RE: [PATCH] pinctrl: pinconf-generic: check error value EOPNOTSUPP

[Peng Fan <peng.fan@xxxxxxx>]

Hi Andy,

> Subject: Re: [PATCH] pinctrl: pinconf-generic: check error value EOPNOTSUPP
> 
> On Thu, Apr 04, 2024 at 01:44:50PM +0200, Linus Walleij wrote:
> > On Mon, Apr 1, 2024 at 4:02 PM Peng Fan (OSS) <peng.fan@xxxxxxxxxxx>
> wrote:
> >
> > > From: Peng Fan <peng.fan@xxxxxxx>
> > >
> > > The SCMI error value SCMI_ERR_SUPPORT maps to linux error value
> > > '-EOPNOTSUPP', so when dump configs, need check the error value
> > > EOPNOTSUPP, otherwise there will be log "ERROR READING CONFIG
> SETTING".
> > >
> > > Signed-off-by: Peng Fan <peng.fan@xxxxxxx>
> > (...)
> > >                         ret = pin_config_get_for_pin(pctldev, pin, &config);
> > >                 /* These are legal errors */
> > > -               if (ret == -EINVAL || ret == -ENOTSUPP)
> > > +               if (ret == -EINVAL || ret == -ENOTSUPP || ret ==
> > > + -EOPNOTSUPP)
> >
> > TBH it's a bit odd to call an in-kernel API such as
> > pin_config_get_for_pin() and get -EOPNOTSUPP back. But it's not like I care
> a lot, so patch applied.
> 
> Hmm... I would like actually to get this being consistent. The documentation
> explicitly says that in-kernel APIs uses Linux error code and not POSIX one.

Would you please share me the documentation?

> 
> This check opens a Pandora box.
> 
> FWIW, it just like dozen or so drivers that needs to be fixed, I prefer to have
> them being moved to ENOTSUPP, rather this patch.

I see many patches convert to use EOPNOTSUPP by checking git log.

And checkpatch.pl reports warning for using ENOTSUPP.

BTW: is there any issue if using EOPNOTSUPP here?

Thanks,
Peng.
> 
> --
> With Best Regards,
> Andy Shevchenko
>