SPRD_IMSR_BREAK_DETECT
if (ims & SPRD_IMSR_BREAK_DETECT)
serial_out(port, SPRD_ICLR, SPRD_IMSR_BREAK_DETECT);
if (ims & (SPRD_IMSR_RX_FIFO_FULL | SPRD_IMSR_BREAK_DETECT |