CDCEEM_ECHO_PAYLOAD
if (pktlen != sizeof(CDCEEM_ECHO_PAYLOAD)) {
pktlen, sizeof(CDCEEM_ECHO_PAYLOAD));
if (memcmp(sc->sc_echo_buffer, CDCEEM_ECHO_PAYLOAD,
sizeof(CDCEEM_ECHO_PAYLOAD)) != 0) {
sizeof(CDCEEM_ECHO_PAYLOAD));
KASSERT(off + sizeof(hdr) + sizeof(CDCEEM_ECHO_PAYLOAD) < maxlen,
off + sizeof(hdr) + sizeof(CDCEEM_ECHO_PAYLOAD)));
hdr |= sizeof(CDCEEM_ECHO_PAYLOAD);
usbd_copy_in(pc, off, CDCEEM_ECHO_PAYLOAD,
sizeof(CDCEEM_ECHO_PAYLOAD));
off += sizeof(CDCEEM_ECHO_PAYLOAD);