ohci_soft_itd
LIST_HEAD(, ohci_soft_itd) sc_hash_itds[OHCI_HASH_SIZE];
struct ohci_soft_itd *nextitd; /* mirrors nexttd in ITD */
struct ohci_soft_itd *dnext; /* next in done list */
struct ohci_soft_itd **held; /* where the ref to this sitd is held */
LIST_ENTRY(ohci_soft_itd) hnext;/* next on hash list */