Commit 1399dfcd authored by Aaron Lu's avatar Aaron Lu Committed by Rafael J. Wysocki
Browse files

ACPI / PM: Introduce os_accessible flag for power_state 



Currently we have valid flag to represent if this ACPI device power
state is valid. A device power state is valid does not necessarily
mean we, as OSPM, has a mean to put the device into that power state,
e.g. D3 cold is always a valid power state for any ACPI device, but if
there is no _PS3 or _PRx for this device, we can't really put that
device into D3 cold power state. The same is true for D0 power state.

So here comes the os_accessible flag, which is only set if the device
has provided us the required means to put it into that power state,
e.g. if we have _PS3 or _PRx, we can put the device into D3 cold state
and thus, D3 cold power state's os_accessible flag will be set in this
case.

And a new wrapper inline function is added to be used to check if
firmware has provided us a way to power off the device during runtime.

Signed-off-by: default avatarAaron Lu <aaron.lu@intel.com>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent ddc150f7

drivers/acpi/scan.c

+8 −1
Original line number Diff line number Diff line
@@ -965,8 +965,10 @@ static int acpi_bus_get_power_flags(struct acpi_device *device) 
		 * D3hot is only valid if _PR3 present.

		 */

		if (ps->resources.count ||

		    (ps->flags.explicit_set && i < ACPI_STATE_D3_HOT))

		    (ps->flags.explicit_set && i < ACPI_STATE_D3_HOT)) {

			ps->flags.valid = 1;

			ps->flags.os_accessible = 1;

		}



		ps->power = -1;	/* Unknown - driver assigned */

		ps->latency = -1;	/* Unknown - driver assigned */
@@ -982,6 +984,11 @@ static int acpi_bus_get_power_flags(struct acpi_device *device) 
	if (device->power.states[ACPI_STATE_D3_HOT].flags.explicit_set)

		device->power.states[ACPI_STATE_D3_COLD].flags.explicit_set = 1;



	/* Presence of _PS3 or _PRx means we can put the device into D3 cold */

	if (device->power.states[ACPI_STATE_D3_HOT].flags.explicit_set ||

			device->power.flags.power_resources)

		device->power.states[ACPI_STATE_D3_COLD].flags.os_accessible = 1;



	acpi_bus_init_power(device);



	return 0;

include/acpi/acpi_bus.h

+6 −0
Original line number Diff line number Diff line
@@ -201,6 +201,7 @@ struct acpi_device_power_flags { 
struct acpi_device_power_state {

	struct {

		u8 valid:1;

		u8 os_accessible:1;

		u8 explicit_set:1;	/* _PSx present? */

		u8 reserved:6;

	} flags;
@@ -500,6 +501,11 @@ static inline bool acpi_device_can_wakeup(struct acpi_device *adev) 
	return adev->wakeup.flags.valid;

}



static inline bool acpi_device_can_poweroff(struct acpi_device *adev)

{

	return adev->power.states[ACPI_STATE_D3_COLD].flags.os_accessible;

}



#else	/* CONFIG_ACPI */



static inline int register_acpi_bus_type(void *bus) { return 0; }

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