<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-toradex.git/drivers/acpi/ec.c, branch v5.5</title>
<subtitle>Linux kernel for Apalis and Colibri modules</subtitle>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/'/>
<entry>
<title>Merge branches 'pm-sleep', 'pm-cpuidle', 'pm-cpufreq', 'pm-devfreq' and 'pm-avs'</title>
<updated>2019-12-04T09:20:17+00:00</updated>
<author>
<name>Rafael J. Wysocki</name>
<email>rafael.j.wysocki@intel.com</email>
</author>
<published>2019-12-04T09:20:17+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=1e4230f56dac141eb149ebec01f41b6fad27e503'/>
<id>1e4230f56dac141eb149ebec01f41b6fad27e503</id>
<content type='text'>
* pm-sleep:
  ACPI: PM: s2idle: Rework ACPI events synchronization
  ACPI: EC: Rework flushing of pending work

* pm-cpuidle:
  cpuidle: minor Kconfig help text fixes
  cpuidle: Drop disabled field from struct cpuidle_state
  cpuidle: Fix Kconfig indentation

* pm-cpufreq:
  cpufreq: Fix Kconfig indentation

* pm-devfreq:
  PM / devfreq: Add missing locking while setting suspend_freq

* pm-avs:
  power: avs: Fix Kconfig indentation
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
* pm-sleep:
  ACPI: PM: s2idle: Rework ACPI events synchronization
  ACPI: EC: Rework flushing of pending work

* pm-cpuidle:
  cpuidle: minor Kconfig help text fixes
  cpuidle: Drop disabled field from struct cpuidle_state
  cpuidle: Fix Kconfig indentation

* pm-cpufreq:
  cpufreq: Fix Kconfig indentation

* pm-devfreq:
  PM / devfreq: Add missing locking while setting suspend_freq

* pm-avs:
  power: avs: Fix Kconfig indentation
</pre>
</div>
</content>
</entry>
<entry>
<title>ACPI: EC: Rework flushing of pending work</title>
<updated>2019-12-02T08:22:54+00:00</updated>
<author>
<name>Rafael J. Wysocki</name>
<email>rafael.j.wysocki@intel.com</email>
</author>
<published>2019-11-28T22:47:51+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=016b87ca5c8c6e9e87db442f04dc99609b11ed36'/>
<id>016b87ca5c8c6e9e87db442f04dc99609b11ed36</id>
<content type='text'>
There is a race condition in the ACPI EC driver, between
__acpi_ec_flush_event() and acpi_ec_event_handler(), that may
cause systems to stay in suspended-to-idle forever after a wakeup
event coming from the EC.

Namely, acpi_s2idle_wake() calls acpi_ec_flush_work() to wait until
the delayed work resulting from the handling of the EC GPE in
acpi_ec_dispatch_gpe() is processed, and that function invokes
__acpi_ec_flush_event() which uses wait_event() to wait for
ec-&gt;nr_pending_queries to become zero on ec-&gt;wait, and that wait
queue may be woken up too early.

Suppose that acpi_ec_dispatch_gpe() has caused acpi_ec_gpe_handler()
to run, so advance_transaction() has been called and it has invoked
acpi_ec_submit_query() to queue up an event work item, so
ec-&gt;nr_pending_queries has been incremented (under ec-&gt;lock).  The
work function of that work item, acpi_ec_event_handler() runs later
and calls acpi_ec_query() to process the event.  That function calls
acpi_ec_transaction() which invokes acpi_ec_transaction_unlocked()
and the latter wakes up ec-&gt;wait under ec-&gt;lock, but it drops that
lock before returning.

