Refer to the Intel SDM Vol.4, the package C-state residency counters
of modern IA micro-architecture are all ticking in TSC frequency,
hence we can apply simple math to transform the ticks into microseconds.
i.e.,
residency (ms) = count / tsc_khz
residency (us) = count / tsc_khz * 1000

This also aligns to other sysfs debug entries of residency counter in
the same metric in microseconds, benefits reading and scripting.

v2: restore the accidentally deleted newline, no function change.
v3: apply kernel do_div() macro to calculate division
Signed-off-by: Harry Pan <harry.pan@intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

Using dev_get_drvdata directly.
Signed-off-by: Fuqian Huang <huangfq.daxian@gmail.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

Add documentation for the new attributes for exposing reset causes for
the next type of resets: caused by different watchdog, BIOS reload,
ASIC reset request.
Signed-off-by: Vadim Pasternak <vadimp@mellanox.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

Add more attributes for reset cause indication for the cases when
system reset has been caused by watchdog, BIOS reload and COMEX
thermal shutdown.
Signed-off-by: Vadim Pasternak <vadimp@mellanox.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

Modify DMI matching order: perform matching based on  DMI_BOARD_NAME
before matching based on DMI_BOARD_VENDOR and DMI_PRODUCT_NAME in order
to reduce the number of ‘dmi_table’ entries necessary for new systems
support and keep matching order in logical way.

For example, the existing check for DMI_PRODUCT_NAME with prefixes
“MSN27", “MSN24”, "MSB” matches systems MSN2700-BXXXX, MSN2700-XXXX,
MSN2410-BXXXX, MSB7800-XXXX, where ‘XXXX’ specifies some systems
hardware flavors.
At the same time these systems also matched by DMI_BOARD_NAME
“VMOD0001”, because they all have the same platform configuration (LED,
interrupt control, mux etcetera).
New systems with different platform configuration, but with similar
DMI_PRODUCT_NAME  MSN2700-2XXXX, MSN2700-2XXXX, MSB7800-2XXXX are about
to be added. These system have similar DMI_PRODUCT_NAME, since they
have same ports configuration as their predecessors. All new systems
will be matched by DMI_BOARD_NAME “VMOD0008”.
With the change provided in the patch it is enough just to add
“VMOD0008” match following natural after “VMOD0007”, otherwise
“VMOD0008” or all “MSN2700-2XXXX”, “MSN2700-2XXXX”, “MSB7800-2XXXX”
should be added on top of ‘mlxplat_dmi_table” in order to be matched
before “MSN27", “MSN24”, "MSB”.
Signed-off-by: Vadim Pasternak <vadimp@mellanox.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

Use separated regamp structures for old and next generation systems.
Next generation systems don’t require write protection removing.
Signed-off-by: Vadim Pasternak <vadimp@mellanox.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

Activate 'i2c-mlxcpld' driver with 'platform_device_register_resndata'
instead off 'platform_device_register_simple' in order to pass platform
specific info.
Add platform i2c data for the next generation systems.
Signed-off-by: Vadim Pasternak <vadimp@mellanox.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

Initialize regmap prior drivers starting to allow passing regmap handle
to 'i2c_mlxcpld' driver.
Signed-off-by: Vadim Pasternak <vadimp@mellanox.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

Added myself as the maintainer.
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

The Intel(R) Speed select technologies contains four features.

Performance profile:An non architectural mechanism that allows multiple
optimized performance profiles per system via static and/or dynamic
adjustment of core count, workload, Tjmax, and TDP, etc. aka ISS
in the documentation.

Base Frequency: Enables users to increase guaranteed base frequency on
certain cores (high priority cores) in exchange for lower base frequency
on remaining cores (low priority cores). aka PBF in the documenation.

Turbo frequency: Enables the ability to set different turbo ratio limits
to cores based on priority. aka FACT in the documentation.

Core power: An Interface that allows user to define per core/tile
priority.

There is a multi level help for commands and options. This can be used
to check required arguments for each feature and commands for the
feature.

