[U-Boot] [RFC v3 PATCH 2/4] pinctrl: add pin control uclass support

[Simon Glass]

Hi Masahiro,

On 25 August 2015 at 19:42, Masahiro Yamada
<yamada.masahiro at socionext.com> wrote:
> Hi Simon,
>
>
>
> 2015-08-26 11:26 GMT+09:00 Simon Glass <sjg at chromium.org>:
>>>
>>>
>>>>> +               return -EINVAL;
>>>>
>>>> That is normally used for an invalid device tree arg. How about -ENOSYS?
>>>
>>>
>>>
>>> This is the comment block in U-Boot:
>>>
>>> #define ENOSYS          38      /* Function not implemented */
>>>
>>>
>>> And this is the one in Linux:
>>>
>>> /*
>>>  * This error code is special: arch syscall entry code will return
>>>  * -ENOSYS if users try to call a syscall that doesn't exist.  To keep
>>>  * failures of syscalls that really do exist distinguishable from
>>>  * failures due to attempts to use a nonexistent syscall, syscall
>>>  * implementations should refrain from returning -ENOSYS.
>>>  */
>>> #define ENOSYS          38      /* Invalid system call number */
>>>
>>>
>>>
>>> From the comment above, I hesitate to use -ENOSYS for normal error cases.
>>>
>>>
>>> I chose ENOTSUPP for unimplemented functions and it is widely used
>>> in Linux's pinctrl drivers.
>>
>> OK, but in U-Boot we use -ENOSYS when there is no driver model method
>> defined for a call. The case you describe does not exist in U-Boot but
>> is analogous to a missing method.
>>
>> It doesn't much matter what one we use, but we do need to be consistent.
>>
>> If we now want to move to ENOTSUPP then we should change all existing
>> users. But ENOTSUPP says
>>
>> /* Operation not supported on transport endpoint */
>>
>> which seems less applicable to me.
>
>
> I was hit by this, too.
>
> I asked the question in LKML:
> https://lkml.org/lkml/2015/7/3/166
>
> I am not sure if you are convinced with this...
>
>
> I agree that we should be consistent with this,
> so I can send v5 with  s/ENOSUPP/ENOSYS/ .
>
>

OK, well other that that:

Acked-by: Simon Glass <sjg at chromium.org>

Two more things:
- What to do about tests?
- Please can you check my patches here and provide your comments:

http://patchwork.ozlabs.org/patch/510082/
http://patchwork.ozlabs.org/patch/510079/

Regards,
Simon