ACPICA: Add option to disable method return value validation and repair

Runtime option can be used to disable return value repair if this
is causing a problem on a particular machine.
Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

drivers/acpi/acpica/acglobal.h

@@ -126,6 +126,12 @@ u8 ACPI_INIT_GLOBAL(acpi_gbl_copy_dsdt_locally, FALSE);
  */
 u8 ACPI_INIT_GLOBAL(acpi_gbl_truncate_io_addresses, FALSE);
 
+/*
+ * Disable runtime checking and repair of values returned by control methods.
+ * Use only if the repair is causing a problem on a particular machine.
+ */
+u8 ACPI_INIT_GLOBAL(acpi_gbl_disable_auto_repair, FALSE);
+
 /* acpi_gbl_FADT is a local copy of the FADT, converted to a common format. */
 
 struct acpi_table_fadt acpi_gbl_FADT;

drivers/acpi/acpica/nspredef.c

@@ -193,14 +193,20 @@ acpi_ns_check_predefined_names(struct acpi_namespace_node *node,
 	}
 
 	/*
-	 * 1) We have a return value, but if one wasn't expected, just exit, this is
-	 * not a problem. For example, if the "Implicit Return" feature is
-	 * enabled, methods will always return a value.
+	 * Return value validation and possible repair.
 	 *
-	 * 2) If the return value can be of any type, then we cannot perform any
-	 * validation, exit.
+	 * 1) Don't perform return value validation/repair if this feature
+	 * has been disabled via a global option.
+	 *
+	 * 2) We have a return value, but if one wasn't expected, just exit,
+	 * this is not a problem. For example, if the "Implicit Return"
+	 * feature is enabled, methods will always return a value.
+	 *
+	 * 3) If the return value can be of any type, then we cannot perform
+	 * any validation, just exit.
 	 */
-	if ((!predefined->info.expected_btypes) ||
+	if (acpi_gbl_disable_auto_repair ||
+	    (!predefined->info.expected_btypes) ||
 	    (predefined->info.expected_btypes == ACPI_RTYPE_ALL)) {
 		goto cleanup;
 	}

include/acpi/acpixf.h

@@ -69,6 +69,7 @@ extern u32 acpi_gbl_trace_flags;
 extern u32 acpi_gbl_enable_aml_debug_object;
 extern u8 acpi_gbl_copy_dsdt_locally;
 extern u8 acpi_gbl_truncate_io_addresses;
+extern u8 acpi_gbl_disable_auto_repair;
 
 extern u32 acpi_current_gpe_count;
 extern struct acpi_table_fadt acpi_gbl_FADT;