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

[Aaron Lu <aaron.lu@amd.com>]

On Mon, Apr 23, 2012 at 09:50:57PM +0200, Rafael J. Wysocki wrote:
> > diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c
> > index 3263b68..187433f 100644
> > --- a/drivers/acpi/bus.c
> > +++ b/drivers/acpi/bus.c
> > @@ -273,6 +273,9 @@ static int __acpi_bus_set_power(struct acpi_device *device, int state)
> >  		}
> >  	} else {
> >  		if (device->power.states[state].flags.explicit_set) {
> > +			/* evaluate _PS3 instead of _PS4 when entering D3Cold */
> > +			if (state == ACPI_STATE_D3)
> > +				object_name[3] -= 1;
> 
> Can you just put '3' here directly?  That'll be much cleaner than the
> subtraction (that could have been -- as well).
> 
> >  			status = acpi_evaluate_object(device->handle,
> >  						      object_name, NULL, NULL);
> >  			if (ACPI_FAILURE(status)) {
> > diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
> > index 7417267..de2ae10 100644
> > --- a/drivers/acpi/scan.c
> > +++ b/drivers/acpi/scan.c
> > @@ -887,8 +887,12 @@ static int acpi_bus_get_power_flags(struct acpi_device *device)
> >  		/* Evaluate "_PSx" to see if we can do explicit sets */
> >  		object_name[2] = 'S';
> >  		status = acpi_get_handle(device->handle, object_name, &handle);
> > -		if (ACPI_SUCCESS(status))
> > +		if (ACPI_SUCCESS(status)) {
> >  			ps->flags.explicit_set = 1;
> > +			/* Also set D3Cold's explicit flag when _PS3 exists */
> > +			if (i == ACPI_STATE_D3_HOT)
> > +				(ps+1)->flags.explicit_set = 1;
> 
> Please don't use pointer arithmetics here.  I know it _happens_ to work,
> but I don't think it's appropriate in this situation at all.
> 

Thanks for the suggestions.

What about this?

diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c
index 3263b68..3a7860f 100644
--- a/drivers/acpi/bus.c
+++ b/drivers/acpi/bus.c
@@ -273,6 +273,9 @@ static int __acpi_bus_set_power(struct acpi_device *device, int state)
 		}
 	} else {
 		if (device->power.states[state].flags.explicit_set) {
+			/* Evaluate _PS3 when entering D3cold */
+			if (state == ACPI_STATE_D3)
+				object_name[3] = '3';
 			status = acpi_evaluate_object(device->handle,
 						      object_name, NULL, NULL);
 			if (ACPI_FAILURE(status)) {
diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index 7417267..734d946 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -908,6 +908,10 @@ static int acpi_bus_get_power_flags(struct acpi_device *device)
 	device->power.states[ACPI_STATE_D3].flags.valid = 1;
 	device->power.states[ACPI_STATE_D3].power = 0;
 
+	/* Also set D3cold's explicit flag when _PS3 exists */
+	if (device->power.states[ACPI_STATE_D3_HOT].flags.explicit_set)
+		device->power.states[ACPI_STATE_D3].flags.explicit_set = 1;
+
 	acpi_bus_init_power(device);
 
 	return 0;

Thanks,
Aaron