When acpi_ec_query() returns, acpi_ec_event_handler() acquires
ec-&gt;lock and decrements ec-&gt;nr_pending_queries, but at that point
__acpi_ec_flush_event() (woken up previously) may already have
acquired ec-&gt;lock, checked the value of ec-&gt;nr_pending_queries (and
it would not have been zero then) and decided to go back to sleep.
Next, if ec-&gt;nr_pending_queries is equal to zero now, the loop
in acpi_ec_event_handler() terminates, ec-&gt;lock is released and
acpi_ec_check_event() is called, but it does nothing unless
ec_event_clearing is equal to ACPI_EC_EVT_TIMING_EVENT (which is
not the case by default).  In the end, if no more event work items
have been queued up while executing acpi_ec_transaction_unlocked(),
there is nothing to wake up __acpi_ec_flush_event() again and it
sleeps forever, so the suspend-to-idle loop cannot make progress and
the system is permanently suspended.

To avoid this issue, notice that it actually is not necessary to
wait for ec-&gt;nr_pending_queries to become zero in every case in
which __acpi_ec_flush_event() is used.

First, during platform-based system suspend (not suspend-to-idle),
__acpi_ec_flush_event() is called by acpi_ec_disable_event() after
clearing the EC_FLAGS_QUERY_ENABLED flag, which prevents
acpi_ec_submit_query() from submitting any new event work items,
so calling flush_scheduled_work() and flushing ec_query_wq
subsequently (in order to wait until all of the queries in that
queue have been processed) would be sufficient to flush all of
the pending EC work in that case.

Second, the purpose of the flushing of pending EC work while
suspended-to-idle described above really is to wait until the
first event work item coming from acpi_ec_dispatch_gpe() is
complete, because it should produce system wakeup events if
that is a valid EC-based system wakeup, so calling
flush_scheduled_work() followed by flushing ec_query_wq is also
sufficient for that purpose.

Rework the code to follow the above observations.

Fixes: 56b9918490 ("PM: sleep: Simplify suspend-to-idle control flow")
Reported-by: Kenneth R. Crudup &lt;kenny@panix.com&gt;
Tested-by: Kenneth R. Crudup &lt;kenny@panix.com&gt;
Cc: 5.4+ &lt;stable@vger.kernel.org&gt; # 5.4+
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
There is a race condition in the ACPI EC driver, between
__acpi_ec_flush_event() and acpi_ec_event_handler(), that may
cause systems to stay in suspended-to-idle forever after a wakeup
event coming from the EC.

Namely, acpi_s2idle_wake() calls acpi_ec_flush_work() to wait until
the delayed work resulting from the handling of the EC GPE in
acpi_ec_dispatch_gpe() is processed, and that function invokes
__acpi_ec_flush_event() which uses wait_event() to wait for
ec-&gt;nr_pending_queries to become zero on ec-&gt;wait, and that wait
queue may be woken up too early.

Suppose that acpi_ec_dispatch_gpe() has caused acpi_ec_gpe_handler()
to run, so advance_transaction() has been called and it has invoked
acpi_ec_submit_query() to queue up an event work item, so
ec-&gt;nr_pending_queries has been incremented (under ec-&gt;lock).  The
work function of that work item, acpi_ec_event_handler() runs later
and calls acpi_ec_query() to process the event.  That function calls
acpi_ec_transaction() which invokes acpi_ec_transaction_unlocked()
and the latter wakes up ec-&gt;wait under ec-&gt;lock, but it drops that
lock before returning.

When acpi_ec_query() returns, acpi_ec_event_handler() acquires
ec-&gt;lock and decrements ec-&gt;nr_pending_queries, but at that point
__acpi_ec_flush_event() (woken up previously) may already have
acquired ec-&gt;lock, checked the value of ec-&gt;nr_pending_queries (and
it would not have been zero then) and decided to go back to sleep.
Next, if ec-&gt;nr_pending_queries is equal to zero now, the loop
in acpi_ec_event_handler() terminates, ec-&gt;lock is released and
acpi_ec_check_event() is called, but it does nothing unless
ec_event_clearing is equal to ACPI_EC_EVT_TIMING_EVENT (which is
not the case by default).  In the end, if no more event work items
have been queued up while executing acpi_ec_transaction_unlocked(),
there is nothing to wake up __acpi_ec_flush_event() again and it
sleeps forever, so the suspend-to-idle loop cannot make progress and
the system is permanently suspended.

