linux-kernel - Re: [PATCH v3 19/24] gpio: remove unnecessary checks from gpiod_to

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Date: Thu, 8 Feb 2024 20:17:14 +0100
From: Bartosz Golaszewski <brgl@...ev.pl>
To: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
Cc: Linus Walleij <linus.walleij@...aro.org>, Kent Gibson <warthog618@...il.com>, 
	Alex Elder <elder@...aro.org>, Geert Uytterhoeven <geert+renesas@...der.be>, 
	"Paul E . McKenney" <paulmck@...nel.org>, Wolfram Sang <wsa@...-dreams.de>, linux-gpio@...r.kernel.org, 
	linux-kernel@...r.kernel.org, 
	Bartosz Golaszewski <bartosz.golaszewski@...aro.org>
Subject: Re: [PATCH v3 19/24] gpio: remove unnecessary checks from gpiod_to_chip()

On Thu, Feb 8, 2024 at 6:39 PM Andy Shevchenko
<andriy.shevchenko@...ux.intel.com> wrote:
>
> On Thu, Feb 08, 2024 at 10:59:15AM +0100, Bartosz Golaszewski wrote:
> > From: Bartosz Golaszewski <bartosz.golaszewski@...aro.org>
> >
> > We don't need to check the gdev pointer in struct gpio_desc - it's
> > always assigned and never cleared. It's also pointless to check
> > gdev->chip before we actually serialize access to it.
>
> ...
>
> >  struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc)
> >  {
> > -     if (!desc || !desc->gdev)
> > +     if (!desc)
>
> Wondering if it makes sense to align with the below and use IS_ERR_OR_NULL() check.
>

Nah, it's not supposed to be used with optional GPIOs anyway as it's
not a consumer facing API.

> >               return NULL;
> >       return desc->gdev->chip;
>
> ...
>
> > -     if (!desc || IS_ERR(desc) || !desc->gdev || !desc->gdev->chip)
> > +     if (!desc || IS_ERR(desc))
>
> IS_ERR_OR_NULL()
>

Ah, good point. It's a small nit though so I'll fix it when applying
barring some major objections for the rest.

Bart

> >               return -EINVAL;
> >
> >       gc = desc->gdev->chip;
>
> --
> With Best Regards,
> Andy Shevchenko
>
>