[U-Boot] [PATCH 02/27] dm: Add a new uclass driver for VirtIO transport devices

[Bin Meng]

Hi Tuomas,

On Fri, Sep 28, 2018 at 6:10 AM Tuomas Tynkkynen
<tuomas.tynkkynen at iki.fi> wrote:
>
> Hi Bin,
>
> Thanks for the patches, they look great. Some minor comments:
>
> On 09/23/2018 04:42 PM, Bin Meng wrote:
> > This adds a new virtio uclass driver for “virtio” [1] family of
> > devices that are are found in virtual environments like QEMU,
> > yet by design they look like physical devices to the guest.
> >
> > The uclass driver provides child_pre_probe() and child_post_probe()
> > methods to do some common operations for virtio device drivers like
> > device and driver supported feature negotiation, etc.
> >
> > [1] http://docs.oasis-open.org/virtio/virtio/v1.0/virtio-v1.0.pdf
> >
> > Signed-off-by: Tuomas Tynkkynen <tuomas.tynkkynen at iki.fi>
> > Signed-off-by: Bin Meng <bmeng.cn at gmail.com>
> > ---...
> >+
> >+config VIRTIO
> >+      bool
> >+      help
> >+        This option is selected by any driver which implements the virtio
> >+        bus, such as CONFIG_VIRTIO_MMIO or CONFIG_VIRTIO_PCI.
>
> I think most other places use the term 'transport' over 'bus'.
>

Changed in v2.

> > +
> > +int virtio_get_config(struct udevice *vdev, unsigned int offset,
> > +                   void *buf, unsigned int len)
> > +{
> > +     struct dm_virtio_ops *ops;
> > +
> > +     ops = virtio_get_ops(vdev->parent);
> > +     if (!ops->get_config)
> > +             return -ENOSYS;
>
> I'm not sure how useful the -ENOSYS fallbacks for most of these ops
> are. E.g. a transport lacking .find_vqs() cannot ever be useful
> for implementing real-world devices.
>

Agreed. Address this in v2.

Regards,
Bin