linux.git/drivers/acpi/device_pm.c, branch v5.3.2

ACPI: PM: Fix regression in acpi_device_set_power()

2019-08-01T21:39:17+00:00

Commit f850a48a0799 ("ACPI: PM: Allow transitions to D0 to occur in
special cases") overlooked the fact that acpi_power_transition() may
change the power.state value for the target device and if that
happens, it may confuse acpi_device_set_power() and cause it to
omit the _PS0 evaluation which on some systems is necessary to
change power states of devices from low-power to D0.

Fix that by saving the current value of power.state for the
target device before passing it to acpi_power_transition() and
using the saved value in a subsequent check.

Fixes: f850a48a0799 ("ACPI: PM: Allow transitions to D0 to occur in special cases")
Reported-by: Kai-Heng Feng 
Reported-by: Mario Limonciello 
Signed-off-by: Rafael J. Wysocki 
Tested-by: Kai-Heng Feng 
Tested-by: Mario Limonciello

Merge branch 'pm-sleep'

2019-07-08T08:51:25+00:00

* pm-sleep:
  PM: sleep: Drop dev_pm_skip_next_resume_phases()
  ACPI: PM: Drop unused function and function header
  ACPI: PM: Introduce "poweroff" callbacks for ACPI PM domain and LPSS
  ACPI: PM: Simplify and fix PM domain hibernation callbacks
  PCI: PM: Simplify bus-level hibernation callbacks
  PM: ACPI/PCI: Resume all devices during hibernation
  kernel: power: swap: use kzalloc() instead of kmalloc() followed by memset()
  PM: sleep: Update struct wakeup_source documentation
  drivers: base: power: remove wakeup_sources_stats_dentry variable
  PM: suspend: Rename pm_suspend_via_s2idle()
  PM: sleep: Show how long dpm_suspend_start() and dpm_suspend_end() take
  PM: hibernate: powerpc: Expose pfn_is_nosave() prototype

Merge branches 'acpi-pm' and 'pm-pci'

2019-07-08T08:49:36+00:00

* acpi-pm:
  ACPI: PM: Make acpi_sleep_state_supported() non-static
  ACPI: PM: Allow transitions to D0 to occur in special cases
  ACPI: PM: Avoid evaluating _PS3 on transitions from D3hot to D3cold
  ACPI / sleep: Switch to use acpi_dev_get_first_match_dev()
  ACPI / LPIT: Correct LPIT end address for lpit_process()

* pm-pci:
  ACPI: PM: Unexport acpi_device_get_power()
  PCI: PM/ACPI: Refresh all stale power state data in pci_pm_complete()
  PCI / ACPI: Add _PR0 dependent devices
  ACPI / PM: Introduce concept of a _PR0 dependent device
  PCI / ACPI: Use cached ACPI device state to get PCI device power state
  PCI: Do not poll for PME if the device is in D3cold
  PCI: Add missing link delays required by the PCIe spec
  PCI: PM: Replace pci_dev_keep_suspended() with two functions
  PCI: PM: Avoid resuming devices in D3hot during system suspend

ACPI: PM: Unexport acpi_device_get_power()

2019-07-04T08:49:57+00:00

Using acpi_device_get_power() outside of ACPI device initialization
and ACPI sysfs is problematic due to the way in which power resources
are handled by it, so unexport it and add a paragraph explaining the
pitfalls to its kerneldoc comment.

Signed-off-by: Rafael J. Wysocki 
Reviewed-by: Mika Westerberg

ACPI: PM: Introduce "poweroff" callbacks for ACPI PM domain and LPSS

2019-07-02T22:13:24+00:00

In general, it is not correct to call pm_generic_suspend(),
pm_generic_suspend_late() and pm_generic_suspend_noirq() during the
hibernation's "poweroff" transition, because device drivers may
provide special callbacks to be invoked then and the wrappers in
question cause system suspend callbacks to be run.  Unfortunately,
that happens in the ACPI PM domain and ACPI LPSS.

To address this potential issue, introduce "poweroff" callbacks
for the ACPI PM and LPSS that will use pm_generic_poweroff(),
pm_generic_poweroff_late() and pm_generic_poweroff_noirq() as
appropriate.

Fixes: 05087360fd7a (ACPI / PM: Take SMART_SUSPEND driver flag into account)
Signed-off-by: Rafael J. Wysocki 
Reviewed-by: Mika Westerberg 
Reviewed-by: Hans de Goede

ACPI: PM: Simplify and fix PM domain hibernation callbacks

2019-07-02T22:13:24+00:00

First, after a previous change causing all runtime-suspended devices
in the ACPI PM domain (and ACPI LPSS devices) to be resumed before
creating a snapshot image of memory during hibernation, it is not
necessary to worry about the case in which them might be left in
runtime-suspend any more, so get rid of the code related to that from
ACPI PM domain and ACPI LPSS hibernation callbacks.

Second, it is not correct to use pm_generic_resume_early() and
acpi_subsys_resume_noirq() in hibernation "restore" callbacks (which
currently happens in the ACPI PM domain and ACPI LPSS), so introduce
proper _restore_late and _restore_noirq callbacks for the ACPI PM
domain and ACPI LPSS.

