linux-kernel - RE: [PATCH] MIPS: ralink: Use min() to fix Coccinelle warning

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Message-ID: <e6ff2dbaf23d4d66bd8ea1bf1b87a26c@AcuMS.aculab.com>
Date: Mon, 15 Apr 2024 08:42:13 +0000
From: David Laight <David.Laight@...LAB.COM>
To: 'Sergio Paracuellos' <sergio.paracuellos@...il.com>, Thorsten Blum
	<thorsten.blum@...lux.com>
CC: John Crispin <john@...ozen.org>, Thomas Bogendoerfer
	<tsbogend@...ha.franken.de>, "linux-mips@...r.kernel.org"
	<linux-mips@...r.kernel.org>, "linux-kernel@...r.kernel.org"
	<linux-kernel@...r.kernel.org>
Subject: RE: [PATCH] MIPS: ralink: Use min() to fix Coccinelle warning

From: Sergio Paracuellos
> Sent: 10 April 2024 11:44
> On Tue, Apr 9, 2024 at 5:36 PM Thorsten Blum <thorsten.blum@...lux.com> wrote:
> >
> > Fixes the following Coccinelle/coccicheck warning reported by
> > minmax.cocci:
> >
> >         WARNING opportunity for min()
> >
> > Signed-off-by: Thorsten Blum <thorsten.blum@...lux.com>
> > ---
> >  arch/mips/ralink/timer.c | 6 +-----
> >  1 file changed, 1 insertion(+), 5 deletions(-)
> >
> > diff --git a/arch/mips/ralink/timer.c b/arch/mips/ralink/timer.c
> > index 54094f6e033e..d271ac98312a 100644
> > --- a/arch/mips/ralink/timer.c
> > +++ b/arch/mips/ralink/timer.c
> > @@ -75,11 +75,7 @@ static int rt_timer_request(struct rt_timer *rt)
> >
> >  static int rt_timer_config(struct rt_timer *rt, unsigned long divisor)

I doubt 'unsigned long' is the best type there.
It should probably be u32 - so still 32bit on 64bit systems.

> >  {
> > -       if (rt->timer_freq < divisor)
> > -               rt->timer_div = rt->timer_freq;
> > -       else
> > -               rt->timer_div = divisor;
> > -
> > +       rt->timer_div = min(rt->timer_freq, divisor);
> 
> I do find the original code more readable.

Probably because it isn't really a 'min()' but avoiding a division
generating a quotient of zero.
It might be better to explicitly avoid the x/x below.

	David
> 
> Best regards,
>     Sergio Paracuellos
> 
> >         rt_timer_w32(rt, TIMER_REG_TMR0LOAD, rt->timer_freq / rt->timer_div);
> >
> >         return 0;
> > --
> > 2.44.0
> >

-
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