linux-toradex.git/drivers/acpi/power.c, branch v4.9.128

ACPI / power: Delay turning off unused power resources after suspend

2018-03-24T10:00:20+00:00

[ Upstream commit 8ece1d83346bcc431090d59a2184276192189cdd ]

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 
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

ACPI / power: Avoid maybe-uninitialized warning

2017-04-27T07:10:38+00:00

commit fe8c470ab87d90e4b5115902dd94eced7e3305c3 upstream.

gcc -O2 cannot always prove that the loop in acpi_power_get_inferred_state()
is enterered at least once, so it assumes that cur_state might not get
initialized:

drivers/acpi/power.c: In function 'acpi_power_get_inferred_state':
drivers/acpi/power.c:222:9: error: 'cur_state' may be used uninitialized in this function [-Werror=maybe-uninitialized]

This sets the variable to zero at the start of the loop, to ensure that
there is well-defined behavior even for an empty list. This gets rid of
the warning.

The warning first showed up when the -Os flag got removed in a bug fix
patch in linux-4.11-rc5.

I would suggest merging this addon patch on top of that bug fix to avoid
introducing a new warning in the stable kernels.

Fixes: 61b79e16c68d (ACPI: Fix incompatibility with mcount-based function graph tracing)
Signed-off-by: Arnd Bergmann 
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Greg Kroah-Hartman

Merge branch 'acpi-pm'

2015-09-01T01:38:43+00:00

* acpi-pm:
  ACPI / bus: Move duplicate code to a separate new function
  mfd: Add support for Intel Sunrisepoint LPSS devices
  dmaengine: add a driver for Intel integrated DMA 64-bit
  mfd: make mfd_remove_devices() iterate in reverse order
  driver core: implement device_for_each_child_reverse()
  klist: implement klist_prev()
  Driver core: wakeup the parent device before trying probe
  ACPI / PM: Attach ACPI power domain only once
  PM / QoS: Make it possible to expose device latency tolerance to userspace
  ACPI / PM: Update the copyright notice and description of power.c

ACPI / PM: Update the copyright notice and description of power.c

2015-07-16T00:01:28+00:00

The description and copyright notice of drivers/acpi/power.c is out
of date, so update it as appropriate.

Signed-off-by: Rafael J. Wysocki

ACPI: Remove FSF mailing addresses

2015-07-08T00:27:32+00:00

There is no need to carry potentially outdated Free Software Foundation
mailing address in file headers since the COPYING file includes it.

Signed-off-by: Jarkko Nikula 
Signed-off-by: Rafael J. Wysocki

ACPI / PM: Turn power resources on and off in the right order during resume

2015-05-25T21:59:54+00:00

According to Section 7.2 of ACPI 6.0, power resources should
always be enabled and disabled in order given by the "resourceorder"
field of the corresponding Power Resource objects: "Power Resource
levels are enabled from low values to high values and are disabled
from high values to low values."

However, this is not what happens during system resume, because
in that case the enabling/disabling is carried out in the power
resource registration order which may not reflect the ordering
required by the platform.

For this reason, make the ordering of the global list of all
power resources in the system (used by the system resume code)
reflect the one given by the "resourceorder" attributes of the
Power Resource objects in the ACPI namespace and modify
acpi_resume_power_resources() to walk the list in the reverse
order when turning off the power resources that had been off
before the system was suspended.

Signed-off-by: Rafael J. Wysocki

ACPI / PM: Rework device power management to follow ACPI 6

2015-05-15T23:55:35+00:00

The ACPI 6 specification has made some changes in the device power
management area.  In particular:

 * The D3hot power state is now supposed to be always available
   (instead of D3cold) and D3cold is only regarded as valid if the
   _PR3 object is present for the given device.

 * The required ordering of transitions into power states deeper than
   D0 is now such that for a transition into state Dx the _PSx method
   is supposed to be executed first, if present, and the states of
   the power resources the device depends on are supposed to be
   changed after that.

 * It is now explicitly forbidden to transition devices from
   lower-power (deeper) into higher-power (shallower) power states
   other than D0.

Those changes have been made so the specification reflects the
Windows' device power management code that the vast majority of
systems using ACPI is validated against.

To avoid artificial differences in ACPI device power management
between Windows and Linux, modify the ACPI device power management
code to follow the new specification.  Add comments explaining the
code flow in some unclear places.

This only may affect some real corner cases in which the OS behavior
expected by the firmware is different from the Windows one, but that's
quite unlikely.  The transition ordering change affects transitions
to D1 and D2 which are rarely used (if at all) and into D3hot and
D3cold for devices actually having _PR3, but those are likely to
be validated against Windows anyway.  The other changes may affect
code calling acpi_device_get_power() or acpi_device_update_power()
where ACPI_STATE_D3_HOT may be returned instead of ACPI_STATE_D3_COLD
(that's why the ACPI fan driver needs to be updated too) and since
transitions into ACPI_STATE_D3_HOT may remove power now, it is better
to avoid this one in acpi_pm_device_sleep_state() if the "no power
off" PM QoS flag is set.

The only existing user of acpi_device_can_poweroff() really cares
about the case when _PR3 is present, so the change in that function
should not cause any problems to happen too.

A plus is that PCI_D3hot can be mapped to ACPI_STATE_D3_HOT
now and the compatibility with older systems should be covered
automatically.

In any case, if any real problems result from this, it still will
be better to follow the Windows' behavior (which now is reflected
by the specification too) in general and handle the cases when it
doesn't work via quirks.

Signed-off-by: Rafael J. Wysocki

ACPI / PM: Drop stale comment from acpi_power_transition()

2015-05-08T20:41:05+00:00

An old comment in acpi_power_transition() indicates that support
for ordering power resources needs to be added, but the current
code handles that already.

Drop the comment to avoid confusion.

Signed-off-by: Rafael J. Wysocki

ACPI: Remove duplicate definitions of PREFIX

2014-03-19T01:01:57+00:00

We already have a macro for PREFIX of "ACPI: " in
drivers/acpi/internal.h, so remove the duplicate ones
in ACPI drivers when internal.h is included.

Signed-off-by: Hanjun Guo 
Signed-off-by: Rafael J. Wysocki

ACPI: Clean up inclusions of ACPI header files

2013-12-07T00:03:14+00:00

Replace direct inclusions of ,  and
, which are incorrect, with 
inclusions and remove some inclusions of those files that aren't
necessary.

First of all, ,  and 
should not be included directly from any files that are built for
CONFIG_ACPI unset, because that generally leads to build warnings about
undefined symbols in !CONFIG_ACPI builds.  For CONFIG_ACPI set,
 includes those files and for CONFIG_ACPI unset it
provides stub ACPI symbols to be used in that case.

Second, there are ordering dependencies between those files that always
have to be met.  Namely, it is required that  be included
prior to  so that the acpi_pci_root declarations the
latter depends on are always there.  And  which provides
basic ACPICA type declarations should always be included prior to any other
ACPI headers in CONFIG_ACPI builds.  That also is taken care of including
 as appropriate.

Signed-off-by: Lv Zheng 
Cc: Greg Kroah-Hartman 
Cc: Matthew Garrett 
Cc: Tony Luck 
Cc: "H. Peter Anvin" 
Acked-by: Bjorn Helgaas  (drivers/pci stuff)
Acked-by: Konrad Rzeszutek Wilk  (Xen stuff)
Signed-off-by: Rafael J. Wysocki