nvme nvme0: Abort status: 0x371
[ 95.332859] nvme nvme0: Abort status: 0x371
[ 95.332909] PM: dpm_run_callback(): pci_pm_resume+0x0/0xe0 returns -16
[ 95.332936] nvme 0000:03:00.0: PM: failed to resume async: error -16
```

The Microsoft documentation for StorageD3Enable mentioned that Windows has
a hardcoded allowlist for D3 support, which was used for these platforms.
Introduce quirks to hardcode them for Linux as well.

As this property is now "standardized", OEM systems using AMD Cezanne and
newer APU's have adopted this property, and quirks like this should not be
necessary.

CC: Shyam-sundar S-k <Shyam-sundar.S-k@amd.com>
CC: Alexander Deucher <Alexander.Deucher@amd.com>
CC: Prike Liang <prike.liang@amd.com>
Link: https://docs.microsoft.com/en-us/windows-hardware/design/component-guidelines/power-management-for-storage-hardware-devices-intro
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: Julian Sikorski <belegdol@gmail.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

ACPI: Check StorageD3Enable _DSD property in ACPI code

Although first implemented for NVME, this check may be usable by
other drivers as well. Microsoft's specification explicitly mentions
that is may be usable by SATA and AHCI devices. Google also indicates
that they have used this with SDHCI in a downstream kernel tree that
a user can plug a storage device into.

Link: https://docs.microsoft.com/en-us/windows-hardware/design/component-guidelines/power-management-for-storage-hardware-devices-intro
Suggested-by: Keith Busch <kbusch@kernel.org>
CC: Shyam-sundar S-k <Shyam-sundar.S-k@amd.com>
CC: Alexander Deucher <Alexander.Deucher@amd.com>
CC: Rafael J. Wysocki <rjw@rjwysocki.net>
CC: Prike Liang <prike.liang@amd.com>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

ACPI: PM: postpone bringing devices to D0 unless we need them

Currently ACPI power domain brings devices into D0 state in the "resume
early" phase. Normally this does not cause any issues, as powering up
happens quickly. However there are peripherals that have certain timing
requirements for powering on, for example some models of Elan
touchscreens need 300msec after powering up/releasing reset line before
they can accept commands from the host. Such devices will dominate
the time spent in early resume phase and cause increase in overall
resume time as we wait for early resume to complete before we can
proceed to the normal resume stage.

There are ways for a driver to indicate that it can tolerate device
being in the low power mode and that it knows how to power the device
back up when resuming, bit that requires changes to individual drivers
that may not really care about details of ACPI controlled power
management.

This change attempts to solve this issue at ACPI power domain level, by
postponing powering up device until we get to the normal resume stage,
unless there is early resume handler defined for the device, or device
does not declare any resume handlers, in which case we continue powering
up such devices early. This allows us to shave off several hundred
milliseconds of resume time on affected systems.

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI: PM / fan: Put fan device IDs into separate header file

The ACPI fan device IDs are shared between the fan driver and the
device power management code. The former is modular, so it needs
to include the table of device IDs for module autoloading and the
latter needs that list to avoid attaching the generic ACPI PM domain
to fan devices (which doesn't make sense) possibly before the fan
driver module is loaded.

Unfortunately, that requires the list of fan device IDs to be
updated in two places which is prone to mistakes, so put it into
a symbol definition in a separate header file so there is only one
copy of it in case it needs to be updated again in the future.

Fixes: b9ea0bae260f ("ACPI: PM: Avoid attaching ACPI PM domain to certain devices")
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI: PM: Add ACPI ID of Alder Lake Fan

Add a new unique fan ACPI device ID for Alder Lake to
support it in acpi_dev_pm_attach() function.

Fixes: 38748bcb940e ("ACPI: DPTF: Support Alder Lake")
Signed-off-by: Sumeet Pawnikar <sumeet.r.pawnikar@intel.com>
Acked-by: Zhang Rui <rui.zhang@intel.com>
Cc: 5.10+ <stable@vger.kernel.org> # 5.10+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI: PM: add a missed blank line after declarations

Add a missed blank line after declarations, reported by checkpatch.pl.

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

ACPI: PM: Clean up printing messages

Replace the remaining ACPI_DEBUG_PRINT() instances in device_pm.c
with dev_dbg() invocations, drop the _COMPONENT and ACPI_MODULE_NAME()
definitions that are not used any more, and drop the no longer needed
ACPI_POWER_COMPONENT definition from the headers and documentation.

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

PM: ACPI: Refresh wakeup device power configuration every time

When wakeup signaling is enabled for a bridge for the second (or every
next) time in a row, its existing device wakeup power configuration
may not match the new conditions. For example, some devices below
it may have been put into low-power states and that changes the
device wakeup power conditions or similar. This causes functional
problems to appear on some systems (for example, because of it the
Thunderbolt port on Dell Precision 5550 cannot detect devices plugged
in after it has been suspended).

For this reason, modify __acpi_device_wakeup_enable() to refresh the
device wakeup power configuration of the target device on every
invocation, not just when it is called for that device first time
in a row.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reported-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Tested-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>

PM: ACPI: PCI: Drop acpi_pm_set_bridge_wakeup()

The idea behind acpi_pm_set_bridge_wakeup() was to allow bridges to
be reference counted for wakeup enabling, because they may be enabled
to signal wakeup on behalf of their subordinate devices and that
may happen for multiple times in a row, whereas for the other devices
it only makes sense to enable wakeup signaling once.

However, this becomes problematic if the bridge itself is suspended,
because it is treated as a "regular" device in that case and the
reference counting doesn't work.

For instance, suppose that there are two devices below a bridge and
they both can signal wakeup. Every time one of them is suspended,
wakeup signaling is enabled for the bridge, so when they both have
been suspended, the bridge's wakeup reference counter value is 2.

Say that the bridge is suspended subsequently and acpi_pci_wakeup()
is called for it. Because the bridge can signal wakeup, that
function will invoke acpi_pm_set_device_wakeup() to configure it
and __acpi_pm_set_device_wakeup() will be called with the last
argument equal to 1. This causes __acpi_device_wakeup_enable()
invoked by it to omit the reference counting, because the reference
counter of the target device (the bridge) is 2 at that time.

Now say that the bridge resumes and one of the device below it
resumes too, so the bridge's reference counter becomes 0 and
wakeup signaling is disabled for it, but there is still the other
suspended device which may need the bridge to signal wakeup on its
behalf and that is not going to work.

To address this scenario, use wakeup enable reference counting for
all devices, not just for bridges, so drop the last argument from
__acpi_device_wakeup_enable() and __acpi_pm_set_device_wakeup(),
which causes acpi_pm_set_device_wakeup() and
acpi_pm_set_bridge_wakeup() to become identical, so drop the latter
and use the former instead of it everywhere.

Fixes: 1ba51a7c1496 ("ACPI / PCI / PM: Rework acpi_pci_propagate_wakeup()")
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: 4.14+ <stable@vger.kernel.org> # 4.14+

ACPI: PM: Avoid using power resources if there are none for D0

As recently reported, some platforms provide a list of power
resources for device power state D3hot, through the _PR3 object,
but they do not provide a list of power resources for device power
state D0.

Among other things, this causes acpi_device_get_power() to return
D3hot as the current state of the device in question if all of the
D3hot power resources are "on", because it sees the power_resources
flag set and calls acpi_power_get_inferred_state() which finds that
D3hot is the shallowest power state with all of the associated power
resources turned "on", so that's what it returns. Moreover, that
value takes precedence over the acpi_dev_pm_explicit_get() return
value, because it means a deeper power state. The device may very
well be in D0 physically at that point, however.

Moreover, the presence of _PR3 without _PR0 for a given device
means that only one D3-level power state can be supported by it.
Namely, because there are no power resources to turn "off" when
transitioning the device from D0 into D3cold (which should be
supported since _PR3 is present), the evaluation of _PS3 should
be sufficient to put it straight into D3cold, but this means that
the effect of turning "on" the _PR3 power resources is unclear,
so it is better to avoid doing that altogether. Consequently,
there is no practical way do distinguish D3cold from D3hot for
the device in question and the power states of it can be labeled
so that D3hot is the deepest supported one (and Linux assumes
that putting a device into D3hot via ACPI may cause power to be
removed from it anyway, for legacy reasons).

To work around the problem described above modify the ACPI
enumeration of devices so that power resources are only used
for device power management if the list of D0 power resources
is not empty and make it mart D3cold as supported only if that
is the case and the D3hot list of power resources is not empty
too.

Fixes: ef85bdbec444 ("ACPI / scan: Consolidate extraction of power resources lists")
Link: https://bugzilla.kernel.org/show_bug.cgi?id=205057
Link: https://lore.kernel.org/linux-acpi/20200603194659.185757-1-hdegoede@redhat.com/
Reported-by: Hans de Goede <hdegoede@redhat.com>
Tested-by: Hans de Goede <hdegoede@redhat.com>
Tested-by: youling257@gmail.com
Cc: 3.10+ <stable@vger.kernel.org> # 3.10+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>

PM: ACPI: Output correct message on target power state

Transitioned power state logged at the end of setting ACPI power.

However, D3cold won't be in the message because state can only be
D3hot at most.

Use target_state to corretly report when power state is D3cold.

Cc: All applicable <stable@vger.kernel.org>
Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

PM: sleep: core: Rename dev_pm_smart_suspend_and_suspended()

Because all callers of dev_pm_smart_suspend_and_suspended use it only
for checking whether or not to skip driver suspend callbacks for a
device, rename it to dev_pm_skip_suspend() in analogy with
dev_pm_skip_resume().

No functional impact.

Suggested-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>

PM: sleep: core: Rename dev_pm_may_skip_resume()

The name of dev_pm_may_skip_resume() may be easily confused with the
power.may_skip_resume flag which is not checked by that function, so
rename the former as dev_pm_skip_resume().

No functional impact.

Suggested-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>

PM: sleep: core: Rework the power.may_skip_resume handling

Because the power.may_skip_resume device status bit is taken
into account in combination with the DPM_FLAG_LEAVE_SUSPENDED
driver flag, it can be set to 'true' for all devices in the
"suspend" phase of a suspend-resume cycle, so do that.

Then, neither the PM core nor the middle-layer (sybsystem) code
handling it needs to set it to 'true' any more and it just has
to be cleared if there is a reason to avoid skipping the "noirq"
and "early" resume callbacks provided by the driver, so update
the code in question accordingly.

Suggested-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>

PM: sleep: core: Do not skip callbacks in the resume phase

The current code in device_resume_noirq() causes the entire early
resume and resume phases of device suspend to be skipped for
devices for which the noirq resume phase have been skipped (due
to the LEAVE_SUSPENDED flag being set) on the premise that those
devices should stay in runtime-suspend after system-wide resume.

However, that may not be correct in two situations. First, the
middle layer (subsystem) noirq resume callback may be missing for
a given device, but its early resume callback may be present and it
may need to do something even if it decides to skip the driver
callback. Second, if the device's wakeup settings were adjusted
in the suspend phase without resuming the device (that was in
runtime suspend at that time), they most likely need to be
adjusted again in the resume phase and so the driver callback
in that phase needs to be run.

For the above reason, modify the core to allow the middle layer
->resume_late callback to run even if its ->resume_noirq callback
is missing (and the core has skipped the driver-level callback
in that phase) and to allow all device callbacks to run in the
resume phase. Also make the core set the PM-runtime status of
devices with SMART_SUSPEND set whose resume callbacks are not
skipped to "active" in the "noirq" resume phase and update the
affected subsystems (PCI and ACPI) accordingly.

After this change, middle-layer (subsystem) callbacks will always
be invoked in all phases of system suspend and resume and driver
callbacks will always run in the prepare, suspend, resume, and
complete phases for all devices.

For devices with SMART_SUSPEND set, driver callbacks will be
skipped in the late and noirq phases of system suspend if those
devices remain in runtime suspend in __device_suspend_late().
Driver callbacks will also be skipped for them during the
noirq and early phases of the "thaw" transition related to
hibernation in that case.

Setting LEAVE_SUSPENDED means that the driver allows its callbacks
to be skipped in the noirq and early phases of system resume, but
some additional conditions need to be met for that to happen (among
other things, the power.may_skip_resume flag needs to be set for the
device during system suspend for the driver callbacks to be skipped
during the subsequent resume transition).

For all devices with SMART_SUSPEND set whose driver callbacks are
invoked during system resume, the PM-runtime status will be set to
"active" (by the core).

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>

ACPI: Update Tiger Lake ACPI device IDs

Tiger Lake's new unique ACPI device IDs for DPTF and fan drivers are not
valid as the IDs are missing 'C'. Fix the IDs by updating them.

After the update, the new IDs should now look like
INT1047 --> INTC1047
INT1040 --> INTC1040
INT1043 --> INTC1043
INT1044 --> INTC1044

Fixes: 55cfe6a5c582 ("ACPI: DPTF: Add Tiger Lake ACPI device IDs")
Fixes: c248dfe7e0ca ("ACPI: fan: Add Tiger Lake ACPI device ID")
Suggested-by: Srinivas Pandruvada <srinivas.pandruvada@intel.com>
Signed-off-by: Gayatri Kammela <gayatri.kammela@intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI: fan: Add Tiger Lake ACPI device ID

Tiger Lake has a new unique ACPI device ID for the ACPI fan that
needs to be added to the fan driver and to the blacklist in
acpi_dev_pm_attach() to support it.

Signed-off-by: Gayatri Kammela <gayatri.kammela@intel.com>
[ rjw: Subject & changelog, fold in another patch ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI: PM: Avoid attaching ACPI PM domain to certain devices

Certain ACPI-enumerated devices represented as platform devices in
Linux, like fans, require special low-level power management handling
implemented by their drivers that is not in agreement with the ACPI
PM domain behavior. That leads to problems with managing ACPI fans
during system-wide suspend and resume.

For this reason, make acpi_dev_pm_attach() skip the affected devices
by adding a list of device IDs to avoid to it and putting the IDs of
the affected devices into that list.

Fixes: e5cc8ef31267 (ACPI / PM: Provide ACPI PM callback routines for subsystems)
Reported-by: Zhang Rui <rui.zhang@intel.com>
Tested-by: Todd Brandt <todd.e.brandt@linux.intel.com>
Cc: 3.10+ <stable@vger.kernel.org> # 3.10+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

PM / wakeup: Show wakeup sources stats in sysfs

Add an ID and a device pointer to 'struct wakeup_source'. Use them to to
expose wakeup sources statistics in sysfs under
/sys/class/wakeup/wakeup<ID>/*.

Co-developed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Co-developed-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Tri Vo <trong@android.com>
Tested-by: Kalesh Singh <kaleshsingh@google.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI: PM: Print debug messages on device power state changes

Add an acpi_handle_debug() statement to acpi_device_set_power() to
allow ACPI device power state changes to be tracked.

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

ACPI: PM: Fix regression in acpi_device_set_power()

Commit f850a48a0799 ("ACPI: PM: Allow transitions to D0 to occur in
special cases") overlooked the fact that acpi_power_transition() may
change the power.state value for the target device and if that
happens, it may confuse acpi_device_set_power() and cause it to
omit the _PS0 evaluation which on some systems is necessary to
change power states of devices from low-power to D0.

Fix that by saving the current value of power.state for the
target device before passing it to acpi_power_transition() and
using the saved value in a subsequent check.

Fixes: f850a48a0799 ("ACPI: PM: Allow transitions to D0 to occur in special cases")
Reported-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Reported-by: Mario Limonciello <mario.limonciello@dell.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Tested-by: Mario Limonciello <mario.limonciello@dell.com>

ACPI: PM: Unexport acpi_device_get_power()

Using acpi_device_get_power() outside of ACPI device initialization
and ACPI sysfs is problematic due to the way in which power resources
are handled by it, so unexport it and add a paragraph explaining the
pitfalls to its kerneldoc comment.

