<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/drivers/acpi/sleep.c, branch v4.13</title>
<subtitle>Linux kernel source tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/'/>
<entry>
<title>ACPI / PM / EC: Flush all EC work in acpi_freeze_sync()</title>
<updated>2017-07-20T14:44:24+00:00</updated>
<author>
<name>Rafael J. Wysocki</name>
<email>rafael.j.wysocki@intel.com</email>
</author>
<published>2017-07-20T01:43:12+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=880a66275ef4d1e08e5d4dcf4cec768de18c68ef'/>
<id>880a66275ef4d1e08e5d4dcf4cec768de18c68ef</id>
<content type='text'>
Commit eed4d47efe95 (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: eed4d47efe95 (ACPI / sleep: Ignore spurious SCI wakeups from suspend-to-idle)
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 eed4d47efe95 (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: eed4d47efe95 (ACPI / sleep: Ignore spurious SCI wakeups from suspend-to-idle)
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ACPI / sleep: EC-based wakeup from suspend-to-idle on recent systems</title>
<updated>2017-06-23T13:24:32+00:00</updated>
<author>
<name>Rafael J. Wysocki</name>
<email>rafael.j.wysocki@intel.com</email>
</author>
<published>2017-06-23T13:24:32+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=8110dd281e155e5010ffd657bba4742ebef7a93f'/>
<id>8110dd281e155e5010ffd657bba4742ebef7a93f</id>
<content type='text'>
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.pdf
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>
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.pdf
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ACPI / PM: Ignore spurious SCI wakeups from suspend-to-idle</title>
<updated>2017-06-14T22:55:44+00:00</updated>
<author>
<name>Rafael J. Wysocki</name>
<email>rafael.j.wysocki@intel.com</email>
</author>
<published>2017-06-12T20:56:34+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=33e4f80ee69b5168badf37edbfed796eb48434b9'/>
<id>33e4f80ee69b5168badf37edbfed796eb48434b9</id>
<content type='text'>
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 -&gt;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 -&gt;sync hook allows all of the relevant event
queues to be flushed so as to prevent events from being missed due
to race conditions.

In addition to that, some ACPI code processing wakeup events needs
to be modified to use the "hard" version of wakeup triggers, so that
it will cause a system resume to happen on device-induced wakeup
events even if the "soft" mechanism to prevent the system from
suspending is not enabled.  However, to preserve the existing
behavior with respect to suspend-to-RAM, this only is done in
the suspend-to-idle case and only if an SCI has occurred while
suspended.

Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
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 -&gt;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 -&gt;sync hook allows all of the relevant event
queues to be flushed so as to prevent events from being missed due
to race conditions.

In addition to that, some ACPI code processing wakeup events needs
to be modified to use the "hard" version of wakeup triggers, so that
it will cause a system resume to happen on device-induced wakeup
events even if the "soft" mechanism to prevent the system from
suspending is not enabled.  However, to preserve the existing
behavior with respect to suspend-to-RAM, this only is done in
the suspend-to-idle case and only if an SCI has occurred while
suspended.

Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ACPI / PM: Clean up device wakeup enable/disable code</title>
<updated>2017-06-14T22:55:43+00:00</updated>
<author>
<name>Rafael J. Wysocki</name>
<email>rafael.j.wysocki@intel.com</email>
</author>
<published>2017-06-12T20:51:07+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=235d81a630ca2d39818da96f0c14bc960ffbaeb5'/>
<id>235d81a630ca2d39818da96f0c14bc960ffbaeb5</id>
<content type='text'>
The wakeup.flags.enabled flag in struct acpi_device is not used
consistently, as there is no reason why it should only apply
to the enabling/disabling of the wakeup GPE, so put the invocation
of acpi_enable_wakeup_device_power() under it too.

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

Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The wakeup.flags.enabled flag in struct acpi_device is not used
consistently, as there is no reason why it should only apply
to the enabling/disabling of the wakeup GPE, so put the invocation
of acpi_enable_wakeup_device_power() under it too.

