Change acpi_ec_suspend() to use pm_suspend_no_platform() instead of
acpi_sleep_no_ec_events(), which allows the latter to be eliminated
along with the s2idle_in_progress variable which is only used by it.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: NKai-Heng Feng <kai.heng.feng@canonical.com>

Add a module parameter to prevent the ACPI LPS0 _DSM functions
from being invoked (if need be) and rework the suspend-to-idle
blacklist entries in acpisleep_dmi_table[] to make them simply
prevent suspend-to-idle from being used by default on the systems
in question (which really is the original purpose of those entries).
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: NKai-Heng Feng <kai.heng.feng@canonical.com>

To allow a subsequent change to be simpler, rearrange the code in
lps0_device_attach() to reduce the indentation level and (while
at it) make it avoid calling lpi_device_get_constraints() when
lps0_device_handle is not going to be set.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: NKai-Heng Feng <kai.heng.feng@canonical.com>

The EC GPE needs to be set up for system wakeup only if there is a
driver depending on it, either intel-hid or intel-vbtn, bound to a
button device that is expected to wake up the system from sleep (such
as the power button on some Dell systems, like the XPS13 9360).  It
doesn't need to be set up for waking up the system from sleep in any
other cases and whether or not it is expected to wake up the system
from sleep doesn't depend on whether or not the LPS0 device is
present in the ACPI namespace.

For this reason, rearrange the ACPI suspend-to-idle code to make the
drivers depending on the EC GPE wakeup take care of setting it up and
decouple that from the LPS0 device handling.

While at it, make intel-hid and intel-vbtn prepare for system wakeup
only if they are allowed to wake up the system from sleep by user
space (via sysfs).

[Note that acpi_ec_mark_gpe_for_wake() and acpi_ec_set_gpe_wake_mask()
 are there to prevent the EC GPE from being disabled by the
 acpi_enable_all_wakeup_gpes() call in acpi_s2idle_prepare(), so on
 systems with either intel-hid or intel-vbtn this change doesn't
 affect any interactions with the hardware or platform firmware.]
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: NAndy Shevchenko <andy.shevchenko@gmail.com>

After commit 33e4f80e ("ACPI / PM: Ignore spurious SCI wakeups
from suspend-to-idle") the "noirq" phases of device suspend and
resume may run for multiple times during suspend-to-idle, if there
are spurious system wakeup events while suspended.  However, this
is complicated and fragile and actually unnecessary.

The main reason for doing this is that on some systems the EC may
signal system wakeup events (power button events, for example) as
well as events that should not cause the system to resume (spurious
system wakeup events).  Thus, in order to determine whether or not
a given event signaled by the EC while suspended is a proper system
wakeup one, the EC GPE needs to be dispatched and to start with that
was achieved by allowing the ACPI SCI action handler to run, which
was only possible after calling resume_device_irqs().

However, dispatching the EC GPE this way turned out to take too much
time in some cases and some EC events might be missed due to that, so
commit 68e22011 ("ACPI: EC: Dispatch the EC GPE directly on
s2idle wake") started to dispatch the EC GPE right after a wakeup
event has been detected, so in fact the full ACPI SCI action handler
doesn't need to run any more to deal with the wakeups coming from the
EC.

Use this observation to simplify the suspend-to-idle control flow
so that the "noirq" phases of device suspend and resume are each
run only once in every suspend-to-idle cycle, which is reported to
significantly reduce power drawn by some systems when suspended to
idle (by allowing them to reach a deep platform-wide low-power state
through the suspend-to-idle flow).  [What appears to happen is that
the "noirq" resume of devices after a spurious EC wakeup brings some
devices into a state in which they prevent the platform from reaching
the deep low-power state going forward, even after a subsequent
"noirq" suspend phase, and on some systems the EC triggers such
wakeups already when the "noirq" suspend of devices is running for
the first time in the given suspend/resume cycle, so the platform
cannot reach the deep low-power state at all.]

First, make acpi_s2idle_wake() use the acpi_ec_dispatch_gpe() return
value to determine whether or not the wakeup may have been triggered
by the EC (in which case the system wakeup is canceled and ACPI
events are processed in order to determine whether or not the event
is a proper system wakeup one) and use rearm_wake_irq() (introduced
by a previous change) in it to rearm the ACPI SCI for system wakeup
detection in case the system will remain suspended.

