linux-kernel - Re: [PATCH v3 4/4] gpio: xilinx: Utilize for_each_set

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Message-ID: <20200430161514.GA7107@syed>
Date:   Thu, 30 Apr 2020 21:45:14 +0530
From:   Syed Nayyar Waris <syednwaris@...il.com>
To:     Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
Cc:     akpm@...ux-foundation.org, vilhelm.gray@...il.com,
        linus.walleij@...aro.org, bgolaszewski@...libre.com,
        michal.simek@...inx.com, linux-gpio@...r.kernel.org,
        linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v3 4/4] gpio: xilinx: Utilize for_each_set_clump macro

On Wed, Apr 29, 2020 at 01:21:14PM +0300, Andy Shevchenko wrote:
> On Wed, Apr 29, 2020 at 04:39:47AM +0530, Syed Nayyar Waris wrote:
> > This patch reimplements the xgpio_set_multiple function in
> > drivers/gpio/gpio-xilinx.c to use the new for_each_set_clump macro.
> > Instead of looping for each bit in xgpio_set_multiple
> > function, now we can check each channel at a time and save cycles.
> 
> > +	const unsigned long state_size = BITS_PER_TYPE(*state);
> 
> This '*state' is unneeded complication, use BITS_PER_U32.
> 
> > +#define TOTAL_BITS BITS_PER_TYPE(chip->gpio_state)
> 
> This macro makes code uglier, besides the fact of absence of #undef.
> And also see above.

Thank you for your review comments. Just want to clarify, you want
 a new macro to be created - 'BITS_PER_U32' ?  
Also, don't you think that with BITS_PER_TYPE(), in case later the type
of 'state' changes, it will be reflected in this code without any code
change?

Let me know if I have misunderstood something.

> 
> > +	DECLARE_BITMAP(old, TOTAL_BITS);
> > +	DECLARE_BITMAP(new, TOTAL_BITS);
> > +	DECLARE_BITMAP(changed, TOTAL_BITS);
> 
> -- 
> With Best Regards,
> Andy Shevchenko
> 
>