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

Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branches 'intel_pstate' and 'pm-sleep'</title>
<updated>2017-06-08T23:25:16+00:00</updated>
<author>
<name>Rafael J. Wysocki</name>
<email>rafael.j.wysocki@intel.com</email>
</author>
<published>2017-06-08T23:25:16+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=fbd78afe34d9cc3a86aff7cc214d9f06e815e63e'/>
<id>fbd78afe34d9cc3a86aff7cc214d9f06e815e63e</id>
<content type='text'>
* intel_pstate:
  cpufreq: intel_pstate: Avoid division by 0 in min_perf_pct_min()

* pm-sleep:
  Revert "ACPI / sleep: Ignore spurious SCI wakeups from suspend-to-idle"
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
* intel_pstate:
  cpufreq: intel_pstate: Avoid division by 0 in min_perf_pct_min()

* pm-sleep:
  Revert "ACPI / sleep: Ignore spurious SCI wakeups from suspend-to-idle"
</pre>
</div>
</content>
</entry>
<entry>
<title>Revert "ACPI / sleep: Ignore spurious SCI wakeups from suspend-to-idle"</title>
<updated>2017-06-06T22:57:37+00:00</updated>
<author>
<name>Rafael J. Wysocki</name>
<email>rafael.j.wysocki@intel.com</email>
</author>
<published>2017-06-06T22:57:37+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=f3b7eaae1b35eb8077610eb7c7db042c9b0645e1'/>
<id>f3b7eaae1b35eb8077610eb7c7db042c9b0645e1</id>
<content type='text'>
Revert commit eed4d47efe95 (ACPI / sleep: Ignore spurious SCI wakeups
from suspend-to-idle) as it turned out to be premature and triggered
a number of different issues on various systems.

That includes, but is not limited to, premature suspend-to-RAM aborts
on Dell XPS 13 (9343) reported by Dominik.

The issue the commit in question attempted to address is real and
will need to be taken care of going forward, but evidently more work
is needed for this purpose.

Reported-by: Dominik Brodowski &lt;linux@dominikbrodowski.net&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>
Revert commit eed4d47efe95 (ACPI / sleep: Ignore spurious SCI wakeups
from suspend-to-idle) as it turned out to be premature and triggered
a number of different issues on various systems.

That includes, but is not limited to, premature suspend-to-RAM aborts
on Dell XPS 13 (9343) reported by Dominik.

The issue the commit in question attempted to address is real and
will need to be taken care of going forward, but evidently more work
is needed for this purpose.

Reported-by: Dominik Brodowski &lt;linux@dominikbrodowski.net&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'acpi-extra-4.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm</title>
<updated>2017-05-10T16:35:42+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2017-05-10T16:35:42+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=dc9edaab90de9441cc28ac570b23b0d2bdba7879'/>
<id>dc9edaab90de9441cc28ac570b23b0d2bdba7879</id>
<content type='text'>
Pull more ACPI updates from Rafael Wysocki:
 "These update the ACPICA code in the kernel to upstream revision
  20170303 which adds a few minor fixes and improvements, update ACPI
  SoC drivers with new device IDs, platform-related information and
  similar, fix the register information in the xpower PMIC driver,
  introduce a concept of "always present" devices to the ACPI device
  enumeration code and use it to fix a problem with one platform, and
  fix a system resume issue related to power resources.

  Specifics:

   - Update the ACPICA code in the kernel to upstream revision 20170303
     which includes:
      * Minor fixes and improvements in the core code (Bob Moore,
        Seunghun Han).
      * Debugger fixes (Colin Ian King, Lv Zheng).
      * Compiler/disassembler improvements (Bob Moore, David Box, Lv
        Zheng).
      * Build-related update (Lv Zheng).

   - Add new device IDs and platform-related information to the ACPI
     drivers for Intel (LPSS) and AMD (APD) SoCs (Hanjun Guo, Hans de
     Goede).

