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=-2.3 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 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 9C36AC11D40 for ; Thu, 20 Feb 2020 01:39:39 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 2C05F21D56 for ; Thu, 20 Feb 2020 01:39:39 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="OVJWK9X4" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2C05F21D56 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:Date: Message-ID:From:References:To:Subject:Reply-To:Content-ID:Content-Description :Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=vwOOIvFupkj8eWE0JlsCXFJeM6zG+LvnrkbEHW173E8=; b=OVJWK9X4vRztG2 DjtIjI7PoYvXXQiGmDGorg/aTFH1QIh6PMWUdEnyDLVxfoj4O+qCMAcyqfW4QzAfmE2hu+GjeuP9x q8QLSu/8w0Zb269VCUNIxRW9RXIJnOpy+/KiqIgkGFvn6BuSMPUQUMMQaeQHaEGrgmO72rKTJZf4a /MurwJ8+Xyj24mh1vj4ACTRMmMFNgOQBFmBwIaYp7TgFT1nuQpWG0tZN72+hILHg74imWyBJJDp7G zSCXveT7ia4Pulxqpb9JMdn2Q6y50vDJfgFFjJyb8v34+kXNBlmSSSA6v26m/YAjmQI8hNF/9uJCb gAVWi//LaKQqHfuZTHrg==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1j4aoO-0007dY-Gk; Thu, 20 Feb 2020 01:39:32 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1j4aoK-0007Yn-3H for linux-arm-kernel@lists.infradead.org; Thu, 20 Feb 2020 01:39:30 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 1EE0031B; Wed, 19 Feb 2020 17:39:24 -0800 (PST) Received: from [192.168.3.111] (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id BFD413F703; Wed, 19 Feb 2020 17:39:19 -0800 (PST) Subject: Re: [RFC PATCH 00/11] Removing Calxeda platform support To: Olof Johansson References: <20200218171321.30990-1-robh@kernel.org> <20200218181356.09ae0779@donnerap.cambridge.arm.com> From: =?UTF-8?Q?Andr=c3=a9_Przywara?= Autocrypt: addr=andre.przywara@arm.com; prefer-encrypt=mutual; keydata= xsFNBFNPCKMBEAC+6GVcuP9ri8r+gg2fHZDedOmFRZPtcrMMF2Cx6KrTUT0YEISsqPoJTKld tPfEG0KnRL9CWvftyHseWTnU2Gi7hKNwhRkC0oBL5Er2hhNpoi8x4VcsxQ6bHG5/dA7ctvL6 kYvKAZw4X2Y3GTbAZIOLf+leNPiF9175S8pvqMPi0qu67RWZD5H/uT/TfLpvmmOlRzNiXMBm kGvewkBpL3R2clHquv7pB6KLoY3uvjFhZfEedqSqTwBVu/JVZZO7tvYCJPfyY5JG9+BjPmr+ REe2gS6w/4DJ4D8oMWKoY3r6ZpHx3YS2hWZFUYiCYovPxfj5+bOr78sg3JleEd0OB0yYtzTT esiNlQpCo0oOevwHR+jUiaZevM4xCyt23L2G+euzdRsUZcK/M6qYf41Dy6Afqa+PxgMEiDto ITEH3Dv+zfzwdeqCuNU0VOGrQZs/vrKOUmU/QDlYL7G8OIg5Ekheq4N+Ay+3EYCROXkstQnf YYxRn5F1oeVeqoh1LgGH7YN9H9LeIajwBD8OgiZDVsmb67DdF6EQtklH0ycBcVodG1zTCfqM AavYMfhldNMBg4vaLh0cJ/3ZXZNIyDlV372GmxSJJiidxDm7E1PkgdfCnHk+pD8YeITmSNyb 7qeU08Hqqh4ui8SSeUp7+yie9zBhJB5vVBJoO5D0MikZAODIDwARAQABzS1BbmRyZSBQcnp5 d2FyYSAoQVJNKSA8YW5kcmUucHJ6eXdhcmFAYXJtLmNvbT7CwXsEEwECACUCGwMGCwkIBwMC BhUIAgkKCwQWAgMBAh4BAheABQJTWSV8AhkBAAoJEAL1yD+ydue63REP/1tPqTo/f6StS00g NTUpjgVqxgsPWYWwSLkgkaUZn2z9Edv86BLpqTY8OBQZ19EUwfNehcnvR+Olw+7wxNnatyxo D2FG0paTia1SjxaJ8Nx3e85jy6l7N2AQrTCFCtFN9lp8Pc0LVBpSbjmP+Peh5Mi7gtCBNkpz KShEaJE25a/+rnIrIXzJHrsbC2GwcssAF3bd03iU41J1gMTalB6HCtQUwgqSsbG8MsR/IwHW XruOnVp0GQRJwlw07e9T3PKTLj3LWsAPe0LHm5W1Q+euoCLsZfYwr7phQ19HAxSCu8hzp43u