linux-kernel - Re: [PATCH] arch: arm: mach-versatile: Add missing of_node

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Message-ID: <CACRpkdaUpmhoXS-K=e85GahQBVY8aL2K+F_88hLOGUtfHa_KEA@mail.gmail.com>
Date:   Thu, 14 Sep 2023 15:57:58 +0200
From:   Linus Walleij <linus.walleij@...aro.org>
To:     Rob Herring <robh@...nel.org>
Cc:     heliang <windhl@....com>, linux@...linux.org.uk,
        linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] arch: arm: mach-versatile: Add missing of_node_put in integrator.c

On Wed, Sep 13, 2023 at 3:01 PM Rob Herring <robh@...nel.org> wrote:
> On Wed, Jun 15, 2022 at 4:06 AM heliang <windhl@....com> wrote:
> >
> > In cm_init(), of_find_matching_node() will return a node pointer with
> > refcount incremented. We should use of_node_put() when the pointer is
> > not used anymore.
> >
> > Signed-off-by: heliang <windhl@....com>
> > ---
> >  arch/arm/mach-versatile/integrator.c | 1 +
> >  1 file changed, 1 insertion(+)
> >
> > diff --git a/arch/arm/mach-versatile/integrator.c b/arch/arm/mach-versatile/integrator.c
> > index fdf9c4db08a7..fba19357171a 100644
> > --- a/arch/arm/mach-versatile/integrator.c
> > +++ b/arch/arm/mach-versatile/integrator.c
> > @@ -76,6 +76,7 @@ void cm_init(void)
> >                 return;
> >         }
> >         cm_base = of_iomap(cm, 0);
> > +       of_node_put(cm);
>
> Not really sure this is right. It is in the sense that the DT node is
> never accessed again. However, the device itself is still accessed and
> I tend to think a ref to the DT node should be held for that lifetime
> which in this case is forever. Really, none of this matters because
> nodes are never removed and these fixes are kind of pointless.

I'm just gonna scrap all these of_node_put() patches these automated
static analyzers have sent to the Versatile board and SoC code, it's
too dangerous.

> Note that cm_get() and cm_control() are never used and can be removed.
> That would be the more useful clean-up.

Yeah :/

Yours,
Linus Walleij