From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marc Kleine-Budde Subject: Re: [PATCH] can: Unify MTU settings for CAN interfaces Date: Fri, 07 Mar 2014 12:40:35 +0100 Message-ID: <5319B033.10705@pengutronix.de> References: <5319820D.6060104@hartkopp.net> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="LRcI6gU5ne334f0w86JULCnAbWg1dF9pI" Return-path: Received: from metis.ext.pengutronix.de ([92.198.50.35]:54669 "EHLO metis.ext.pengutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751590AbaCGLkl (ORCPT ); Fri, 7 Mar 2014 06:40:41 -0500 In-Reply-To: <5319820D.6060104@hartkopp.net> Sender: linux-can-owner@vger.kernel.org List-ID: To: Oliver Hartkopp Cc: "linux-can@vger.kernel.org" This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --LRcI6gU5ne334f0w86JULCnAbWg1dF9pI Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable On 03/07/2014 09:23 AM, Oliver Hartkopp wrote: > CAN interfaces only support MTU values of 16 (CAN 2.0) and 72 (CAN FD).= > Setting the MTU to other values is pointless but it does not really hur= t. > With the introduction of the CAN FD support in drivers/net/can a new > function to switch the MTU for CAN FD has been introduced. >=20 > This patch makes use of this can_change_mtu() function to check for cor= rect > MTU settings also in legacy CAN (2.0) devices. >=20 > Signed-off-by: Oliver Hartkopp > diff --git a/drivers/net/can/slcan.c b/drivers/net/can/slcan.c > index 3fcdae2..f5b16e0 100644 > --- a/drivers/net/can/slcan.c > +++ b/drivers/net/can/slcan.c > @@ -411,10 +411,16 @@ static void slc_free_netdev(struct net_device *de= v) > slcan_devs[i] =3D NULL; > } > =20 > +static int slcan_change_mtu(struct net_device *dev, int new_mtu) > +{ > + return -EINVAL; > +} > + Why is the slcan special? > static const struct net_device_ops slc_netdev_ops =3D { > .ndo_open =3D slc_open, > .ndo_stop =3D slc_close, > .ndo_start_xmit =3D slc_xmit, > + .ndo_change_mtu =3D slcan_change_mtu, > }; > =20 > static void slc_setup(struct net_device *dev) Marc --=20 Pengutronix e.K. | Marc Kleine-Budde | Industrial Linux Solutions | Phone: +49-231-2826-924 | Vertretung West/Dortmund | Fax: +49-5121-206917-5555 | Amtsgericht Hildesheim, HRA 2686 | http://www.pengutronix.de | --LRcI6gU5ne334f0w86JULCnAbWg1dF9pI Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 Comment: Using GnuPG with Icedove - http://www.enigmail.net/ iEYEARECAAYFAlMZsDMACgkQjTAFq1RaXHOo2ACfaaxK4z/QKesbvyEyBz1VEuSB lV0Ani+9qsSzwX8Twvv2B3eQ30cuRNqB =8HhP -----END PGP SIGNATURE----- --LRcI6gU5ne334f0w86JULCnAbWg1dF9pI--