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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 CB4FDC2D0C9 for ; Thu, 12 Dec 2019 16:33:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A335E22527 for ; Thu, 12 Dec 2019 16:33:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729857AbfLLQd1 (ORCPT ); Thu, 12 Dec 2019 11:33:27 -0500 Received: from sauhun.de ([88.99.104.3]:37048 "EHLO pokefinder.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729591AbfLLQd1 (ORCPT ); Thu, 12 Dec 2019 11:33:27 -0500 Received: from localhost (p54B331D1.dip0.t-ipconnect.de [84.179.49.209]) by pokefinder.org (Postfix) with ESMTPSA id 7C6252C04D8; Thu, 12 Dec 2019 17:33:23 +0100 (CET) Date: Thu, 12 Dec 2019 17:33:15 +0100 From: Wolfram Sang To: Luca Ceresoli Cc: Daniel Mack , linux-kernel@vger.kernel.org, linux-gpio@vger.kernel.org, linux-i2c@vger.kernel.org, alsa-devel@alsa-project.org, devicetree@vger.kernel.org, linux-clk@vger.kernel.org, mturquette@baylibre.com, sboyd@kernel.org, robh+dt@kernel.org, broonie@kernel.org, lee.jones@linaro.org, lars@metafoo.de, pascal.huerst@gmail.com Subject: Re: [PATCH 07/10] i2c: Add driver for AD242x bus controller Message-ID: <20191212163315.GA3932@kunai> References: <20191209183511.3576038-1-daniel@zonque.org> <20191209183511.3576038-9-daniel@zonque.org> <64adf5d7-754a-f1da-aa9b-11579c5a2780@lucaceresoli.net> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="x+6KMIRAuhnl3hBn" Content-Disposition: inline In-Reply-To: <64adf5d7-754a-f1da-aa9b-11579c5a2780@lucaceresoli.net> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-clk-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-clk@vger.kernel.org --x+6KMIRAuhnl3hBn Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Hi Luca, thanks for the review! > good, but I think there's a problem in this function. A "normal" > master_xfer function issues a repeated start between one msg and the > next one, at least in the typical case where all msgs have the same > slave address. Your implementation breaks repeated start. At first sight > we might need more complex code here to coalesce all consecutive msgs > with the same address into a single i2c_transfer() call. Note that it is by far the standard case that all messages in a transfer have the same client address (99,999%?). But technically, this is not a requirement and the repeated start on the bus is totally independent of the addresses used. It is just a master wanting to send without being interrupted by another master. Wolfram --x+6KMIRAuhnl3hBn Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEEOZGx6rniZ1Gk92RdFA3kzBSgKbYFAl3ya8cACgkQFA3kzBSg KbZBdQ/6ApPjJEPmloupECtcOPxRdHIBMJSbDi9HpBk6QSvFwtknvv6ybcJHJ3Dc 2GkbUK4EAcDvvDx4mTqhw7t8JPay3Bu3O13a/wXP5PDb7DeHJ5xDaBsEYVLC9id2 E1I5aEfdrrxsL1HFUZn86BmmthMuupvelZAyfL7pXDT3AU5oNkPipfKzoiC0EiBP MPu2HN8BIX7l1ECvOL9j0pZYCfz00UHA4PtWHwz7zjiCG7RmY3qlm6xw5l6XFeq3 wbcmTXcLr8OIG/8sw0PMJjJFqHfH9Vlj8aYcRrsgjDEHQbSTKAQ/RTDw9rcmAktW /1u6RUea0ckwX6rhKWZSXVktPzCV5LWaywD6lsMGXxhF/0T2tvKRqV6+xIngUY3n 8KnzpK2i3gvLmP9BYYxa/BM8qiuR4SimZi35lmofttUzXUs/5fgJwxFg2UuJqpPD Ex/lyLc1AUbRRp8mDsSMsGg7Ku6WUt5T7OxmVjzvIYPLJ84GlTvZLA4WIskzWFVw aZ2+E4YZq35snfMfawdrDmTOOmNOEPfVuT5Cm2ul1HVTprAgF/DVkQHVWPzNtOo9 xxwPgX9lrN0I+Ek2F1kSJguphMzVjIFRvFCl77TJUQ7qvBEWYDLQs1hBdmXieBxA bNZoxeVI6DmFF5qTxkQ3Qh9NUGWkPKuslRF2Fh7dWQIoS9FauJo= =Gmcp -----END PGP SIGNATURE----- --x+6KMIRAuhnl3hBn--