DMA_BYTE_COUNT_MASK
req->req.actual = req->req.length - (DMA_BYTE_COUNT_MASK & dmacount);
if (ep_dmacount & DMA_BYTE_COUNT_MASK)
count &= DMA_BYTE_COUNT_MASK;
count &= DMA_BYTE_COUNT_MASK;
if (_req->length > (~0 & DMA_BYTE_COUNT_MASK)) {