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=-6.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,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 47494C433DB for ; Wed, 31 Mar 2021 07:19:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E40CF619D8 for ; Wed, 31 Mar 2021 07:19:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233780AbhCaHSu (ORCPT ); Wed, 31 Mar 2021 03:18:50 -0400 Received: from mail.kernel.org ([198.145.29.99]:39562 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231523AbhCaHSj (ORCPT ); Wed, 31 Mar 2021 03:18:39 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 04B08619AB; Wed, 31 Mar 2021 07:18:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1617175118; bh=8beEdFjtCAW+MZgiUCa4tYu3TEKJK3jHtRssNTqgmzg=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=CXCYOT31EaTt/xV9uUEkFHglHFUrw+VWuEQuvaHKqZLdUmbw7D7kdlu9IROqbck16 iA7R7qVtoxa28s/80+yANQSBa4vLQfdPkD/iWkjPPG+1kYascbEQfdg9Rto3bx2m+I CDAF7HKX1FPEdK1soNI08hOeMLDQaRaPoRgkDH17T6TStzwfw8Jr8T4c0v1NGSZ0am Kr3WqslciQUHKP9sTrjz/swTsIs0CvKu5KTNwxyboH3lRA7n1BmCdwQHICgF8q36bU pnISfbtIxzIkgkpIhsOp9Wv3pdwjLMehEFIIzokDUIKi04qe4d4MHSA/8eubIzNCXC YHx/BtlWydN7g== Date: Wed, 31 Mar 2021 09:18:35 +0200 From: Wolfram Sang To: Zhou Yanjie Cc: paul@crapouillou.net, stable@vger.kernel.org, linux-mips@vger.kernel.org, linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org, dongsheng.qiu@ingenic.com, aric.pzqi@ingenic.com, sernia.zhou@foxmail.com Subject: Re: [PATCH] I2C: JZ4780: Fix bug for Ingenic X1000. Message-ID: <20210331071835.GB1025@ninjato> References: <1616084743-112402-1-git-send-email-zhouyanjie@wanyeetech.com> <1616084743-112402-2-git-send-email-zhouyanjie@wanyeetech.com> <20210318170623.GA1961@ninjato> <644d19d8-9444-4dde-a891-c9dfd523389e@wanyeetech.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="4SFOXa2GPu3tIq4H" Content-Disposition: inline In-Reply-To: <644d19d8-9444-4dde-a891-c9dfd523389e@wanyeetech.com> Precedence: bulk List-ID: X-Mailing-List: linux-i2c@vger.kernel.org --4SFOXa2GPu3tIq4H Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Hi,=20 > > Any write operation? I wonder then why nobody noticed before? >=20 >=20 > The standard I2C communication should look like this: >=20 > Read: >=20 > device_addr + w, reg_addr, device_addr + r, data; >=20 > Write: >=20 > device_addr + w, reg_addr, data; >=20 >=20 > But without this patch, it looks like this: >=20 > Read: >=20 > device_addr + w, reg_addr, device_addr + r, data; >=20 > Write: >=20 > device_addr + w, reg_addr, device_addr + w, data; >=20 > This is clearly not correct. Thanks for the additional information! I understand now. I added a bit of this to the commit message of v2 to explain the situation. --4SFOXa2GPu3tIq4H Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEEOZGx6rniZ1Gk92RdFA3kzBSgKbYFAmBkIksACgkQFA3kzBSg KbZykQ//eDkcN/ZQvGDP0emgsNO6lU3HtajHI/lRiW/APQ3o+w69CqfEgOtbnJ00 5Kf0rOkFKeeuMNlv7xZNLOxJoq+V52e1g0S5m5DsVkFFL5rxmfYfBdOAChGoCzHp 6AfwU+QJjG0ETWgEq/4Wh8wqPbIYeYtATkJA8FcFQEu1bAA5JyGr/xuNNToTd/ln PDpoJ0laVjU5ADjQJUBZSctEW07TfdOPumwVYmmpoAtmbc/O26aGp9R/ptZGMxVV vTSVI2ghYL70Maoom42YfBQHUNVgqyU14jBw24Jkhu3+lB/B2IHszjG/qyRlEjTM gHcu1wSPrXtKGjcicqFU/DVcJviOOZqni2la1ExLkuXE3xVOERAfcMZWZ05C410P kB+YWBa5qE3iZllEgDN7f55SXZNX4kT7QpV6o/KGtJ6kPmQtPAb5X/9yTe69ogSe PSaNpicjhmiUmgKh+Zu3ttxDREZNmhIbX6h1YMkYN1Ocz8PG9l42zRuFRLnqqRND zcSIlK2PfO2XWYXaSNqo3weN66/oLX6kRjJSsTLpsfkuMU0SqE3LFjjqeCJRIEtP v2okUgzFcqL9YuyQrwklbUxZ9fe4/cXpsHqwzpFPqlbgyqa16oxzIuNOQ/AG0M3S m7s+bQ566uplLlH/VWW+Kg5Ak70k4tuAZCNB5Z2TaTRmpVO/02Y= =cthv -----END PGP SIGNATURE----- --4SFOXa2GPu3tIq4H--