Fixes: 05087360fd7a (ACPI / PM: Take SMART_SUSPEND driver flag into account)
Signed-off-by: Rafael J. Wysocki 
Reviewed-by: Mika Westerberg 
Reviewed-by: Hans de Goede

PM: ACPI/PCI: Resume all devices during hibernation

2019-07-02T22:13:24+00:00

Both the PCI bus type and the ACPI PM domain avoid resuming
runtime-suspended devices with DPM_FLAG_SMART_SUSPEND set during
hibernation (before creating the snapshot image of system memory),
but that turns out to be a mistake.  It leads to functional issues
and adds complexity that's hard to justify.

For this reason, resume all runtime-suspended PCI devices and all
devices in the ACPI PM domains before creating a snapshot image of
system memory during hibernation.

Fixes: 05087360fd7a (ACPI / PM: Take SMART_SUSPEND driver flag into account)
Fixes: c4b65157aeef (PCI / PM: Take SMART_SUSPEND driver flag into account)
Link: https://lore.kernel.org/linux-acpi/917d4399-2e22-67b1-9d54-808561f9083f@uwyo.edu/T/#maf065fe6e4974f2a9d79f332ab99dfaba635f64c
Reported-by: Robert R. Howell 
Tested-by: Robert R. Howell 
Signed-off-by: Rafael J. Wysocki 
Reviewed-by: Mika Westerberg 
Reviewed-by: Hans de Goede

ACPI: PM: Allow transitions to D0 to occur in special cases

2019-06-27T10:30:00+00:00

If a device with ACPI PM is left in D0 during a system-wide
transition to the S3 (suspend-to-RAM) or S4 (hibernation) sleep
state, the actual state of the device need not be D0 during resume
from it, although its power.state value will still reflect D0 (that
is, the power state from before the system-wide transition).

In that case, the acpi_device_set_power() call made to ensure that
the power state of the device will be D0 going forward has no effect,
because the new state (D0) is equal to the one reflected by the
device's power.state value.  That does not affect power resources,
which are taken care of by acpi_resume_power_resources() called from
acpi_pm_finish() during resume from system-wide sleep states, but it
still may be necessary to invoke _PS0 for the device on top of that
in order to finalize its transition to D0.

For this reason, modify acpi_device_set_power() to allow transitions
to D0 to occur even if D0 is the current power state of the device
according to its power.state value.

That will not affect power resources, which are assumed to be in
the right configuration already (as reflected by the current values
of their reference counters), but it may cause _PS0 to be evaluated
for the device.  However, evaluating _PS0 for a device already in D0
may lead to confusion in general, so invoke _PSC (if present) to
check the device's current power state upfront and only evaluate
_PS0 for it if _PSC has returned a power state different from D0.
[If _PSC is not present or the evaluation of it fails, the power
state of the device is assumed to be D0 at this point.]

Fixes: 20dacb71ad28 (ACPI / PM: Rework device power management to follow ACPI 6)
Signed-off-by: Rafael J. Wysocki 
Reviewed-by: Mika Westerberg

ACPI: PM: Avoid evaluating _PS3 on transitions from D3hot to D3cold

2019-06-27T10:29:59+00:00

If the power state of a device with ACPI PM is changed from D3hot to
D3cold, it merely is a matter of dropping references to additional
power resources (specifically, those in the list returned by _PR3),
and the _PS3 method should not be invoked for the device then (as
it has already been evaluated during the previous transition to
D3hot).

Fixes: 20dacb71ad28 (ACPI / PM: Rework device power management to follow ACPI 6)
Signed-off-by: Rafael J. Wysocki 
Reviewed-by: Mika Westerberg

Merge tag 'pm-5.2-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

2019-05-31T17:38:35+00:00

Pull power management fixes from Rafael Wysocki:
 "These fix three issues in the system-wide suspend and hibernation area
  related to PCI device PM handling by suspend-to-idle, device wakeup
  optimizations and arbitrary differences between suspend and
  hiberantion.

  Specifics:

   - Modify the PCI bus type's PM code to avoid putting devices left by
     their drivers in D0 on purpose during suspend to idle into
     low-power states as doing that may confuse the system resume
     callbacks of the drivers in question (Rafael Wysocki).

   - Avoid checking ACPI wakeup configuration during system-wide suspend
     for suspended devices that do not use ACPI-based wakeup to allow
     them to stay in suspend more often (Rafael Wysocki).

   - The last phase of hibernation is analogous to system-wide suspend
     also because on platforms with ACPI it passes control to the
     platform firmware to complete the transision, so make it indicate
     that by calling pm_set_suspend_via_firmware() to allow the drivers
     that care about this to do the right thing (Rafael Wysocki)"

* tag 'pm-5.2-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  PCI: PM: Avoid possible suspend-to-idle issue
  ACPI: PM: Call pm_set_suspend_via_firmware() during hibernation
  ACPI/PCI: PM: Add missing wakeup.flags.valid checks