From: Zhao Yakui <yakui.zhao@xxxxxxxxx>
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@xxxxxxxxx>
---
drivers/acpi/processor_core.c | 6 ++--
drivers/acpi/processor_perflib.c | 50 ++++++++++++++++++++++++++++++++++++---
include/acpi/processor.h | 5 ++-
3 files changed, 53 insertions(+), 8 deletions(-)
Index: linux-2.6/drivers/acpi/processor_perflib.c
===================================================================
--- linux-2.6.orig/drivers/acpi/processor_perflib.c 2009-10-15 17:47:22.000000000 +0800
+++ linux-2.6/drivers/acpi/processor_perflib.c 2009-10-15 17:48:12.000000000 +0800
@@ -152,15 +152,59 @@
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
Index: linux-2.6/drivers/acpi/processor_core.c
===================================================================
--- linux-2.6.orig/drivers/acpi/processor_core.c 2009-10-15 17:47:22.000000000 +0800
+++ linux-2.6/drivers/acpi/processor_core.c 2009-10-15 17:48:12.000000000 +0800
@@ -722,7 +722,7 @@
switch (event) {
case ACPI_PROCESSOR_NOTIFY_PERFORMANCE:
saved = pr->performance_platform_limit;
- acpi_processor_ppc_has_changed(pr);
+ acpi_processor_ppc_has_changed(pr, 1);
if (saved == pr->performance_platform_limit)
break;
acpi_bus_generate_proc_event(device, event,
@@ -758,7 +758,7 @@
struct acpi_processor *pr = per_cpu(processors, cpu);
if (action == CPU_ONLINE && pr) {
- acpi_processor_ppc_has_changed(pr);
+ acpi_processor_ppc_has_changed(pr, 0);
acpi_processor_cst_has_changed(pr);
acpi_processor_tstate_has_changed(pr);
}
@@ -830,7 +830,7 @@
arch_acpi_processor_cleanup_pdc(pr);
#ifdef CONFIG_CPU_FREQ
- acpi_processor_ppc_has_changed(pr);
+ acpi_processor_ppc_has_changed(pr, 0);
#endif
acpi_processor_get_throttling_info(pr);
acpi_processor_get_limit_info(pr);
Index: linux-2.6/include/acpi/processor.h
===================================================================
--- linux-2.6.orig/include/acpi/processor.h 2009-09-09 09:38:31.000000000 +0800
+++ linux-2.6/include/acpi/processor.h 2009-10-15 17:48:12.000000000 +0800
@@ -294,7 +294,7 @@
#ifdef CONFIG_CPU_FREQ
void acpi_processor_ppc_init(void);
void acpi_processor_ppc_exit(void);
-int acpi_processor_ppc_has_changed(struct acpi_processor *pr);
+int acpi_processor_ppc_has_changed(struct acpi_processor *pr, int event_flag);
#else
static inline void acpi_processor_ppc_init(void)
{
@@ -304,7 +304,8 @@
{
return;
}
-static inline int acpi_processor_ppc_has_changed(struct acpi_processor *pr)
+static inline int acpi_processor_ppc_has_changed(struct acpi_processor *pr,
+ int event_flag)
{
static unsigned int printout = 1;
if (printout) {
--
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