XDMA_DESC_BLEN_MAX
len = min_t(u32, left, XDMA_DESC_BLEN_MAX);
desc_num = sg_nents_for_dma(sgl, sg_len, XDMA_DESC_BLEN_MAX);
if (period_size > XDMA_DESC_BLEN_MAX) {
xdma_err(xdev, "period size limited to %lu bytes\n", XDMA_DESC_BLEN_MAX);
desc_num += DIV_ROUND_UP(xt->sgl[i].size, XDMA_DESC_BLEN_MAX);