MDM_UL1
if (*toggle == 0 && read_iir & MDM_UL1) {
writew(MDM_UL1, dc->reg_fcr);
if (read_iir & MDM_UL1) {
writew(MDM_UL1, dc->reg_fcr);
#define MDM_UL (MDM_UL1 | MDM_UL2)
if (interrupt & MDM_UL1)