linux-kernel - Re: [PATCH] gpiolib: Fix inverted check in gpiochip

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Message-ID: <20200302105309.GP1224808@smile.fi.intel.com>
Date:   Mon, 2 Mar 2020 12:53:09 +0200
From:   Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
To:     Geert Uytterhoeven <geert+renesas@...der.be>
Cc:     Linus Walleij <linus.walleij@...aro.org>,
        Bartosz Golaszewski <bgolaszewski@...libre.com>,
        linux-gpio@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] gpiolib: Fix inverted check in gpiochip_remove()

On Mon, Mar 02, 2020 at 09:24:48AM +0100, Geert Uytterhoeven wrote:
> The optimization to check for requested lines actually optimized for the
> uncomon error case, where one of the GPIO lines is still in use.
> Hence the error message must be printed when the loop is terminated
> early, not when it went through all available GPIO lines.
> 
> Fixes: 869233f81337bfb3 ("gpiolib: Optimize gpiochip_remove() when check for requested line")
> Signed-off-by: Geert Uytterhoeven <geert+renesas@...der.be>
> ---
> Noticed by review, tested by creating and destroying an otherwise unused
> GPIO aggregator, which triggers:
> 
>     gpio gpiochip8: REMOVING GPIOCHIP WITH GPIOS STILL REQUESTED

Thank you!

Acked-by: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>

Linus, see below.

> ---
>  drivers/gpio/gpiolib.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
> index 4e78bdc2739693c3..6180cf84fab7ce5e 100644
> --- a/drivers/gpio/gpiolib.c
> +++ b/drivers/gpio/gpiolib.c
> @@ -1823,7 +1823,7 @@ void gpiochip_remove(struct gpio_chip *chip)
>  	}
>  	spin_unlock_irqrestore(&gpio_lock, flags);
>  
> -	if (i == gdev->ngpio)
> +	if (i != gdev->ngpio)

I prefer more explicit <.

I had sent a patch (before I noticed this), so it's up to Linus which one to choose.

>  		dev_crit(&gdev->dev,
>  			 "REMOVING GPIOCHIP WITH GPIOS STILL REQUESTED\n");
>  
> -- 
> 2.17.1
> 

-- 
With Best Regards,
Andy Shevchenko