UPF_SPD_MASK
if (baud == 38400 && (port->flags & UPF_SPD_MASK) == UPF_SPD_CUST)
if (((old_flags ^ uport->flags) & UPF_SPD_MASK) ||
if (uport->flags & UPF_SPD_MASK) {
upf_t flags = port->flags & UPF_SPD_MASK;
if (baud == 38400 && (port->flags & UPF_SPD_MASK) == UPF_SPD_CUST)
#define UPF_USR_MASK ((__force upf_t) (UPF_SPD_MASK|UPF_LOW_LATENCY))