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; >>>> + }