To avoid this issue, notice that it actually is not necessary to
wait for ec-&gt;nr_pending_queries to become zero in every case in
which __acpi_ec_flush_event() is used.

First, during platform-based system suspend (not suspend-to-idle),
__acpi_ec_flush_event() is called by acpi_ec_disable_event() after
clearing the EC_FLAGS_QUERY_ENABLED flag, which prevents
acpi_ec_submit_query() from submitting any new event work items,
so calling flush_scheduled_work() and flushing ec_query_wq
subsequently (in order to wait until all of the queries in that
queue have been processed) would be sufficient to flush all of
the pending EC work in that case.

Second, the purpose of the flushing of pending EC work while
suspended-to-idle described above really is to wait until the
first event work item coming from acpi_ec_dispatch_gpe() is
complete, because it should produce system wakeup events if
that is a valid EC-based system wakeup, so calling
flush_scheduled_work() followed by flushing ec_query_wq is also
sufficient for that purpose.

Rework the code to follow the above observations.

Fixes: 56b9918490 ("PM: sleep: Simplify suspend-to-idle control flow")
Reported-by: Kenneth R. Crudup &lt;kenny@panix.com&gt;
Tested-by: Kenneth R. Crudup &lt;kenny@panix.com&gt;
Cc: 5.4+ &lt;stable@vger.kernel.org&gt; # 5.4+
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ACPI: EC: add support for hardware-reduced systems</title>
<updated>2019-10-28T15:00:09+00:00</updated>
<author>
<name>Daniel Drake</name>
<email>drake@endlessm.com</email>
</author>
<published>2019-10-14T08:56:02+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=406857f773b082bc88edfd24967facf4ed07ac85'/>
<id>406857f773b082bc88edfd24967facf4ed07ac85</id>
<content type='text'>
As defined in the ACPI spec section 12.11, ACPI hardware-reduced
platforms define the EC SCI interrupt as a GpioInt in the _CRS object.

This replaces the previous way of using a GPE for this interrupt;
GPE blocks are not available on reduced hardware platforms.

Add support for handling this interrupt as an EC event source, and
avoid GPE usage on reduced hardware platforms.

This enables the use of several media keys (e.g. screen brightness
up/down) on Asus UX434DA.

Signed-off-by: Daniel Drake &lt;drake@endlessm.com&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
As defined in the ACPI spec section 12.11, ACPI hardware-reduced
platforms define the EC SCI interrupt as a GpioInt in the _CRS object.

This replaces the previous way of using a GPE for this interrupt;
GPE blocks are not available on reduced hardware platforms.

Add support for handling this interrupt as an EC event source, and
avoid GPE usage on reduced hardware platforms.

This enables the use of several media keys (e.g. screen brightness
up/down) on Asus UX434DA.

Signed-off-by: Daniel Drake &lt;drake@endlessm.com&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ACPI: EC: tweak naming in preparation for GpioInt support</title>
<updated>2019-10-28T15:00:09+00:00</updated>
<author>
<name>Daniel Drake</name>
<email>drake@endlessm.com</email>
</author>
<published>2019-10-14T08:56:01+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=4446abc9a10954e5d09dd2b894912348a22e7009'/>
<id>4446abc9a10954e5d09dd2b894912348a22e7009</id>
<content type='text'>
In preparation for supporting reduced hardware platforms which use a
GpioInt instead of a GPE, rename some functions and constants to have
more appropriate names. No logical changes.

Signed-off-by: Daniel Drake &lt;drake@endlessm.com&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
In preparation for supporting reduced hardware platforms which use a
GpioInt instead of a GPE, rename some functions and constants to have
more appropriate names. No logical changes.

