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

[Peng Fan <peng.fan@xxxxxxx>]

Hi Linus, Andy

> Subject: Re: [PATCH] pinctrl: pinconf-generic: check error value EOPNOTSUPP
> 
> On Thu, Apr 04, 2024 at 09:03:02PM +0200, Linus Walleij wrote:
> > On Thu, Apr 4, 2024 at 7:05 PM Andy Shevchenko
> > <andriy.shevchenko@xxxxxxxxx> wrote:
> > > 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.

ok. Got it. 

> > >
> > > 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.
> 
> $ git grep -lw EOPNOTSUPP -- drivers/pinctrl/ drivers/gpio/ drivers/gpio/gpio-
> crystalcove.c drivers/gpio/gpio-pcie-idio-24.c drivers/gpio/gpio-regmap.c
> drivers/gpio/gpio-wcove.c // drivers/gpio/gpiolib-cdev.c <<< Here it goes to
> user space, no need to fix drivers/pinctrl/actions/pinctrl-s500.c
> drivers/pinctrl/mediatek/mtk-eint.c
> drivers/pinctrl/mediatek/mtk-eint.h
> drivers/pinctrl/nxp/pinctrl-s32cc.c
> drivers/pinctrl/pinctrl-at91-pio4.c
> // drivers/pinctrl/pinctrl-aw9523.c <<< Should be fixed in Linus' tree by me
> drivers/pinctrl/pinctrl-ocelot.c drivers/pinctrl/renesas/pinctrl-rzg2l.c
> drivers/pinctrl/renesas/pinctrl-rzv2m.c
> drivers/pinctrl/sunplus/sppctl.c
> drivers/pinctrl/visconti/pinctrl-common.c
> 
> > Andy is one of the wisest men I know so I have taken out the patch.
> >
> > Peng, what about fixing the problem at its source? 

Sure.
Patch away, we will
> > help you if need be.
Let me try to fix it by myself, that would give me more practice.

Thanks,
Peng.

> 
> Indeed.
> 
> --
> With Best Regards,
> Andy Shevchenko
>