To start navigating the features start with

$sudo intel-speed-select --help

For help on a specific feature for example
$sudo intel-speed-select perf-profile --help

To get help for a command for a feature for example
$sudo intel-speed-select perf-profile get-lock-status --help
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Acked-by: Len Brown <len.brown@intel.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

Commands which causes PUNIT writes, store them and restore them on system
resume. The driver stores all such requests in a hash table and stores the
the latest mailbox request parameters. On resume these commands mail box
commands are executed again. There are only 5 such mail box commands which
will trigger such processing so a very low overhead in store and execute
on resume. Also there is no order requirement for mail box commands for
these write/set commands. There is one MSR request for changing turbo
ratio limits, this also stored and get restored on resume and cpu online.
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

While using new non arhitectural features using PUNIT Mailbox and MMIO
read/write interface, still there is need to operate using MSRs to
control PUNIT. User space could have used user user-space MSR interface for
this, but when user space MSR access is disabled, then it can't. Here only
limited number of MSRs are allowed using this new interface.
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

Add an IOCTL to send mailbox commands to PUNIT using PUNIT MSRs for
mailbox. Some CPU models don't have PCI device, so need to use MSRs.
A limited set of mailbox commands can be sent to PUNIT.

This MMIO interface is used by the intel-speed-select tool under
tools/x86/power to enumerate and control Intel Speed Select features.
The MBOX commands ids and semantics of the message can be checked from
the source code of the tool.
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

Add an IOCTL to send mailbox commands to PUNIT using PUNIT PCI device.
A limited set of mailbox commands can be sent to PUNIT.

This MMIO interface is used by the intel-speed-select tool under
tools/x86/power to enumerate and control Intel Speed Select features.
The MBOX commands ids and semantics of the message can be checked from
the source code of the tool.
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

Added MMIO interface to read/write specific offsets in PUNIT PCI device
which export core priortization. This MMIO interface can be used using
ioctl interface on /dev/isst_interface using IOCTL ISST_IF_IO_CMD.

This MMIO interface is used by the intel-speed-select tool under
tools/x86/power to enumerate and set core priority. The MMIO offsets and
semantics of the message can be checked from the source code of the tool.
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

Add processing for IOCTL command ISST_IF_GET_PHY_ID. This converts from the
Linux logical CPU to PUNIT CPU numbering scheme.
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

There are two per CPU data needs to be stored and cached to avoid repeated
MSR readings for accessing them later:

- Physical to logical CPU conversion
The PUNIT uses a different CPU numbering scheme which is not APIC id based.
So we need to establish relationship between PUNIT CPU number and Linux
logical CPU numbering which is based on APIC id. There is an MSR 0x53
(MSR_THREAD_ID), which gets physical CPU number for the local CPU where it
is read. Also the CPU mask in some messages will inform which CPUs needs
to be online/offline for a TDP level. During TDP switch if user offlined
some CPUs, then the physical CPU mask can't be converted as we can't
read MSR on an offlined CPU to go to a lower TDP level by onlining more
CPUs. So the mapping needs to be established at the boot up time.

- Bus number corresponding to a CPU
A group of CPUs are in a control of a PUNIT. The PUNIT device is exported
as PCI device. To do operation on a PUNIT for a CPU, we need to find out
to which PCI device it is related to. This is done by reading MSR 0x128
(MSR_CPU_BUS_NUMBER).

So during CPU online stages the above MSRs are read and stored. Later
this stored information is used to process IOCTLs request from the user
space.
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

Encapsulate common functions which all Intel Speed Select Technology
interface drivers can use. This creates API to register misc device for
user kernel communication and handle all common IOCTLs. As part of the
registry it allows a callback which is to handle domain specific ioctl
processing.

There can be multiple drivers register for services, which can be built
as modules. So this driver handle contention during registry and as well
as during removal. Once user space opened the misc device, the registered
driver will be prevented from removal. Also once misc device is opened by
the user space new client driver can't register, till the misc device is
closed.

There are two types of client drivers, one to handle mail box interface
and the other is to allow direct read/write to some specific MMIO space.

This common driver implements IOCTL ISST_IF_GET_PLATFORM_INFO.
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

Reserve ioctl numbers for intel Speed Select Technology interface
drivers.
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

Replace custom grown macro with generic INTEL_CPU_FAM6() one.