Second, drop acpi_s2idle_sync(), which is not needed any more, and
the corresponding global platform suspend-to-idle callback.

Next, drop the pm_wakeup_pending() check (which is an optimization
only) from __device_suspend_noirq() to prevent it from returning
errors on system wakeups occurring before the "noirq" phase of
device suspend is complete (as in the case of suspend-to-idle it is
not known whether or not these wakeups are suprious at that point),
in order to avoid having to carry out a "noirq" resume of devices
on a spurious system wakeup.

Finally, change the code flow in s2idle_loop() to (1) run the
"noirq" suspend of devices once before starting the loop, (2) check
for spurious EC wakeups (via the platform ->wake callback) for the
first time before calling s2idle_enter(), and (3) run the "noirq"
resume of devices once after leaving the loop.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: NThomas Gleixner <tglx@linutronix.de>

The role of the s2idle_wakeup variable is to cause
acpi_pm_wakeup_event() and acpi_pm_notify_handler() to
increment pm_abort_suspend and trigger a wakeup from
suspend-to-idle in case the ACPI SCI wakeup was canceled
by acpi_s2idle_wake().

However, for this purpose it need not be set in acpi_s2idle_wake()
and cleared in acpi_s2idle_sync(), respectively.  In fact, it
may be set as early as in acpi_s2idle_prepare() and cleared as
late as in acpi_s2idle_restore(), so do that to allow subsequent
changes to be simpler.

This change is not expected to alter functionality.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: NThomas Gleixner <tglx@linutronix.de>

With some upcoming patches to save/restore the Hyper-V drivers related
states, a Linux VM running on Hyper-V will be able to hibernate. When
a Linux VM hibernates, unluckily we must disable the memory hot-add/remove
and balloon up/down capabilities in the hv_balloon driver
(drivers/hv/hv_balloon.c), because these can not really work according to
the design of the related back-end driver on the host.

By default, Hyper-V does not enable the virtual ACPI S4 state for a VM;
on recent Hyper-V hosts, the administrator is able to enable the virtual
ACPI S4 state for a VM, so we hope to use the presence of the virtual ACPI
S4 state as a hint for hv_balloon to disable the aforementioned
capabilities. In this way, hibernation will work more reliably, from the
user's perspective.

By marking acpi_sleep_state_supported() non-static, we'll be able to
implement a hv_is_hibernation_supported() API in the always-built-in
module arch/x86/hyperv/hv_init.c, and the API will be called by hv_balloon.
Signed-off-by: NDexuan Cui <decui@microsoft.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

There is an arbitrary difference between the prototypes of
bus_find_device() and class_find_device() preventing their callers
from passing the same pair of data and match() arguments to both of
them, which is the const qualifier used in the prototype of
class_find_device().  If that qualifier is also used in the
bus_find_device() prototype, it will be possible to pass the same
match() callback function to both bus_find_device() and
class_find_device(), which will allow some optimizations to be made in
order to avoid code duplication going forward.  Also with that, constify
the "data" parameter as it is passed as a const to the match function.

For this reason, change the prototype of bus_find_device() to match
the prototype of class_find_device() and adjust its callers to use the
const qualifier in accordance with the new prototype of it.

Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andrew Lunn <andrew@lunn.ch>
Cc: Andreas Noever <andreas.noever@gmail.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Corey Minyard <minyard@acm.org>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: David Kershner <david.kershner@unisys.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: David Airlie <airlied@linux.ie>
Cc: Felipe Balbi <balbi@kernel.org>
Cc: Frank Rowand <frowand.list@gmail.com>
Cc: Grygorii Strashko <grygorii.strashko@ti.com>
Cc: Harald Freudenberger <freude@linux.ibm.com>
Cc: Hartmut Knaack <knaack.h@gmx.de>
Cc: Heiko Stuebner <heiko@sntech.de>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jonathan Cameron <jic23@kernel.org>
Cc: "James E.J. Bottomley" <jejb@linux.ibm.com>
Cc: Len Brown <lenb@kernel.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michael Jamet <michael.jamet@intel.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: Peter Oberparleiter <oberpar@linux.ibm.com>
Cc: Sebastian Ott <sebott@linux.ibm.com>
Cc: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Cc: Yehezkel Bernat <YehezkelShB@gmail.com>
Cc: rafael@kernel.org
Acked-by: NCorey Minyard <minyard@acm.org>
Acked-by: NDavid Kershner <david.kershner@unisys.com>
Acked-by: NMark Brown <broonie@kernel.org>
Acked-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: NSrinivas Kandagatla <srinivas.kandagatla@linaro.org>
Acked-by: Wolfram Sang <wsa@the-dreams.de> # for the I2C parts
Acked-by: NRob Herring <robh@kernel.org>
Signed-off-by: NSuzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Switch the acpi_pm_finish() to use acpi_dev_get_first_match_dev() instead of
custom approach.
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Based on 1 normalized pattern(s):

