From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id DEA85C04A68 for ; Wed, 27 Jul 2022 11:31:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230110AbiG0LbL (ORCPT ); Wed, 27 Jul 2022 07:31:11 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48996 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229719AbiG0LbK (ORCPT ); Wed, 27 Jul 2022 07:31:10 -0400 Received: from metis.ext.pengutronix.de (metis.ext.pengutronix.de [IPv6:2001:67c:670:201:290:27ff:fe1d:cc33]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BE82413CDE for ; Wed, 27 Jul 2022 04:31:09 -0700 (PDT) Received: from gallifrey.ext.pengutronix.de ([2001:67c:670:201:5054:ff:fe8d:eefb] helo=bjornoya.blackshift.org) by metis.ext.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1oGfFk-0003VQ-Px; Wed, 27 Jul 2022 13:31:00 +0200 Received: from pengutronix.de (unknown [IPv6:2a01:4f8:1c1c:29e9:22:41ff:fe00:1400]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-256) server-signature RSA-PSS (4096 bits) server-digest SHA256) (Client did not present a certificate) (Authenticated sender: mkl-all@blackshift.org) by smtp.blackshift.org (Postfix) with ESMTPSA id ACA2ABC135; Wed, 27 Jul 2022 11:30:57 +0000 (UTC) Date: Wed, 27 Jul 2022 13:30:54 +0200 From: Marc Kleine-Budde To: Dario Binacchi Cc: linux-kernel@vger.kernel.org, linux-can@vger.kernel.org, Oliver Hartkopp , michael@amarulasolutions.com, Amarula patchwork , Jeroen Hofstee , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Wolfgang Grandegger , netdev@vger.kernel.org Subject: Re: [RFC PATCH v3 8/9] can: slcan: add support to set bit time register (btr) Message-ID: <20220727113054.ffcckzlcipcxer2c@pengutronix.de> References: <20220726210217.3368497-1-dario.binacchi@amarulasolutions.com> <20220726210217.3368497-9-dario.binacchi@amarulasolutions.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="wo6f23lv67r22v2k" Content-Disposition: inline In-Reply-To: <20220726210217.3368497-9-dario.binacchi@amarulasolutions.com> X-SA-Exim-Connect-IP: 2001:67c:670:201:5054:ff:fe8d:eefb X-SA-Exim-Mail-From: mkl@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-can@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-can@vger.kernel.org --wo6f23lv67r22v2k Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On 26.07.2022 23:02:16, Dario Binacchi wrote: > It allows to set the bit time register with tunable values. > The setting can only be changed if the interface is down: >=20 > ip link set dev can0 down > ethtool --set-tunable can0 can-btr 0x31c > ip link set dev can0 up As far as I understand, setting the btr is an alternative way to set the bitrate, right? I don't like the idea of poking arbitrary values into a hardware from user space. Do you have a use case for this? Marc --=20 Pengutronix e.K. | Marc Kleine-Budde | Embedded Linux | https://www.pengutronix.de | Vertretung West/Dortmund | Phone: +49-231-2826-924 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | --wo6f23lv67r22v2k Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAABCgAdFiEEBsvAIBsPu6mG7thcrX5LkNig010FAmLhIesACgkQrX5LkNig 013QcAgAki/APZw2NZdx7MYizFEMgcZs7wph/ASDUdNrNRR41Q+qDqxCS3MMn+Sx mbORSwe2pNt1z1CrjnOMqHLNWCZ86ejIHa52iGlWOGhc88oC9U5wKk2kTP97C8tf Pd+vsu1J/cA53Z2dmDfIrl58+xRJOdqfRzvh4J/nL0AfXfTjvXCVFGIBN/Dv8JXp 6caqLbi3HRCp0gJ87lWk8TnLvJ2rlLXHVYHxwe6+tZ3CJn7/HaB69mBVDPEGE1sg 6laYbxsGKk9qiD+Is8lvHzWUT3Bq8Gniu+vpp8GV6cnxeBSCLDUIChPK+kLhbYkz bpo+kfyfBJgF2W6pVbapeLD4BiFhVA== =bFCW -----END PGP SIGNATURE----- --wo6f23lv67r22v2k--