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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by aws-us-west-2-korg-lkml-1.web.codeaurora.org (Postfix) with ESMTP id D4120C433EF for ; Thu, 14 Jun 2018 08:15:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 94B02208CB for ; Thu, 14 Jun 2018 08:15:58 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 94B02208CB Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=the-dreams.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754829AbeFNIP4 (ORCPT ); Thu, 14 Jun 2018 04:15:56 -0400 Received: from sauhun.de ([88.99.104.3]:50022 "EHLO pokefinder.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752837AbeFNIPw (ORCPT ); Thu, 14 Jun 2018 04:15:52 -0400 Received: from localhost (softbank126012118084.bbtec.net [126.12.118.84]) by pokefinder.org (Postfix) with ESMTPSA id F056A54006A; Thu, 14 Jun 2018 10:15:49 +0200 (CEST) Date: Thu, 14 Jun 2018 17:15:42 +0900 From: Wolfram Sang To: Boris Brezillon Cc: linux-i2c@vger.kernel.org, Jonathan Corbet , linux-doc@vger.kernel.org, Greg Kroah-Hartman , Arnd Bergmann , Przemyslaw Sroka , Arkadiusz Golec , Alan Douglas , Bartosz Folta , Damian Kos , Alicja Jurasik-Urbaniak , Cyprian Wronka , Suresh Punnoose , Rafal Ciepiela , Thomas Petazzoni , Nishanth Menon , Rob Herring , Pawel Moll , Mark Rutland , Ian Campbell , Kumar Gala , devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, Vitor Soares , Geert Uytterhoeven , Linus Walleij , Xiang Lin , linux-gpio@vger.kernel.org Subject: Re: [PATCH v4 01/10] i3c: Add core I3C infrastructure Message-ID: <20180614081541.zlxu6ga47gdg42un@ninjato> References: <20180330074751.25987-1-boris.brezillon@bootlin.com> <20180330074751.25987-2-boris.brezillon@bootlin.com> <20180614041941.4i2cadzoevujmzha@ninjato> <20180614090758.17180594@bbrezillon> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="7unw2cj2dmujiusg" Content-Disposition: inline In-Reply-To: <20180614090758.17180594@bbrezillon> User-Agent: NeoMutt/20170113 (1.7.2) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --7unw2cj2dmujiusg Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable > > I don't know if typical I3C transfers will be similar to I2C with > > usually small payloads where DMA usually makes not much sense. Yet, I > > think, that it might be a good idea to think about how this shall be > > handled with I3C right away. Maybe simply enforcing buffers to be > > DMA-safe. Or whatever. > >=20 > > A clear rule on that might save you hazzle later. >=20 > I completely agree. I'll clarify that and for people to pass DMA-able > buffers to this struct (just as the SPI framework does). Note that we Ok, cool! > don't really have a way to ensure that the buffer is actually > DMA-safe from the core, because this notion is architecture/SoC > dependent. True, we can't ensure it at the core. Still, a documented rule will make it clear that everything else is considered a bug. Much better than a gray area you have to deal with later. Kind regards, Wolfram --7unw2cj2dmujiusg Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAABCAAdFiEEOZGx6rniZ1Gk92RdFA3kzBSgKbYFAlsiJC0ACgkQFA3kzBSg KbZEnQ//dFjlQ2ROtEDcAOlzSfstcuOOulEjtSAycl1EYPFpn+G0xs/n3rHqiZmP wmjHmKAmqNHSAmyUSjlqCmXirzruB8Rln7eCb1OUFZSEyp2hDh3VA73xJaEdFOFF EgyoyN1SchNgUxeEj08r3zBDv5KFPh6dCEgIQOwFRB299v4BD6xS+O2gvzgveWGW oUXd8l1qeVBC25/DbnlxT0iqC/1q0U+usrR/Eu2KInztK5ug9vQ43hTkJaZ+SbiI cmKv0AOWAhd3wAtg5oCmFuC8tzIW07uq+RsDiRpsc6BFwKtNCAbhI3cUAy3CCI17 5iCIqlCremt3nYLPERYwhVT10pM7j75mYqOsO7VQDsomFEyMWKxTp6DyqgIgRBJO EG4+9/rmHKPdbSSiWZ3GpVf/MFcdNlzRkN0+lzml5juz/SLaeyBr6Jxh5VxCzRLI yOnXfvPMEGFEr8E45vaoeOqpgm3cb0ivC4pgJ/buPDHiVetGAWHzF96sT3xSXYv5 8PlJDovgHEPwuXPXvtPlpkBndzls7dKvW+Gmyz2czQphwHo+C9ww/PhpY16zSZRk dZbZU4V7OFmjO9bWPj1jWpLEnoYlrGMziOuX43CsCNOjSQe6oMEdXFZw5QjB2SQ1 eSn45yFoypMWEvTZtZyP+wvHKcnYm7VxEYQWy9QAtaWzkEe1fWk= =x3M4 -----END PGP SIGNATURE----- --7unw2cj2dmujiusg--