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 AE855C4332F for ; Tue, 14 Dec 2021 10:22:01 +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:MIME-Version:References:In-Reply-To: Subject:Cc:To:From:Message-ID:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=/ZcoLjBJ2mrQE22Sj9dZT98KSxcp0TlvL7MmPOigNMc=; b=V3Jx4GvqdBzEGT yAMnTU6I4PIXlHWpCJhUtsu4RovLRg24/yvKQaNvhArqlmYXkJ3WKdhG+7S6Nid2dwrEBCHNutKLQ gTrtWWFeJHHj+iLHm/4/nKcCKmndDMSNGb/4zV/DYS9PyTlX9UYMKKXhy988W5fUPNmeEtKf67CxP Zlio88OrCuXLfsMqjcWEtXDYcyMkfHBE9FCozjrLptShUQTOS4EjuUe1jkg8De4Zu6uDLdzhUXktw V4IE6rW7upX2Wj5JBMSf6E34DLm2q1YtO8LmPfFUm+JnGE9TzZqFLthJC9Qg9h+PZx9s5PLESxTg1 2x5rKGEJjjH5cmCA9CwQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1mx4vL-00DRyi-Nb; Tue, 14 Dec 2021 10:20:43 +0000 Received: from dfw.source.kernel.org ([2604:1380:4641:c500::1]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1mx4vH-00DRxj-Pz for linux-arm-kernel@lists.infradead.org; Tue, 14 Dec 2021 10:20:41 +0000 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 4CA1C61423; Tue, 14 Dec 2021 10:20:39 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id AC5BDC34600; Tue, 14 Dec 2021 10:20:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1639477238; bh=gXDlyXCPmGIg3pQ+XQq1nSiP4XFFwOsh8JAjsjMMkNg=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=sT1P/SVv2s8BXa6JVtHZ9jsVbR4EfxsFBwrNCTIXqT+Ju8/gMKcmCifqwsf24hGrG bPgO/nyTQPE6GPFoIBTlQm2jq42HqseHT+yjjEkD4aUEA+MF4VaN8X6HopOh4QKbBc uHmw5ZQeg1GgaKntr06g/YcO7+jG7s8T14dd36PSsVQCMQJYpucA+hb1hWZp+/TAwk UyGmWRQvMedqCQ17bGOGVFy6WMepRGVCp+8PQgjmPKnLXBX/ypprAXoD8utNU8H4M6 P+VTXioPhXwzPyFKbwwwQhsjXmV2o4H/cx7uhx/pxwcySeL4AVFPlInxW1uVxVt0QT XP3q4esA6qVSg== Received: from cfbb000407.r.cam.camfibre.uk ([185.219.108.64] helo=why.misterjones.org) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1mx4vE-00C1CJ-NM; Tue, 14 Dec 2021 10:20:36 +0000 Date: Tue, 14 Dec 2021 10:20:36 +0000 Message-ID: <87czlzjxmz.wl-maz@kernel.org> From: Marc Zyngier To: Vladimir Oltean Cc: "devicetree@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , Rob Herring , Shawn Guo , Leo Li , Biwen Li , "Z.Q. Hou" , Kurt Kanzenbach , Rasmus Villemoes Subject: Re: [RFC PATCH devicetree 00/10] Do something about ls-extirq interrupt-map breakage In-Reply-To: <20211214095853.4emzycaxkuqr4tun@skbuf> References: <20211214013800.2703568-1-vladimir.oltean@nxp.com> <87ilvrk1r0.wl-maz@kernel.org> <20211214095853.4emzycaxkuqr4tun@skbuf> User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI-EPG/1.14.7 (Harue) FLIM-LB/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL-LB/10.8 EasyPG/1.0.0 Emacs/27.1 (x86_64-pc-linux-gnu) MULE/6.0 (HANACHIRUSATO) MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue") X-SA-Exim-Connect-IP: 185.219.108.64 X-SA-Exim-Rcpt-To: vladimir.oltean@nxp.com, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, robh+dt@kernel.org, shawnguo@kernel.org, leoyang.li@nxp.com, biwen.li@nxp.com, zhiqiang.hou@nxp.com, kurt@linutronix.de, linux@rasmusvillemoes.dk X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20211214_022039_946232_B870A2B3 X-CRM114-Status: GOOD ( 27.91 ) 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 Tue, 14 Dec 2021 09:58:54 +0000, Vladimir Oltean wrote: > > Hi Marc (with a c), > > I wish the firmware for these SoCs was smart enough to be compatible > with the bindings that are in the kernel and provide a blob that the > kernel could actually use. Some work has been started there and this is > work in progress. True, I don't know what other OF-based firmware some > other customers may use, but I trust it isn't a lot more advanced than > what U-Boot currently has :) > > Also, the machines may have been in the wild for years, but the > ls-extirq driver was added in November 2019. So not with the > introduction of the SoC device trees themselves. That isn't so long ago. > > As for compatibility between old kernel and new DT: I guess you'll hear > various opinions on this one. > https://www.spinics.net/lists/linux-mips/msg07778.html > > | > Are we okay with the new device tree blobs breaking the old kernel? > | > | From my point of view, newer device trees are not required to work on > | older kernel, this would impose an unreasonable limitation and the use > | case is very limited. My views are on the opposite side. DT is an ABI, full stop. If you change something, you *must* guarantee forward *and* backward compatibility. That's because: - you don't control how updatable the firmware is - people may need to revert to other versions of the kernel because the new one is broken - there are plenty of DT users beyond Linux, and we are not creating bindings for Linux only. You may disagree with this, but for the subsystems I maintain, this is the rule I intent to stick to. M. -- Without deviation from the norm, progress is not possible. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel