Hi,
On Thu, Mar 29, 2012 at 02:09:38PM +0800, Lin Ming wrote:
> From: Zhang Rui <rui.zhang@xxxxxxxxx>
>
> If a device has _PR3, it means the device supports D3_COLD.
> Add the ability to validate and enter D3_COLD state in ACPI.
Since we are going to support two D3 states, I think maybe we should
clear their meanings in Linux. So D3 means D3 hot, right?
If so, I think the following code has problems:
static int acpi_bus_get_power_flags(struct acpi_device *device)
{
... ...
/* Set defaults for D0 and D3 states (always valid) */
device->power.states[ACPI_STATE_D0].flags.valid = 1;
device->power.states[ACPI_STATE_D0].power = 100;
device->power.states[ACPI_STATE_D3].flags.valid = 1;
device->power.states[ACPI_STATE_D3].power = 0;
}
The problem is, D3's valid flag shouldn't be set and its power shouldn't
be 0 since it's D3 hot. It feels like D3_COLD should be used instead.
What do you think? Thanks.
-Aaron
>
> Signed-off-by: Zhang Rui <rui.zhang@xxxxxxxxx>
> Signed-off-by: Lin Ming <ming.m.lin@xxxxxxxxx>
> ---
> drivers/acpi/power.c | 4 ++--
> drivers/acpi/scan.c | 7 +++++++
> 2 files changed, 9 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/acpi/power.c b/drivers/acpi/power.c
> index 9ac2a9f..0d681fb 100644
> --- a/drivers/acpi/power.c
> +++ b/drivers/acpi/power.c
> @@ -500,14 +500,14 @@ int acpi_power_transition(struct acpi_device *device, int state)
> {
> int result;
>
> - if (!device || (state < ACPI_STATE_D0) || (state > ACPI_STATE_D3))
> + if (!device || (state < ACPI_STATE_D0) || (state > ACPI_STATE_D3_COLD))
> return -EINVAL;
>
> if (device->power.state == state)
> return 0;
>
> if ((device->power.state < ACPI_STATE_D0)
> - || (device->power.state > ACPI_STATE_D3))
> + || (device->power.state > ACPI_STATE_D3_COLD))
> return -ENODEV;
>
> /* TBD: Resources must be ordered. */
> diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
> index 8ab80ba..571396c 100644
> --- a/drivers/acpi/scan.c
> +++ b/drivers/acpi/scan.c
> @@ -885,6 +885,13 @@ static int acpi_bus_get_power_flags(struct acpi_device *device)
> acpi_bus_add_power_resource(ps->resources.handles[j]);
> }
>
> + /* The exist of _PR3 indicates D3Cold support */
> + if (i == ACPI_STATE_D3) {
> + status = acpi_get_handle(device->handle, object_name, &handle);
> + if (ACPI_SUCCESS(status))
> + device->power.states[ACPI_STATE_D3_COLD].flags.valid = 1;
> + }
> +
> /* Evaluate "_PSx" to see if we can do explicit sets */
> object_name[2] = 'S';
> status = acpi_get_handle(device->handle, object_name, &handle);
> --
> 1.7.2.5
>
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