Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
From:   Luca Weiss <luca@z3ntu.xyz>
To:     Sakari Ailus <sakari.ailus@iki.fi>, Pavel Machek <pavel@ucw.cz>
Cc:     linux-leds@vger.kernel.org, Dan Murphy <dmurphy@ti.com>,
        Heiko Stuebner <heiko@sntech.de>,
        Icenowy Zheng <icenowy@aosc.io>,
        Jacek Anaszewski <jacek.anaszewski@gmail.com>,
        Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
        Mark Rutland <mark.rutland@arm.com>,
        Maxime Ripard <mripard@kernel.org>,
        Rob Herring <robh+dt@kernel.org>,
        Shawn Guo <shawnguo@kernel.org>, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org, ~postmarketos/upstreaming@lists.sr.ht
Subject: Re: [PATCH 3/3] leds: add sgm3140 driver
Date:   Mon, 09 Mar 2020 23:52:06 +0100
Message-ID: <2804366.mvXUDI8C0e@g550jk>
In-Reply-To: <20200309224926.GA2917@duo.ucw.cz>
References: <20200309203558.305725-1-luca@z3ntu.xyz> <20200309221805.GD2619@valkosipuli.retiisi.org.uk> <20200309224926.GA2917@duo.ucw.cz>
MIME-Version: 1.0
Content-Transfer-Encoding: quoted-printable
Content-Type: text/plain; charset="iso-8859-1"
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

Hi Pavel

On Montag, 9. M=E4rz 2020 23:49:27 CET Pavel Machek wrote:
> Hi!
>=20
> > > +#define FLASH_TIMEOUT_DEFAULT		250000 /* 250ms */
> > > +#define FLASH_MAX_TIMEOUT_DEFAULT	300000 /* 300ms */
> >=20
> > Add U, and you can remove the cast elsewhere.
>=20
> I'll disagree here. Avoid U, avoid cast. Neither is needed.

If neither cast to u32 nor the U suffix is used, then this warning will be=
=20
printed:

In file included from ./include/asm-generic/bug.h:19,
                 from ./arch/arm64/include/asm/bug.h:26,
                 from ./include/linux/bug.h:5,
                 from ./include/linux/gpio/consumer.h:5,
                 from drivers/leds/leds-sgm3140.c:4:
drivers/leds/leds-sgm3140.c: In function 'sgm3140_probe':
=2E/include/linux/kernel.h:835:29: warning: comparison of distinct pointer =
types=20
lacks a cast
  835 |   (!!(sizeof((typeof(x) *)1 =3D=3D (typeof(y) *)1)))
      |                             ^~
=2E/include/linux/kernel.h:849:4: note: in expansion of macro '__typecheck'
  849 |   (__typecheck(x, y) && __no_side_effects(x, y))
      |    ^~~~~~~~~~~
=2E/include/linux/kernel.h:859:24: note: in expansion of macro '__safe_cmp'
  859 |  __builtin_choose_expr(__safe_cmp(x, y), \
      |                        ^~~~~~~~~~
=2E/include/linux/kernel.h:868:19: note: in expansion of macro '__careful_c=
mp'
  868 | #define min(x, y) __careful_cmp(x, y, <)
      |                   ^~~~~~~~~~~~~
drivers/leds/leds-sgm3140.c:187:18: note: in expansion of macro 'min'
  187 |  priv->timeout =3D min(priv->max_timeout, FLASH_TIMEOUT_DEFAULT);
      |                  ^~~

So one of both is needed.

>=20
> Best regards,
> 							=09
	Pavel

Regards
Luca