linux-kernel - Re: [PATCH v3] gpio: sim: simplify code with cleanup helpers

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Message-ID: <ZNtT37d3eR6FcQyR@smile.fi.intel.com>
Date:   Tue, 15 Aug 2023 13:30:55 +0300
From:   Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
To:     Bartosz Golaszewski <brgl@...ev.pl>
Cc:     Linus Walleij <linus.walleij@...aro.org>,
        Kent Gibson <warthog618@...il.com>, linux-gpio@...r.kernel.org,
        linux-kernel@...r.kernel.org,
        Bartosz Golaszewski <bartosz.golaszewski@...aro.org>
Subject: Re: [PATCH v3] gpio: sim: simplify code with cleanup helpers

On Sat, Aug 12, 2023 at 08:36:35PM +0200, Bartosz Golaszewski wrote:
> From: Bartosz Golaszewski <bartosz.golaszewski@...aro.org>
> 
> Use macros defined in linux/cleanup.h to automate resource lifetime
> control in gpio-sim.

...

>  static void gpio_sim_set(struct gpio_chip *gc, unsigned int offset, int value)
>  {
>  	struct gpio_sim_chip *chip = gpiochip_get_data(gc);
>  
> -	mutex_lock(&chip->lock);
> -	__assign_bit(offset, chip->value_map, value);
> -	mutex_unlock(&chip->lock);
> +	scoped_guard(mutex, &chip->lock)
> +		__assign_bit(offset, chip->value_map, value);

But this can also be guarded.

	guard(mutex)(&chip->lock);

	__assign_bit(offset, chip->value_map, value);

>  }

...

>  {
>  	struct gpio_sim_chip *chip = gpiochip_get_data(gc);
>  
> -	mutex_lock(&chip->lock);
> -	bitmap_replace(chip->value_map, chip->value_map, bits, mask, gc->ngpio);
> -	mutex_unlock(&chip->lock);
> +	scoped_guard(mutex, &chip->lock)
> +		bitmap_replace(chip->value_map, chip->value_map, bits, mask,
> +			       gc->ngpio);

Ditto.

	guard(mutex)(&chip->lock);

	bitmap_replace(chip->value_map, chip->value_map, bits, mask, gc->ngpio);

(exactly 80 for the sectants of 80 characters :).

>  }

...

>  {
>  	struct gpio_sim_chip *chip = gpiochip_get_data(gc);
>  
> -	mutex_lock(&chip->lock);
> -	__assign_bit(offset, chip->value_map, !!test_bit(offset, chip->pull_map));
> -	mutex_unlock(&chip->lock);
> +	scoped_guard(mutex, &chip->lock)
> +		__assign_bit(offset, chip->value_map,
> +			     !!test_bit(offset, chip->pull_map));

Ditto.

	guard(mutex)(&chip->lock);

	__assign_bit(offset, chip->value_map, test_bit(offset, chip->pull_map));

(in this form fanatics of 80 can sleep well :-)

Note that !! is redundant as test_bit() family of functions were fixed to
return boolean.

>  }

-- 
With Best Regards,
Andy Shevchenko