Re: [PATCH v2 1/1] iio: humidity: hdc100x: add manufacturer and device ID cehck

[Potin Lai]

Andy Shevchenko 於 7/27/2022 7:56 PM 寫道:
> On Wed, Jul 27, 2022 at 12:42 PM Potin Lai <potin.lai.pt@xxxxxxxxx> wrote:
>> On 7/27/22 18:00, Andy Shevchenko wrote:
>>> On Wed, Jul 27, 2022 at 8:46 AM Potin Lai <potin.lai.pt@xxxxxxxxx> wrote:
> ...
>
>>>> +       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.
> No, but as I said you may guarantee that by obliging developers not to
> shoot in their feet.
Thanks for the explanation, I will remove the checking part.

Potin
>> 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?
> Why is this check needed? We do not like dead code.
>
>>>> +               if (!data->support_mfr_check)
>>>> +                       return true;
>>>> +       }