From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wolfgang Grandegger Subject: Re: [RFC] can: Introducing CANFD for af_can & can-raw Date: Thu, 22 Mar 2012 11:06:44 +0100 Message-ID: <4F6AF9B4.2020002@grandegger.com> References: <20120321091055.GA433@vandijck-laurijssen.be> <20120321110502.GA3372@vandijck-laurijssen.be> <4F69BEE3.2040705@pengutronix.de> <20120321120846.GB3372@vandijck-laurijssen.be> <4F69CA74.3020607@pengutronix.de> <4F69D5D2.5080003@hartkopp.net> <20120321135339.GB6428@vandijck-laurijssen.be> <4F69EC19.7090205@grandegger.com> <4F69EE38.9000904@hartkopp.net> <20120322095730.GC426@vandijck-laurijssen.be> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Received: from ngcobalt02.manitu.net ([217.11.48.102]:38741 "EHLO ngcobalt02.manitu.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932251Ab2CVKGy (ORCPT ); Thu, 22 Mar 2012 06:06:54 -0400 In-Reply-To: <20120322095730.GC426@vandijck-laurijssen.be> Sender: linux-can-owner@vger.kernel.org List-ID: To: Oliver Hartkopp , Marc Kleine-Budde , dev@sebastianhaas.info, linux-can@vger.kernel.org Hi Kurt, On 03/22/2012 10:57 AM, Kurt Van Dijck wrote: > On Wed, Mar 21, 2012 at 04:05:28PM +0100, Oliver Hartkopp wrote: >> On 21.03.2012 15:56, Wolfgang Grandegger wrote: >> >>>>> >>>>> I think it's much more tricky to find a proper solution here. >>>> As I mentioned before, I just use CAN_RAW with this. Actually, I just >>>> ran a real CAN program that I wrote years ago. It still operates! >>> >>> Would you program still run if the payload is bigger than 8 bytes? >>> I agree with Oliver. >> > The other side would have noticed at design time that it cannot > send >8 bytes :-) > > Did I miss something here? Is there a reason why existing programs > may or should not work on a CANFD bus? I wanted to incorporate > CANFD functionality _without_ putting an alternative API next to the > current one, so to be able to use existing binaries on a future > CANFD bus _without_ recompile (and thus not using the extras > possibilities for that program). I believe that 99% of the existing apps, including candump, do work with a (hard-coded) maximum length of 8 bytes instead of a variable length. Wolfgang.