  this file is released under the gplv2

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 68 file(s).
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NArmijn Hemel <armijn@tjaldur.nl>
Reviewed-by: NAllison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190531190114.292346262@linutronix.deSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

On systems with ACPI platform firmware the last stage of hibernation
is analogous to system suspend to S3 (suspend-to-RAM), so it should
be handled analogously.  In particular, pm_suspend_via_firmware()
should return 'true' in that stage to let the callers of it know that
control will be passed to the platform firmware going forward, so
pm_set_suspend_via_firmware() needs to be called then in analogy with
acpi_suspend_begin().

However, the platform hibernation ->begin() callback is invoked
during the "freeze" transition (before creating a snapshot image of
system memory) as well as during the "hibernate" transition which is
the last stage of it and pm_set_suspend_via_firmware() should be
invoked by that callback in the latter stage only.

In order to implement that redefine the hibernation ->begin()
callback to take a pm_message_t argument to indicate which stage
of hibernation is taking place and rework acpi_hibernation_begin()
and acpi_hibernation_begin_old() to take it into account as needed.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

I noticed that recently multiple systems (chromebooks) couldn't wake
from S0ix using LID or Keyboard after updating to a newer kernel. I
bisected and it turned up commit f941d3e4 ("ACPI: EC / PM: Disable
non-wakeup GPEs for suspend-to-idle"). I checked that the issue got
fixed if that commit was reverted.

I debugged and found that although PNP0C0D:00 (representing the LID)
is wake capable and should wakeup the system per the code in
acpi_wakeup_gpe_init() and in drivers/acpi/button.c:

localhost /sys # cat /proc/acpi/wakeup
Device  S-state   Status   Sysfs node
LID0      S4    *enabled   platform:PNP0C0D:00
CREC      S5    *disabled  platform:GOOG0004:00
                *disabled  platform:cros-ec-dev.1.auto
                *disabled  platform:cros-ec-accel.0
                *disabled  platform:cros-ec-accel.1
                *disabled  platform:cros-ec-gyro.0
                *disabled  platform:cros-ec-ring.0
                *disabled  platform:cros-usbpd-charger.2.auto
                *disabled  platform:cros-usbpd-logger.3.auto
D015      S3    *enabled   i2c:i2c-ELAN0000:00
PENH      S3    *enabled   platform:PRP0001:00
XHCI      S3    *enabled   pci:0000:00:14.0
GLAN      S4    *disabled
WIFI      S3    *disabled  pci:0000:00:14.3
localhost /sys #

On debugging, I found that its corresponding GPE is not being enabled.
The particular GPE's "gpe_register_info->enable_for_wake" does not
have any bits set when acpi_enable_all_wakeup_gpes() comes around to
use it. I looked at code and could not find any other code path that
should set the bits in "enable_for_wake" bitmask for the wake enabled
devices for s2idle.  [I do see that it happens for S3 in
acpi_sleep_prepare()].

Thus I used the same call to enable the GPEs for wake enabled devices,
and verified that this fixes the regression I was seeing on multiple
of my devices.

[ rjw: The problem is that commit f941d3e4 ("ACPI: EC / PM:
  Disable non-wakeup GPEs for suspend-to-idle") forgot to add
  the acpi_enable_wakeup_devices() call for s2idle along with
  acpi_enable_all_wakeup_gpes(). ]

Fixes: f941d3e4 ("ACPI: EC / PM: Disable non-wakeup GPEs for suspend-to-idle")
Link: https://bugzilla.kernel.org/show_bug.cgi?id=203579Signed-off-by: NRajat Jain <rajatja@google.com>
[ rjw: Subject & changelog ]
Cc: 5.0+ <stable@vger.kernel.org> # 5.0+
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

After a previous change, all non-wakeup GPEs are disabled for
suspend-to-idle unless full Low-Power S0 (LPS0) mode is in use, so
it is not necessary to do anything in acpi_s2idle_wake() unless in
full LPS0 mode, which is only when lps0_device_handle is set.

