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,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 B3E2BC4360C for ; Sun, 29 Sep 2019 11:07:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7B1DF218AC for ; Sun, 29 Sep 2019 11:07:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729054AbfI2LHX (ORCPT ); Sun, 29 Sep 2019 07:07:23 -0400 Received: from relay1-d.mail.gandi.net ([217.70.183.193]:60859 "EHLO relay1-d.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725924AbfI2LHX (ORCPT ); Sun, 29 Sep 2019 07:07:23 -0400 X-Originating-IP: 93.158.25.216 Received: from nexussix (93-158-25-216.subs.ibrowse.com [93.158.25.216]) (Authenticated sender: cengiz@kernel.wtf) by relay1-d.mail.gandi.net (Postfix) with ESMTPSA id 57ED5240004; Sun, 29 Sep 2019 11:07:19 +0000 (UTC) Message-ID: <2a3f9ec1955e8b785888994e2a9b7cc0d5800a71.camel@kernel.wtf> Subject: Re: [PATCH] i2c: pca954x: Add property to skip disabling PCA954x MUX device From: Cengiz Can Reply-To: cengiz@kernel.wtf To: Biwen Li Cc: linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org, peda@axentia.se, leoyang.li@nxp.com, Wolfram Sang Date: Sun, 29 Sep 2019 14:07:19 +0300 In-Reply-To: <20190929103638.46038-1-biwen.li@nxp.com> References: <20190929103638.46038-1-biwen.li@nxp.com> Content-Type: text/plain; charset="UTF-8" User-Agent: Evolution 3.34.0 MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello Biwen, > + /* Errata ID E-00013 on board LS2088ARDB and LS2088ARDB: > + * The point here is that you must not disable a mux if there > + * are no pullups on the input or you mess up the I2C. This > + * needs to be put into the DTS really as the kernel cannot > + * know this otherwise. > + */ Can you please explain what a "mess up" is? And also, should we put this new DTS property in related default bindings? If not, are you planning a documentation update for the users to notify them about this? -- Cengiz Can