NERRS_MAX
if (drvp->n_dmaerrs >= NERRS_MAX && drvp->n_xfers <= NXFER) {
drvp->n_dmaerrs = NERRS_MAX-1;
if ((NERRS_MAX - 2) > 0)
wd->drvp->n_dmaerrs = NERRS_MAX - 2;
if ((NERRS_MAX - 2) > 0)
drvp->n_dmaerrs = NERRS_MAX - 2;