Modify the code accordingly.
Tested-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

There are systems in which non-wakeup GPEs fire during the "noirq"
suspend stage of suspending devices and that effectively prevents the
system that tries to suspend to idle from entering any low-power
state at all.  If the offending GPE fires regularly and often enough,
the system appears to be suspended, but in fact it is in a tight loop
over "noirq" suspend and "noirq" resume of devices all the time.

To prevent that from happening, disable all non-wakeup GPEs except
for the EC GPE for suspend-to-idle (the EC GPE is special, because
on some systems it has to be enabled for power button wakeup events
to be generated as expected).

Fixes: 147a7d9d (ACPI / PM: Do not reconfigure GPEs for suspend-to-idle)
Link: https://bugzilla.kernel.org/show_bug.cgi?id=201987Reported-by: NZhang Rui <rui.zhang@intel.com>
Tested-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Tested-by: NZhang Rui <rui.zhang@intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Every time I tried to upgrade my laptop from 3.10.x to 4.x I faced an
issue by which the fan would run at full speed upon resume. Bisecting
it showed me the issue was introduced in 3.17 by commit 821d6f03
(ACPI / sleep: Do not save NVS for new machines to accelerate S3). This
code only affects machines built starting as of 2012, but this Asus
1025C laptop was made in 2012 and apparently needs the NVS data to be
saved, otherwise the CPU's thermal state is not properly reported on
resume and the fan runs at full speed upon resume.

Here's a very simple way to check if such a machine is affected :

  # cat /sys/class/thermal/thermal_zone0/temp
  55000

  ( now suspend, wait one second and resume )

  # cat /sys/class/thermal/thermal_zone0/temp
  0

  (and after ~15 seconds the fan starts to spin)

Let's apply the same quirk as commit cbc00c13 (ACPI: save NVS memory
for Lenovo G50-45) and reuse the function it provides. Note that this
commit was already backported to 4.9.x but not 4.4.x.

Cc: 3.17+ <stable@vger.kernel.org> # 3.17+: requires cbc00c13Signed-off-by: NWilly Tarreau <w@1wt.eu>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The Dell Venue Pro 7140 supports the Low Power S0 Idle state, but
does not support any of the _DSM functions that the current heuristic
checks for.

Since suspend-to-mem can not be safely performed on this machine,
and since the bitfield check can't cover this case, it is safer
to enable s2idle by default by checking for the presence of the
_DSM alone and removing the bitfield check.
Signed-off-by: NTristian Celestin <tristiancelestin@fastmail.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

On platforms where the Low Power S0 Idle _DSM interface is used,
on wakeup from suspend-to-idle, when it is known that the ACPI SCI
has triggered while suspended, dispatch the EC GPE in order to catch
all EC events that may have triggered the wakeup before carrying out
the noirq phase of device resume.

That is needed to handle power button wakeup on some platforms where
the EC goes into a low-power mode during suspend-to-idle and while in
that mode it will discard events after a timeout.  If that timeout is
shorter than the time it takes to complete the noirq resume of
devices, looking for EC events after the latter is too late.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Reported-by: NZhang Rui <rui.zhang@intel.com>
Tested-by: NWendy Wang <wendy.wang@intel.com>

ThinkPad X1 Tablet(2016) is reported to have issues with
the Low Power S0 Idle _DSM interface and since this machine
model generally can do ACPI S3 just fine, and user would
like to use S3 as default sleep model, add a blacklist
entry to disable that interface for ThinkPad X1 Tablet(2016).

Link: https://bugzilla.kernel.org/show_bug.cgi?id=199057Reported-and-tested-by: NRobin Lee <robinlee.sysu@gmail.com>
Signed-off-by: NChen Yu <yu.c.chen@intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

This issue happens on new ASUS laptop UX331UA which has modern
standby mode (suspend-to-idle). Pressing keys on the PS2 keyboard
can't wake up the system from suspend-to-idle which is not expected.
However, pressing power button can wake up without problem.

