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Date:   Tue, 26 Oct 2021 16:44:25 +0530
From:   Viresh Kumar <viresh.kumar@linaro.org>
To:     Wolfram Sang <wsa@kernel.org>, Jie Deng <jie.deng@intel.com>,
        "Michael S. Tsirkin" <mst@redhat.com>,
        Jason Wang <jasowang@redhat.com>
Cc:     Vincent Guittot <vincent.guittot@linaro.org>,
        Arnd Bergmann <arnd@kernel.org>,
        stratos-dev@op-lists.linaro.org,
        Alex =?utf-8?Q?Benn=C3=A9e?= <alex.bennee@linaro.org>,
        cohuck@redhat.com,
        Vincent Whitchurch <vincent.whitchurch@axis.com>,
        linux-i2c@vger.kernel.org,
        virtualization@lists.linux-foundation.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH] i2c: virtio: Add support for zero-length requests
Message-ID: <20211026111425.nigbol5stajopkrw@vireshk-i7>
References: <7c58868cd26d2fc4bd82d0d8b0dfb55636380110.1634808714.git.viresh.kumar@linaro.org>
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On 21-10-21, 15:17, Viresh Kumar wrote:
> The virtio specification received a new mandatory feature
> (VIRTIO_I2C_F_ZERO_LENGTH_REQUEST) for zero length requests. Fail if the
> feature isn't offered by the device.
> 
> For each read-request, set the VIRTIO_I2C_FLAGS_M_RD flag, as required
> by the VIRTIO_I2C_F_ZERO_LENGTH_REQUEST feature.
> 
> This allows us to support zero length requests, like SMBUS Quick, where
> the buffer need not be sent anymore.
> 
> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
> ---
> Hi Wolfram,
> 
> Please do not apply this until the spec changes [1] are merged, sending it early
> to get review done. I will ping you later once the spec is merged.
> 
> [1] https://lists.oasis-open.org/archives/virtio-dev/202110/msg00109.html

Michael,

Can this be merged as well based on the current voting at the ballot ?

https://www.oasis-open.org/committees/ballot.php?id=3659

Wolfram,

I am asking as this patch should be considered as a fix, which needs to be
applied to the 5.15 kernel itself if possible (now or via stable), as we are
implementing a new mandatory feature, which will make the currently merged
version of the driver unusable going forward (since this won't be backwards
compatible).

-- 
viresh