ACPI: Reevaluate whether the T-state is supported or not after cpu is online/offline

[karo-tx-linux.git] / drivers / acpi / processor_throttling.c

diff --git a/drivers/acpi/processor_throttling.c b/drivers/acpi/processor_throttling.c
index ffc859c61393d55fb65bf5b713535b8d6a1492c4..4305d560b065973bc40fdcb9ccd33f150aa5638a 100644 (file)
--- a/drivers/acpi/processor_throttling.c
+++ b/drivers/acpi/processor_throttling.c
@@ -369,6 +369,58 @@ int acpi_processor_tstate_has_changed(struct acpi_processor *pr)
        return acpi_processor_set_throttling(pr, target_state, false);
 }
 
+/*
+ * 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
  */