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authorZhao Yakui <yakui.zhao@intel.com>2011-01-10 16:35:45 +0800
committerLen Brown <len.brown@intel.com>2011-01-10 12:35:28 -0500
commit5a344a505093dd65f82f338ffdb7208321b3630e (patch)
tree398d26e9108e54537be840e658cbe7972a810fb4 /drivers/acpi/processor_throttling.c
parentdaef1f35ea1e2cca125eecd5f078f40b55eb9105 (diff)
ACPI: Reevaluate whether the T-state is supported or not after cpu is online/offline
After one CPU is offlined, it is unnecessary to switch T-state for it. So it will be better that the throttling is disabled after the cpu is offline. At the same time after one cpu is online, we should check whether the T-state is supported and then set the corresponding T-state flag. Signed-off-by: Zhao Yakui <yakui.zhao@intel.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.c52
1 files changed, 52 insertions, 0 deletions
diff --git a/drivers/acpi/processor_throttling.c b/drivers/acpi/processor_throttling.c
index ffc859c6139..4305d560b06 100644
--- a/drivers/acpi/processor_throttling.c
+++ b/drivers/acpi/processor_throttling.c
@@ -370,6 +370,58 @@ int acpi_processor_tstate_has_changed(struct acpi_processor *pr)
}
/*
+ * This function is used to reevaluate whether the T-state is valid
+ * after one CPU is onlined/offlined.
+ * It is noted that it won't reevaluate the following properties for
+ * the T-state.
+ * 1. Control method.
+ * 2. the number of supported T-state
+ * 3. TSD domain
+ */
+void acpi_processor_reevaluate_tstate(struct acpi_processor *pr,
+ unsigned long action)
+{
+ int result = 0;
+
+ if (action == CPU_DEAD) {
+ /* When one CPU is offline, the T-state throttling
+ * will be invalidated.
+ */
+ pr->flags.throttling = 0;
+ return;
+ }
+ /* the following is to recheck whether the T-state is valid for
+ * the online CPU
+ */
+ if (!pr->throttling.state_count) {
+ /* If the number of T-state is invalid, it is
+ * invalidated.
+ */
+ pr->flags.throttling = 0;
+ return;
+ }
+ pr->flags.throttling = 1;
+
+ /* Disable throttling (if enabled). We'll let subsequent
+ * policy (e.g.thermal) decide to lower performance if it
+ * so chooses, but for now we'll crank up the speed.
+ */
+
+ result = acpi_processor_get_throttling(pr);
+ if (result)
+ goto end;
+
+ if (pr->throttling.state) {
+ result = acpi_processor_set_throttling(pr, 0, false);
+ if (result)
+ goto end;
+ }
+
+end:
+ if (result)
+ pr->flags.throttling = 0;
+}
+/*
* _PTC - Processor Throttling Control (and status) register location
*/
static int acpi_processor_get_throttling_control(struct acpi_processor *pr)