Replace the last instance of acpi_bus_get_device(), added recently
by commit 87e59b36 ("spi: Support selection of the index of the
ACPI Spi Resource before alloc"), with acpi_fetch_acpi_dev() and
finally drop acpi_bus_get_device() that has no more users.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Mark Brown <broonie@kernel.org>

Revert commit 87ebbb8c ("ACPI: processor: idle: Only flush cache
on entering C3") that broke the assumptions of the acpi_idle_play_dead()
callers.

Namely, the CPU cache must always be flushed in acpi_idle_play_dead(),
regardless of the target C-state that is going to be requested, because
this is likely to be part of a CPU offline procedure or preparation for
entering a system-wide sleep state and the lack of synchronization
between the CPU cache and RAM may lead to problems going forward, for
example when the CPU is brought back online.

In particular, it breaks resume from suspend-to-RAM on Lenovo ThinkPad
C13 which fails occasionally until the problematic commit is reverted.

Signed-off-by: Akihiko Odaki <akihiko.odaki@gmail.com>
[ rjw: Changelog ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Change the default error code returned by acpi_cppc_processor_probe()
from -EFAULT (which is completely inadequate) to -ENODATA and change
the debug messages printed by it to contain more information and be
more consistent.

While at it, format some white space to follow the coding style.

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

If the NumEntries field in the _CPC return package is less than 2, do
not attempt to access the "Revision" element of that package, because
it may not be present then.

Fixes: 337aadff ("ACPI: Introduce CPU performance controls using CPPC")
BugLink: https://lore.kernel.org/lkml/20220322143534.GC32582@xsang-OptiPlex-9020/


Reported-by: kernel test robot <oliver.sang@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Huang Rui <ray.huang@amd.com>

Without fix:
  [    0.005429] ACPI: LAPIC_ADDR_OVR (address[(____ptrval____)])

With fix:
  [    0.005429] ACPI: LAPIC_ADDR_OVR (address[0x800fee00000])

Co-developed-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Signed-off-by: Vasant Hegde <vasant.hegde@amd.com>
[ rjw: Subject edits ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

To move the list iterator variable into the list_for_each_entry_*()
macro in the future it should be avoided to use the list iterator
variable after the loop body.

To *never* use the list iterator variable after the loop it was
concluded to use a separate iterator variable instead of a
found boolean [1].

This removes the need to use a found variable and simply checking if
the variable was set, can determine if the break/goto was hit.

Link: https://lore.kernel.org/all/CAHk-=wgRr_D8CB-D9Kg-c=EHreAsk5SqXPwr9Y7k9sA6cWXJ6w@mail.gmail.com/


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

While the original code is valid, it is not the obvious choice for the
sizeof() call and in preparation to limit the scope of the list iterator
variable the sizeof should be changed to the size of the variable
being allocated.

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

Currenty the latest thing run during a suspend to idle attempt is
the LPS0 `prepare_late` callback and the earliest thing is the
`resume_early` callback.

There is a desire for the `amd-pmc` driver to suspend later in the
suspend process (ideally the very last thing), so create a callback
that it or any other driver can hook into to do this.

Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://lore.kernel.org/r/20220317141445.6498-1-mario.limonciello@amd.com


Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

If the platform firmware indicates that it does not support CPPC by
clearing the OSC_SB_CPC_SUPPORT and OSC_SB_CPCV2_SUPPORT bits in the
platform _OSC capabilities mask, avoid attempting to evaluate _CPC
which may fail in that case.

Because the OSC_SB_CPC_SUPPORT and OSC_SB_CPCV2_SUPPORT bits are only
added to the supported platform capabilities mask on x86, when
X86_FEATURE_HWP is supported, allow _CPC to be evaluated regardless
in the other cases.

