Re: [PATCH V5 2/2] virtio: i2c: Allow zero-length transactions

[Cornelia Huck <cohuck@redhat.com>]

On Wed, Oct 13 2021, Viresh Kumar <viresh.kumar@linaro.org> wrote:

> On 13-10-21, 11:26, Cornelia Huck wrote:
>> On Tue, Oct 12 2021, Viresh Kumar <viresh.kumar@linaro.org> wrote:
>> > +A device SHOULD implement the VIRTIO_I2C_F_ZERO_LENGTH_REQUEST feature.
>> 
>> Same here, I would make this "MUST offer", and simply make old device
>> implementations non-compliant.
>
>> The device should also reject any driver that does not negotiate the
>> flag, I think?
>
> Thinking about this a bit more, in practice the device doesn't get to
> know about what the driver does with the flag. So how can a device
> reject the driver ?

It can fail setting FEATURES_OK, if the driver does not set the feature.