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

ACPI: PM: Introduce "poweroff" callbacks for ACPI PM domain and LPSS

In general, it is not correct to call pm_generic_suspend(),
pm_generic_suspend_late() and pm_generic_suspend_noirq() during the
hibernation's "poweroff" transition, because device drivers may
provide special callbacks to be invoked then and the wrappers in
question cause system suspend callbacks to be run. Unfortunately,
that happens in the ACPI PM domain and ACPI LPSS.

To address this potential issue, introduce "poweroff" callbacks
for the ACPI PM and LPSS that will use pm_generic_poweroff(),
pm_generic_poweroff_late() and pm_generic_poweroff_noirq() as
appropriate.

Fixes: 05087360fd7a (ACPI / PM: Take SMART_SUSPEND driver flag into account)
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>

ACPI: PM: Simplify and fix PM domain hibernation callbacks

First, after a previous change causing all runtime-suspended devices
in the ACPI PM domain (and ACPI LPSS devices) to be resumed before
creating a snapshot image of memory during hibernation, it is not
necessary to worry about the case in which them might be left in
runtime-suspend any more, so get rid of the code related to that from
ACPI PM domain and ACPI LPSS hibernation callbacks.

Second, it is not correct to use pm_generic_resume_early() and
acpi_subsys_resume_noirq() in hibernation "restore" callbacks (which
currently happens in the ACPI PM domain and ACPI LPSS), so introduce
proper _restore_late and _restore_noirq callbacks for the ACPI PM
domain and ACPI LPSS.

Fixes: 05087360fd7a (ACPI / PM: Take SMART_SUSPEND driver flag into account)
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>

PM: ACPI/PCI: Resume all devices during hibernation

Both the PCI bus type and the ACPI PM domain avoid resuming
runtime-suspended devices with DPM_FLAG_SMART_SUSPEND set during
hibernation (before creating the snapshot image of system memory),
but that turns out to be a mistake. It leads to functional issues
and adds complexity that's hard to justify.

For this reason, resume all runtime-suspended PCI devices and all
devices in the ACPI PM domains before creating a snapshot image of
system memory during hibernation.

Fixes: 05087360fd7a (ACPI / PM: Take SMART_SUSPEND driver flag into account)
Fixes: c4b65157aeef (PCI / PM: Take SMART_SUSPEND driver flag into account)
Link: https://lore.kernel.org/linux-acpi/917d4399-2e22-67b1-9d54-808561f9083f@uwyo.edu/T/#maf065fe6e4974f2a9d79f332ab99dfaba635f64c
Reported-by: Robert R. Howell <RHowell@uwyo.edu>
Tested-by: Robert R. Howell <RHowell@uwyo.edu>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>

ACPI: PM: Allow transitions to D0 to occur in special cases

If a device with ACPI PM is left in D0 during a system-wide
transition to the S3 (suspend-to-RAM) or S4 (hibernation) sleep
state, the actual state of the device need not be D0 during resume
from it, although its power.state value will still reflect D0 (that
is, the power state from before the system-wide transition).

In that case, the acpi_device_set_power() call made to ensure that
the power state of the device will be D0 going forward has no effect,
because the new state (D0) is equal to the one reflected by the
device's power.state value. That does not affect power resources,
which are taken care of by acpi_resume_power_resources() called from
acpi_pm_finish() during resume from system-wide sleep states, but it
still may be necessary to invoke _PS0 for the device on top of that
in order to finalize its transition to D0.

For this reason, modify acpi_device_set_power() to allow transitions
to D0 to occur even if D0 is the current power state of the device
according to its power.state value.

That will not affect power resources, which are assumed to be in
the right configuration already (as reflected by the current values
of their reference counters), but it may cause _PS0 to be evaluated
for the device. However, evaluating _PS0 for a device already in D0
may lead to confusion in general, so invoke _PSC (if present) to
check the device's current power state upfront and only evaluate
_PS0 for it if _PSC has returned a power state different from D0.
[If _PSC is not present or the evaluation of it fails, the power
state of the device is assumed to be D0 at this point.]

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

ACPI: PM: Avoid evaluating _PS3 on transitions from D3hot to D3cold

If the power state of a device with ACPI PM is changed from D3hot to
D3cold, it merely is a matter of dropping references to additional
power resources (specifically, those in the list returned by _PR3),
and the _PS3 method should not be invoked for the device then (as
it has already been evaluated during the previous transition to
D3hot).

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

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 174

Based on 1 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation this program is
distributed in the hope that it will be useful but without any
warranty without even the implied warranty of merchantability or
fitness for a particular purpose see the gnu general public license
for more details

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference in 655 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070034.575739538@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

ACPI/PCI: PM: Add missing wakeup.flags.valid checks

Both acpi_pci_need_resume() and acpi_dev_needs_resume() check if the
current ACPI wakeup configuration of the device matches what is
expected as far as system wakeup from sleep states is concerned, as
reflected by the device_may_wakeup() return value for the device.

However, they only should do that if wakeup.flags.valid is set for
the device's ACPI companion, because otherwise the wakeup.prepare_count
value for it is meaningless.

Add the missing wakeup.flags.valid checks to these functions.

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

treewide: Switch printk users from %pf and %pF to %ps and %pS, respectively

%pF and %pf are functionally equivalent to %pS and %ps conversion
specifiers. The former are deprecated, therefore switch the current users
to use the preferred variant.

The changes have been produced by the following command:

git grep -l '%p[fF]' | grep -v '^\(tools\|Documentation\)/' | \
while read i; do perl -i -pe 's/%pf/%ps/g; s/%pF/%pS/g;' $i; done

And verifying the result.

Link: http://lkml.kernel.org/r/20190325193229.23390-1-sakari.ailus@linux.intel.com
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: sparclinux@vger.kernel.org
Cc: linux-um@lists.infradead.org
Cc: xen-devel@lists.xenproject.org
Cc: linux-acpi@vger.kernel.org
Cc: linux-pm@vger.kernel.org
Cc: drbd-dev@lists.linbit.com
Cc: linux-block@vger.kernel.org
Cc: linux-mmc@vger.kernel.org
Cc: linux-nvdimm@lists.01.org
Cc: linux-pci@vger.kernel.org
Cc: linux-scsi@vger.kernel.org
Cc: linux-btrfs@vger.kernel.org
Cc: linux-f2fs-devel@lists.sourceforge.net
Cc: linux-mm@kvack.org
Cc: ceph-devel@vger.kernel.org
Cc: netdev@vger.kernel.org
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Acked-by: David Sterba <dsterba@suse.com> (for btrfs)
Acked-by: Mike Rapoport <rppt@linux.ibm.com> (for mm/memblock.c)
Acked-by: Bjorn Helgaas <bhelgaas@google.com> (for drivers/pci)
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>

ACPI: PM: Print debug messages when enabling GPEs for wakeup

In sufficiently complicated GPE configurations it is hard to
determine which GPE could be the source of system wakeup from a sleep
state, so make __acpi_device_wakeup_enable() print that information
to the kernel log if debugging is enabled.

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

ACPI / PM: Export acpi_device_get_power() for use by modular build drivers

Export acpi_device_get_power() for use by modular build drivers.

Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

PM / Domains: Allow a better error handling of dev_pm_domain_attach()

The callers of dev_pm_domain_attach() currently checks the returned error
code for -EPROBE_DEFER and needs to ignore other error codes. This is an
unnecessary limitation, which also leads to a rather strange behaviour in
the error path.

Address this limitation, by changing the return codes from
acpi_dev_pm_attach() and genpd_dev_pm_attach(). More precisely, let them
return 0, when no PM domain is needed for the device and then return 1, in
case the device was successfully attached to its PM domain. In this way,
dev_pm_domain_attach(), gets a better understanding of what happens in the
attach attempts and also allowing its caller to better act on real errors
codes.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

PM / Domains: Check for existing PM domain in dev_pm_domain_attach()

Instead of checking if an existing PM domain pointer has been assigned in
genpd_dev_pm_attach() and acpi_dev_pm_attach(), move the check to the
common path in dev_pm_domain_attach(), thus potentially avoid one
unnecessary check.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI / PM: Allow deeper wakeup power states with no _SxD nor _SxW

acpi_dev_pm_get_state() is used to determine the range of allowable
device power states when going into S3 suspend. This is implemented
by executing the _S3D and _S3W ACPI methods.

