PM / PCI / ACPI: Kick devices that might have been reset by firmware

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There is a concern that if the platform firmware was involved in
the system resume that's being completed,  some devices might have
been reset by it and if those devices had the power.direct_complete
flag set during the preceding suspend transition, they may stay
in a reset-power-on state indefinitely (until they are runtime-resumed
and then suspended again).  That may not be a big deal from the
individual device's perspective, but if the system is an SoC, it may
be prevented from entering deep SoC-wide low-power states on idle
because of that.

The devices that are most likely to be affected by this issue are
PCI devices and ACPI-enumerated devices using the general ACPI PM
domain, so to prevent it from happening for those devices, force a
runtime resume for them if they have their power.direct_complete
flags set and the platform firmware was involved in the resume
transition currently in progress.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

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This commit is contained in:

Rafael J. Wysocki 2015-10-07 00:50:24 +02:00

parent ef25ba0476

commit 58a1fbbb2e

5 changed files with 27 additions and 20 deletions

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2

drivers/acpi/acpi_lpss.c

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19

drivers/acpi/device_pm.c

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23

drivers/base/power/generic_ops.c

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2

drivers/pci/pci-driver.c

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1

include/linux/pm.h

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