Hello! I note the following in the serial console: if (is_rproc_serial(vdev)) { /* * Allocate DMA memory from ancestor. When a virtio * device is created by remoteproc, the DMA memory is * associated with the grandparent device: * vdev => rproc => platform-dev. */ if (!vdev->dev.parent || !vdev->dev.parent->parent) goto free_buf; buf->dev = vdev->dev.parent->parent; /* Increase device refcnt to avoid freeing it */ get_device(buf->dev); buf->buf = dma_alloc_coherent(buf->dev, buf_size, &buf->dma, GFP_KERNEL); } Added here: commit 1b6370463e88b0c1c317de16d7b962acc1dab4f2 Author: Sjur Brændeland <sjur.brandeland@xxxxxxxxxxxxxx> Date: Fri Dec 14 14:40:51 2012 +1030 virtio_console: Add support for remoteproc serial I am not familiar with rproc so I have a question: why is it required to use coherent memory here, and why through a grandparent device? Would it work to instead change vring_use_dma_api to whitelist rproc (like we do for xen)? I can sent a patch for your testing. Thanks! -- MST -- To unsubscribe from this list: send the line "unsubscribe linux-remoteproc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html