VTBLK_FLAG_BUSDMA_WAIT
sc->vtblk_flags |= VTBLK_FLAG_BUSDMA_WAIT;
sc->vtblk_flags &= ~VTBLK_FLAG_BUSDMA_WAIT;
if (sc->vtblk_flags & (VTBLK_FLAG_SUSPEND | VTBLK_FLAG_BUSDMA_WAIT))