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Subject: Re: [PATCH v10] i2c: virtio: add a virtio i2c frontend driver
To:     Wolfram Sang <wsa@kernel.org>, linux-i2c@vger.kernel.org,
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        u.kleine-koenig@pengutronix.de, bjorn.andersson@linaro.org,
        yu1.wang@intel.com, shuo.a.liu@intel.com, viresh.kumar@linaro.org,
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From:   Jie Deng <jie.deng@intel.com>
Message-ID: <3016ab8b-cbff-1309-6a1f-080703a4130f@intel.com>
Date:   Wed, 30 Jun 2021 15:51:08 +0800
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On 2021/6/30 15:32, Wolfram Sang wrote:
>>>> +	snprintf(vi->adap.name, sizeof(vi->adap.name), "Virtio I2C Adapter");
>>> Is there something to add so you can distinguish multiple instances?
>>> Most people want that.
>>
>> I find the I2C core will set a device name "i2c-%d" for this purpose, right?
>>
>> I think this name can be used to distinguish the adapter types while
>> "i2c-%d" can be used to
>>
>> distinguish instances. Does it make sense ?
> That alone does not help. See the 'i2cdetect -l' output of my Renesas
> board here:
>
> i2c-4	i2c       	e66d8000.i2c                    	I2C adapter
> i2c-2	i2c       	e6510000.i2c                    	I2C adapter
> i2c-7	i2c       	e60b0000.i2c                    	I2C adapter
>
> Notice that the third column carries the base address, so you know which
> i2c-%d is which physical bus. I don't know if it makes sense in your
> "virtual" case, but so far it would always print "Virtio I2C Adapter".
> Maybe it makes sense to add some parent device name, too?
>
> And if this is not reasonable, just skip it. As I said, it can be
> helpful at times, but it is definately not a show stopper.


OK. I will add the virtio_device index for this purpose.
which indicates the unique position on the virtio bus.

Thanks Wolfram, I will fix it and send the v11.