From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jarkko Nikula Subject: Re: [PATCH] i2c: Fix modalias for ACPI enumerated I2C devices Date: Mon, 14 Oct 2013 09:45:53 +0300 Message-ID: <525B9321.5000906@linux.intel.com> References: <1381414669-26115-1-git-send-email-jarkko.nikula@linux.intel.com> <2393462.4JRAMNeigd@vostro.rjw.lan> <20131012050413.GY3521@intel.com> <2878883.SYGmCkS5Bt@vostro.rjw.lan> <20131012161805.GB3521@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from mga03.intel.com ([143.182.124.21]:58957 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750854Ab3JNGp6 (ORCPT ); Mon, 14 Oct 2013 02:45:58 -0400 In-Reply-To: <20131012161805.GB3521@intel.com> Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: Mika Westerberg Cc: "Rafael J. Wysocki" , linux-i2c@vger.kernel.org, linux-acpi@vger.kernel.org, Wolfram Sang On 10/12/2013 07:18 PM, Mika Westerberg wrote: > If we have two ACPI enumerated devices, they have following modalias: > > i2c-device0: i2c:INTABCD:00 > acpi:INTABCD > > i2c-device1: i2c:INTABCD:01 > acpi:INTABCD > > Likelihood that some random I2C driver has INTABCD:00 or INTABCD:01 ids in > their list is minimal. However, when you turn it to this: > > > i2c-device0: i2c:INTABCD > acpi:INTABCD > > i2c-device1: i2c:INTABCD > acpi:INTABCD > > It might be possible that we get a match that isn't supposed to happen. > Well, OK it is pretty remote but anyway :-) Well, name conflicts could occur of course but still I don't think we should generate illegal or wrong modaliases. I'm not an udev expert but I suppose trying to load nonexisting drivers (i2c_INTABCD:xy) could slow booting a little and perhaps pollute needlessly error log compared to if it can see that driver is already loaded or tries to load the same driver again. I don't think name conflicts can pose too big risk as they are trivial to fix in sources and can be queued to stable too. -- Jarkko