itdend
ex->itdend, ex->isdone);
KASSERT(ex->itdstart != NULL && ex->itdend != NULL);
KASSERT(ex->itdstart != NULL && ex->itdend != NULL);
ex->itdend = NULL;
ex->itdend = itd;
ex->itdend = itd;
struct ehci_soft_itd *itd = ex->itdend;
KASSERT(ex->itdstart != NULL && ex->itdend != NULL);