Re: [PATCH 2/2 v2] gpio: sim: simplify code with cleanup helpers

From: Bartosz Golaszewski
Date: Fri Aug 11 2023 - 10:28:53 EST


On Fri, Aug 11, 2023 at 4:24 PM Andy Shevchenko
<andriy.shevchenko@xxxxxxxxxxxxxxx> wrote:
>
> On Fri, Aug 11, 2023 at 03:14:27PM +0200, Bartosz Golaszewski wrote:
> > From: Bartosz Golaszewski <bartosz.golaszewski@xxxxxxxxxx>
> >
> > Use macros defined in linux/cleanup.h to automate resource lifetime
> > control in gpio-sim.
>
> ...
>
> > struct gpio_sim_chip *chip = gpiochip_get_data(gc);
> > int ret;
> >
> > - mutex_lock(&chip->lock);
> > - ret = !!test_bit(offset, chip->value_map);
> > - mutex_unlock(&chip->lock);
> > + scoped_guard(mutex, &chip->lock)
> > + ret = !!test_bit(offset, chip->value_map);
> >
> > return ret;
>
> Isn't the same approach applicable here?
>
> ...
>
> > {
> > struct gpio_sim_chip *chip = gpiochip_get_data(gc);
>
> With
>
> unsigned long *map = ...->value_map;
>
> > - 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);
>
> ...you can satisfy me as well :-)
>

You are a tough negotiator...

> bitmap_replace(map, map, bits, mask, gc->ngpio);
>
> > }
>
> ...
>
> > {
> > 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 (I checked the line size).
>
> > }
>
> ...
>
> > struct gpio_sim_device *dev = gpio_sim_bank_get_device(bank);
> > struct gpio_sim_chip_name_ctx ctx = { bank->swnode, page };
> > - int ret;
> >
> > - mutex_lock(&dev->lock);
> > + guard(mutex)(&dev->lock);
> > +
> > if (gpio_sim_device_is_live_unlocked(dev))
> > - ret = device_for_each_child(&dev->pdev->dev, &ctx,
> > - gpio_sim_emit_chip_name);
> > - else
> > - ret = sprintf(page, "none\n");
> > - mutex_unlock(&dev->lock);
> > + return device_for_each_child(&dev->pdev->dev, &ctx,
> > + gpio_sim_emit_chip_name);
> >
> > - return ret;
> > + return sprintf(page, "none\n");
>
> I looked at the original and at the change and maybe it could be done as
>

What's the difference?!

> struct device *parent = &dev->pdev->dev; // Naming?
> bool live;
>
> live = gpio_sim_device_is_live_unlocked(dev);
> if (!live)
> return sprintf(page, "none\n");
>
> return device_for_each_child(parent, &ctx, gpio_sim_emit_chip_name);
>
> ...
>
> > int ret;
> >
> > - mutex_lock(&dev->lock);
> > - ret = sprintf(page, "%s\n", hog->name ?: "");
> > - mutex_unlock(&dev->lock);
> > + scoped_guard(mutex, &dev->lock)
> > + ret = sprintf(page, "%s\n", hog->name ?: "");
> >
> > return ret;
>
> guard() ?
>
> --
> With Best Regards,
> Andy Shevchenko
>
>

Bart