From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965694AbXIGNeS (ORCPT ); Fri, 7 Sep 2007 09:34:18 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S965168AbXIGNeI (ORCPT ); Fri, 7 Sep 2007 09:34:08 -0400 Received: from smtp-105-friday.nerim.net ([62.4.16.105]:50854 "EHLO kraid.nerim.net" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S965417AbXIGNeH (ORCPT ); Fri, 7 Sep 2007 09:34:07 -0400 Date: Fri, 7 Sep 2007 15:35:59 +0200 From: Jean Delvare To: Greg KH Cc: LKML , David Brownell Subject: Platform device id Message-ID: <20070907153559.17faf9d1@hyperion.delvare> X-Mailer: Sylpheed-Claws 2.5.5 (GTK+ 2.10.6; 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 X-Mailing-List: linux-kernel@vger.kernel.org Hi Greg, all, While platform_device.id is a u32, platform_device_add() handles "-1" as a special id value. This has potential for confusion and bugs. One such bug was reported to me by David Brownell: http://lists.lm-sensors.org/pipermail/i2c/2007-September/001787.html And since then I've found two other drivers affected (uartlite and i2c-pxa). Could we at least make platform_device.id an int so as to clear up the confusion? I doubt that the id will ever be a large number anyway. To go one step further, I am questioning the real value of this naming exception for these "unique" platform devices. On top of the bugs I mentioned above, it has potential for compatibility breakage: adding a second device of the same type will rename the first one from "foo" to "foo.0". It also requires specific checks in many individual platform drivers. All this, as I understand it, for a purely aesthetic reason. I don't think this is worth it. Would there be any objection to simply getting rid of this exception and having all platform devices named "foo.%d"? -- Jean Delvare