No functional change intended.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>

The CB4063 board uses pmc_plt_clk* clocks for ethernet controllers. This
adds it to the critclk_systems DMI table so the clocks are marked as
CLK_CRITICAL and not turned off.

Fixes: 648e9218 ("clk: x86: Stop marking clocks as CLK_IS_CRITICAL")
Signed-off-by: Steffen Dirkwinkel <s.dirkwinkel@beckhoff.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

In preparation to enabling -Wimplicit-fallthrough, mark switch
cases where we are expecting to fall through.

This patch fixes the following warnings:

drivers/platform/x86/acer-wmi.c: In function ‘set_u32’:
drivers/platform/x86/acer-wmi.c:1378:33: warning: this statement may fall through [-Wimplicit-fallthrough=]
    if (cap == ACER_CAP_WIRELESS ||
                                 ^
drivers/platform/x86/acer-wmi.c:1386:3: note: here
   case ACER_WMID:
   ^~~~
drivers/platform/x86/acer-wmi.c:1393:12: warning: this statement may fall through [-Wimplicit-fallthrough=]
    else if (wmi_has_guid(WMID_GUID2))
            ^
drivers/platform/x86/acer-wmi.c:1395:3: note: here
   default:
   ^~~~~~~
drivers/platform/x86/acer-wmi.c: In function ‘get_u32’:
drivers/platform/x86/acer-wmi.c:1340:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
   if (cap == ACER_CAP_MAILLED) {
      ^
drivers/platform/x86/acer-wmi.c:1344:2: note: here
  case ACER_WMID:
  ^~~~
drivers/platform/x86/acer-wmi.c: In function ‘WMID_get_u32’:
drivers/platform/x86/acer-wmi.c:1013:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
   if (quirks->mailled == 1) {
      ^
drivers/platform/x86/acer-wmi.c:1018:2: note: here
  default:
  ^~~~~~~

Warning level 3 was used: -Wimplicit-fallthrough=3

This patch is part of the ongoing efforts to enable
-Wimplicit-fallthrough.
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

Turns out the Hi10 Air is built by multiple companies so using Hampoo
as a filter is not enough to cover all variants.

This has been verified as working on the Hampoo and Morshow version.
Signed-off-by: Christian Oder <me@myself5.de>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

Some function keys on the built in keyboard on Xiaomi's notebooks does
not produce any key events when pressed in combination with the function
key. Some of these keys do report that they are being pressed via WMI
events.

This driver reports key events for Fn+F7 and double tap on Fn.

Other WMI events that are reported by the hardware but not utilized by
this driver are Caps Lock(which already work) and Fn lock/unlock.
Signed-off-by: Mattias Jacobsson <2pi@mok.nu>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

The struct wmi_device_id has a context pointer field, forward this
pointer as an argument to the probe function in struct wmi_driver.

Update existing users of the same probe function to accept this new
context argument.
Signed-off-by: Mattias Jacobsson <2pi@mok.nu>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

When using wmi_install_notify_handler() to initialize a WMI handler a
data pointer can be supplied which will be passed on to the notification
handler. No similar feature exist when handling WMI events via struct
wmi_driver.

Add a context field pointer to struct wmi_device_id and add a function
find_guid_context() to retrieve that context pointer.
Signed-off-by: Mattias Jacobsson <2pi@mok.nu>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

The keyboard backlight is automatically disabled when the module is
unloaded as it is exposed as a ledclass device. Change this behavior to
ignore setting brightness when the device is in unloading state.
Signed-off-by: Yurii Pavlovskyi <yurii.pavlovskyi@gmail.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

The WMI exposes a write-only device ID where up to three fan modes can be
switched on some laptops (TUF Gaming FX505GM). There is a hotkey
combination Fn-F5 that does have a fan icon, which is designed to toggle
between fan modes. The DSTS of the device ID returns information about the
presence of this capability and the presence of each of the two additional
fan modes as a bitmask (0x01 - overboost present, 0x02 - silent present)
[1].

Add a SysFS entry that reads the last written value and updates value in
WMI on write and a hotkey handler that toggles the modes taking into
account their availability according to DSTS.

