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 X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 797ACC4338F for ; Tue, 17 Aug 2021 20:01:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 51C3C60F39 for ; Tue, 17 Aug 2021 20:01:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232862AbhHQUCB (ORCPT ); Tue, 17 Aug 2021 16:02:01 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48438 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229466AbhHQUCB (ORCPT ); Tue, 17 Aug 2021 16:02:01 -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 053A8C061764 for ; Tue, 17 Aug 2021 13:01:28 -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 1mG5H4-0008Vq-GQ; Tue, 17 Aug 2021 22:01:26 +0200 Received: from pengutronix.de (unknown [IPv6:2a02:810a:8940:aa0:4c82:b09e:fec8:3248]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-384) 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 E577966923E; Tue, 17 Aug 2021 20:01:24 +0000 (UTC) Date: Tue, 17 Aug 2021 22:01:23 +0200 From: Marc Kleine-Budde To: Vincent MAILHOL Cc: linux-can , Stefan =?utf-8?B?TcOkdGpl?= , netdev , open list Subject: Re: [PATCH v5 2/7] can: bittiming: allow TDC{V,O} to be zero and add can_tdc_const::tdc{v,o,f}_min Message-ID: <20210817200123.4wcdwsdfsdjr3ovk@pengutronix.de> References: <20210815033248.98111-1-mailhol.vincent@wanadoo.fr> <20210815033248.98111-3-mailhol.vincent@wanadoo.fr> <20210816084235.fr7fzau2ce7zl4d4@pengutronix.de> <20210816122519.mme272z6tqrkyc6x@pengutronix.de> <20210816123309.pfa57tke5hrycqae@pengutronix.de> <20210816134342.w3bc5zjczwowcjr4@pengutronix.de> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="fgszt33qh4cysmqa" Content-Disposition: inline In-Reply-To: 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 --fgszt33qh4cysmqa Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On 17.08.2021 00:49:35, Vincent MAILHOL wrote: > > We have 4 operations: > > - tdc-mode off switch off tdc altogether > > - tdc-mode manual tdco X tdcv Y configure X and Y for tdco and tdcv > > - tdc-mode auto tdco X configure X tdco and > > controller measures tdcv automatically > > - /* nothing */ configure default value for tdco > > controller measures tdcv automatically >=20 > The "nothing" does one more thing: it decides whether TDC should > be activated or not. >=20 > > The /* nothing */ operation is what the old "ip" tool does, so we're > > backwards compatible here (using the old "ip" tool on an updated > > kernel/driver). >=20 > That's true but this isn't the real intent. By doing this design, > I wanted the user to be able to transparently use TDC while > continuing to use the exact same ip commands she or he is used > to using. Backwards compatibility using an old ip tool on a new kernel/driver must work. In case of the mcp251xfd the tdc mode must be activated and tdcv set to the automatic calculated value and tdco automatically measured. 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 | --fgszt33qh4cysmqa Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAABCgAdFiEEK3kIWJt9yTYMP3ehqclaivrt76kFAmEcFZAACgkQqclaivrt 76kISAgArgGcU281RHaeyZUy9SjeALqqLzwDzBizUD8/TDKXcOCcPAALwCUcvm9x bl9gCKZ1o74Fpgy5zWW7j5i45oMSqjZjsc28uCm6jilOufzgFlYF1BZRCBe3RU4h kXfhw2QOVFbC4Oj8ms6Ef9rhBy4yZWG6yHXP+kha/DtK2aQYRHJaAUcaZsO0svBI 24ZUrdpfE/JVzKYSEeyJ+kqPQ1dasfA8YTS+3fUAnrGCNqRSwy+l5airszziNzqn IPBK5faP6XsyeHlVDXSGImq51A75TCpYweaNJwuiJTJg9AByOed2G/v2XVOju0UO 0tedqIa4SpxwS0LtH3xsJmKV6O0l5A== =cADg -----END PGP SIGNATURE----- --fgszt33qh4cysmqa--