Link: https://lore.kernel.org/linux-acpi/CAJZ5v0i=ecAksq0TV+iLVObm-=fUfdqPABzzkgm9K6KxO1ZCcg@mail.gmail.com


Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: Mario Limonciello <mario.limonciello@amd.com>
Acked-by: Huang Rui <ray.huang@amd.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>

Revert commit 159d8c27 ("ACPI: Pass the same capabilities to the
_OSC regardless of the query flag") which caused legitimate usage
scenarios (when the platform firmware does not want the OS to control
certain platform features controlled by the system bus scope _OSC) to
break and was misguided by some misleading language in the _OSC
definition in the ACPI specification (in particular, Section 6.2.11.1.3
"Sequence of _OSC Calls" that contradicts other perts of the _OSC
definition).

Link: https://lore.kernel.org/linux-acpi/CAJZ5v0iStA0JmO0H3z+VgQsVuQONVjKPpw0F5HKfiq=Gb6B5yw@mail.gmail.com


Reported-by: Mario Limonciello <Mario.Limonciello@amd.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: Mario Limonciello <mario.limonciello@amd.com>
Acked-by: Huang Rui <ray.huang@amd.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>

Clevo NL5xRU and NL5xNU/TUXEDO Aura 15 Gen1 and Gen2 have both a working
native and video interface. However the default detection mechanism first
registers the video interface before unregistering it again and switching
to the native interface during boot. This results in a dangling SBIOS
request for backlight change for some reason, causing the backlight to
switch to ~2% once per boot on the first power cord connect or disconnect
event. Setting the native interface explicitly circumvents this buggy
behaviour by avoiding the unregistering process.

Signed-off-by: Werner Sembach <wse@tuxedocomputers.com>
Cc: All applicable <stable@vger.kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

The ACPI specification says that OSPM should refuse to restore from
hibernate if the hardware signature changes, and should boot from
scratch. However, real BIOSes often vary the hardware signature in cases
where we *do* want to resume from hibernate, so Linux doesn't follow the
spec by default.

However, in a virtual environment there's no reason for the VMM to vary
the hardware signature *unless* it wants to trigger a clean reboot as
defined by the ACPI spec. So enable the check by default if a hypervisor
is detected.

Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Revert commit e38f9ff6 ("ACPI: scan: Do not add device IDs from _CID
if _HID is not valid"), because it has introduced regressions on
multiple systems, even though it only has effect on clearly invalid
firmware.

Reported-by: Pierre-Louis Bossart <notifications@github.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Now that the nd_namespace_blk infrastructure is removed, delete all the
region machinery to coordinate provisioning aliased capacity between
PMEM and BLK.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/164688418803.2879318.1302315202397235855.stgit@dwillia2-desk3.amr.corp.intel.com


Signed-off-by: Dan Williams <dan.j.williams@intel.com>

Delete the code to parse interleave-descriptor-tables and coordinate I/O
through a BLK aperture.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/164688418240.2879318.400185926874596938.stgit@dwillia2-desk3.amr.corp.intel.com


Signed-off-by: Dan Williams <dan.j.williams@intel.com>

init_freq_invariance_cppc() was called in acpi_cppc_processor_probe(),
after CPU performance information and controls were populated from the
per-cpu _CPC objects.

But these _CPC objects provide information that helps with both CPU
(u-arch) and frequency invariance. Therefore, change the function name
to a more generic one, while adding the arch_ prefix, as this function
is expected to be defined differently by different architectures.

Signed-off-by: Ionela Voinescu <ionela.voinescu@arm.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: Valentin Schneider <valentin.schneider@arm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI for Arm Components 1.1 Platform Design Document v1.1 [0] specifices
Arm Generic Diagnostic Device Interface (AGDI). It allows an admin to
issue diagnostic dump and reset via an SDEI event or an interrupt.
This patch implements SDEI path.

[0] https://developer.arm.com/documentation/den0093/latest/



Signed-off-by: Ilkka Koskinen <ilkka@os.amperecomputing.com>
Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Add AGDI to the list of known ACPI table signatures to allow the
kernel to recognize it when upgrading tables via initrd.

