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=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_RED 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 51429C433E0 for ; Tue, 19 Jan 2021 10:57:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 046E32075F for ; Tue, 19 Jan 2021 10:57:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389179AbhASKuk (ORCPT ); Tue, 19 Jan 2021 05:50:40 -0500 Received: from mail.kernel.org ([198.145.29.99]:43826 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2404389AbhASKfe (ORCPT ); Tue, 19 Jan 2021 05:35:34 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id B0CE120867; Tue, 19 Jan 2021 10:34:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1611052493; bh=Ai9OtUYE17P/PsNgazL93C2QuNBAGpf3R4vtI8UU7tU=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=qFRNSgW3Phy8vew+1a95X5kmhqMA1QVSxeV/v+QNU2W1CjRdJbVoEEFxU+MWUM02h 2DbPo1jagUWGtrttWrzJaB8//4Nk1CztWgxvQLBQLDFvD1qhKaf0zFyLJu66ud/02r FYwE1BBXlCiLLU1DbVyIFNnZE0An7DU/psfcJBtw= Date: Tue, 19 Jan 2021 11:34:50 +0100 From: Greg Kroah-Hartman To: Andy Shevchenko Cc: Kai-Heng Feng , "Rafael J. Wysocki" , AceLan Kao , "Rafael J. Wysocki" , Mika Westerberg , Len Brown , "open list:ACPI" , open list Subject: Re: [PATCH] ACPI / device_sysfs: Use OF_MODALIAS for "compatible" modalias Message-ID: References: <20210119081513.300938-1-kai.heng.feng@canonical.com> <20210119094159.GQ4077@smile.fi.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210119094159.GQ4077@smile.fi.intel.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jan 19, 2021 at 11:41:59AM +0200, Andy Shevchenko wrote: > On Tue, Jan 19, 2021 at 04:41:48PM +0800, Kai-Heng Feng wrote: > > On Tue, Jan 19, 2021 at 4:27 PM Greg Kroah-Hartman > > wrote: > > > On Tue, Jan 19, 2021 at 04:15:13PM +0800, Kai-Heng Feng wrote: > > ... > > > > Who will use OF_MODALIAS and where have you documented it? > > > > After this lands in mainline, I'll modify the pull request for systemd > > to add a new rule for OF_MODALIAS. > > I'll modify the comment on the function to document the change. > > I'm wondering why to have two fixes in two places instead of fixing udev to > understand multiple MODALIAS= events? It's not a matter of multiple events, it's a single event with a key/value pair with duplicate keys and different values. What is this event with different values supposed to be doing in userspace? Do you want multiple invocations of `modprobe` or something else? Usually a "device" only has a single "signature" that modprobe uses to look up the correct module for. Modules can support any number of device signatures, but traditionally it is odd to think that a device itself can be supported by multiple modules, which is what you are saying is happening here. So what should userspace do with this, and why does a device need to have multiple module alias signatures? thanks, greg k-h