Re: [PATCH v10] i2c: virtio: add a virtio i2c frontend driver

Viresh Kumar
2021-06-29T10:56:55Z

On 29-06-21, 12:43, Wolfram Sang wrote:
>
> > From the spec:
> >
> > The case when ``length of \field{write_buf}''=0, and at the same time,
> > ``length of \field{read_buf}''=0 doesn't make any sense.
> >
> > I mentioned this in my first reply and to my understanding I did not get
> > a reply that this has changed meanwhile.
> >
>
> Also, this code as mentioned before:
>
> > + if (!msgs[i].len)
> > + break;
>
> I hope this can extended in the future to allow zero-length messages. If
> this is impossible we need to set an adapter quirk instead.

Ahh, yeah I saw these messages but I wasn't able to relate them to the
I2C_FUNC_SMBUS_QUICK thing. My bad.

Looked at Spec, Linux driver and my backends, I don't there is
anything that breaks if we allow this. So the best thing (looking
ahead) is if Jie sends a patch for spec to be modified like this.

The case when ``length of \field{write_buf}''=0, and at the same time,
``length of \field{read_buf}''=0 is called not-a-read-write request
and result for such a request is I2C device specific.

--
viresh