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 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 7558BEE49AB for ; Tue, 22 Aug 2023 20:13:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:CC:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=UDVF/Tw4UXX50EPpY6Qb2WaKsIM9Qha0+rQ0nKcoFf4=; b=4MkhAOD2a/puw5 PRtTkhHj6QnBcnIBtAC9GFDaVIHzTd+Z9BAtX2/J3Ic7A53d2UPbwYRr/PuX4yxDM7xG3s/U54bnn gFr/saox+9ECFDBTriQtCWaC1WgxVoHUr+iApx9YtjxBK8HGjM8gxTU/b+ZIPtoXJB5vWMDHHlHpJ n87erKTvnnOkGeEWgvXGItIyo1uN7i8PZEX3Y7NjuxaYeTU263OGzLuMAA/9kT1hfUt5PTkJs18uL cKgN+LI2nP72MOT1ycqyfKOjlL9M6TciJOYyIIOvmvUVAfKWgbfe5tOXw1sAMld+s0z1bDY1f2L1c IuhN2XEFUu5NuhB9eYHA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1qYXjs-00GlC5-1Z; Tue, 22 Aug 2023 20:12:32 +0000 Received: from lelv0142.ext.ti.com ([198.47.23.249]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1qYXjp-00GlBg-0S for linux-arm-kernel@lists.infradead.org; Tue, 22 Aug 2023 20:12:30 +0000 Received: from lelv0266.itg.ti.com ([10.180.67.225]) by lelv0142.ext.ti.com (8.15.2/8.15.2) with ESMTP id 37MKC5v0107163; Tue, 22 Aug 2023 15:12:05 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ti.com; s=ti-com-17Q1; t=1692735125; bh=3uY4F+iiq0UOCGgwUgVNnVWyBxLrlfcH+x9S6RaaL5k=; h=Date:From:To:CC:Subject:References:In-Reply-To; b=F1jYFejffpbZVGp6+P8viB9vaSQrXOueWHczWIBEa9PAuOczDEUoADCV2vilzo4hH 6P83mVsDvndZ9iFuMm3r/TxKsIZnyBIiH/0t0tAdRWr4+7ek7w+XOgVKpWYbhSBhpb BkZXjGteJKPGB96vBL4oytP2bqGqoqHtN7t8Zh4c= Received: from DLEE114.ent.ti.com (dlee114.ent.ti.com [157.170.170.25]) by lelv0266.itg.ti.com (8.15.2/8.15.2) with ESMTPS id 37MKC5Xm078864 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=FAIL); Tue, 22 Aug 2023 15:12:05 -0500 Received: from DLEE114.ent.ti.com (157.170.170.25) by DLEE114.ent.ti.com (157.170.170.25) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2507.23; Tue, 22 Aug 2023 15:12:05 -0500 Received: from fllv0040.itg.ti.com (10.64.41.20) by DLEE114.ent.ti.com (157.170.170.25) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2507.23 via Frontend Transport; Tue, 22 Aug 2023 15:12:05 -0500 Received: from localhost (ileaxei01-snat2.itg.ti.com [10.180.69.6]) by fllv0040.itg.ti.com (8.15.2/8.15.2) with ESMTP id 37MKC5C5075342; Tue, 22 Aug 2023 15:12:05 -0500 Date: Tue, 22 Aug 2023 15:12:05 -0500 From: Nishanth Menon To: Mathieu Poirier CC: Bjorn Andersson , , , , Robert Nelson , Kevin Cahalan Subject: Re: [PATCH] remoteproc: core: Honor device tree /alias entries when assigning IDs Message-ID: <20230822201205.4csoj4kym2yhuyrf@decrease> References: <20230807140247.956255-1-nm@ti.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: X-EXCLAIMER-MD-CONFIG: e1e8a2fd-e40a-4ac6-ac9b-f7e9cc9ee180 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230822_131229_342047_6B72E70A X-CRM114-Status: GOOD ( 22.77 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 13:25-20230822, Mathieu Poirier wrote: > Hi Nishanth, > > On Mon, Aug 07, 2023 at 09:02:47AM -0500, Nishanth Menon wrote: > > On many platforms, such as Beaglebone-AI64 with many remote > > processors, firmware configurations provided by the distributions can > > vary substantially depending on the distribution build's functionality > > and the specific remote cores enabled in that variant. Ensuring > > consistent udev rules mapping remoteproc nodes to constant remote > > proc device indices across distributions (yocto, ubuntu, debian and > > it's variants, ...) on a board basis can be challenging due to the > > various functions of these distributions. Varied device node paths > > create challenges for applications that operate on remote processors, > > especially in minimal embedded systems(initrd like) that may not > > have udev-like capabilities and rely on a more straightforward bare > > filesystem. This challenge is similar to that faced by I2C, RTC or the > > GPIO subsystems. > > > > I'm puzzled by this patch. I can see how using an alias can help in boards with > various HW configuration. That said, and as written above, FW files for remote > processors can vary based on the build's functionality. As such "remoteproc3" > will reference the same HW device on all distributions but the functionality > enacted by the FW may be different. As such I don't see how an alias can help > here. Can you provide a concrete example that highlights the benefits? Correct - *if* remoteproc3 is the constant node reference. To take a trivial example: We ran into this issue with: https://github.com/kaofishy/bbai64_cortex-r5_example/blob/main/Makefile#L28 remoteproc18 apparently changed numbering in a different build. If remoteproc18 remained the same between different distro builds that would have probably kept the userspace constant. but it does'nt. it dependent purely on probe order, which does'nt let userspace remain consistent. Same reason and motivation to do the following: https://git.beagleboard.org/beagleboard/repos-arm64/-/blob/main/bb-customizations/suite/bookworm/debian/86-remoteproc-noroot.rules in one technique to do it - but that only works if all the distros follow the same udev rules - and there is no reasonable way to enforce that across distributions. -- Regards, Nishanth Menon Key (0xDDB5849D1736249D) / Fingerprint: F8A2 8693 54EB 8232 17A3 1A34 DDB5 849D 1736 249D _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel