ASY_MSR_DSR
(msr & ASY_MSR_DSR) ? "DSR " : " ",
if (msr_r & ASY_MSR_DSR)
b |= ASY_MSR_DSR;
((x) & (ASY_MSR_CTS | ASY_MSR_DSR | ASY_MSR_RI | ASY_MSR_DCD))