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path: root/drivers/acpi/processor_throttling.c
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Diffstat (limited to 'drivers/acpi/processor_throttling.c')
-rw-r--r--drivers/acpi/processor_throttling.c53
1 files changed, 37 insertions, 16 deletions
diff --git a/drivers/acpi/processor_throttling.c b/drivers/acpi/processor_throttling.c
index dc5b85932ea2..0b8204e7082a 100644
--- a/drivers/acpi/processor_throttling.c
+++ b/drivers/acpi/processor_throttling.c
@@ -47,6 +47,9 @@ ACPI_MODULE_NAME("processor_throttling");
static int acpi_processor_get_throttling(struct acpi_processor *pr);
int acpi_processor_set_throttling(struct acpi_processor *pr, int state);
+/*
+ * _TPC - Throttling Present Capabilities
+ */
static int acpi_processor_get_platform_limit(struct acpi_processor *pr)
{
acpi_status status = 0;
@@ -55,8 +58,10 @@ static int acpi_processor_get_platform_limit(struct acpi_processor *pr)
if (!pr)
return -EINVAL;
status = acpi_evaluate_integer(pr->handle, "_TPC", NULL, &tpc);
- if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
- ACPI_EXCEPTION((AE_INFO, status, "Evaluating _TPC"));
+ if (ACPI_FAILURE(status)) {
+ if (status != AE_NOT_FOUND) {
+ ACPI_EXCEPTION((AE_INFO, status, "Evaluating _TPC"));
+ }
return -ENODEV;
}
pr->throttling_platform_limit = (int)tpc;
@@ -68,9 +73,9 @@ int acpi_processor_tstate_has_changed(struct acpi_processor *pr)
return acpi_processor_get_platform_limit(pr);
}
-/* --------------------------------------------------------------------------
- _PTC, _TSS, _TSD support
- -------------------------------------------------------------------------- */
+/*
+ * _PTC - Processor Throttling Control (and status) register location
+ */
static int acpi_processor_get_throttling_control(struct acpi_processor *pr)
{
int result = 0;
@@ -81,7 +86,9 @@ static int acpi_processor_get_throttling_control(struct acpi_processor *pr)
status = acpi_evaluate_object(pr->handle, "_PTC", NULL, &buffer);
if (ACPI_FAILURE(status)) {
- ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PTC"));
+ if (status != AE_NOT_FOUND) {
+ ACPI_EXCEPTION((AE_INFO, status, "Evaluating _PTC"));
+ }
return -ENODEV;
}
@@ -132,6 +139,10 @@ static int acpi_processor_get_throttling_control(struct acpi_processor *pr)
return result;
}
+
+/*
+ * _TSS - Throttling Supported States
+ */
static int acpi_processor_get_throttling_states(struct acpi_processor *pr)
{
int result = 0;
@@ -144,7 +155,9 @@ static int acpi_processor_get_throttling_states(struct acpi_processor *pr)
status = acpi_evaluate_object(pr->handle, "_TSS", NULL, &buffer);
if (ACPI_FAILURE(status)) {
- ACPI_EXCEPTION((AE_INFO, status, "Evaluating _TSS"));
+ if (status != AE_NOT_FOUND) {
+ ACPI_EXCEPTION((AE_INFO, status, "Evaluating _TSS"));
+ }
return -ENODEV;
}
@@ -201,6 +214,10 @@ static int acpi_processor_get_throttling_states(struct acpi_processor *pr)
return result;
}
+
+/*
+ * _TSD - T-State Dependencies
+ */
static int acpi_processor_get_tsd(struct acpi_processor *pr)
{
int result = 0;
@@ -213,6 +230,9 @@ static int acpi_processor_get_tsd(struct acpi_processor *pr)
status = acpi_evaluate_object(pr->handle, "_TSD", NULL, &buffer);
if (ACPI_FAILURE(status)) {
+ if (status != AE_NOT_FOUND) {
+ ACPI_EXCEPTION((AE_INFO, status, "Evaluating _TSD"));
+ }
return -ENODEV;
}
@@ -525,9 +545,6 @@ int acpi_processor_get_throttling_info(struct acpi_processor *pr)
int result = 0;
int step = 0;
int i = 0;
- int no_ptc = 0;
- int no_tss = 0;
- int no_tsd = 0;
ACPI_DEBUG_PRINT((ACPI_DB_INFO,
"pblk_address[0x%08x] duty_offset[%d] duty_width[%d]\n",
@@ -538,12 +555,14 @@ int acpi_processor_get_throttling_info(struct acpi_processor *pr)
if (!pr)
return -EINVAL;
- /* TBD: Support ACPI 2.0 objects */
- no_ptc = acpi_processor_get_throttling_control(pr);
- no_tss = acpi_processor_get_throttling_states(pr);
- no_tsd = acpi_processor_get_tsd(pr);
-
- if (no_ptc || no_tss) {
+ /*
+ * Evaluate _PTC, _TSS and _TPC
+ * They must all be present or none of them can be used.
+ */
+ if (acpi_processor_get_throttling_control(pr) ||
+ acpi_processor_get_throttling_states(pr) ||
+ acpi_processor_get_platform_limit(pr))
+ {
pr->throttling.acpi_processor_get_throttling =
&acpi_processor_get_throttling_fadt;
pr->throttling.acpi_processor_set_throttling =
@@ -555,6 +574,8 @@ int acpi_processor_get_throttling_info(struct acpi_processor *pr)
&acpi_processor_set_throttling_ptc;
}
+ acpi_processor_get_tsd(pr);
+
if (!pr->throttling.address) {
ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No throttling register\n"));
return 0;