Signed-off-by: Ilkka Koskinen <ilkka@os.amperecomputing.com>
Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Platforms with large BERT table data can trigger soft lockup errors
while attempting to print the entire BERT table data to the console at
boot:

  watchdog: BUG: soft lockup - CPU#160 stuck for 23s! [swapper/0:1]

Observed on Ampere Altra systems with a single BERT record of ~250KB.

The original bert driver appears to have assumed relatively small table
data. Since it is impractical to reassemble large table data from
interwoven console messages, and the table data is available in

  /sys/firmware/acpi/tables/data/BERT

limit the size for tables printed to the console to 1024 (for no reason
other than it seemed like a good place to kick off the discussion, would
appreciate feedback from existing users in terms of what size would
maintain their current usage model).

Alternatively, we could make printing a CONFIG option, use the
bert_disable boot arg (or something similar), or use a debug log level.
However, all those solutions require extra steps or change the existing
behavior for small table data. Limiting the size preserves existing
behavior on existing platforms with small table data, and eliminates the
soft lockups for platforms with large table data, while still making it
available.

Signed-off-by: Darren Hart <darren@os.amperecomputing.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

__setup() handlers should return 1 to indicate that the boot option
has been handled. Returning 0 causes a boot option to be listed in
the Unknown kernel command line parameters and also added to init's
arg list (if no '=' sign) or environment list (if of the form 'a=b').

Unknown kernel command line parameters "erst_disable
  bert_disable hest_disable BOOT_IMAGE=/boot/bzImage-517rc6", will be
  passed to user space.

 Run /sbin/init as init process
   with arguments:
     /sbin/init
     erst_disable
     bert_disable
     hest_disable
   with environment:
     HOME=/
     TERM=linux
     BOOT_IMAGE=/boot/bzImage-517rc6

Fixes: a3e2acc5 ("ACPI / APEI: Add Boot Error Record Table (BERT) support")
Fixes: a08f82d0 ("ACPI, APEI, Error Record Serialization Table (ERST) support")
Fixes: 9dc96664 ("ACPI, APEI, HEST table parsing")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reported-by: Igor Zhbanov <i.zhbanov@omprussia.ru>
Link: lore.kernel.org/r/64644a2f-4a20-bab3-1e15-3b2cdd0defe3@omprussia.ru
Reviewed-by: "Huang, Ying" <ying.huang@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

The Yoga Tablet 1050F/L is a x86 ACPI tablet which ships with Android x86
as factory OS. Its DSDT contains a bunch of I2C devices which are not
actually there, causing various resource conflicts (the Android x86
kernel fork ignores I2C devices described in the DSDT).

Add a ACPI_QUIRK_SKIP_I2C_CLIENTS for the Nextbook Ares 8 to the
acpi_quirk_skip_dmi_ids table to woraround this.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

The Nextbook Ares 8 is a x86 ACPI tablet which ships with Android x86
as factory OS. Its DSDT contains a bunch of I2C devices which are not
actually there, causing various resource conflicts (the Android x86
kernel fork ignores I2C devices described in the DSDT).

Add a ACPI_QUIRK_SKIP_I2C_CLIENTS for the Nextbook Ares 8 to the
acpi_quirk_skip_dmi_ids table to woraround this.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPICA commit b1c3656ef4950098e530be68d4b589584f06cddc

Prevent acpi_ns_walk_namespace() from crashing when called with
start_node equal to ACPI_ROOT_OBJECT if the Namespace has not been
instantiated yet and acpi_gbl_root_node is NULL.

For instance, this can happen if the kernel is run with "acpi=off"
in the command line.

Link: https://github.com/acpica/acpica/commit/b1c3656ef4950098e530be68d4b589584f06cddc
Link: https://lore.kernel.org/linux-acpi/CAJZ5v0hJWW_vZ3wwajE7xT38aWjY7cZyvqMJpXHzUL98-SiCVQ@mail.gmail.com/


Reported-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ghes_init() sticks out in acpi_init() because it is the only functions
without an "acpi_" prefix.

Rename ghes_init with an "acpi_" prefix, then all looks fine.

