[PATCH V2] ACPI: Support D3 COLD device in old BIOS for ZPODD

From: Ken Xue
Date: Wed Dec 09 2015 - 03:23:19 EST

D3cold is only regarded as valid if the "_PR3" object is
present for the given device after the commit 20dacb71ad28
("ACPI/PM: Rework device power management to follow ACPI 6").

But some old BIOS only defined "_PS3" for the D3COLD device,
such as ZPODD device. And old kernel also believes the device with
"_PS3" is a D3COLD device.

So, add some logics for supporting D3 COLD device with old BIOS
which is compatible with earlier ACPI spec and kernel behavior.


Signed-off-by: Ken Xue <Ken.Xue@xxxxxxx>
Reported-and-tested-by: Gang Long <Gang.Long@xxxxxxx>
include/acpi/acpi_bus.h | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h
index ad0a5ff..9894b75 100644
--- a/include/acpi/acpi_bus.h
+++ b/include/acpi/acpi_bus.h
@@ -631,7 +631,9 @@ static inline bool acpi_device_can_wakeup(struct acpi_device *adev)

static inline bool acpi_device_can_poweroff(struct acpi_device *adev)
- return adev->power.states[ACPI_STATE_D3_COLD].flags.valid;
+ return adev->power.states[ACPI_STATE_D3_COLD].flags.valid ||
+ ((acpi_gbl_FADT.header.revision < 6) &&
+ adev->power.states[ACPI_STATE_D3_HOT].flags.explicit_set);

#else /* CONFIG_ACPI */

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