From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752304AbdCCPlM (ORCPT ); Fri, 3 Mar 2017 10:41:12 -0500 Received: from ec2-52-27-115-49.us-west-2.compute.amazonaws.com ([52.27.115.49]:53363 "EHLO osg.samsung.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751703AbdCCPgs (ORCPT ); Fri, 3 Mar 2017 10:36:48 -0500 Subject: Re: [PATCH 00/13] rtc: Add OF device table to I2C drivers that are missing it To: Alexandre Belloni References: <20170303142925.17915-1-javier@osg.samsung.com> <20170303150134.qacfd7ccemqxwq3p@piout.net> From: Javier Martinez Canillas Cc: linux-kernel@vger.kernel.org, rtc-linux@googlegroups.com, Alessandro Zummo Message-ID: Date: Fri, 3 Mar 2017 12:27:23 -0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.6.0 MIME-Version: 1.0 In-Reply-To: <20170303150134.qacfd7ccemqxwq3p@piout.net> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello Alexandre, On 03/03/2017 12:01 PM, Alexandre Belloni wrote: > Hi, > > On 03/03/2017 at 11:29:11 -0300, Javier Martinez Canillas wrote: >> This series add OF device ID tables to RTC I2C drivers whose devices are >> either used in Device Tree source files or are listed in binding docs as >> a compatible string. >> >> That's done because the plan is to change the I2C core to report proper OF >> modaliases instead of always reporting a MODALIAS=i2c: regardless if >> a device was registered via DT or using the legacy platform data. >> > > Doesn't that break the DT ABI for all i2c devices? A lot of people are > getting the vendor wrong in the compatible string and because the i2c > core doesn't care, the driver is still probed. Dropping that will break > all those DTBs. > Or will that only affect module autoload? > The change will only be for module autoload. The I2C core will still attempt to match the I2C device ID table as a fallback if fails to match the OF one. So there's no change in the match logic for drivers that do the wrong thing. If someone is using a wrong vendor prefix and the DT can't be changed, then an entry in the OF device ID table has to be added for "wrong_vendor,device" so the MODALIAS uevent can be "of:N*T*wrong_vendor,device". This is the RFC patch for the I2C core so you get a better idea: https://patchwork.kernel.org/patch/6903981/ Best regards, -- Javier Martinez Canillas Open Source Group Samsung Research America