linux-kernel - Re: [PATCH v3 3/3] gpio: xilinx: Utilize generic bitmap_get_value and _set

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Date:   Mon, 29 Mar 2021 18:24:36 +0300
From:   Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
To:     Syed Nayyar Waris <syednwaris@...il.com>
Cc:     bgolaszewski@...libre.com, vilhelm.gray@...il.com,
        michal.simek@...inx.com, arnd@...db.de, rrichter@...vell.com,
        linus.walleij@...aro.org, yamada.masahiro@...ionext.com,
        akpm@...ux-foundation.org, rui.zhang@...el.com,
        daniel.lezcano@...aro.org, amit.kucheria@...durent.com,
        linux-arch@...r.kernel.org, linux-gpio@...r.kernel.org,
        linux-kernel@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
        linux-pm@...r.kernel.org
Subject: Re: [PATCH v3 3/3] gpio: xilinx: Utilize generic bitmap_get_value
 and _set_value

On Sat, Mar 06, 2021 at 07:36:30PM +0530, Syed Nayyar Waris wrote:
> This patch reimplements the xgpio_set_multiple() function in
> drivers/gpio/gpio-xilinx.c to use the new generic functions:
> bitmap_get_value() and bitmap_set_value(). The code is now simpler
> to read and understand. Moreover, instead of looping for each bit
> in xgpio_set_multiple() function, now we can check each channel at
> a time and save cycles.

...

> +	u32 *const state = chip->gpio_state;

Looking at this... What's the point of the const here?

Am I right that this tells: pointer is a const, while the data underneath
can be modified?

> +	unsigned int *const width = chip->gpio_width;

Ditto.

Putting const:s here and there for sake of the const is not good practice.
It makes code harder to read.

-- 
With Best Regards,
Andy Shevchenko