Signed-off-by: Shuai Xue <xueshuai@linux.alibaba.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

From commit e147133a ("ACPI / APEI: Make hest.c manage the estatus
memory pool") was merged, ghes_init() relies on acpi_hest_init() to manage
the estatus memory pool. On the other hand, ghes_init() relies on
sdei_init() to detect the SDEI version and (un)register events. The
dependencies are as follows:

    ghes_init() => acpi_hest_init() => acpi_bus_init() => acpi_init()
    ghes_init() => sdei_init()

HEST is not PCI-specific and initcall ordering is implicit and not
well-defined within a level.

Based on above, remove acpi_hest_init() from acpi_pci_root_init() and
convert ghes_init() and sdei_init() from initcalls to explicit calls in the
following order:

    acpi_hest_init()
    ghes_init()
        sdei_init()

Signed-off-by: Shuai Xue <xueshuai@linux.alibaba.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

When `osc_pc_lpi_support_confirmed` is set through `_OSC` and `_LPI` is
populated then the cpuidle driver assumes that LPI is fully functional.

However currently the kernel only provides architectural support for LPI
on ARM.  This leads to high power consumption on X86 platforms that
otherwise try to enable LPI.

So probe whether or not LPI support is implemented before enabling LPI in
the kernel.  This is done by overloading `acpi_processor_ffh_lpi_probe` to
check whether it returns `-EOPNOTSUPP`. It also means that all future
implementations of `acpi_processor_ffh_lpi_probe` will need to follow
these semantics as well.

Reviewed-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

In order to avoid exposing acpi_bus_type to modules, introduce an
acpi_bus_for_each_dev() helper for iterating over all ACPI device
objects and make typec_link_ports() use it instead of the raw
bus_for_each_dev() along with acpi_bus_type.

Having done that, drop the acpi_bus_type export.

No intentional functional impact.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>

The drivers/platform/surface/surface3_button.c code is alsmost a 1:1 copy
of the soc_button_array code.

The only big difference is that it binds to an i2c_client rather then to
a platform_device. The cause of this is the ACPI resources for the MSHW0028
device containing a bogus I2cSerialBusV2 resource which causes the kernel
to instantiate an i2c_client for it instead of a platform_device.

Add "MSHW0028" to the ignore_serial_bus_ids[] list in drivers/apci/scan.c,
so that a platform_device will be instantiated and add support for
the MSHW0028 HID to soc_button_array.

This fully replaces surface3_button, which will be removed in a separate
commit (since it binds to the now no longer created i2c_client it no
longer does anyyhing after this commit).

Note the MSHW0028 id is used by Microsoft to describe the tablet buttons on
both the Surface 3 and the Surface 3 Pro and the actual API/implementation
for the Surface 3 Pro is quite different. The changes in this commit should
not impact the separate surfacepro3_button driver:

1. Because of the bogus I2cSerialBusV2 resource problem that driver binds
   to the acpi_device itself, so instantiating a platform_device instead of
   an i2c_client does not matter.

2. The soc_button_array driver will not bind to the MSHW0028 device on
   the Surface 3 Pro, because it has no GPIO resources.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Maximilian Luz <luzmaximilian@gmail.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Link: https://lore.kernel.org/r/20220224110241.9613-2-hdegoede@redhat.com

The SPI driver wants to know the exact type of the controller. Provide this
information to it, hence allow to fix Intel Wildcat Point case in the future.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

The properties are static and not supposed to be modified, constify them.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Properties are not and should not be changed in the callee, hence constify
properties parameter in acpi_create_platform_device().

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

For some reason, the Microsoft Surface Go 3 uses the standard ACPI
interface for battery information, but does not use the standard PNP0C0A
HID. Instead it uses MSHW0146 as identifier. Add that ID to the driver
as this seems to work well.

Additionally, the power state is not updated immediately after the AC
has been (un-)plugged, so add the respective quirk for that.

