linux-kernel - Re: [PATCH 8/8] gpiolib: sanitize the return value of gpio_chip::get

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Message-ID: <Z7zVvgcEeWnYr9vZ@surfacebook.localdomain>
Date: Mon, 24 Feb 2025 22:25:34 +0200
From: Andy Shevchenko <andy.shevchenko@...il.com>
To: Bartosz Golaszewski <brgl@...ev.pl>
Cc: Andy Shevchenko <andriy.shevchenko@...el.com>,
	Linus Walleij <linus.walleij@...aro.org>,
	linux-gpio@...r.kernel.org, linux-kernel@...r.kernel.org,
	Bartosz Golaszewski <bartosz.golaszewski@...aro.org>
Subject: Re: [PATCH 8/8] gpiolib: sanitize the return value of
 gpio_chip::get_direction()

Mon, Feb 24, 2025 at 08:55:26PM +0100, Bartosz Golaszewski kirjoitti:
> On Mon, Feb 24, 2025 at 5:33 PM Andy Shevchenko
> <andriy.shevchenko@...el.com> wrote:
> > On Mon, Feb 10, 2025 at 11:52:02AM +0100, Bartosz Golaszewski wrote:

...

> > > +static int gpiochip_get_direction(struct gpio_chip *gc, unsigned int offset)
> > > +{
> > > +     int ret;
> > > +
> > > +     lockdep_assert_held(&gc->gpiodev->srcu);
> > > +
> > > +     if (WARN_ON(!gc->get_direction))
> > > +             return -EOPNOTSUPP;
> > > +
> > > +     ret = gc->get_direction(gc, offset);
> > > +     if (ret > 1)
> >
> > Would it be better to use the respective GPIO*... macro instead of 1?
> >
> 
> I did consider it but I don't like comparing against enums, it doesn't
> feel right as the value behind the name can change. I think I prefer
> it like this even if it's not the best solution either. Maybe we could
> be more explicit and say:
> 
>     if (!(ret == IN || ret == OUT || ret < 0)
> 
> ?

Yep, I like this.

-- 
With Best Regards,
Andy Shevchenko