linux-kernel - Re: [PATCH] gpio: viperboard: remove platform_set

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Date:   Wed, 21 Jul 2021 17:13:30 +0300
From:   Alexandru Ardelean <aardelean@...iqon.com>
To:     Bartosz Golaszewski <bgolaszewski@...libre.com>
Cc:     linux-gpio <linux-gpio@...r.kernel.org>,
        LKML <linux-kernel@...r.kernel.org>,
        Linus Walleij <linus.walleij@...aro.org>
Subject: Re: [PATCH] gpio: viperboard: remove platform_set_drvdata() call in probe

On Wed, 21 Jul 2021 at 16:16, Bartosz Golaszewski
<bgolaszewski@...libre.com> wrote:
>
> On Wed, Jul 7, 2021 at 3:51 PM Alexandru Ardelean <aardelean@...iqon.com> wrote:
> >
> > The platform_set_drvdata() call is only useful if we need to retrieve back
> > the private information.
> > Since the driver doesn't do that, it's not useful to have it.
> >
> > This change removes it.
> >
> > Signed-off-by: Alexandru Ardelean <aardelean@...iqon.com>
> > ---
> >  drivers/gpio/gpio-viperboard.c | 6 +-----
> >  1 file changed, 1 insertion(+), 5 deletions(-)
> >
> > diff --git a/drivers/gpio/gpio-viperboard.c b/drivers/gpio/gpio-viperboard.c
> > index c301c1d56dd2..98ddd6590362 100644
> > --- a/drivers/gpio/gpio-viperboard.c
> > +++ b/drivers/gpio/gpio-viperboard.c
> > @@ -422,12 +422,8 @@ static int vprbrd_gpio_probe(struct platform_device *pdev)
> >         vb_gpio->gpiob.direction_input = vprbrd_gpiob_direction_input;
> >         vb_gpio->gpiob.direction_output = vprbrd_gpiob_direction_output;
> >         ret = devm_gpiochip_add_data(&pdev->dev, &vb_gpio->gpiob, vb_gpio);
> > -       if (ret < 0) {
> > +       if (ret < 0)
> >                 dev_err(vb_gpio->gpiob.parent, "could not add gpio b");
> > -               return ret;
> > -       }
> > -
> > -       platform_set_drvdata(pdev, vb_gpio);
> >
> >         return ret;
> >  }
> > --
> > 2.31.1
> >
>
> The log is not really needed, we'll get an error message from gpiolib
> core. Can you remove it while you're at it and just return the result
> of devm_gpiochip_add_data()?

I thought about removing it, but in this driver there are 2
devm_gpiochip_add_data() calls.
It registers 2 GPIOchip instances.
Which is not so easy to see in this patch.

First one says "could not add gpio a"  and this one says "could not add gpio b".
I hesitated to remove either of these.

In this case, it may be a little helpful to know which GPIOchip failed
to be registered.

But I don't mind removing them both.
Whatever you prefer. I'm undecided.

>
> Bart