Re: [PATCH 3/3] Replace for_each_*_bit_from() with for_each_*_bit() where appropriate

Andy Shevchenko
2021-06-19T10:55:22Z

On Sat, Jun 19, 2021 at 01:49:58PM +0300, Andy Shevchenko wrote:
> On Fri, Jun 18, 2021 at 12:57:35PM -0700, Yury Norov wrote:
> > A couple of kernel functions call for_each_*_bit_from() with start
> > bit equal to 0. Replace them with for_each_*_bit().
> >
> > No functional changes, but might improve on readability.
>
> ...
>
> > --- a/drivers/hwmon/ltc2992.c
> > +++ b/drivers/hwmon/ltc2992.c
> > @@ -248,8 +248,7 @@ static int ltc2992_gpio_get_multiple(struct gpio_chip *chip, unsigned long *mask
> >
> > gpio_status = reg;
> >
> > - gpio_nr = 0;
> > - for_each_set_bit_from(gpio_nr, mask, LTC2992_GPIO_NR) {
> > + for_each_set_bit(gpio_nr, mask, LTC2992_GPIO_NR) {
> > if (test_bit(LTC2992_GPIO_BIT(gpio_nr), &gpio_status))
> > set_bit(gpio_nr, bits);
> > }
>
> I would replace the entire loop by bitmap_replace() call.
>
> Something like
> bitmap_replace(bits, bits, &gpio_status, mask, LTC2992_GPIO_NR);

Okay, it wouldn't work directly because it involves LTC2992_GPIO_BIT()
macro. So, it rather some kind of bitmap_remap().

--
With Best Regards,
Andy Shevchenko