Linux follows the ACPI spec behaviour in that when _S3D is implemented
and _S3W is not, Linux will not go into a power state deeper than the one
returned by _S3D for a wakeup-enabled device.

However, this same logic is being applied to the case when neither
_S3D nor _S3W are present, and the result is that this function
decides that the device must stay in D0 (fully on) state.

This is breaking USB wakeups on Asus V222GA and Acer XC-830. _S3D and
_S3W are not present, so the USB controller is left in the D0 running
state during S3, and hence it is unable to generate a PME# wake event.

The ACPI spec is unclear on which power states are permissable for
wakeup-enabled devices when both _S3D and _S3W are missing.
However, USB wakeups work fine on these platforms under Windows, where
device manager shows that they are using D3 device state for the USB
controller in S3.

I assume that the "max = min" clamping done by the code here is
specifically written for the _S3D but no _S3W case. By making the
code true to those conditions, avoiding them on these platforms,
the controller will be put into D3 state and USB wakeups start working.

Additionally I feel that this change makes the code more directly
mirror the wording of the ACPI spec and it's associated lack of clarity.

Thanks to Mathias Nyman for pointing us in the right direction.

Signed-off-by: Daniel Drake <drake@endlessm.com>
Link: http://lkml.kernel.org/r/CAB4CAwf_k-WsF3zL4epm9TKAOu0h=Bv1XhXV_gY3bziOo_NPKA@mail.gmail.com

https://phabricator.endlessm.com/T21410
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

PM / sleep: Avoid excess pm_runtime_enable() calls in device_resume()

Middle-layer code doing suspend-time optimizations for devices with
the DPM_FLAG_SMART_SUSPEND flag set (currently, the PCI bus type and
the ACPI PM domain) needs to make the core skip ->thaw_early and
->thaw callbacks for those devices in some cases and it sets the
power.direct_complete flag for them for this purpose.

However, it turns out that setting power.direct_complete outside of
the PM core is a bad idea as it triggers an excess invocation of
pm_runtime_enable() in device_resume().

For this reason, provide a helper to clear power.is_late_suspended
and power.is_suspended to be invoked by the middle-layer code in
question instead of setting power.direct_complete and make that code
call the new helper.

Fixes: c4b65157aeef (PCI / PM: Take SMART_SUSPEND driver flag into account)
Fixes: 05087360fd7a (ACPI / PM: Take SMART_SUSPEND driver flag into account)
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>

ACPI / PM: Support for LEAVE_SUSPENDED driver flag in ACPI PM domain

Add support for DPM_FLAG_LEAVE_SUSPENDED to the ACPI PM domain by
making it (a) set the power.may_skip_resume status bit for devices
that, from its perspective, may be left in suspend after system
wakeup from sleep and (b) return early from acpi_subsys_resume_noirq()
for devices whose remaining resume callbacks during the transition
under way are going to be skipped by the PM core.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

ACPI / PM: Fix acpi_pm_notifier_lock vs flush_workqueue() deadlock

acpi_remove_pm_notifier() ends up calling flush_workqueue() while
holding acpi_pm_notifier_lock, and that same lock is taken by
by the work via acpi_pm_notify_handler(). This can deadlock.

To fix the problem let's split the single lock into two: one to
protect the dev->wakeup between the work vs. add/remove, and
another one to handle notifier installation vs. removal.

After commit a1d14934ea4b "workqueue/lockdep: 'Fix' flush_work()
annotation" I was able to kill the machine (Intel Braswell)
very easily with 'powertop --auto-tune', runtime suspending i915,
and trying to wake it up via the USB keyboard. The cases when
it didn't die are presumably explained by lockdep getting disabled
by something else (cpu hotplug locking issues usually).

Fortunately I still got a lockdep report over netconsole
(trickling in very slowly), even though the machine was
otherwise practically dead:

[ 112.179806] ======================================================
[ 114.670858] WARNING: possible circular locking dependency detected
[ 117.155663] 4.13.0-rc6-bsw-bisect-00169-ga1d14934ea4b #119 Not tainted
[ 119.658101] ------------------------------------------------------
[ 121.310242] xhci_hcd 0000:00:14.0: xHCI host not responding to stop endpoint command.
[ 121.313294] xhci_hcd 0000:00:14.0: xHCI host controller not responding, assume dead
[ 121.313346] xhci_hcd 0000:00:14.0: HC died; cleaning up
[ 121.313485] usb 1-6: USB disconnect, device number 3
[ 121.313501] usb 1-6.2: USB disconnect, device number 4
[ 134.747383] kworker/0:2/47 is trying to acquire lock:
[ 137.220790] (acpi_pm_notifier_lock){+.+.}, at: [<ffffffff813cafdf>] acpi_pm_notify_handler+0x2f/0x80
[ 139.721524]
[ 139.721524] but task is already holding lock:
[ 144.672922] ((&dpc->work)){+.+.}, at: [<ffffffff8109ce90>] process_one_work+0x160/0x720
[ 147.184450]
[ 147.184450] which lock already depends on the new lock.
[ 147.184450]
[ 154.604711]
[ 154.604711] the existing dependency chain (in reverse order) is:
[ 159.447888]
[ 159.447888] -> #2 ((&dpc->work)){+.+.}:
[ 164.183486] __lock_acquire+0x1255/0x13f0
[ 166.504313] lock_acquire+0xb5/0x210
[ 168.778973] process_one_work+0x1b9/0x720
[ 171.030316] worker_thread+0x4c/0x440
[ 173.257184] kthread+0x154/0x190
[ 175.456143] ret_from_fork+0x27/0x40
[ 177.624348]
[ 177.624348] -> #1 ("kacpi_notify"){+.+.}:
[ 181.850351] __lock_acquire+0x1255/0x13f0
[ 183.941695] lock_acquire+0xb5/0x210
[ 186.046115] flush_workqueue+0xdd/0x510
[ 190.408153] acpi_os_wait_events_complete+0x31/0x40
[ 192.625303] acpi_remove_notify_handler+0x133/0x188
[ 194.820829] acpi_remove_pm_notifier+0x56/0x90
[ 196.989068] acpi_dev_pm_detach+0x5f/0xa0
[ 199.145866] dev_pm_domain_detach+0x27/0x30
[ 201.285614] i2c_device_probe+0x100/0x210
[ 203.411118] driver_probe_device+0x23e/0x310
[ 205.522425] __driver_attach+0xa3/0xb0
[ 207.634268] bus_for_each_dev+0x69/0xa0
[ 209.714797] driver_attach+0x1e/0x20
[ 211.778258] bus_add_driver+0x1bc/0x230
[ 213.837162] driver_register+0x60/0xe0
[ 215.868162] i2c_register_driver+0x42/0x70
[ 217.869551] 0xffffffffa0172017
[ 219.863009] do_one_initcall+0x45/0x170
[ 221.843863] do_init_module+0x5f/0x204
[ 223.817915] load_module+0x225b/0x29b0
[ 225.757234] SyS_finit_module+0xc6/0xd0
[ 227.661851] do_syscall_64+0x5c/0x120
[ 229.536819] return_from_SYSCALL_64+0x0/0x7a
[ 231.392444]
[ 231.392444] -> #0 (acpi_pm_notifier_lock){+.+.}:
[ 235.124914] check_prev_add+0x44e/0x8a0
[ 237.024795] __lock_acquire+0x1255/0x13f0
[ 238.937351] lock_acquire+0xb5/0x210
[ 240.840799] __mutex_lock+0x75/0x940
[ 242.709517] mutex_lock_nested+0x1c/0x20
[ 244.551478] acpi_pm_notify_handler+0x2f/0x80
[ 246.382052] acpi_ev_notify_dispatch+0x44/0x5c
[ 248.194412] acpi_os_execute_deferred+0x14/0x30
[ 250.003925] process_one_work+0x1ec/0x720
[ 251.803191] worker_thread+0x4c/0x440
[ 253.605307] kthread+0x154/0x190
[ 255.387498] ret_from_fork+0x27/0x40
[ 257.153175]
[ 257.153175] other info that might help us debug this:
[ 257.153175]
[ 262.324392] Chain exists of:
[ 262.324392] acpi_pm_notifier_lock --> "kacpi_notify" --> (&dpc->work)
[ 262.324392]
[ 267.391997] Possible unsafe locking scenario:
[ 267.391997]
[ 270.758262] CPU0 CPU1
[ 272.431713] ---- ----
[ 274.060756] lock((&dpc->work));
[ 275.646532] lock("kacpi_notify");
[ 277.260772] lock((&dpc->work));
[ 278.839146] lock(acpi_pm_notifier_lock);
[ 280.391902]
[ 280.391902] *** DEADLOCK ***
[ 280.391902]
[ 284.986385] 2 locks held by kworker/0:2/47:
[ 286.524895] #0: ("kacpi_notify"){+.+.}, at: [<ffffffff8109ce90>] process_one_work+0x160/0x720
[ 288.112927] #1: ((&dpc->work)){+.+.}, at: [<ffffffff8109ce90>] process_one_work+0x160/0x720
[ 289.727725]

Fixes: c072530f391e (ACPI / PM: Revork the handling of ACPI device wakeup notifications)
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: 3.17+ <stable@vger.kernel.org> # 3.17+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI / PM: Take SMART_SUSPEND driver flag into account

Make the ACPI PM domain take DPM_FLAG_SMART_SUSPEND into account in
its system suspend callbacks.

