[PATCH] gpiolib: Fix inverted check in gpiochip_remove()

[PATCH] gpiolib: Fix inverted check in gpiochip_remove()

[Geert Uytterhoeven]

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@glider.be>
---
Noticed by review, tested by creating and destroying an otherwise unused
GPIO aggregator, which triggers:

    gpio gpiochip8: REMOVING GPIOCHIP WITH GPIOS STILL REQUESTED
---
 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)
 		dev_crit(&gdev->dev,
 			 "REMOVING GPIOCHIP WITH GPIOS STILL REQUESTED\n");
 
-- 
2.17.1

Re: [PATCH] gpiolib: Fix inverted check in gpiochip_remove()

[Andy Shevchenko]

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@glider.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@linux.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

Re: [PATCH] gpiolib: Fix inverted check in gpiochip_remove()

[Linus Walleij]

On Mon, Mar 2, 2020 at 9:24 AM Geert Uytterhoeven
<geert+renesas@glider.be> 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@glider.be>

Patch applied with Andy's ACK.

Yours,
Linus Walleij