Signed-off-by: Maximilian Luz <luzmaximilian@gmail.com>
Cc: All applicable <stable@vger.kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Add additional attributes, which helps in implementing algorithm in
the user space to optimize fan control. These attributes are presented
in the same directory as the existing performance state attributes.

Additional attributes:

1. Support of fine grain control
Publish support of presence of fine grain control so that fan speed
can be tuned correctly. This attribute is called "fine_grain_control".

2. fan speed
Publish the actual fan rpm in sysfs. Knowing fan rpm is helpful to
reduce noise level and use passive control instead. Also fan performance
may not be same over time, so the same control value may not be enough
to run the fan at a speed. So a feedback value of speed is helpful. This
sysfs attribute is called "fan_speed_rpm".

Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

When _FIF object specifies support for fine grain control, then fan speed
can be set from 0 to 100% with the recommended minimum "step size" via
_FSL object. Here the control value doesn't need to match any value from
_FPS object.

Currently we have a simple solution implemented which just pick maximum
control value from _FPS to display the actual state, but this is not
optimal when there is a big window between two control values in
_FPS. Also there is no way to set to any speed which doesn't match
control values in _FPS. The system firmware can start the fan at speed
which doesn't match any control value.

To support fine grain control (when supported) via thermal sysfs:
- cooling device max state is not _FPS state count but it will be
100 / _FIF.step_size
Step size can be from 1 to 9.
- cooling device current state is _FST.control / _FIF.step_size
- cooling device set state will set the control value
cdev.curr_state * _FIF.step_size plus any adjustment for 100%.
By the spec, when control value do not sum to 100% because of
_FIF.step_size, OSPM may select an appropriate ending Level increment
to reach 100%.

There is no rounding during calculation. For example if step size
is 6:
thermal sysfs cooling device max_state = 100/6 = 16
So user can set any value from 0-16.

If the system boots with a _FST.control which is not multiples
of step_size, the thermal sysfs cur_state will be based on the
range. For example for step size = 6:
_FST.control	thermal sysfs cur_state
------------------------------------------------
0-5		0
6-11		1
..
..
90-95		15
96-100		16

While setting the _FST.control, the compensation will be at
the last step for cur_state = 16, which will set the _FST.control
to 100.

Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

We don't need u64 to store the information about _FIF. There are two
booleans (fine_grain_ctrl and low_speed_notification) and one field
step_size which can take value from 1-9. There are no internal users
of revision field. So convert all fields to u8, by not directly
extracting the _FIF info the struct. Use an intermediate buffer to
extract and assign.

This will help to do u32 math using these fields. No functional
changes are expected.

Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Move the functionality of creation of sysfs attributes under acpi device
to a new file fan_attr.c. This cleans up the core fan code, which just
use thermal sysfs interface. The original fan.c is renamed to
fan_core.c.

No functional changes are expected.

Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

When user get/set cur_state fails, it should be some negative error
value instead of whatever returned by acpi_evaluate_object() or from
acpi_execute_simple_method(). The return value from these apis is
some positive values greater than 0. For example if AE_NOT_FOUND
is returned it will be "5".

In other ACPI drivers, -ENODEV is returned when ACPI_FAILURE(status)
is true. Do the same thing here for thermal sysfs callbacks for
get and set for failures.

Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Remove the second 'on' and 'those'.

Signed-off-by: Tom Rix <trix@redhat.com>
[ rjw: Subject adjustments ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

In the snippets like the following

	if (...)
		return / goto / break / continue ...;
	else
		...

the 'else' is redundant. Get rid of it.

While at it, replace conditional '<= 0' for unsigned type by '== 0'
in acpi_data_prop_read(); update comment in the
__acpi_node_get_property_reference() on how we parse the reference.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

As recommended in include/linux/idr.h, use ida_alloc() instead of
ida_simple_get() for creating unique device object names and for
symmetry replace ida_simple_remove() with ida_free() (and fix up
the related overly long code line while at it).

Also drop the ACPI_MAX_DEVICE_INSTANCES limit that is not necessary
any more and may not be sufficient for future platforms.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>