+ /*
+ * Serial back end is available on Unix. However, we have to
+ * mask out a couple of the configuration options: mark and
+ * space parity are not conveniently supported, and neither is
+ * DSR/DTR flow control.
+ */
+ if (!midsession || (protocol == PROT_SERIAL))
+ ser_setup_config_box(b, midsession, 0x07, 0x07);