[Note that the pm_runtime_suspended() check in acpi_dev_needs_resume()
is an optimization, because if is not passed, all of the subsequent
checks may be skipped and some of them are much more overhead in
general.]

Also use the observation that if the device is in runtime suspend
at the beginning of the "late" phase of a system-wide suspend-like
transition, its state cannot change going forward (runtime PM is
disabled for it at that time) until the transition is over and the
subsequent system-wide PM callbacks should be skipped for it (as
they generally assume the device to not be suspended), so add
checks for that in acpi_subsys_suspend_late/noirq() and
acpi_subsys_freeze_late/noirq().

Moreover, if acpi_subsys_resume_noirq() is called during the
subsequent system-wide resume transition and if the device was left
in runtime suspend previously, its runtime PM status needs to be
changed to "active" as it is going to be put into the full-power
state going forward, so add a check for that too in there.

In turn, if acpi_subsys_thaw_noirq() runs after the device has been
left in runtime suspend, the subsequent "thaw" callbacks need
to be skipped for it (as they may not work correctly with a
suspended device), so set the power.direct_complete flag for the
device then to make the PM core skip those callbacks.

On top of the above, make the analogous changes in the acpi_lpss
driver that uses the ACPI PM domain callbacks.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

PM / core: Add NEVER_SKIP and SMART_PREPARE driver flags

The motivation for this change is to provide a way to work around
a problem with the direct-complete mechanism used for avoiding
system suspend/resume handling for devices in runtime suspend.

The problem is that some middle layer code (the PCI bus type and
the ACPI PM domain in particular) returns positive values from its
system suspend ->prepare callbacks regardless of whether the driver's
->prepare returns a positive value or 0, which effectively prevents
drivers from being able to control the direct-complete feature.
Some drivers need that control, however, and the PCI bus type has
grown its own flag to deal with this issue, but since it is not
limited to PCI, it is better to address it by adding driver flags at
the core level.

To that end, add a driver_flags field to struct dev_pm_info for flags
that can be set by device drivers at the probe time to inform the PM
core and/or bus types, PM domains and so on on the capabilities and/or
preferences of device drivers. Also add two static inline helpers
for setting that field and testing it against a given set of flags
and make the driver core clear it automatically on driver remove
and probe failures.

Define and document two PM driver flags related to the direct-
complete feature: NEVER_SKIP and SMART_PREPARE that can be used,
respectively, to indicate to the PM core that the direct-complete
mechanism should never be used for the device and to inform the
middle layer code (bus types, PM domains etc) that it can only
request the PM core to use the direct-complete mechanism for
the device (by returning a positive value from its ->prepare
callback) if it also has been requested by the driver.

While at it, make the core check pm_runtime_suspended() when
setting power.direct_complete so that it doesn't need to be
checked by ->prepare callbacks.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>

ACPI / PM: Combine device suspend routines

On top of a previous change getting rid of the PM QoS flag
PM_QOS_FLAG_REMOTE_WAKEUP, combine two ACPI device suspend routines,
acpi_dev_runtime_suspend() and acpi_dev_suspend_late(), into one,
acpi_dev_suspend(), to eliminate some code duplication.

It also avoids enabling wakeup for devices handled by the ACPI
LPSS middle layer on driver removal.

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

PM / QoS: Drop PM_QOS_FLAG_REMOTE_WAKEUP

The PM QoS flag PM_QOS_FLAG_REMOTE_WAKEUP is not used consistently
and the vast majority of code simply assumes that remote wakeup
should be enabled for devices in runtime suspend if they can
generate wakeup signals, so drop it.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>

ACPI / PM: Split code validating need for runtime resume in ->prepare()

Move the code dealing with validation of whether runtime resuming the
device is needed during system suspend.

In this way it becomes more clear for what circumstances ACPI is prevented
from trying the direct_complete path.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI / PM: Restore acpi_subsys_complete()

Commit 58a1fbbb2ee8 (PM / PCI / ACPI: Kick devices that might have
been reset by firmware), made PCI's and ACPI's ->complete() callbacks
to be assigned to a new API called pm_complete_with_resume_check(),
which was introduced in the same change.

Later it turned out that using pm_complete_with_resume_check() wasn't
good enough for PCI, as it needed additional PCI specific checks,
before deciding whether runtime resuming the device is needed when
running the ->complete() callback.

This leaves ACPI as the only user of pm_complete_with_resume_check().
Therefore let's restore ACPI's acpi_subsys_complete(), which was
dropped in commit 58a1fbbb2ee8 (PM / PCI / ACPI: Kick devices that
might have been reset by firmware).

This enables us to remove the pm_complete_with_resume_check() API in
a following change, but it also enables ACPI to add more ACPI
specific checks in acpi_subsys_complete() if that turns out to be
necessary.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI / PM: Combine two identical device resume routines

Notice that acpi_dev_runtime_resume() and acpi_dev_resume_early() are
actually literally identical after some more-or-less recent changes,
so rename acpi_dev_runtime_resume() to acpi_dev_resume(), use it
everywhere instead of acpi_dev_resume_early() and drop the latter.

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

ACPI / PM: Add debug statements to acpi_pm_notify_handler()

Add statements to trace invocations of the ACPI PM notify handler
and the work functions called by it.

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

ACPI / PCI / PM: Rework acpi_pci_propagate_wakeup()

The acpi_pci_propagate_wakeup() routine is there to handle cases in
which PCI bridges (or PCIe ports) are expected to signal wakeup
for devices below them, but currently it doesn't do that correctly.

The problem is that acpi_pci_propagate_wakeup() uses
acpi_pm_set_device_wakeup() for bridges and if that routine is
called for multiple times to disable wakeup for the same device,
it will disable it on the first invocation and the next calls
will have no effect (it works analogously when called to enable
wakeup, but that is not a problem).

Now, say acpi_pci_propagate_wakeup() has been called for two
different devices under the same bridge and it has called
acpi_pm_set_device_wakeup() for that bridge each time. The
bridge is now enabled to generate wakeup signals. Next,
suppose that one of the devices below it resumes and
acpi_pci_propagate_wakeup() is called to disable wakeup for that
device. It will then call acpi_pm_set_device_wakeup() for the bridge
and that will effectively disable remote wakeup for all devices under
it even though some of them may still be suspended and remote wakeup
may be expected to work for them.

To address this (arguably theoretical) issue, allow
wakeup.enable_count under struct acpi_device to grow beyond 1 in
certain situations. In particular, allow that to happen in
acpi_pci_propagate_wakeup() when wakeup is enabled or disabled
for PCI bridges, so that wakeup is actually disabled for the
bridge when all devices under it resume and not when just one
of them does that.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>

ACPI / PM: Split acpi_device_wakeup()

To prepare for a subsequent change and make the code somewhat easier
to follow, do the following in the ACPI device wakeup handling code:

* Replace wakeup.flags.enabled under struct acpi_device with
wakeup.enable_count as that will be necessary going forward.

