Re: [PATCH] ACPI: evaluate _PS3 when entering D3 Cold

Rafael J. Wysocki
2012-04-23T11:43:03Z

On Monday, April 23, 2012, Aaron Lu wrote:
> Hi Rafael and Ming,
>
> Do you have any more comments on this patch?
> If not, can I have your ack? Thanks.
>
> -Aaron
>
> On Sun, Apr 01, 2012 at 02:18:30AM +0800, Aaron Lu wrote:
> > When entering D3 Cold from a higher device state, evaluate _PS3 first
> > and then make the proper power transition.
> > This is used to solve the ZPODD problem on AMD's platform, _PS3 on such
> > platforms will power off the ODD device and thus make the device enter
> > D3 cold state.
> >
> > Signed-off-by: Aaron Lu <aaron.lu@amd.com>
> > Cc: Andiry Xu <andiry.xu@amd.com>
> > Cc: Alex He <alex.he@amd.com>
> > ---
> > drivers/acpi/bus.c | 17 ++++++++++++++---
> > 1 file changed, 14 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c
> > index 3263b68..68e593f 100644
> > --- a/drivers/acpi/bus.c
> > +++ b/drivers/acpi/bus.c
> > @@ -227,6 +227,8 @@ static int __acpi_bus_set_power(struct acpi_device *device, int state)
> > int result = 0;
> > acpi_status status = AE_OK;
> > char object_name[5] = { '_', 'P', 'S', '0' + state, '\0' };
> > + struct acpi_device_power_state *ps;
> > + u8 explicit_set;
> >
> > if (!device || (state < ACPI_STATE_D0) || (state > ACPI_STATE_D3_COLD))
> > return -EINVAL;
> > @@ -239,7 +241,8 @@ static int __acpi_bus_set_power(struct acpi_device *device, int state)
> > return 0;
> > }
> >
> > - if (!device->power.states[state].flags.valid) {
> > + ps = &device->power.states[state];
> > + if (!ps->flags.valid) {
> > printk(KERN_WARNING PREFIX "Device does not support D%d\n", state);
> > return -ENODEV;
> > }
> > @@ -263,7 +266,7 @@ static int __acpi_bus_set_power(struct acpi_device *device, int state)
> > if (result)
> > goto end;
> > }
> > - if (device->power.states[state].flags.explicit_set) {
> > + if (ps->flags.explicit_set) {
> > status = acpi_evaluate_object(device->handle,
> > object_name, NULL, NULL);
> > if (ACPI_FAILURE(status)) {
> > @@ -272,7 +275,15 @@ static int __acpi_bus_set_power(struct acpi_device *device, int state)
> > }
> > }
> > } else {
> > - if (device->power.states[state].flags.explicit_set) {
> > + /* If state is D3 Cold, try to evaluate _PS3 first */
> > + if (state == ACPI_STATE_D3_COLD) {
> > + explicit_set = (ps - 1)->flags.explicit_set;
> > + object_name[3] -= 1;
> > + }
> > + else {
> > + explicit_set = ps->flags.explicit_set;
> > + }

I really don't like this. I think you should modify acpi_bus_get_power_flags(),
on top of the recent Lin Ming's patch, so that it sets flags.explicit_set for
D3_COLD if _PS3 is present and _PR3 is not.

I'm not sure you'll need the $subject patch any more then.

> > + if (explicit_set) {
> > status = acpi_evaluate_object(device->handle,
> > object_name, NULL, NULL);
> > if (ACPI_FAILURE(status)) {

Thanks,
Rafael