Per the engineers of ASUS, the keypress event is routed to Embedded
Controller (EC) in standby mode. EC then signals the SCI event to
BIOS so BIOS would Notify() power button to wake up the system. It's
from BIOS perspective. What we observe here is that kernel receives
the SCI event from SCI interrupt handler which informs that the GPE
status bit belongs to EC needs to be handled and then queries the EC
to find out what event is pending. Then execute the following ACPI
_QDF method which defined in ACPI DSDT for EC to notify power button.

 Method (_QDF, 0, NotSerialized)  // _Qxx: EC Query
        {
            Notify (PWRB, 0x80) // Status Change
        }

With more debug messages added to analyze this problem, we find that
the keypress does wake up the system from suspend-to-idle but it's back
to suspend again almost immediately. As we see in the following messages,
the acpi_button_notify() is invoked but acpi_pm_wakeup_event() can not
really wake up the system here because acpi_s2idle_wakeup() is false.
The acpi_s2idle_wakeup() returnd false because the acpi_s2idle_sync() has
alrealdy exited.

[   52.987048] s2idle_loop going s2idle
[   59.713392] acpi_s2idle_wake enter
[   59.713394] acpi_s2idle_wake exit
[   59.760888] acpi_ev_gpe_detect enter
[   59.760893] acpi_s2idle_sync enter
[   59.760893] acpi_ec_query_flushed ec pending queries 0
[   59.760953] Read registers for GPE 50-57: Status=01, Enable=01, RunEnable=01, WakeEnable=00
[   59.760955] ACPI: EC: ===== IRQ (1) =====
[   59.760972] ACPI: EC: EC_SC(R) = 0x28 SCI_EVT=1 BURST=0 CMD=1 IBF=0 OBF=0
[   59.760979] ACPI: EC: +++++ Polling enabled +++++
[   59.760979] ACPI: EC: ##### Command(QR_EC) submitted/blocked #####
[   59.761003] acpi_s2idle_sync exit
[   59.769587] ACPI: EC: ##### Query(0xdf) started #####
[   59.769611] ACPI: EC: ##### Query(0xdf) stopped #####
[   59.774154] acpi_button_notify button type 1
[   59.813175] s2idle_loop going s2idle

acpi_s2idle_sync() already makes an effort to flush the EC event
queue, but in this case, the EC event has yet to be generated when
the call to acpi_ec_flush_work() is made. The event is generated
shortly after, through the ongoing handling of the SCI interrupt
which is happening on another CPU, and we must synchronize that
to make sure that it has run and completed. Adding another call to
acpi_os_wait_events_complete() solves this issue, since that
function synchronizes with SCI interrupt completion.
Signed-off-by: NChris Chiu <chiu@endlessm.com>
[ rjw: Subject ]
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

If a device referred to by ACPI LPI constrains (coming from function 1
of the Low Power S0 Idle _DSM interface) is not power-manageable via
ACPI (no _PS0 method and no power resources), the code generating
diagnostic information for the LPI constraints will print a message
about that to the kernel log on every system suspend-resume cycle
(possibly for multiple times).

That is not very useful and noisy, so modify that code to disregard
the LPI list entries corresponding to the devices that are not power-
manageable after printing that information for them once.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: NSrinivas Pandruvada <srinivas.pandruvada@linux.intel.com>

...instead of open coding its functionality.

No changes in functionality.
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Jean Delvare <jdelvare@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-acpi@vger.kernel.org
Cc: linux-pci@vger.kernel.org
Link: http://lkml.kernel.org/r/20180222125923.57385-3-andriy.shevchenko@linux.intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

It is reported that commit 235d81a6 (ACPI / PM: Clean up device
wakeup enable/disable code) broke wakeup from suspend-to-idle on
some platforms.  That is due to the acpi_enable_all_wakeup_gpes() in
acpi_s2idle_prepare() which needs acpi_enable_wakeup_devices() to be
called before it as the latter sets up the GPE masks used by the
former and commit 235d81a6 removed acpi_enable_wakeup_devices()
invocation from the suspend-to-idle path.

However, acpi_enable_wakeup_devices() does more than just setting
the GPE masks and the remaining part of it is not necessary for
suspend-to-idle.  Moreover, non-wakeup GPEs are disabled on suspend-
to-idle entry to avoid spurious wakeups, but that should not be
strictly necessary any more after commit 33e4f80e (ACPI / PM:
Ignore spurious SCI wakeups from suspend-to-idle) which prevents
spurious GPE wakeups from resuming the system.  The only consequence
of leaving non-wakeup GPEs enabled may be more interrupt-related
activity while suspended, which is not ideal (more energy is used
if that happens), but it is not critical too.

For this reason, drop the GPE reconfiguration from the suspend-to-idle
path entirely.

This change also allows Dells XPS13 9360 blacklisted by commit
71630b7a (ACPI / PM: Blacklist Low Power S0 Idle _DSM for Dell
XPS13 9360) to use the power button for waking up from suspend-
to-idle and it helps at least one other older Dell system (the
wakeup button GPE on that one is not listed in _PRW for any
devices, so it is not regarded as a wakeup one and gets disabled
on suspend-to-idle entry today).

Fixes: 235d81a6 (ACPI / PM: Clean up device wakeup enable/disable code)
Reported-by: NDu Wenkai <wenkai.du@intel.com>
Tested-by: NDu Wenkai <wenkai.du@intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Some systems don't support the ACPI_LPS0_ENTRY and ACPI_LPS0_EXIT
functions in their Low Power S0 Idle _DSM, but still expect EC
events to be processed in the suspend-to-idle state for power button
wakeup (among other things) to work.  Surface Pro3 turns out to be
one of them.

Fortunately, it still provides Low Power S0 Idle _DSM with the screen
on/off functions supported, so modify the ACPI suspend-to-idle to use
the Low Power S0 Idle code path for all systems supporting the
ACPI_LPS0_ENTRY and ACPI_LPS0_EXIT or the ACPI_LPS0_SCREEN_OFF and
ACPI_LPS0_SCREEN_ON functions in their Low Power S0 Idle _DSM.

Potentially, that will cause more systems to use suspend-to-idle by
default, so some future corrections may be necessary if it leads
to issues, but let it remain more straightforward for now.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=198389#add_commentReported-by: NValentin Manea <valy@mrs.ro>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: NValentin Manea <valy@mrs.ro>

The ACPI code supporting system transitions to sleep states uses
an internal blacklist to apply special handling to some machines
reported to behave incorrectly in some ways.

However, some entries of that blacklist cover problematic as well as
non-problematic systems, so give the users of the latter a chance to
ignore the blacklist and run their systems in the default way by
adding acpi_sleep=nobl to the kernel command line.

For example, that allows the users of Dell XPS13 9360 systems not
affected by the issue that caused the blacklist entry for this
machine to be added by commit 71630b7a (ACPI / PM: Blacklist Low
Power S0 Idle _DSM for Dell XPS13 9360) to use suspend-to-idle with
the Low Power S0 Idle _DSM interface which in principle should be
more energy-efficient than S3 on them.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

At least one Dell XPS13 9360 is reported to have serious issues with
the Low Power S0 Idle _DSM interface and since this machine model
generally can do ACPI S3 just fine, add a blacklist entry to disable
that interface for Dell XPS13 9360.

Fixes: 8110dd28 (ACPI / sleep: EC-based wakeup from suspend-to-idle on recent systems)
Link: https://bugzilla.kernel.org/show_bug.cgi?id=196907Reported-by: NPaul Menzel <pmenzel@molgen.mpg.de>
Tested-by: NPaul Menzel <pmenzel@molgen.mpg.de>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: 4.13+ <stable@vger.kernel.org> # 4.13+

... and __initconst if applicable.

Based on similar work for an older kernel in the Grsecurity patch.

[JD: fix toshiba-wmi build]
[JD: add htcpen]
[JD: move __initconst where checkscript wants it]
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJean Delvare <jdelvare@suse.de>

For SoC to achieve its lowest power platform idle state a set of hardware
preconditions must be met. These preconditions or constraints can be
obtained by issuing a device specific method (_DSM) with function "1".
Refer to the document provided in the link below.

Here during initialization (from attach() callback of LPS0 device), invoke
function 1 to get the device constraints. Each enabled constraint is
stored in a table.

The devices in this table are used to check whether they were in required
minimum state, while entering suspend. This check is done from platform
freeze wake() callback, only when /sys/power/pm_debug_messages attribute
is non zero.

