On Mon, 28 Nov 2016 20:08:23 +0800 Gonglei <arei.gonglei@xxxxxxxxxx> wrote: > +static int virtcrypto_update_status(struct virtio_crypto *vcrypto) > +{ > + u32 status; > + int err; > + > + virtio_cread(vcrypto->vdev, > + struct virtio_crypto_config, status, &status); > + > + /* Ignore unknown (future) status bits */ > + status &= VIRTIO_CRYPTO_S_HW_READY; I'm wondering what the driver really should do if it encounters unknown status bits. I'd expect that new status bits are guarded by a feature bit and that the device should not set status bits if the respective feature bit has not been negotiated. Therefore, unknown status bits would be a host error and the driver should consider the device to be broken. Thoughts? > + > + if (vcrypto->status == status) > + return 0; > + > + vcrypto->status = status; > + > + if (vcrypto->status & VIRTIO_CRYPTO_S_HW_READY) { > + err = virtcrypto_dev_start(vcrypto); > + if (err) { > + dev_err(&vcrypto->vdev->dev, > + "Failed to start virtio crypto device.\n"); > + virtcrypto_dev_stop(vcrypto); > + return -EPERM; > + } > + dev_info(&vcrypto->vdev->dev, "Accelerator is ready\n"); > + } else { > + virtcrypto_dev_stop(vcrypto); > + dev_info(&vcrypto->vdev->dev, "Accelerator is not ready\n"); > + } > + > + return 0; > +} > + -- To unsubscribe from this list: send the line "unsubscribe linux-crypto" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html