Re: [PATCH v1 2/5] extcon: Return -EPROBE_DEFER when extcon device is not found

From: Andy Shevchenko
Date: Wed Nov 14 2018 - 03:36:01 EST


On Wed, Nov 14, 2018 at 1:53 AM Chanwoo Choi <cw00.choi@xxxxxxxxxxx> wrote:

> I was thinking about again to change from NULL to EPROBE_DEFER.
>
> extcon_get_extcon_dev() function was almost called in the probe function.
> But, this function might be called on other position instead of probe.

*Might be* sounds like a theoretical thing, care to share what is in you mind?
Current users and more important the new coming one are *all* doing the same.

> ENODEV is more correct error instead of EPROBE_DEFER.

So, you are proposing to continue duplicating conversion from ENODEV
to EPROBE_DEFER in *each* caller?

> Sorry. I'll withdraw my opinion related acked-by tag until we are clarifying it.

I honestly don't know what to clarify here.

When we would have a real case we can change API correspondingly.
For now, the score is 5:0 with use cases in practice.

> On 2018ë 11ì 12ì 09:24, Chanwoo Choi wrote:
> > On 2018ë 11ì 11ì 03:10, Andy Shevchenko wrote:
> >> All current users of extcon_get_extcon_dev() API considers
> >> an extcon device a mandatory to appear. Thus, they all convert
> >> NULL pointer to -EPROBE_DEFER error code.
> >>
> >> There is one more caller anticipated with the same requirements.
> >>
> >> To decrease a code duplication and a burden to the callers,
> >> return -EPROBE_DEFER directly from extcon_get_extcon_dev().

--
With Best Regards,
Andy Shevchenko