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Date: Fri, 5 Apr 2024 10:46:04 +0100
From: Sudeep Holla <sudeep.holla@arm.com>
To: Andy Shevchenko <andriy.shevchenko@intel.com>,
	Linus Walleij <linus.walleij@linaro.org>
Cc: Peng Fan <peng.fan@nxp.com>, Sudeep Holla <sudeep.holla@arm.com>,
	"Peng Fan (OSS)" <peng.fan@oss.nxp.com>,
	"brgl@bgdev.pl" <brgl@bgdev.pl>,
	"linux-gpio@vger.kernel.org" <linux-gpio@vger.kernel.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"cristian.marussi@arm.com" <cristian.marussi@arm.com>
Subject: Re: [PATCH] pinctrl: pinconf-generic: check error value EOPNOTSUPP
Message-ID: <Zg_IXLNPakLmbbc7@bogus>
References: <20240401141031.3106216-1-peng.fan@oss.nxp.com>
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On Fri, Apr 05, 2024 at 02:13:28AM +0000, Peng Fan wrote:
> 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@oss.nxp.com>
> > wrote:
> > >
> > > > From: Peng Fan <peng.fan@nxp.com>
> > > >
> > > > 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@nxp.com>
> > > (...)
> > > >                         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?
>

+1, I am interested in knowing more about this as I wasn't aware of this.

> >
> > 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.
>

Exactly, I do remember changing ENOTSUPP to EOPNOTSUPP based on checkpatch
suggestion. So either the checkpatch.pl or the document you are referring
is inconsistent and needs fixing either way.

--
Regards,
Sudeep