   - Make it possible to quirk ACPI-enumerated devices as "always
     present" on platforms where they are incorrectly reported as not
     present by the AML and add the INT0002 device ID to the list of
     "always present" devices (Hans de Goede).

   - Fix the register information in the xpower PMIC driver and add
     comments to map the registers to symbols used by AML to it (Hans de
     Goede).

   - Move the code turning off unused ACPI power resources during system
     resume to a point after all devices have been resumed to avoid
     issues with power resources that do not behave as expected (Hans de
     Goede)"

* tag 'acpi-extra-4.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (22 commits)
  ACPI / power: Delay turning off unused power resources after suspend
  ACPI / PMIC: xpower: Fix power_table addresses
  ACPI / LPSS: Call pwm_add_table() for Bay Trail PWM device
  ACPICA: Update version to 20170303
  ACPICA: iasl: add ASL conversion tool
  ACPICA: Local cache support: Allow small cache objects
  ACPICA: Disassembler: Do not unconditionally remove temporary names
  ACPICA: iasl: Fix IORT SMMU GSI disassembling
  ACPICA: Cleanup AML opcode definitions, no functional change
  ACPICA: Debugger: Add interpreter blocking mark for single-step mode
  ACPICA: debugger: fix memory leak on Pathname
  ACPICA: Update for automatic repair code for objects returned by evaluate_object
  ACPICA: Namespace: fix operand cache leak
  ACPICA: Fix several incorrect invocations of ACPICA return macro
  ACPICA: Fix a module for excessive debug output
  ACPICA: Update some function headers, no funtional change
  ACPICA: Disassembler: Enhance resource descriptor detection
  i2c: designware: Add ACPI HID for Hisilicon Hip07/08 I2C controller
  ACPI / APD: Add clock frequency for Hisilicon Hip07/08 I2C controller
  ACPI / bus: Add INT0002 to list of always-present devices
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull more ACPI updates from Rafael Wysocki:
 "These update the ACPICA code in the kernel to upstream revision
  20170303 which adds a few minor fixes and improvements, update ACPI
  SoC drivers with new device IDs, platform-related information and
  similar, fix the register information in the xpower PMIC driver,
  introduce a concept of "always present" devices to the ACPI device
  enumeration code and use it to fix a problem with one platform, and
  fix a system resume issue related to power resources.

  Specifics:

   - Update the ACPICA code in the kernel to upstream revision 20170303
     which includes:
      * Minor fixes and improvements in the core code (Bob Moore,
        Seunghun Han).
      * Debugger fixes (Colin Ian King, Lv Zheng).
      * Compiler/disassembler improvements (Bob Moore, David Box, Lv
        Zheng).
      * Build-related update (Lv Zheng).

   - Add new device IDs and platform-related information to the ACPI
     drivers for Intel (LPSS) and AMD (APD) SoCs (Hanjun Guo, Hans de
     Goede).

   - Make it possible to quirk ACPI-enumerated devices as "always
     present" on platforms where they are incorrectly reported as not
     present by the AML and add the INT0002 device ID to the list of
     "always present" devices (Hans de Goede).

   - Fix the register information in the xpower PMIC driver and add
     comments to map the registers to symbols used by AML to it (Hans de
     Goede).

   - Move the code turning off unused ACPI power resources during system
     resume to a point after all devices have been resumed to avoid
     issues with power resources that do not behave as expected (Hans de
     Goede)"

