netdev - Re: [PATCH v2] net: mdio: switch to using gpiod_get

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Message-ID: <CAHp75VdtnpO6GU8w_cTdc9dM4ob_hDt56aPU9a8iOgVw06uKQg@mail.gmail.com>
Date:   Sun, 15 Sep 2019 14:13:46 +0300
From:   Andy Shevchenko <andy.shevchenko@...il.com>
To:     Dmitry Torokhov <dmitry.torokhov@...il.com>
Cc:     Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
        Andrew Lunn <andrew@...n.ch>,
        Florian Fainelli <f.fainelli@...il.com>,
        Heiner Kallweit <hkallweit1@...il.com>,
        "David S. Miller" <davem@...emloft.net>,
        Linus Walleij <linus.walleij@...aro.org>,
        netdev <netdev@...r.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v2] net: mdio: switch to using gpiod_get_optional()

On Sun, Sep 15, 2019 at 9:26 AM Dmitry Torokhov
<dmitry.torokhov@...il.com> wrote:
> On Sat, Sep 14, 2019 at 08:09:33PM +0300, Andy Shevchenko wrote:
> > On Fri, Sep 13, 2019 at 03:55:47PM -0700, Dmitry Torokhov wrote:

> > > +   mdiodev->reset_gpio = gpiod_get_optional(&mdiodev->dev,
> > > +                                            "reset", GPIOD_OUT_LOW);
> > > +   error = PTR_ERR_OR_ZERO(mdiodev->reset_gpio);
> > > +   if (error)
> > > +           return error;

> > > +   if (mdiodev->reset_gpio)
> >
> > This is redundant check.
>
> I see that gpiod_* API handle NULL desc and usually return immediately,
> but frankly I am not that comfortable with it. I'm OK with functions
> that free/destroy objects that recognize NULL resources,

> but it is
> unusual for other types of APIs.

CLK, reset, ... frameworks do check for NULL pointer since they
provide an *_optional() getters. So, it's not unusual.
--
With Best Regards,
Andy Shevchenko