+ /*
+ * Perform a read first to preserve certain bits (per ACPI spec)
+ *
+ * Note: This includes SCI_EN, we never want to change this bit
+ */
+ status = acpi_hw_register_read(ACPI_MTX_DO_NOT_LOCK,
+ ACPI_REGISTER_PM1_CONTROL,
+ &read_value);
+ if (ACPI_FAILURE(status)) {
+ goto unlock_and_exit;
+ }
+
+ /* Insert the bits to be preserved */
+
+ ACPI_INSERT_BITS(value, ACPI_PM1_CONTROL_PRESERVED_BITS,
+ read_value);
+
+ /* Now we can write the data */
+