* tag 'acpi-extra-4.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (22 commits)
  ACPI / power: Delay turning off unused power resources after suspend
  ACPI / PMIC: xpower: Fix power_table addresses
  ACPI / LPSS: Call pwm_add_table() for Bay Trail PWM device
  ACPICA: Update version to 20170303
  ACPICA: iasl: add ASL conversion tool
  ACPICA: Local cache support: Allow small cache objects
  ACPICA: Disassembler: Do not unconditionally remove temporary names
  ACPICA: iasl: Fix IORT SMMU GSI disassembling
  ACPICA: Cleanup AML opcode definitions, no functional change
  ACPICA: Debugger: Add interpreter blocking mark for single-step mode
  ACPICA: debugger: fix memory leak on Pathname
  ACPICA: Update for automatic repair code for objects returned by evaluate_object
  ACPICA: Namespace: fix operand cache leak
  ACPICA: Fix several incorrect invocations of ACPICA return macro
  ACPICA: Fix a module for excessive debug output
  ACPICA: Update some function headers, no funtional change
  ACPICA: Disassembler: Enhance resource descriptor detection
  i2c: designware: Add ACPI HID for Hisilicon Hip07/08 I2C controller
  ACPI / APD: Add clock frequency for Hisilicon Hip07/08 I2C controller
  ACPI / bus: Add INT0002 to list of always-present devices
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>ACPI / sleep: Ignore spurious SCI wakeups from suspend-to-idle</title>
<updated>2017-05-05T20:54:28+00:00</updated>
<author>
<name>Rafael J. Wysocki</name>
<email>rafael.j.wysocki@intel.com</email>
</author>
<published>2017-04-26T21:23:03+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=eed4d47efe9508b855b09754cf6de4325d8a2f0d'/>
<id>eed4d47efe9508b855b09754cf6de4325d8a2f0d</id>
<content type='text'>
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 -&gt;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 -&gt;sync hook allows all of the relevant event
queues to be flushed so as to prevent events from being missed due
to race conditions.

In addition to that, some ACPI code processing wakeup events needs
to be modified to use the "hard" version of wakeup triggers, so that
it will cause a system resume to happen on device-induced wakeup
events even if the "soft" mechanism to prevent the system from
suspending is not enabled (that also helps to catch device-induced
wakeup events occurring during suspend transitions in progress).

Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
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<pre>
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 -&gt;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 -&gt;sync hook allows all of the relevant event
queues to be flushed so as to prevent events from being missed due
to race conditions.

In addition to that, some ACPI code processing wakeup events needs
to be modified to use the "hard" version of wakeup triggers, so that
it will cause a system resume to happen on device-induced wakeup
events even if the "soft" mechanism to prevent the system from
suspending is not enabled (that also helps to catch device-induced
wakeup events occurring during suspend transitions in progress).

Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ACPI / power: Delay turning off unused power resources after suspend</title>
<updated>2017-05-01T21:11:21+00:00</updated>
<author>
<name>Hans de Goede</name>
<email>hdegoede@redhat.com</email>
</author>
<published>2017-04-30T20:54:16+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=8ece1d83346bcc431090d59a2184276192189cdd'/>
<id>8ece1d83346bcc431090d59a2184276192189cdd</id>
<content type='text'>
Commit 660b1113e0f3 (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: Hans de Goede &lt;hdegoede@redhat.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 660b1113e0f3 (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: Hans de Goede &lt;hdegoede@redhat.com&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ACPI: save NVS memory for Lenovo G50-45</title>
<updated>2017-01-31T21:46:59+00:00</updated>
<author>
<name>Zhang Rui</name>
<email>rui.zhang@intel.com</email>
</author>
<published>2017-01-16T02:55:45+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=cbc00c1310d34139a63946482b40a6b261a03fb9'/>
<id>cbc00c1310d34139a63946482b40a6b261a03fb9</id>
<content type='text'>
In commit 821d6f0359b0 (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=189431
Tested-by: Przemek &lt;soprwa@gmail.com&gt;
Signed-off-by: Zhang Rui &lt;rui.zhang@intel.com&gt;
[ rjw: Drop unnecessary code ]
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 commit 821d6f0359b0 (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=189431
Tested-by: Przemek &lt;soprwa@gmail.com&gt;
Signed-off-by: Zhang Rui &lt;rui.zhang@intel.com&gt;
[ rjw: Drop unnecessary code ]
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</pre>
</div>
</content>
</entry>
</feed>
