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ACPI: Notify the _PPC evaluation status to the platform

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According to the ACPI spec(section 8.4.4.3) OSPM should convey the _PPC
evaluations status to the platform if there exists the _OST object.
The _OST contains two arguments:
	The first is the PERFORMANCE notificatin event.
	The second is the status of _PPC object.
OSPM will convey the _PPC evaluation status to the platform.
Of course when the module parameter of "ignore_ppc" is added, OSPM won't
evaluate the _PPC object. But it will call the _OST object.

At the same time the _OST object will be evaluated only when the PERFORMANCE
notification event is received.

Signed-off-by: Zhao Yakui <yakui.zhao@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
This commit is contained in:
Zhao Yakui
2009-10-16 09:20:41 +08:00
committed by Len Brown
parent b419148e56
commit d81c45e1c9
3 changed files with 53 additions and 8 deletions
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50
drivers/acpi/processor_perflib.c
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@ -152,15 +152,59 @@ static int acpi_processor_get_platform_limit(struct acpi_processor *pr)
return 0;
}
int acpi_processor_ppc_has_changed(struct acpi_processor *pr)
#define ACPI_PROCESSOR_NOTIFY_PERFORMANCE 0x80
/*
* acpi_processor_ppc_ost: Notify firmware the _PPC evaluation status
* @handle: ACPI processor handle
* @status: the status code of _PPC evaluation
* 0: success. OSPM is now using the performance state specificed.
* 1: failure. OSPM has not changed the number of P-states in use
*/
static void acpi_processor_ppc_ost(acpi_handle handle, int status)
{
union acpi_object params[2] = {
{.type = ACPI_TYPE_INTEGER,},
{.type = ACPI_TYPE_INTEGER,},
};
struct acpi_object_list arg_list = {2, params};
acpi_handle temp;
params[0].integer.value = ACPI_PROCESSOR_NOTIFY_PERFORMANCE;
params[1].integer.value = status;
/* when there is no _OST , skip it */
if (ACPI_FAILURE(acpi_get_handle(handle, "_OST", &temp)))
return;
acpi_evaluate_object(handle, "_OST", &arg_list, NULL);
return;
}
int acpi_processor_ppc_has_changed(struct acpi_processor *pr, int event_flag)
{
int ret;
if (ignore_ppc)
if (ignore_ppc) {
/*
* Only when it is notification event, the _OST object
* will be evaluated. Otherwise it is skipped.
*/
if (event_flag)
acpi_processor_ppc_ost(pr->handle, 1);
return 0;
}
ret = acpi_processor_get_platform_limit(pr);
/*
* Only when it is notification event, the _OST object
* will be evaluated. Otherwise it is skipped.
*/
if (event_flag) {
if (ret < 0)
acpi_processor_ppc_ost(pr->handle, 1);
else
acpi_processor_ppc_ost(pr->handle, 0);
}
if (ret < 0)
return (ret);
else