Re: [PATCH v2 6/7] gpio: mockup: improve the error message

[Bartosz Golaszewski]

2017-05-31 17:26 GMT+02:00 Bartosz Golaszewski <brgl@xxxxxxxx>:
> 2017-05-31 17:00 GMT+02:00 Andy Shevchenko <andy.shevchenko@xxxxxxxxx>:
>> On Wed, May 31, 2017 at 1:54 PM, Bartosz Golaszewski <brgl@xxxxxxxx> wrote:
>>> 2017-05-30 20:59 GMT+02:00 Andy Shevchenko <andy.shevchenko@xxxxxxxxx>:
>>>> On Tue, May 30, 2017 at 11:58 AM, Bartosz Golaszewski <brgl@xxxxxxxx> wrote:
>>>>> Indicate the error number and make the message a bit more elaborate.
>>>>
>>>>> +                       dev_err(dev,
>>>>> +                               "adding gpiochip failed: %d (base: %d, ngpio: %d)\n",
>>>>> +                               ret, base, base < 0 ? ngpio : base + ngpio);
>>>>
>>>> You may consider to use
>>>> 'gpio_mockup_add' instead of 'adding gpiochip'. The latter points the
>>>> reader first to gpiochip_add family of functions while you run a
>>>> wrapper on top of it.
>>>>
>>>
>>> But this message can also be emitted if the module params are invalid,
>>> in which case we don't even enter gpio_mockup_add().
>>
>> ...which unveils bad phrasing in the message. In that case "adding
>> gpiochip" is also misleading.
>>
>
> Not really. You can pass an invalid value later in the list which will
> only become apparent when it's reached. In that case previous
> gpiochips will be added correctly but probe will fail with -EINVAL
> after reaching the bad one in which case the message is right. I hope
> I'm being clear.
>

Which made me think: maybe the next step would be to parse the
arguments in the module init function and probe each dummy gpiochip
separately...

Best regards,
Bartosz Golaszewski