XHCI_TRB_MAXSIZE
ntrb = howmany(xfer->length, XHCI_TRB_MAXSIZE);
len = XHCI_TRB_MAXSIZE - (paddr & (XHCI_TRB_MAXSIZE - 1));
ntrb = howmany(xfer->length - len, XHCI_TRB_MAXSIZE) + 1;
len = min(remain, XHCI_TRB_MAXSIZE);
ntrb += howmany(xfer->frlengths[i], XHCI_TRB_MAXSIZE);
len = XHCI_TRB_MAXSIZE - (paddr & (XHCI_TRB_MAXSIZE - 1));
ntrb = howmany(xfer->frlengths[i], XHCI_TRB_MAXSIZE);
len = XHCI_TRB_MAXSIZE - (paddr & (XHCI_TRB_MAXSIZE - 1));
len = min(remain, XHCI_TRB_MAXSIZE);