If any constraint is not met and device is ACPI power managed then it
prints the device information to kernel logs.

Also if debug is enabled in acpi/sleep.c, the constraint table and state
of each device on wake is dumped in kernel logs.

Since pm_debug_messages_on setting is used as condition to check
constraints outside kernel/power/main.c, pm_debug_messages_on is changed
to a global variable.

Link: http://www.uefi.org/sites/default/files/resources/Intel_ACPI_Low_Power_S0_Idle.pdfSigned-off-by: NSrinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Rename struct platform_freeze_ops to platform_s2idle_ops to make it
clear that the callbacks in it are used during suspend-to-idle
suspend/resume transitions and rename the related functions,
variables and so on accordingly.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

To make it clear that the symbol in question refers to
suspend-to-idle, rename it from PM_SUSPEND_FREEZE to
PM_SUSPEND_TO_IDLE.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Modify the ACPI system sleep support setup code to select
suspend-to-idle as the default system sleep state if
(1) the ACPI_FADT_LOW_POWER_S0 flag is set in the FADT and
(2) the Low Power Idle S0 _DSM interface has been discovered and
(3) the default sleep state was not selected from the kernel command
line.

The main motivation for this change is that systems where the (1) and
(2) conditions are met typically ship with OSes that don't exercise
the S3 path in the platform firmware which remains untested and turns
out to be non-functional at least in some cases.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: NMario Limonciello <mario.limonciello@dell.com>

Function acpi_sleep_syscore_init has no external user so it should be
static.
Signed-off-by: NJean Delvare <jdelvare@suse.de>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Commit eed4d47e (ACPI / sleep: Ignore spurious SCI wakeups from
suspend-to-idle) introduced acpi_freeze_sync() whose purpose is to
flush all of the processing of possible wakeup events signaled via
the ACPI SCI.  However, it doesn't flush the query workqueue used
by the EC driver, so the events generated by the EC may not be
processed timely which leads to issues (increased overhead at least,
lost events possibly).

To fix that introduce acpi_ec_flush_work() that will flush all of
the outstanding EC work and call it from acpi_freeze_sync().

Fixes: eed4d47e (ACPI / sleep: Ignore spurious SCI wakeups from suspend-to-idle)
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Some recent Dell laptops, including the XPS13 model numbers 9360 and
9365, cannot be woken up from suspend-to-idle by pressing the power
button which is unexpected and makes that feature less usable on
those systems.  Moreover, on the 9365 ACPI S3 (suspend-to-RAM) is
not expected to be used at all (the OS these systems ship with never
exercises the ACPI S3 path in the firmware) and suspend-to-idle is
the only viable system suspend mechanism there.

The reason why the power button wakeup from suspend-to-idle doesn't
work on those systems is because their power button events are
signaled by the EC (Embedded Controller), whose GPE (General Purpose
Event) line is disabled during suspend-to-idle transitions in Linux.
That is done on purpose, because in general the EC tends to be noisy
for various reasons (battery and thermal updates and similar, for
example) and all events signaled by it would kick the CPUs out of
deep idle states while in suspend-to-idle, which effectively might
defeat its purpose.

Of course, on the Dell systems in question the EC GPE must be enabled
during suspend-to-idle transitions for the button press events to
be signaled while suspended at all, but fortunately there is a way
out of this puzzle.

First of all, those systems have the ACPI_FADT_LOW_POWER_S0 flag set
in their ACPI tables, which means that the OS is expected to prefer
the "low power S0 idle" system state over ACPI S3 on them.  That
causes the most recent versions of other OSes to simply ignore ACPI
S3 on those systems, so it is reasonable to expect that it should not
be necessary to block GPEs during suspend-to-idle on them.

Second, in addition to that, the systems in question provide a special
firmware interface that can be used to indicate to the platform that
the OS is transitioning into a system-wide low-power state in which
certain types of activity are not desirable or that it is leaving
such a state and that (in principle) should allow the platform to
adjust its operation mode accordingly.

That interface is a special _DSM object under a System Power
Management Controller device (PNP0D80).  The expected way to use it
is to invoke function 0 from it on system initialization, functions
3 and 5 during suspend transitions and functions 4 and 6 during
resume transitions (to reverse the actions carried out by the
former).  In particular, function 5 from the "Low-Power S0" device
_DSM is expected to cause the platform to put itself into a low-power
operation mode which should include making the EC less verbose (so to
speak).  Next, on resume, function 6 switches the platform back to
the "working-state" operation mode.

