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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham 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 E8D14C04AB6 for ; Tue, 28 May 2019 09:20:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CC1A6208C3 for ; Tue, 28 May 2019 09:20:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727013AbfE1JT7 (ORCPT ); Tue, 28 May 2019 05:19:59 -0400 Received: from mx2.suse.de ([195.135.220.15]:48302 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725943AbfE1JT7 (ORCPT ); Tue, 28 May 2019 05:19:59 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id ACD4CAFE8; Tue, 28 May 2019 09:19:57 +0000 (UTC) Date: Tue, 28 May 2019 11:19:53 +0200 From: Jean Delvare To: Wolfram Sang Cc: Pali =?UTF-8?B?Um9ow6Fy?= , Andy Shevchenko , Jean Delvare , =?UTF-8?B?TWljaGHFgiBLxJlwaWXFhA==?= , Steven Honeyman , Valdis Kletnieks , Jochen Eisinger , Gabriele Mazzotta , Andy Lutomirski , Mario Limonciello , Alex Hung , Takashi Iwai , linux-i2c , Linux Kernel Mailing List , Platform Driver Subject: Re: [PATCH v2] i2c: i801: Register optional lis3lv02d i2c device on Dell machines Message-ID: <20190528111953.0e5415f4@endymion> In-Reply-To: <20180226203255.lnnzipipjz5l2itz@ninjato> References: <20180128144509.pobnj7cayc4psgrj@pali> <20180131120348.azy25aqvn5wrdkeh@pali> <20180212153012.vffvjmz26ifyxbj5@pali> <20180213150004.5d2v7y7wwuure4io@pali> <20180213165023.xmzovx7fd3gdljxw@pali> <20180226203255.lnnzipipjz5l2itz@ninjato> Organization: SUSE Linux X-Mailer: Claws Mail 3.13.2 (GTK+ 2.24.31; x86_64-suse-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 26 Feb 2018 21:32:55 +0100, Wolfram Sang wrote: > > I'm not maintainer of i2c-i801.ko, Jean Delvare & Wolfram Sang are. > > Therefore instructing future contributors would be up to them. > > This is really Jean's realm. Sorry for the delay. As a general rule I'm all in favor of instantiating I2C devices from i2c-i801 when we can, as it makes the user's life easier. However I agree with Andy that: 1* We want to have an explicit list of supported ACPI device IDs, not a just a prefix. 2* We don't want to over-engineer it with a common header file or an exported symbol. I see no problem with duplicating the lists if 2 drivers happen to be needed on the same set of devices. This is easily managed by adding a comment before each list that the other list may need to be kept in sync. It also gives us the flexibility to *not* keep them in sync if needed. Instantiating the I2C device from dell-smo8800 doesn't seem practical because that driver has no idea about the i2c subsystem in the first place. What worries me is that we seem to have 2 drivers binding to the same device (the accelerometer), one natively (lis3lv02d), and one through an ACPI layer (dell-smo8800). I don't really understand why this is needed (don't they serve the same purpose?) nor how it can be safe (what guarantees that both drivers won't attempt to access the hardware at the same time?) -- Jean Delvare SUSE L3 Support