Re: [PATCH v5] i2c: virtio: add a virtio i2c frontend driver

[Jie Deng <jie.deng@intel.com>]

On 2021/3/1 20:07, Andy Shevchenko wrote:
> On Mon, Mar 01, 2021 at 02:41:35PM +0800, Jie Deng wrote:
>> Add an I2C bus driver for virtio para-virtualization.
>>
>> The controller can be emulated by the backend driver in
>> any device model software by following the virtio protocol.
>>
>> The device specification can be found on
>> https://lists.oasis-open.org/archives/virtio-comment/202101/msg00008.html.
>>
>> By following the specification, people may implement different
>> backend drivers to emulate different controllers according to
>> their needs.
> ...
>
>> +		buf = kzalloc(msgs[i].len, GFP_KERNEL);
>> +		if (!buf)
>> +			break;
>> +
>> +		if (msgs[i].flags & I2C_M_RD) {
> kzalloc()
>
>> +			reqs[i].read_buf = buf;
>> +			sg_init_one(&msg_buf, reqs[i].read_buf, msgs[i].len);
>> +			sgs[outcnt + incnt++] = &msg_buf;
>> +		} else {
>> +			reqs[i].write_buf = buf;
>> +			memcpy(reqs[i].write_buf, msgs[i].buf, msgs[i].len);
> kmemdup() ?
Do you mean using "kzalloc" in the if condition and "kmemdup" in the 
else condition ?
Then we have to check the NULL twice which is also not good.
>> +			sg_init_one(&msg_buf, reqs[i].write_buf, msgs[i].len);
>> +			sgs[outcnt++] = &msg_buf;
>> +		}
> ...
>
>> +
>> +
> One blank line is enough.
Will fix it. Thank you.
> ...
>
>
>> +	ret = virtio_i2c_send_reqs(vq, reqs, msgs, num);
>> +	if (ret == 0)
>> +		goto err_unlock_free;
>> +	else
> Redundant.
Good catch !
>> +		nr = ret;