For now, wakeup.enable_count is not allowed to grow beyond 1,
so the current behavior is retained.

* Split acpi_device_wakeup() into acpi_device_wakeup_enable()
and acpi_device_wakeup_disable() and modify the callers of
it accordingly.

* Introduce a new acpi_wakeup_lock mutex to protect the wakeup
enabling/disabling code from races in case it is executed
more than once in parallel for the same device (which may
happen for bridges theoretically).

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

PCI / PM: Drop pme_interrupt flag from struct pci_dev

The pme_interrupt flag in struct pci_dev is set when PMEs generated
by the device are going to be signaled via root port PME interrupts.

Ironically enough, that information is only used by the code setting
up device wakeup through ACPI which returns as soon as it sees the
pme_interrupt flag set while setting up "remote runtime wakeup".
That is questionable, however, because in theory there may be PCIe
devices using out-of-band PME signaling under root ports handled
by the native PME code or devices requiring wakeup power setup to be
carried out by AML. For such devices, ACPI wakeup should be invoked
regardless of whether or not native PME signaling is used in general.

For this reason, drop the pme_interrupt flag and rework the code
using it which then allows the ACPI-based device wakeup handling
in PCI to be consolidated to use one code path for both "runtime
remote wakeup" and system wakeup (from sleep states).

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>

ACPI / PM: Consolidate device wakeup settings code

Currently, there are two separate ways of handling device wakeup
settings in the ACPI core, depending on whether this is runtime
wakeup or system wakeup (from sleep states). However, after the
previous commit eliminating the run_wake ACPI device wakeup flag,
there is no difference between the two any more at the ACPI level,
so they can be combined.

For this reason, introduce acpi_pm_set_device_wakeup() to replace both
acpi_pm_device_run_wake() and acpi_pm_device_sleep_wake() and make it
check the ACPI device object's wakeup.valid flag to determine whether
or not the device can be set up to generate wakeup signals.

Also notice that zpodd_enable/disable_run_wake() only call
device_set_run_wake() because acpi_pm_device_run_wake() called
device_run_wake(), which is not done by acpi_pm_set_device_wakeup(),
so drop the now redundant device_set_run_wake() calls from there.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>

ACPI: Constify argument to acpi_device_is_present()

This will be needed in constifying the fwnode API.

The side effects the function had have been moved to the callers.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI / PM: Ignore spurious SCI wakeups from suspend-to-idle

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. However, to preserve the existing
behavior with respect to suspend-to-RAM, this only is done in
the suspend-to-idle case and only if an SCI has occurred while
suspended.

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

ACPI / PM: Clean up device wakeup enable/disable code

The wakeup.flags.enabled flag in struct acpi_device is not used
consistently, as there is no reason why it should only apply
to the enabling/disabling of the wakeup GPE, so put the invocation
of acpi_enable_wakeup_device_power() under it too.

Moreover, it is not necessary to call
acpi_enable_wakeup_devices() and acpi_disable_wakeup_devices() for
suspend-to-idle, so don't do that.

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

ACPI / PM: Change log level of wakeup-related message

Change the log level of the "System wakeup enabled/disabled by ACPI"
message in acpi_pm_device_sleep_wake() to "debug" to reduce to log
noise level.

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

ACPI / PM: Run wakeup notify handlers synchronously

The work functions provided by the users of acpi_add_pm_notifier()
should be run synchronously before re-enabling the wakeup GPE in
case they are used to clear the status and/or disable the wakeup
signaling at the source. Otherwise, which is the case currently in
the PCI bus type code, the same wakeup event may be signaled for
multiple times while the execution of the work function in response
to it has already been queued up.

Fortunately, acpi_add_pm_notifier() is only used by PCI and by
ACPI device PM code internally, so the change is relatively
straightforward to make.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>

Revert "ACPI / sleep: Ignore spurious SCI wakeups from suspend-to-idle"

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>

ACPI / sleep: Ignore spurious SCI wakeups from suspend-to-idle

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>

ACPI / PM: Export acpi_device_fix_up_power()

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>

PM / Domains: add setter for dev.pm_domain

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>

PM / PCI / ACPI: Kick devices that might have been reset by firmware

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: Use target_state to set the device power state

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>

ACPI / PM: Attach ACPI power domain only once

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>

ACPI: Remove FSF mailing addresses

There is no need to carry potentially outdated Free Software Foundation
mailing address in file headers since the COPYING file includes it.

Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI / PM: Add missing pm_generic_complete() invocation

Add missing invocation of pm_generic_complete() to
acpi_subsys_complete() to allow ->complete callbacks provided
by the drivers of devices using the ACPI PM domain to be executed
during system resume.

Fixes: f25c0ae2b4c4 (ACPI / PM: Avoid resuming devices in ACPI PM domain during system suspend)
Cc: 3.16+ <stable@vger.kernel.org> # 3.16+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI / PM: Rework device power management to follow ACPI 6

The ACPI 6 specification has made some changes in the device power
management area. In particular:

* The D3hot power state is now supposed to be always available
(instead of D3cold) and D3cold is only regarded as valid if the
_PR3 object is present for the given device.

* The required ordering of transitions into power states deeper than
D0 is now such that for a transition into state Dx the _PSx method
is supposed to be executed first, if present, and the states of
the power resources the device depends on are supposed to be
changed after that.

* It is now explicitly forbidden to transition devices from
lower-power (deeper) into higher-power (shallower) power states
other than D0.

Those changes have been made so the specification reflects the
Windows' device power management code that the vast majority of
systems using ACPI is validated against.

To avoid artificial differences in ACPI device power management
between Windows and Linux, modify the ACPI device power management
code to follow the new specification. Add comments explaining the
code flow in some unclear places.

This only may affect some real corner cases in which the OS behavior
expected by the firmware is different from the Windows one, but that's
quite unlikely. The transition ordering change affects transitions
to D1 and D2 which are rarely used (if at all) and into D3hot and
D3cold for devices actually having _PR3, but those are likely to
be validated against Windows anyway. The other changes may affect
code calling acpi_device_get_power() or acpi_device_update_power()
where ACPI_STATE_D3_HOT may be returned instead of ACPI_STATE_D3_COLD
(that's why the ACPI fan driver needs to be updated too) and since
transitions into ACPI_STATE_D3_HOT may remove power now, it is better
to avoid this one in acpi_pm_device_sleep_state() if the "no power
off" PM QoS flag is set.

The only existing user of acpi_device_can_poweroff() really cares
about the case when _PR3 is present, so the change in that function
should not cause any problems to happen too.

A plus is that PCI_D3hot can be mapped to ACPI_STATE_D3_HOT
now and the compatibility with older systems should be covered
automatically.

In any case, if any real problems result from this, it still will
be better to follow the Windows' behavior (which now is reflected
by the specification too) in general and handle the cases when it
doesn't work via quirks.

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

ACPI / PM: Remove unneeded nested #ifdef

In commit 5de21bb998b8 ("ACPI / PM: Drop CONFIG_PM_RUNTIME from the
ACPI core"), all occurrences of CONFIG_PM_RUNTIME were replaced with
CONFIG_PM. This created the following structure of #ifdef blocks in
the code:

[...]
#ifdef CONFIG_PM
#ifdef CONFIG_PM
/* always on / undead */
#ifdef CONFIG_PM_SLEEP
[...]
#endif
#endif
[...]
#endif

This patch removes the inner "#ifdef CONFIG_PM" block as it will
always be enabled when the outer block is enabled. This inconsistency
was found using the undertaker-checkpatch tool.

Signed-off-by: Andreas Ruprecht <rupran@einserver.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI / PM: Fix PM initialization for devices that are not present

If an ACPI device object whose _STA returns 0 (not present and not
functional) has _PR0 or _PS0, its power_manageable flag will be set
and acpi_bus_init_power() will return 0 for it. Consequently, if
such a device object is passed to the ACPI device PM functions, they
will attempt to carry out the requested operation on the device,
although they should not do that for devices that are not present.

