Re: [RFC PATCH v4 2/2] clk: Use devm_add in managed functions

From: Geert Uytterhoeven <geert@linux-m68k.org>
To: Marc Gonzalez <marc.w.gonzalez@free.fr>
Cc: Stephen Boyd <sboyd@kernel.org>,
	Michael Turquette <mturquette@baylibre.com>,
	Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>,
	Russell King <linux@armlinux.org.uk>,
	Sudip Mukherjee <sudipm.mukherjee@gmail.com>,
	Dmitry Torokhov <dmitry.torokhov@gmail.com>,
	Guenter Roeck <linux@roeck-us.net>,
	Bjorn Andersson <bjorn.andersson@linaro.org>,
	Robin Murphy <robin.murphy@arm.com>,
	Arnd Bergmann <arnd@arndb.de>,
	Ard Biesheuvel <ard.biesheuvel@linaro.org>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Rafael Wysocki <rjw@rjwysocki.net>,
	Suzuki Poulose <suzuki.poulose@arm.com>,
	Mark Rutland <mark.rutland@arm.com>,
	linux-clk <linux-clk@vger.kernel.org>,
	Linux ARM <linux-arm-kernel@lists.infradead.org>,
	LKML <linux-kernel@vger.kernel.org>
Subject: Re: [RFC PATCH v4 2/2] clk: Use devm_add in managed functions
Date: Mon, 2 Mar 2020 11:14:21 +0100	[thread overview]
Message-ID: <CAMuHMdVYghD_xLeXVFD+PGBKECSkQ+_KxPBwFmUDDO3W5skscQ@mail.gmail.com> (raw)
In-Reply-To: <7622db71-b1f4-62b4-86ee-78e00d5bd52c@free.fr>

Hi Marc,

On Mon, Mar 2, 2020 at 11:01 AM Marc Gonzalez <marc.w.gonzalez@free.fr> wrote:
> On 27/02/2020 14:36, Geert Uytterhoeven wrote:
> > On Wed, Feb 26, 2020 at 4:55 PM Marc Gonzalez <marc.w.gonzalez@free.fr> wrote:
> >> Using the helper produces simpler code, and smaller object size.

> >> --- a/drivers/clk/clk-devres.c
> >> +++ b/drivers/clk/clk-devres.c

> >> @@ -128,30 +109,22 @@ static int devm_clk_match(struct device *dev, void *res, void *data)
> >>
> >>  void devm_clk_put(struct device *dev, struct clk *clk)
> >>  {
> >> -       int ret;
> >> -
> >> -       ret = devres_release(dev, devm_clk_release, devm_clk_match, clk);
> >> -
> >> -       WARN_ON(ret);
> >> +       WARN_ON(devres_release(dev, my_clk_put, devm_clk_match, clk));
> >
> > Getting rid of "ret" is an unrelated change, which actually increases
> > kernel size, as the WARN_ON() parameter is stringified for the warning
> > message.
>
> Weird... Are you sure about that? I built the preprocessed file,
> and it didn't appear to be so.
>
> #ifndef WARN_ON
> #define WARN_ON(condition) ({                                           \
>         int __ret_warn_on = !!(condition);                              \
>         if (unlikely(__ret_warn_on))                                    \
>                 __WARN();                                               \
>         unlikely(__ret_warn_on);                                        \
> })
> #endif
>
> Maybe you were thinking of i915's WARN_ON?
>
> #define WARN_ON(x) WARN((x), "%s", "WARN_ON(" __stringify(x) ")")

Oops, you're right.  I got trapped again by an override of a standard macro
(IMHO this should be removed).

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds