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path: root/drivers/acpi/processor_core.c
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Diffstat (limited to 'drivers/acpi/processor_core.c')
-rw-r--r--drivers/acpi/processor_core.c13
1 files changed, 13 insertions, 0 deletions
diff --git a/drivers/acpi/processor_core.c b/drivers/acpi/processor_core.c
index 9a803f85ccf..4e1bb89fd6c 100644
--- a/drivers/acpi/processor_core.c
+++ b/drivers/acpi/processor_core.c
@@ -265,7 +265,20 @@ static int acpi_processor_set_pdc(struct acpi_processor *pr)
if (!pdc_in)
return status;
+ if (idle_nomwait) {
+ /*
+ * If mwait is disabled for CPU C-states, the C2C3_FFH access
+ * mode will be disabled in the parameter of _PDC object.
+ * Of course C1_FFH access mode will also be disabled.
+ */
+ union acpi_object *obj;
+ u32 *buffer = NULL;
+ obj = pdc_in->pointer;
+ buffer = (u32 *)(obj->buffer.pointer);
+ buffer[2] &= ~(ACPI_PDC_C_C2C3_FFH | ACPI_PDC_C_C1_FFH);
+
+ }
status = acpi_evaluate_object(pr->handle, "_PDC", pdc_in, NULL);
if (ACPI_FAILURE(status))