To fix that problem make acpi_bus_init_power() return an error code
for devices that are not present which will cause power_manageable to
be cleared for them as appropriate in acpi_bus_get_power_flags().
However, the lists of power resources should not be freed for the
device in that case, so modify acpi_bus_get_power_flags() to keep
those lists even if acpi_bus_init_power() returns an error.
Accordingly, when deciding whether or not the lists of power
resources need to be freed, acpi_free_power_resources_lists()
should check the power.flags.power_resources flag instead of
flags.power_manageable, so make that change too.

Furthermore, if acpi_bus_attach() sees that flags.initialized is
unset for the given device, it should reset the power management
settings of the device and re-initialize them from scratch instead
of relying on the previous settings (the device may have appeared
after being not present previously, for example), so make it use
the 'valid' flag of the D0 power state as the initial value of
flags.power_manageable for it and call acpi_bus_init_power() to
discover its current power state.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Cc: 3.10+ <stable@vger.kernel.org> # 3.10+

ACPI / PM: Do not disable wakeup GPEs that have not been enabled

In some cases acpi_device_wakeup() may be called to ensure wakeup
power to be off for a given device even though that device's wakeup
GPE has not been enabled so far. It calls acpi_disable_gpe() on a
GPE that's not enabled and this causes ACPICA to return the AE_LIMIT
status code from that call which then is reported as an error by the
ACPICA's debug facilities (if enabled). This may lead to a fair
amount of confusion, so introduce a new ACPI device wakeup flag
to store the wakeup GPE status and avoid disabling wakeup GPEs
that have not been enabled.

Reported-and-tested-by: Venkat Raghavulu <venkat.raghavulu@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI / PM: Drop CONFIG_PM_RUNTIME from the ACPI core

After commit b2b49ccbdd54 (PM: Kconfig: Set PM_RUNTIME if PM_SLEEP is
selected) PM_RUNTIME is always set if PM is set, so quite a few
depend on CONFIG_PM.

Replace CONFIG_PM_RUNTIME with CONFIG_PM in the ACPI core code.

Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Kevin Hilman <khilman@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI / PM: Fixed a typo in a comment

Signed-off-by: Huang Rui <ray.huang@amd.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI / PM: Ignore wakeup setting if the ACPI companion can't wake up

As reported by Dmitry, on some Chromebooks there are devices with
corresponding ACPI objects and with unusual system wakeup
configuration. Namely, they technically are wakeup-capable, but the
wakeup is handled via a platform-specific out-of-band mechanism and
the ACPI PM layer has no information on the wakeup capability. As
a result, device_may_wakeup(dev) called from acpi_dev_suspend_late()
returns 'true' for those devices, but the wakeup.flags.valid flag is
unset for the corresponding ACPI device objects, so acpi_device_wakeup()
reproducibly fails for them causing acpi_dev_suspend_late() to return
an error code. The entire system suspend is then aborted and the
machines in question cannot suspend at all.

Address the problem by ignoring the device_may_wakeup(dev) return
value in acpi_dev_suspend_late() if the ACPI companion of the device
being handled has wakeup.flags.valid unset (in which case it is clear
that the wakeup is supposed to be handled by other means).

This fixes a regression introduced by commit a76e9bd89ae7 (i2c:
attach/detach I2C client device to the ACPI power domain) as the
affected systems could suspend and resume successfully before that
commit.

Fixes: a76e9bd89ae7 (i2c: attach/detach I2C client device to the ACPI power domain)
Reported-by: Dmitry Torokhov <dtor@chromium.org>
Reviewed-by: Dmitry Torokhov <dtor@chromium.org>
Cc: 3.13+ <stable@vger.kernel.org> # 3.13+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI: invoke acpi_device_wakeup() with correct parameters

Fix a bug that invokes acpi_device_wakeup() with wrong parameters.

Fixes: f35cec255557 (ACPI / PM: Always enable wakeup GPEs when enabling device wakeup)
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Cc: 3.17+ <stable@vger.kernel.org> # 3.17+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI / fan: use acpi_device_xxx_power instead of acpi_bus equivelant

When we have the acpi_device pointer, there is no need to pass the
device's handle to the acpi_bus_xxx_power functions to get/set/update
the device's power state, instead, use the acpi_device_xxx_power
functions directly.

To make this happen for fan module, export acpi_device_update_power.

Signed-off-by: Aaron Lu <aaron.lu@intel.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>

ACPI / PM: Convert acpi_dev_pm_detach() into a static function

The ->detach() callback for the PM domain has now been fully adopted,
thus there no users left of the acpi_dev_pm_detach() API. This allow us
to convert it into a static function.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI / PM: Assign the ->detach() callback when attaching the PM domain

As as preparation to simplify the detachment of devices from their PM
domains, we assign the ->detach() callback to genpd_dev_pm_detach().

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI / PM: Use ACPI_COMPANION() instead of ACPI_HANDLE()

The ACPI_HANDLE() macro evaluates ACPI_COMPANION() internally to
return the handle of the device's ACPI companion, so it is much
more straightforward and efficient to use ACPI_COMPANION()
directly to obtain the device's ACPI companion object instead of
using ACPI_HANDLE() and acpi_bus_get_device() on the returned
handle for the same thing.

Do that in three places in the ACPI device PM code.

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

ACPI / PM: Always enable wakeup GPEs when enabling device wakeup

Wakeup GPEs are currently only enabled when setting up devices for
remote wakeup at run time. During system-wide transitions they are
enabled by ACPICA at the very last stage of suspend (before asking
the BIOS to take over). Of course, that only works for system
sleep states supported by ACPI, so in particular it doesn't work
for the "freeze" sleep state.

For this reason, modify the ACPI core device PM code to enable wakeup
GPEs for devices when setting them up for wakeup regardless of whether
that is remote wakeup at runtime or system wakeup. That allows the
same device wakeup setup routine to be used for both runtime PM and
system-wide PM and makes it possible to reduce code size quite a bit.

This make ACPI-based PCI Wake-on-LAN work with the "freeze" sleep
state on my venerable Toshiba Portege R500 and should help other
systems too.

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

ACPI / PM: Revork the handling of ACPI device wakeup notifications

Since ACPI wakeup GPEs are going to be enabled during system suspend
as well as for runtime wakeup by a subsequent patch and the same
notify handlers will be used in both cases, rework the ACPI device
wakeup notification framework so that the part specific to physical
devices is always run asynchronously from the PM workqueue. This
prevents runtime resume callbacks for those devices from being
run during system suspend and resume which may not be appropriate,
among other things.

Also make ACPI device wakeup notification handling a bit more robust
agaist subsequent removal of ACPI device objects, whould that ever
happen, and create a wakeup source object for each ACPI device
configured for wakeup so that wakeup notifications for those
devices can wake up the system from the "freeze" sleep state.

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

ACPI / PM: Export rest of the subsys PM callbacks

No reason for excluding the remaining ones.

Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
[rjw: Rebased and exported the new acpi_subsys_complete() too.]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI / PM: Avoid resuming devices in ACPI PM domain during system suspend

Rework the ACPI PM domain's PM callbacks to avoid resuming devices
during system suspend (in order to modify their wakeup settings etc.)
if that isn't necessary.

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

ACPI / PM: Resume runtime-suspended devices later during system suspend

Runtime-suspended devices are resumed during system suspend by
acpi_subsys_prepare() for two reasons: First, because they may need
to be reprogrammed in order to change their wakeup settings and,
second, because they may need to be operatonal for their children
to be successfully suspended. That is a problem, though, if there
are many runtime-suspended devices that need to be resumed this
way during system suspend, because the .prepare() PM callbacks of
devices are executed sequentially and the times taken by them
accumulate, which may increase the total system suspend time quite
a bit.

For this reason, move the resume of runtime-suspended devices up
to the next phase of device suspend (during system suspend), except
for the ones that have power.ignore_children set. The exception is
made, because the devices with power.ignore_children set may still
be necessary for their children to be successfully suspended (during
system suspend) and they won't be resumed automatically as a result
of the runtime resume of their children.

