Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Date:   Wed, 15 Sep 2021 13:51:41 +0100
From:   Mark Brown <broonie@kernel.org>
To:     Lucas Tanure <tanureal@opensource.cirrus.com>
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        "Rafael J . Wysocki" <rafael@kernel.org>,
        linux-kernel@vger.kernel.org, patches@opensource.cirrus.com
Subject: Re: [PATCH v3 2/2] regmap: spi: Check raw_[read|write] against max
 message size
Message-ID: <20210915125140.GE5389@sirena.org.uk>
References: <20210915120951.29907-1-tanureal@opensource.cirrus.com>
 <20210915120951.29907-2-tanureal@opensource.cirrus.com>
MIME-Version: 1.0
Content-Type: multipart/signed; micalg=pgp-sha512;
        protocol="application/pgp-signature"; boundary="Oiv9uiLrevHtW1RS"
Content-Disposition: inline
In-Reply-To: <20210915120951.29907-2-tanureal@opensource.cirrus.com>
User-Agent: Mutt/1.10.1 (2018-07-13)
Precedence: bulk


--Oiv9uiLrevHtW1RS
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
Content-Transfer-Encoding: quoted-printable

On Wed, Sep 15, 2021 at 01:09:51PM +0100, Lucas Tanure wrote:
> regmap-spi will split data and address between two transfers
> in the same message, so max_[read|write] must include space
> for the address and padding
>=20
> Signed-off-by: Lucas Tanure <tanureal@opensource.cirrus.com>
> ---
>=20
> Changes v3:
> New series

The changelog in patch 1 claimed that v2 was the first version of a new
series.  Which is it?  If you're going to include an inter-version
changelog it should be meaningful, just writing something for the sake
of providing a changelog tends to only cause confusion.

> +		if (spi_max_message_size(spi) !=3D SIZE_MAX)
> +			bus->max_combined_rw =3D spi_max_message_size(spi);
> +

Why is this conditional?  The whole point in returning SIZE_MAX is that
users don't need to care if there's a limit or not, any client logic
checking sizes will always work.

> +			if (map->max_raw_read  < map->format.buf_size ||
> +			    map->max_raw_write < map->format.buf_size) {
> +				ret =3D -EINVAL;
> +				goto err_hwlock;
> +			}
> +		}

This is at best an assert that the logic in _init() is self-consistent
so just silently returning an error doesn't seem like the right thing to
do, it's going to be super obscure for users.

--Oiv9uiLrevHtW1RS
Content-Type: application/pgp-signature; name="signature.asc"

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

iQEzBAABCgAdFiEEreZoqmdXGLWf4p/qJNaLcl1Uh9AFAmFB7FwACgkQJNaLcl1U
h9Dt7gf/XlEhf5FUSoGuccLAcieIplRgz2zkt4w3YWo8myCkOrEq/BoSfXmqOmXN
40BQwG95M8RXz/AUg9kA5iM2y3kaIn1iNrOjzWUCofJOfP8LJMcIc7q8Xr3Oygv/
Aeb955CnlbWC51cN5/XvCzK5WpSRkuUHtEN8Nl/G/gFWehU/V2ZfsmyBwkgkDuvJ
3YOhXwq9d3Dq+7NlMw/Ej7NBZXE4V9SDn8fWVL9IyDBQCw7ao0R9ClKPK16UdGWe
MADbdjQFFUshlbGdCovokcwFlWEYA7s+RR/2uCr8TBBa1uUQbvMV+ShlXMasaqsK
Vj1dxZhJpwYGYs7dOo/S6XMsxE43ww==
=Yo+T
-----END PGP SIGNATURE-----

--Oiv9uiLrevHtW1RS--