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Date:   Tue, 29 Jun 2021 16:46:30 +0530
From:   Viresh Kumar <viresh.kumar@linaro.org>
To:     Wolfram Sang <wsa@kernel.org>, Jie Deng <jie.deng@intel.com>,
        linux-i2c@vger.kernel.org,
        virtualization@lists.linux-foundation.org,
        linux-kernel@vger.kernel.org, mst@redhat.com, jasowang@redhat.com,
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        arnd@arndb.de, kblaiech@mellanox.com,
        jarkko.nikula@linux.intel.com, Sergey.Semin@baikalelectronics.ru,
        rppt@kernel.org, loic.poulain@linaro.org, tali.perry1@gmail.com,
        u.kleine-koenig@pengutronix.de, bjorn.andersson@linaro.org,
        yu1.wang@intel.com, shuo.a.liu@intel.com, stefanha@redhat.com,
        pbonzini@redhat.com
Subject: Re: [PATCH v10] i2c: virtio: add a virtio i2c frontend driver
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On 29-06-21, 13:11, Wolfram Sang wrote:
> 
> > 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.
> 
> Obviously, I don't know much about the specs and their wording. Still I
> wonder if we can't call it a zero length transfer?

Maybe that.

> This is allowed by
> the I2C standard and SMBus has even a proper name for it (SMBUS_QUICK).
> From my point of view, I would not say it is device specific because
> devices are expected to ACK such a message.

Actually we should skip the last line from my diff, i.e. completely
drop "and result for such a request is I2C device specific".

The device (host in virtio spec terminology) still needs to return
success/failure as it does for other requests. Nothing special here.

-- 
viresh