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;
Date:   Thu, 3 Jan 2019 13:10:33 +0000
From:   Mark Brown <broonie@kernel.org>
To:     Yizhuo <yzhai003@ucr.edu>
Cc:     csong@cs.ucr.edu, zhiyunq@cs.ucr.edu,
        Bard Liao <bardliao@realtek.com>,
        Oder Chiou <oder_chiou@realtek.com>,
        Liam Girdwood <lgirdwood@gmail.com>,
        Jaroslav Kysela <perex@perex.cz>,
        Takashi Iwai <tiwai@suse.com>, alsa-devel@alsa-project.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH] In function rt274_i2c_probe(), if the regmap_read fails.
 The variable "val" could leave uninitialized but used in if statement.
Message-ID: <20190103131033.GU1846@sirena.org.uk>
References: <20190103023839.15314-1-yzhai003@ucr.edu>
MIME-Version: 1.0
Content-Type: multipart/signed; micalg=pgp-sha512;
        protocol="application/pgp-signature"; boundary="1YSLKY9nNiKnepPi"
Content-Disposition: inline
In-Reply-To: <20190103023839.15314-1-yzhai003@ucr.edu>
User-Agent: Mutt/1.10.1 (2018-07-13)
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk


--1YSLKY9nNiKnepPi
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
Content-Transfer-Encoding: quoted-printable

On Wed, Jan 02, 2019 at 06:38:39PM -0800, Yizhuo wrote:

>  	int ret;
> -	unsigned int val;
> +	unsigned int val =3D ~0;
> =20

This just shuts warnings up which may mask further problem, it is better
to just leave it and fix the users.

> -	regmap_read(rt274->regmap,
> +	ret =3D regmap_read(rt274->regmap,
>  		RT274_GET_PARAM(AC_NODE_ROOT, AC_PAR_VENDOR_ID), &val);
> -	if (val !=3D RT274_VENDOR_ID) {
> +	if (ret || val !=3D RT274_VENDOR_ID) {
>  		dev_err(&i2c->dev,
>  			"Device with ID register %#x is not rt274\n", val);
>  		return -ENODEV;

If the read returned an error we should pass back the error code we got
=66rom it, not mask it with another error code.  This is especially true
here where the error message would be very misleading if there's a
problem with I/O.

--1YSLKY9nNiKnepPi
Content-Type: application/pgp-signature; name="signature.asc"

-----BEGIN PGP SIGNATURE-----

iQEzBAABCgAdFiEEreZoqmdXGLWf4p/qJNaLcl1Uh9AFAlwuCcgACgkQJNaLcl1U
h9ATcQf/eBbwaS5qgEtEK51OPB3FNB6vrxxUk5HGFZqdFxZQVgcz3XNeMEDhcccS
cKGpg1ksiEpLIog6GK6KmLkHrfiA8aWoHhkuDGxMnogfySqU9qA3V8LbQoBGAh56
x3tnhky9Iuyj+Wcj0WKw00dsBlDxrorF3z9297WkFsopR3J7Sd7OHZjQFYopthin
mhAuUkwTfP1QQDANxH3AciBZwA8CJQQ+XqB/ORavzZqWfi8znP9NnN+fdOuHzqWK
qbzU2aLsWFiGzfOxFUjyJTWSr0UlgKTE8YpORTWNsSQhYTchJLnwAqStlaFW00VA
Dczuw8DOS8aDFgHNENAmUUhiSv0KpQ==
=D6U7
-----END PGP SIGNATURE-----

--1YSLKY9nNiKnepPi--