On Wednesday, November 21, 2012 08:24:20 PM Aaron Lu wrote:
> 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.
Applied to linux-pm.git/linux-next as v3.8 material.
Thanks,
Rafael
> Signed-off-by: Aaron Lu <aaron.lu@xxxxxxxxx>
> ---
> v2:
> Rename swset to os_accessible as suggested by Rafael Wysocki.
> Fold patch 2 into patch 1 as suggested by Rafael Wysocki.
>
> drivers/acpi/scan.c | 9 ++++++++-
> include/acpi/acpi_bus.h | 6 ++++++
> 2 files changed, 14 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
> index 3c646e6..f250c5b 100644
> --- a/drivers/acpi/scan.c
> +++ b/drivers/acpi/scan.c
> @@ -1062,8 +1062,10 @@ 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 */
> @@ -1079,6 +1081,11 @@ 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;
> diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h
> index ce77cd7..644d941 100644
> --- a/include/acpi/acpi_bus.h
> +++ b/include/acpi/acpi_bus.h
> @@ -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; }
>
--
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.
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