On Friday, November 09, 2012 09:54:55 AM 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 swset 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 swset flag will be set in this case.
>
> This flag is mainly used to check if firmware has provided us a way to
> put the device into D3 cold state, as the valid flag for D3 cold is
> always true.
I would prefer the new flag to be called os_accessible. The meaning of it
would be more clear this way in my opinion.
Please also fold patch [2/2] into [1/2].
Apart from this it looks OK.
Thanks,
Rafael
> Signed-off-by: Aaron Lu <aaron.lu@xxxxxxxxx>
> ---
> drivers/acpi/scan.c | 9 ++++++++-
> include/acpi/acpi_bus.h | 1 +
> 2 files changed, 9 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
> index 95ff1e8..60d271a 100644
> --- a/drivers/acpi/scan.c
> +++ b/drivers/acpi/scan.c
> @@ -1038,8 +1038,10 @@ 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.swset = 1;
> + }
>
> ps->power = -1; /* Unknown - driver assigned */
> ps->latency = -1; /* Unknown - driver assigned */
> @@ -1055,6 +1057,11 @@ 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.swset = 1;
> +
> acpi_bus_init_power(device);
>
> return 0;
> diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h
> index 2242c10..7d20617 100644
> --- a/include/acpi/acpi_bus.h
> +++ b/include/acpi/acpi_bus.h
> @@ -200,6 +200,7 @@ struct acpi_device_power_flags {
> struct acpi_device_power_state {
> struct {
> u8 valid:1;
> + u8 swset:1;
> u8 explicit_set:1; /* _PSx present? */
> u8 reserved:6;
> } flags;
>
--
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.
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