In accordance with the above, modify the ACPI suspend-to-idle code
to look for the "Low-Power S0" _DSM interface on platforms with the
ACPI_FADT_LOW_POWER_S0 flag set in the ACPI tables.  If it's there,
use it during suspend-to-idle transitions as prescribed and avoid
changing the GPE configuration in that case.  [That should reflect
what the most recent versions of other OSes do.]

Also modify the ACPI EC driver to make it handle events during
suspend-to-idle in the usual way if the "Low-Power S0" _DSM interface
is going to be used to make the power button events work while
suspended on the Dell machines mentioned above

Link: http://www.uefi.org/sites/default/files/resources/Intel_ACPI_Low_Power_S0_Idle.pdfSigned-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

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

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

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

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

In addition to that, some ACPI code processing wakeup events needs
to be modified to use the "hard" version of wakeup triggers, so that
it will cause a system resume to happen on device-induced wakeup
events even if the "soft" mechanism to prevent the system from
suspending is not enabled.  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: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

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

Revert commit eed4d47e (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: NDominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

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

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

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

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

In addition to that, some ACPI code processing wakeup events needs
to be modified to use the "hard" version of wakeup triggers, so that
it will cause a system resume to happen on device-induced wakeup
events even if the "soft" mechanism to prevent the system from
suspending is not enabled (that also helps to catch device-induced
wakeup events occurring during suspend transitions in progress).
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Commit 660b1113 (ACPI / PM: Fix consistency check for power resources
during resume) introduced a check for ACPI power resources which have
been turned on by the BIOS during suspend and turns these back off again.

This is causing problems on a Dell Venue Pro 11 7130 (i5-4300Y) it causes
the following messages to show up in dmesg:

[  131.014605] ACPI: Waking up from system sleep state S3
[  131.150271] acpi LNXPOWER:07: Turning OFF
[  131.150323] acpi LNXPOWER:06: Turning OFF
[  131.150911] acpi LNXPOWER:00: Turning OFF
[  131.169014] ACPI : EC: interrupt unblocked
[  131.181811] xhci_hcd 0000:00:14.0: System wakeup disabled by ACPI
[  133.535728] pci_raw_set_power_state: 76 callbacks suppressed
[  133.535735] iwlwifi 0000:01:00.0: Refused to change power state,
               currently in D3
[  133.597672] PM: noirq resume of devices complete after 2428.891 msecs

Followed by a bunch of iwlwifi errors later on and the pcie device
dropping from the bus (acpiphp thinks it has been unplugged).

Disabling the turning off of unused power resources fixes this. Instead
of adding a quirk for this system, this commit fixes this by moving the
disabling of unused power resources to later in the resume sequence
when the iwlwifi card has been moved out of D3 so the ref_count for
its power resource no longer is 0.

This new behavior seems to match the intend of the original commit which
commit-msg says: "(... which means that no devices are going to need them
any time soon) and we should turn them off".

This also avoids power resources which we need when bringing devices out
of D3 from getting bounced off and then back on again.
Signed-off-by: NHans de Goede <hdegoede@redhat.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

In commit 821d6f03 (ACPI / sleep: Do not save NVS for new machines to
accelerate S3), to optimize S3 suspend/resume speed, code is introduced
to ignore NVS memory saving during S3 for all the platforms later than
2012.

But, Lenovo G50-45, a platform released in 2015, still needs NVS memory
saving during S3. A quirk is introduced for this platform.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=189431Tested-by: NPrzemek <soprwa@gmail.com>
Signed-off-by: NZhang Rui <rui.zhang@intel.com>
[ rjw: Drop unnecessary code ]
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Revert commit 08b98d32 (PM / sleep / ACPI: Use the ACPI_FADT_LOW_POWER_S0
flag) as it caused system suspend (in the default configuration) to fail
on Dell XPS13 (9360) with the Kaby Lake processor.

Fixes: 08b98d32 (PM / sleep / ACPI: Use the ACPI_FADT_LOW_POWER_S0 flag)
Reported-by: NPaul Menzel <pmenzel@molgen.mpg.de>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>