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Date:   Fri, 22 Oct 2021 12:28:08 +0530
From:   Viresh Kumar <viresh.kumar@linaro.org>
To:     Jie Deng <jie.deng@intel.com>
Cc:     Wolfram Sang <wsa@kernel.org>,
        "Michael S. Tsirkin" <mst@redhat.com>,
        Jason Wang <jasowang@redhat.com>,
        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, conghui.chen@intel.com
Subject: Re: [PATCH] i2c: virtio: Add support for zero-length requests
Message-ID: <20211022065808.2rvbr6nvollz5mz6@vireshk-i7>
References: <7c58868cd26d2fc4bd82d0d8b0dfb55636380110.1634808714.git.viresh.kumar@linaro.org>
 <0adf1c36-a00b-f16f-e631-439148c4f956@intel.com>
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On 22-10-21, 14:51, Jie Deng wrote:
> > +	if (!virtio_has_feature(vdev, VIRTIO_I2C_F_ZERO_LENGTH_REQUEST)) {
> > +		dev_err(&vdev->dev, "Zero-length request feature is mandatory\n");
> > +		return -EINVAL;
> 
> 
> It might be better to return -EOPNOTSUPP ?

Maybe that or one of these:

#define	EBADE		52	/* Invalid exchange */
#define	EPROTO		71	/* Protocol error */
#define	EPFNOSUPPORT	96	/* Protocol family not supported */
#define	ECONNREFUSED	111	/* Connection refused */

Arnd, any suggestions ? This is about the mandatory feature not being offered by
the device.

-- 
viresh