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author | Zhao Yakui <yakui.zhao@intel.com> | 2009-10-16 01:20:41 (GMT) |
---|---|---|
committer | Len Brown <len.brown@intel.com> | 2009-11-06 06:58:07 (GMT) |
commit | d81c45e1c9369855901420f79114852eba2ea16a (patch) | |
tree | 910e9b4044bee76568c9eaeff70aac2fbc2385ab /drivers/acpi/processor_perflib.c | |
parent | b419148e567728f6af0c3b01965c1cc141e3e13a (diff) | |
download | linux-d81c45e1c9369855901420f79114852eba2ea16a.tar.xz |
ACPI: Notify the _PPC evaluation status to the platform
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>
Diffstat (limited to 'drivers/acpi/processor_perflib.c')
-rw-r--r-- | drivers/acpi/processor_perflib.c | 50 |
1 files changed, 47 insertions, 3 deletions
diff --git a/drivers/acpi/processor_perflib.c b/drivers/acpi/processor_perflib.c index 8ba0ed0..fc1f49bb 100644 --- a/drivers/acpi/processor_perflib.c +++ b/drivers/acpi/processor_perflib.c @@ -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 |