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authorZhang Rui <rui.zhang@intel.com>2009-05-11 09:35:57 +0800
committerLen Brown <len.brown@intel.com>2009-05-15 23:21:43 -0400
commit56c213fa012f2bad9eff908292ff2500f840b020 (patch)
treef4dad271e04fe7dabf02a0debf8945061083e146 /drivers/acpi/processor_throttling.c
parent091bf7624d1c90cec9e578a18529f615213ff847 (diff)
ACPI processor: introduce module parameter processor.ignore_tpc
Introduce module parameter processor.ignore_tpc. Some laptops are shipped with buggy _TPC, this module parameter is used to to disable the buggy support. http://bugzilla.kernel.org/show_bug.cgi?id=13259 Signed-off-by: Zhang Rui <rui.zhang@intel.com> Tested-by: James Ettle <theholyettlz@googlemail.com> Signed-off-by: Len Brown <len.brown@intel.com>
Diffstat (limited to 'drivers/acpi/processor_throttling.c')
-rw-r--r--drivers/acpi/processor_throttling.c17
1 files changed, 17 insertions, 0 deletions
diff --git a/drivers/acpi/processor_throttling.c b/drivers/acpi/processor_throttling.c
index d0d1f4d5043..5f09fb8c0e0 100644
--- a/drivers/acpi/processor_throttling.c
+++ b/drivers/acpi/processor_throttling.c
@@ -45,6 +45,14 @@
#define _COMPONENT ACPI_PROCESSOR_COMPONENT
ACPI_MODULE_NAME("processor_throttling");
+/* ignore_tpc:
+ * 0 -> acpi processor driver doesn't ignore _TPC values
+ * 1 -> acpi processor driver ignores _TPC values
+ */
+static int ignore_tpc;
+module_param(ignore_tpc, int, 0644);
+MODULE_PARM_DESC(ignore_tpc, "Disable broken BIOS _TPC throttling support");
+
struct throttling_tstate {
unsigned int cpu; /* cpu nr */
int target_state; /* target T-state */
@@ -283,6 +291,10 @@ static int acpi_processor_get_platform_limit(struct acpi_processor *pr)
if (!pr)
return -EINVAL;
+
+ if (ignore_tpc)
+ goto end;
+
status = acpi_evaluate_integer(pr->handle, "_TPC", NULL, &tpc);
if (ACPI_FAILURE(status)) {
if (status != AE_NOT_FOUND) {
@@ -290,6 +302,8 @@ static int acpi_processor_get_platform_limit(struct acpi_processor *pr)
}
return -ENODEV;
}
+
+end:
pr->throttling_platform_limit = (int)tpc;
return 0;
}
@@ -302,6 +316,9 @@ int acpi_processor_tstate_has_changed(struct acpi_processor *pr)
struct acpi_processor_limit *limit;
int target_state;
+ if (ignore_tpc)
+ return 0;
+
result = acpi_processor_get_platform_limit(pr);
if (result) {
/* Throttling Limit is unsupported */