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

ACPI / PM: Use ACPI_COMPANION() to get ACPI companions of devices

The ACPI device PM code in device_pm.c uses a special function,
acpi_dev_pm_get_node(), to obtain an ACPI companion object of a given
device. However, that is not necessary any more after recent changes
that introduced the ACPI_COMPANION() macro serving exactly the same
purpose, but working in a much more straightforward way. For this
reason, drop acpi_dev_pm_get_node() and use ACPI_COMPANION() instead
of it everywhere.

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

ACPI / scan: Add acpi_device objects for all device nodes in the namespace

Modify the ACPI namespace scanning code to register a struct
acpi_device object for every namespace node representing a device,
processor and so on, even if the device represented by that namespace
node is reported to be not present and not functional by _STA.

There are multiple reasons to do that. First of all, it avoids
quite a lot of overhead when struct acpi_device objects are
deleted every time acpi_bus_trim() is run and then added again
by a subsequent acpi_bus_scan() for the same scope, although the
namespace objects they correspond to stay in memory all the time
(which always is the case on a vast majority of systems).

Second, it will allow user space to see that there are namespace
nodes representing devices that are not present at the moment and may
be added to the system. It will also allow user space to evaluate
_SUN for those nodes to check what physical slots the "missing"
devices may be put into and it will make sense to add a sysfs
attribute for _STA evaluation after this change (that will be
useful for thermal management on some systems).

Next, it will help to consolidate the ACPI hotplug handling among
subsystems by making it possible to store hotplug-related information
in struct acpi_device objects in a standard common way.

Finally, it will help to avoid a race condition related to the
deletion of ACPI namespace nodes. Namely, namespace nodes may be
deleted as a result of a table unload triggered by _EJ0 or _DCK.
If a hotplug notification for one of those nodes is triggered
right before the deletion and it executes a hotplug callback
via acpi_hotplug_execute(), the ACPI handle passed to that
callback may be stale when the callback actually runs. One way
to work around that is to always pass struct acpi_device pointers
to hotplug callbacks after doing a get_device() on the objects in
question which eliminates the use-after-free possibility (the ACPI
handles in those objects are invalidated by acpi_scan_drop_device(),
so they will trigger ACPICA errors on attempts to use them).

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

ACPI: Eliminate the DEVICE_ACPI_HANDLE() macro

Since DEVICE_ACPI_HANDLE() is now literally identical to
ACPI_HANDLE(), replace it with the latter everywhere and drop its
definition from include/acpi.h.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

ACPI / driver core: Store an ACPI device pointer in struct acpi_dev_node

Modify struct acpi_dev_node to contain a pointer to struct acpi_device
associated with the given device object (that is, its ACPI companion
device) instead of an ACPI handle corresponding to it. Introduce two
new macros for manipulating that pointer in a CONFIG_ACPI-safe way,
ACPI_COMPANION() and ACPI_COMPANION_SET(), and rework the
ACPI_HANDLE() macro to take the above changes into account.
Drop the ACPI_HANDLE_SET() macro entirely and rework its users to
use ACPI_COMPANION_SET() instead. For some of them who used to
pass the result of acpi_get_child() directly to ACPI_HANDLE_SET()
introduce a helper routine acpi_preset_companion() doing an
equivalent thing.

The main motivation for doing this is that there are things
represented by struct acpi_device objects that don't have valid
ACPI handles (so called fixed ACPI hardware features, such as
power and sleep buttons) and we would like to create platform
device objects for them and "glue" them to their ACPI companions
in the usual way (which currently is impossible due to the
lack of valid ACPI handles). However, there are more reasons
why it may be useful.

First, struct acpi_device pointers allow of much better type checking
than void pointers which are ACPI handles, so it should be more
difficult to write buggy code using modified struct acpi_dev_node
and the new macros. Second, the change should help to reduce (over
time) the number of places in which the result of ACPI_HANDLE() is
passed to acpi_bus_get_device() in order to obtain a pointer to the
struct acpi_device associated with the given "physical" device,
because now that pointer is returned by ACPI_COMPANION() directly.
Finally, the change should make it easier to write generic code that
will build both for CONFIG_ACPI set and unset without adding explicit
compiler directives to it.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com> # on Haswell
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Aaron Lu <aaron.lu@intel.com> # for ATA and SDIO part

ACPI / PM: Drop two functions that are not used any more

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: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI / PM: allow child devices to ignore parent power state

Some serial buses like I2C and SPI don't require that the parent device is
in D0 before any of its children transitions to D0, but instead the parent
device can control its own power independently from the children.

This does not follow the ACPI specification as it requires the parent to be
powered on before its children. However, Windows seems to ignore this
requirement so I think we can do the same in Linux.

Implement this by adding a new power flag 'ignore_parent' to struct
acpi_device. If this flag is set the ACPI core ignores checking of the
parent device power state when the device is powered on/off.

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

ACPI / PM: Add state information to error message in acpi_device_set_power()

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

ACPI / PM: Remove redundant power manageable check from acpi_bus_set_power()

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

ACPI / PM: Make messages in acpi_device_set_power() print device names

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: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Aaron Lu <aaron.lu@intel.com>

ACPI / PM: Only set power states of devices that are power manageable

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: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI / PM: Fix corner case in acpi_bus_update_power()

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: Fix possible NULL pointer deref in acpi_pm_device_sleep_state()

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>

ACPI / LPSS: Power up LPSS devices during enumeration

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>

ACPI / PM: Rework and clean up acpi_dev_pm_get_state()

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>

ACPI / PM: Replace ACPI_STATE_D3 with ACPI_STATE_D3_COLD in device_pm.c

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>

ACPI / PM: Rename function acpi_device_power_state() and make it static

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>

ACPI / PM: Do not execute _PS0 for devices without _PSC during initialization

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>

PM / Runtime: Rework the "runtime idle" helper routine

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: Mika Westerberg <mika.westerberg@linux.intel.com>
Tested-by: Kevin Hilman <khilman@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Kevin Hilman <khilman@linaro.org>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Alan Stern <stern@rowland.harvard.edu>

ACPI / PM: Allow device power states to be used for CONFIG_PM unset

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: Zhang Rui <rui.zhang@intel.com>
Reported-and-tested-by: Michel Lespinasse <walken@google.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: 3.9+ <stable@vger.kernel.org>

ACPI / PM: Fix potential problem in acpi_device_get_power()

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: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Aaron Lu <aaron.lu@intel.com>

ACPI / PM: Handle missing _PSC in acpi_bus_update_power()

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: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI / PM: Do not power manage devices in unknown initial states

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: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: Peter Wu <lekensteyn@gmail.com>

ACPI / PM: Fix acpi_bus_get_device() check in drivers/acpi/device_pm.c

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: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI / PM: Fix device power state value after transitions to D3cold

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: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI / PM: Use string "D3cold" to represent ACPI_STATE_D3_COLD

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: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI / PM: Always evaluate _PSn after setting power resources

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: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI / PM: Introduce helper for executing _PSn methods

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: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI / PM: Make acpi_bus_init_power() more robust

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

ACPI / PM: remove leading whitespace from #ifdef

It is there probably due to an accident, get rid of it so that the format
is consistent across the file.

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

ACPI / PM: Move device power management functions to device_pm.c

Move ACPI device power management functions from drivers/acpi/bus.c
to drivers/acpi/device_pm.c.

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

ACPI / PM: Rework the handling of devices depending on power resources

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: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI / PM: Do not apply ACPI_SUCCESS() to acpi_bus_get_device() result

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: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>

ACPI / PCI: Rework the setup and cleanup of device wakeup

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: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Yinghai Lu <yinghai@kernel.org>
Acked-by: Toshi Kani <toshi.kani@hp.com>

ACPI / PM: Allow attach/detach routines to change device power states

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: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com>

ACPI / PM: Provide ACPI PM callback routines for subsystems

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: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI / PM: Move device PM functions related to sleep states

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: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI / PM: Split device wakeup management routines

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: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI / PM: Move runtime remote wakeup setup routine to device_pm.c

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: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI / PM: Move device power state selection routine to device_pm.c

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: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI / PM: Move routines for adding/removing device wakeup notifiers

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: Rafael J. Wysocki <rafael.j.wysocki@intel.com>