DW_UART_LSR_ADDR_RCVD
p->ignore_status_mask |= DW_UART_LSR_ADDR_RCVD;
p->read_status_mask |= DW_UART_LSR_ADDR_RCVD;
up->lsr_save_mask = LSR_SAVE_FLAGS | DW_UART_LSR_ADDR_RCVD;