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Message-ID: <a385e266-b24e-7ffb-c083-891edd4b0b14@gmail.com>
Date:   Wed, 27 Jul 2022 18:40:37 +0800
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Subject: Re: [PATCH v2 1/1] iio: humidity: hdc100x: add manufacturer and
 device ID cehck
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To:     Andy Shevchenko <andy.shevchenko@gmail.com>
Cc:     Jonathan Cameron <jic23@kernel.org>,
        Lars-Peter Clausen <lars@metafoo.de>,
        Patrick Williams <patrick@stwcx.xyz>,
        Potin Lai <potin.lai@quantatw.com>,
        linux-iio <linux-iio@vger.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
References: <20220727064415.940690-1-potin.lai.pt@gmail.com>
 <CAHp75VfNmq12Yv7mqVeijqK0vwRdPsSrH5wMzg9qR15+t7ArSQ@mail.gmail.com>
From:   Potin Lai <potin.lai.pt@gmail.com>
In-Reply-To: <CAHp75VfNmq12Yv7mqVeijqK0vwRdPsSrH5wMzg9qR15+t7ArSQ@mail.gmail.com>
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On 7/27/22 18:00, Andy Shevchenko wrote:
> On Wed, Jul 27, 2022 at 8:46 AM Potin Lai <potin.lai.pt@gmail.com> wrote:
>> Add manufacturer and device ID checking during probe, and skip the
>> checking if chip model not supported.
>>
>> Supported:
>> - HDC1000
>> - HDC1010
>> - HDC1050
>> - HDC1080
>>
>> Not supported:
>> - HDC1008
> Thanks for an update, my comments below.
>
> ...
>
>> +       const struct of_device_id *match;
> Don't you have a compiler warning? Always compile your code with `make W=1`
>
> ...

You are correct, I will remove this unused variable.

>> +       data = device_get_match_data(&client->dev);
>> +       if (data) {
> This check is redundant. Too much protective programming. Just oblige
> that matched ID has to always have an associated data.
Is it guaranteed that device_get_match_data will not return NULL? I find some examples in other drivers, all of them have a check on returned data.

Will it be more appropriate if I move device_get_match_data to probe function, and return EINVAL when we get a NULL pointer from device_get_match_data?

>> +               if (!data->support_mfr_check)
>> +                       return true;
>> +       }
> ...
>
>> -       .probe = hdc100x_probe,
>> +       .probe_new = hdc100x_probe,
> Make this a separate patch before the presented one.
>
got it, will move this into a separate patch in next version.

thanks,
Potin