Modes:
* 0x00 - normal or balanced,
* 0x01 - overboost, increased fan RPM,
* 0x02 - silent, decreased fan RPM

[1] Link: https://lkml.org/lkml/2019/4/12/110Signed-off-by: Yurii Pavlovskyi <yurii.pavlovskyi@gmail.com>
Suggested-by: Daniel Drake <drake@endlessm.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

The obviously wrong value 1 for temperature device ID in this driver is
returned by at least some devices, including TUF Gaming series laptops,
instead of 0 as expected previously. Observable effect is that a
temp1_input in hwmon reads temperature near absolute zero.

Consider 0.1 K an erroneous value in addition to 0 K.
Signed-off-by: Yurii Pavlovskyi <yurii.pavlovskyi@gmail.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

The driver has grown pretty big and will grow more, which makes it hard to
navigate and understand. Add uniform comments to the code and ensure that
it is sorted into logical sections.
Signed-off-by: Yurii Pavlovskyi <yurii.pavlovskyi@gmail.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

Remove exit label as it is only used once from the point in code where no
cleanup is required and return can be called immediately.
Signed-off-by: Yurii Pavlovskyi <yurii.pavlovskyi@gmail.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

The microphone mute key is missing from sparse keymap. It is present on
FX505GM and possibly other laptops. Add the missing code.

Also, comment on the fan mode switch key, which has the same code as the
already used key.
Signed-off-by: Yurii Pavlovskyi <yurii.pavlovskyi@gmail.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

Event codes are expected to be retrieved from a queue on at least some
models. Specifically, very likely the ACPI WMI devices with _UID ATK are
queued whereas those with ASUSWMI are not [1].

The WMI event codes are pushed into a circular buffer queue. After the INIT
method is called, ACPI code is allowed to push events into this buffer.
The INIT method cannot be reverted. If the module is unloaded and an event
(such as hotkey press) gets emitted before inserting it back the events get
processed delayed by one or if the queue overflows, additionally delayed by
about 3 seconds.

It might be considered a minor issue and no normal user would likely
observe this (there is little reason unloading the driver), but it does
significantly frustrate a developer who is unlucky enough to encounter
this. Therefore, the fallback to unqueued behavior occurs whenever
something unexpected happens.

The fix flushes the old key codes out of the queue on load. After receiving
event the queue is read until either ..FFFF or 1 is encountered. Also as
noted in [1] it is checked whether notify code is equal to 0xFF before
enabling queue processing in WMI notify handler.

DSDT examples:

FX505GM
Device (ATKD)
{ ..
    Name (ATKQ, Package (0x10)
    {
        0xFFFFFFFF, ..
    }

    Method (IANQ, 1, Serialized)
    {
        If ((AQNO >= 0x10))
        {
            Local0 = 0x64
            While ((Local0 && (AQNO >= 0x10)))
            {
                Local0--
                Sleep (0x0A)
            }
            ...
        ..
        AQTI++
        AQTI &= 0x0F
        ATKQ [AQTI] = Arg0
        ...
    }

    Method (GANQ, 0, Serialized)
    {
        ..
        If (AQNO)
        {
            ...
            Local0 = DerefOf (ATKQ [AQHI])
            AQHI++
            AQHI &= 0x0F
            Return (Local0)
        }

        Return (One)
    }

This code is almost identical to K54C, which does return Ones on empty
queue.

K54C:
Method (GANQ, 0, Serialized)
{
    If (AQNO)
    {
        ...
        Return (Local0)
    }

    Return (Ones)
}

[1] Link: https://lkml.org/lkml/2019/4/12/104Signed-off-by: Yurii Pavlovskyi <yurii.pavlovskyi@gmail.com>
Suggested-by: Daniel Drake <drake@endlessm.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

Refactor WMI event handling into separate functions for getting the event
code and handling the retrieved event code as a preparation for
introduction of WMI event queue support.
Signed-off-by: Yurii Pavlovskyi <yurii.pavlovskyi@gmail.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

The DSTS method detection mistakenly selects DCTS instead of DSTS if
nothing is returned when the method ID is not defined in WMNB. As a result,
the control of keyboard backlight is not functional for TUF Gaming series
laptops. Implement detection based on _UID of the WMI device instead.

