EF4_BUF_SIZE
dma_addr = buffer->buf.dma_addr + (i * EF4_BUF_SIZE);
len = ALIGN(len, EF4_BUF_SIZE);
buffer->entries = len / EF4_BUF_SIZE;
BUG_ON(buffer->buf.dma_addr & (EF4_BUF_SIZE - 1));