Signed-off-by: Daniel Drake &lt;drake@endlessm.com&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ACPI: PM: s2idle: Always set up EC GPE for system wakeup</title>
<updated>2019-08-21T21:56:05+00:00</updated>
<author>
<name>Rafael J. Wysocki</name>
<email>rafael.j.wysocki@intel.com</email>
</author>
<published>2019-08-21T09:40:19+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=b90ff3554aa3e123bb7e6d08789f6fd92d86ddde'/>
<id>b90ff3554aa3e123bb7e6d08789f6fd92d86ddde</id>
<content type='text'>
Commit 10a08fd65ec1 ("ACPI: PM: Set up EC GPE for system wakeup from
drivers that need it") assumed that the EC GPE would only need to be
set up for system wakeup if either the intel-hid or the intel-vbtn
driver was in use, but that turns out to be incorrect.  In particular,
on ASUS Zenbook UX430UNR/i7-8550U, if the EC GPE is not enabled while
suspended, the system cannot be woken up by opening the lid or
pressing a key, and that machine doesn't use any of the drivers
mentioned above.

For this reason, always set up the EC GPE for system wakeup from
suspend-to-idle by setting and clearing its wake mask in the ACPI
suspend-to-idle callbacks.

Fixes: 10a08fd65ec1 ("ACPI: PM: Set up EC GPE for system wakeup from drivers that need it")
Reported-by: Kristian Klausen &lt;kristian@klausen.dk&gt;
Tested-by: Kristian Klausen &lt;kristian@klausen.dk&gt;
Acked-by: Andy Shevchenko &lt;andriy.shevchenko@linux.intel.com&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Commit 10a08fd65ec1 ("ACPI: PM: Set up EC GPE for system wakeup from
drivers that need it") assumed that the EC GPE would only need to be
set up for system wakeup if either the intel-hid or the intel-vbtn
driver was in use, but that turns out to be incorrect.  In particular,
on ASUS Zenbook UX430UNR/i7-8550U, if the EC GPE is not enabled while
suspended, the system cannot be woken up by opening the lid or
pressing a key, and that machine doesn't use any of the drivers
mentioned above.

For this reason, always set up the EC GPE for system wakeup from
suspend-to-idle by setting and clearing its wake mask in the ACPI
suspend-to-idle callbacks.

Fixes: 10a08fd65ec1 ("ACPI: PM: Set up EC GPE for system wakeup from drivers that need it")
Reported-by: Kristian Klausen &lt;kristian@klausen.dk&gt;
Tested-by: Kristian Klausen &lt;kristian@klausen.dk&gt;
Acked-by: Andy Shevchenko &lt;andriy.shevchenko@linux.intel.com&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ACPI: EC: PM: Make acpi_ec_dispatch_gpe() print debug message</title>
<updated>2019-08-08T09:25:53+00:00</updated>
<author>
<name>Rafael J. Wysocki</name>
<email>rafael.j.wysocki@intel.com</email>
</author>
<published>2019-07-31T09:06:00+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=29113f2f0a7d8d5332bfdfdfca995c06d0896e83'/>
<id>29113f2f0a7d8d5332bfdfdfca995c06d0896e83</id>
<content type='text'>
Add a pm_pr_dbg() debug statement to acpi_ec_dispatch_gpe() to print
a message when the EC GPE has been dispatched (because its status
was set).

Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Tested-by: Kai-Heng Feng &lt;kai.heng.feng@canonical.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Add a pm_pr_dbg() debug statement to acpi_ec_dispatch_gpe() to print
a message when the EC GPE has been dispatched (because its status
was set).

Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Tested-by: Kai-Heng Feng &lt;kai.heng.feng@canonical.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ACPI: EC: PM: Consolidate some code depending on PM_SLEEP</title>
<updated>2019-08-08T09:25:43+00:00</updated>
<author>
<name>Rafael J. Wysocki</name>
<email>rafael.j.wysocki@intel.com</email>
</author>
<published>2019-07-31T09:05:52+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=d7589404932be148fabe696b56b7c391bad6bdb1'/>
<id>d7589404932be148fabe696b56b7c391bad6bdb1</id>
<content type='text'>
Move some routines, including acpi_ec_dispatch_gpe(), that are only
used if CONFIG_PM_SLEEP is set to the #ifdef block containing the EC
suspend and resume callbacks, to make the "full EC PM picture" easier
to follow.

While at it, move the header of acpi_ec_dispatch_gpe() in the
header file to a CONFIG_PM_SLEEP #ifdef block.

Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Tested-by: Kai-Heng Feng &lt;kai.heng.feng@canonical.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Move some routines, including acpi_ec_dispatch_gpe(), that are only
used if CONFIG_PM_SLEEP is set to the #ifdef block containing the EC
suspend and resume callbacks, to make the "full EC PM picture" easier
to follow.

While at it, move the header of acpi_ec_dispatch_gpe() in the
header file to a CONFIG_PM_SLEEP #ifdef block.

Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Tested-by: Kai-Heng Feng &lt;kai.heng.feng@canonical.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ACPI: PM: s2idle: Eliminate acpi_sleep_no_ec_events()</title>
<updated>2019-08-08T09:25:37+00:00</updated>
<author>
<name>Rafael J. Wysocki</name>
<email>rafael.j.wysocki@intel.com</email>
</author>
<published>2019-07-31T09:05:42+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=6e86633a791fdf631617ef3a9af3263141d34bc9'/>
<id>6e86633a791fdf631617ef3a9af3263141d34bc9</id>
<content type='text'>
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: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Tested-by: Kai-Heng Feng &lt;kai.heng.feng@canonical.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
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: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Tested-by: Kai-Heng Feng &lt;kai.heng.feng@canonical.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ACPI: PM: s2idle: Switch EC over to polling during "noirq" suspend</title>
<updated>2019-08-08T09:25:30+00:00</updated>
<author>
<name>Rafael J. Wysocki</name>
<email>rafael.j.wysocki@intel.com</email>
</author>
<published>2019-07-31T09:05:33+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=fcd0a04267ac7c5d5f9a27d2af824270f2091760'/>
<id>fcd0a04267ac7c5d5f9a27d2af824270f2091760</id>
<content type='text'>
Since the ACPI SCI is set up for system wakeup before the "noirq"
suspend of devices, it is better to make suspend-to-idle follow
suspend-to-RAM (S3) and switch over the EC to polling during "noirq"
suspend (and back to interrupt-based flow during "noirq" resume).

The frequency of spurious wakeup interrupts from the EC may be
reduced this way.

Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Tested-by: Kai-Heng Feng &lt;kai.heng.feng@canonical.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Since the ACPI SCI is set up for system wakeup before the "noirq"
suspend of devices, it is better to make suspend-to-idle follow
suspend-to-RAM (S3) and switch over the EC to polling during "noirq"
suspend (and back to interrupt-based flow during "noirq" resume).

The frequency of spurious wakeup interrupts from the EC may be
reduced this way.

Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Tested-by: Kai-Heng Feng &lt;kai.heng.feng@canonical.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ACPI: PM: Set up EC GPE for system wakeup from drivers that need it</title>
<updated>2019-07-30T10:26:21+00:00</updated>
<author>
<name>Rafael J. Wysocki</name>
<email>rafael.j.wysocki@intel.com</email>
</author>
<published>2019-07-30T09:55:59+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=10a08fd65ec1a68ccd86b19ec822ed5f2e50113f'/>
<id>10a08fd65ec1a68ccd86b19ec822ed5f2e50113f</id>
<content type='text'>
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: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Reviewed-by: Andy Shevchenko &lt;andy.shevchenko@gmail.com&gt;
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<pre>
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: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Reviewed-by: Andy Shevchenko &lt;andy.shevchenko@gmail.com&gt;
</pre>
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</content>
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