There is evidence that DCTS is handled by ACPI WMI devices that have _UID
ASUSWMI, whereas none of the devices without ASUSWMI respond to DCTS and
DSTS is used instead [1].

DSDT examples:

FX505GM (_UID ATK):
Method (WMNB, 3, Serialized)
{ ...
    If ((Local0 == 0x53545344))
    {
        ...
        Return (Zero)
    }
    ...
    // No return
}

K54C (_UID ATK):
Method (WMNB, 3, Serialized)
{ ...
    If ((Local0 == 0x53545344))
    {
        ...
        Return (0x02)
    }
    ...
    Return (0xFFFFFFFE)
}

[1] Link: https://lkml.org/lkml/2019/4/11/322Signed-off-by: Yurii Pavlovskyi <yurii.pavlovskyi@gmail.com>
Suggested-by: Daniel Drake <drake@endlessm.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

Add a new function to acpi.h / wmi.c that returns _UID of the ACPI WMI
device. For example, it returns "ATK" for the following declaration in
DSDT:
Device (ATKD)
{
    Name (_HID, "PNP0C14" /* Windows Management Instrumentation Device */)
      // _HID: Hardware ID
    Name (_UID, "ATK")  // _UID: Unique ID
    ..

Generally, it is possible that multiple PNP0C14 ACPI devices are present in
the system as mentioned in the commit message of commit bff431e4
("ACPI: WMI: Add ACPI-WMI mapping driver").

Therefore the _UID is returned for a specific ACPI device that declares the
given GUID, to which it is also mapped by other methods of wmi module.
Signed-off-by: Yurii Pavlovskyi <yurii.pavlovskyi@gmail.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

The asus-nb-wmi driver is matched by WMI alias but fails to load on TUF
Gaming series laptops producing multiple ACPI errors in the kernel log.

The input buffer for WMI method invocation size is 2 dwords, whereas
3 are expected by this model.

FX505GM:
..
Method (WMNB, 3, Serialized)
{
    P8XH (Zero, 0x11)
    CreateDWordField (Arg2, Zero, IIA0)
    CreateDWordField (Arg2, 0x04, IIA1)
    CreateDWordField (Arg2, 0x08, IIA2)
    Local0 = (Arg1 & 0xFFFFFFFF)
    ...

Compare with older K54C:
...
Method (WMNB, 3, NotSerialized)
{
    CreateDWordField (Arg2, 0x00, IIA0)
    CreateDWordField (Arg2, 0x04, IIA1)
    Local0 = (Arg1 & 0xFFFFFFFF)
    ...

Increase buffer size to 3 dwords. No negative consequences of this change
are expected, as the input buffer size is not verified. The original
function is replaced by a wrapper for a new method passing value 0 for the
last parameter. The new function will be used to control RGB keyboard
backlight.
Signed-off-by: Yurii Pavlovskyi <yurii.pavlovskyi@gmail.com>
Reviewed-by: Daniel Drake <drake@endlessm.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

The error code and return value are mixed up. The intensity is always set
to 0 on load as kbd_led_read returns either 0 or negative value. To
reproduce set backlight to maximum, reload driver and try to increase it
using keyboard hotkey, the intensity will drop as a result. Correct the
implementation.
Signed-off-by: Yurii Pavlovskyi <yurii.pavlovskyi@gmail.com>
Reviewed-by: Daniel Drake <drake@endlessm.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

The driver does not clean up the hwmon device on exit or error. To
reproduce the bug, repeat rmmod, insmod to verify that device number
/sys/devices/platform/asus-nb-wmi/hwmon/hwmon?? grows every time. Replace
call for registering device with devm_* version that unregisters it
automatically.
Signed-off-by: Yurii Pavlovskyi <yurii.pavlovskyi@gmail.com>
Reviewed-by: Daniel Drake <drake@endlessm.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

When calling debugfs functions, there is no need to ever check the
return value.  The function can work or not, but the code logic should
never do something different based on this.

Cc: Rajneesh Bhardwaj <rajneesh.bhardwaj@linux.intel.com>
Cc: "David E. Box" <david.e.box@linux.intel.com>
Cc: Darren Hart <dvhart@infradead.org>
Cc: Andy Shevchenko <andy@infradead.org>
Cc: platform-driver-x86@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>