zSw0+sEQsO+9wz2nGDgQCGepCcJR1lygVn2zwRTQKbq7Hjs+IWZ0gN2nDajScuR1RsxTE4WR lj0+Ne6VrAmPiW6QqRhliDO+e82riI75ywSWrJb9TQw0+UkIQ2DlNr0u0TwCUTcQNN6aKnru ouVt3qoRlcD5MuRhLH+ttAcmNITMg7GQ6RQajWrSKuKFrt6iuDbjgO2cnaTrLbNBBKPTG4oF D6kX8Zea0KvVBagBsaC1CDTDQQMxYBPDBSlqYCb/b2x7KHTvTAHUBSsBRL6MKz8wwruDodTM 4E4ToV9URl4aE/msBZ4GLTtEmUHBh4/AYwk6ACYByYKyx5r3PDG0iHnJ8bV0OeyQ9ujfgBBP B2t4oASNnIOeGEEcQ2rjzsFNBFNPCKMBEACm7Xqafb1Dp1nDl06aw/3O9ixWsGMv1Uhfd2B6 it6wh1HDCn9HpekgouR2HLMvdd3Y//GG89irEasjzENZPsK82PS0bvkxxIHRFm0pikF4ljIb 6tca2sxFr/H7CCtWYZjZzPgnOPtnagN0qVVyEM7L5f7KjGb1/o5EDkVR2SVSSjrlmNdTL2Rd zaPqrBoxuR/y/n856deWqS1ZssOpqwKhxT1IVlF6S47CjFJ3+fiHNjkljLfxzDyQXwXCNoZn BKcW9PvAMf6W1DGASoXtsMg4HHzZ5fW+vnjzvWiC4pXrcP7Ivfxx5pB+nGiOfOY+/VSUlW/9 GdzPlOIc1bGyKc6tGREH5lErmeoJZ5k7E9cMJx+xzuDItvnZbf6RuH5fg3QsljQy8jLlr4S6 8YwxlObySJ5K+suPRzZOG2+kq77RJVqAgZXp3Zdvdaov4a5J3H8pxzjj0yZ2JZlndM4X7Msr P5tfxy1WvV4Km6QeFAsjcF5gM+wWl+mf2qrlp3dRwniG1vkLsnQugQ4oNUrx0ahwOSm9p6kM CIiTITo+W7O9KEE9XCb4vV0ejmLlgdDV8ASVUekeTJkmRIBnz0fa4pa1vbtZoi6/LlIdAEEt PY6p3hgkLLtr2GRodOW/Y3vPRd9+rJHq/tLIfwc58ZhQKmRcgrhtlnuTGTmyUqGSiMNfpwAR AQABwsFfBBgBAgAJBQJTTwijAhsMAAoJEAL1yD+ydue64BgP/33QKczgAvSdj9XTC14wZCGE U8ygZwkkyNf021iNMj+o0dpLU48PIhHIMTXlM2aiiZlPWgKVlDRjlYuc9EZqGgbOOuR/pNYA JX9vaqszyE34JzXBL9DBKUuAui8z8GcxRcz49/xtzzP0kH3OQbBIqZWuMRxKEpRptRT0wzBL O31ygf4FRxs68jvPCuZjTGKELIo656/Hmk17cmjoBAJK7JHfqdGkDXk5tneeHCkB411p9WJU vMO2EqsHjobjuFm89hI0pSxlUoiTL0Nuk9Edemjw70W4anGNyaQtBq+qu1RdjUPBvoJec7y/ EXJtoGxq9Y+tmm22xwApSiIOyMwUi9A1iLjQLmngLeUdsHyrEWTbEYHd2sAM2sqKoZRyBDSv ejRvZD6zwkY/9nRqXt02H1quVOP42xlkwOQU6gxm93o/bxd7S5tEA359Sli5gZRaucpNQkwd KLQdCvFdksD270r4jU/rwR2R/Ubi+txfy0dk2wGBjl1xpSf0Lbl/KMR5TQntELfLR4etizLq Xpd2byn96Ivi8C8u9zJruXTueHH8vt7gJ1oax3yKRGU5o2eipCRiKZ0s/T7fvkdq+8beg9ku fDO4SAgJMIl6H5awliCY2zQvLHysS/Wb8QuB09hmhLZ4AifdHyF1J5qeePEhgTA+BaUbiUZf i4aIXCH3Wv6K Organization: ARM Ltd. Message-ID: <9723b5df-e218-1ea9-e8eb-9e781b23af49@arm.com> Date: Thu, 20 Feb 2020 01:38:48 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.3.1 MIME-Version: 1.0 In-Reply-To: Content-Language: en-US X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200219_173928_244761_26C67422 X-CRM114-Status: GOOD ( 35.77 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Langsdorf , kvm@vger.kernel.org, Viresh Kumar , linux-ide@vger.kernel.org, Will Deacon , linux-clk , Rob Herring , SoC Team , Joerg Roedel , Daniel Lezcano , DTML , Jon Loeliger , linux-pm@vger.kernel.org, Eric Auger , Alex Williamson , Tony Luck , Alexander Graf , Mauro Carvalho Chehab , Linux ARM Mailing List , linux-edac@vger.kernel.org, Jens Axboe , Matthias Brugger , Stephen Boyd , Network Development , Cornelia Huck , "Rafael J. Wysocki" , Linux Kernel Mailing List , iommu@lists.linux-foundation.org, Robert Richter , James Morse , Borislav Petkov , Robin Murphy , "David S. Miller" Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 19/02/2020 22:54, Olof Johansson wrote: Hi, > On Tue, Feb 18, 2020 at 10:14 AM Andre Przywara wrote: >> >> On Tue, 18 Feb 2020 11:13:10 -0600 >> Rob Herring wrote: >> >> Hi, >> >>> Calxeda has been defunct for 6 years now. Use of Calxeda servers carried >>> on for some time afterwards primarily as distro builders for 32-bit ARM. >>> AFAIK, those systems have been retired in favor of 32-bit VMs on 64-bit >>> hosts. >>> >>> The other use of Calxeda Midway I'm aware of was testing 32-bit ARM KVM >>> support as there are few or no other systems with enough RAM and LPAE. Now >>> 32-bit KVM host support is getting removed[1]. >>> >>> While it's not much maintenance to support, I don't care to convert the >>> Calxeda DT bindings to schema nor fix any resulting errors in the dts files >>> (which already don't exactly match what's shipping in firmware). >> >> While every kernel maintainer seems always happy to take patches with a negative diffstat, I wonder if this is really justification enough to remove a perfectly working platform. I don't really know about any active users, but experience tells that some platforms really are used for quite a long time, even if they are somewhat obscure. N900 or Netwinder, anyone? > > One of the only ways we know to confirm whether there are active users > or not, is to propose removing a platform. > > The good news is that if/when you do, and someone cares enough about > it to want to keep it alive, they should also have access to hardware > and can help out in maintaining it and keeping it in a working state. > > For some hardware platforms, at some point in time it no longer makes > sense to keep the latest kernel available on them, especially if > maintainers and others no longer have easy access to hardware and > resources/time to keep it functional. > > It's really more about "If you care about this enough to keep it > going, please speak up and help out". I understand that, hence this email ;-) I just wanted to avoid the impression that, by looking at the replies on the list, *everybody* seems to be happy with the removal and it just goes ahead. I have no idea how many actual *users* read this list and this email. >> So to not give the impression that actually *everyone* (from that small subset of people actively reading the kernel list) is happy with that, I think that having support for at least Midway would be useful. On the one hand it's a decent LPAE platform (with memory actually exceeding 4GB), and on the other hand it's something with capable I/O (SATA) and networking, so one can actually stress test the system. Which is the reason I was using that for KVM testing, but even with that probably going away now there remain still some use cases, and be it for general ARM(32) testing. > > How many bugs have you found on this platform that you would not have > on a more popular one? And, how many of those bugs only affected this > platform, i.e. just adding onto the support burden without positive > impact to the broader community? I have found and helped fixing (or fixed myself) multiple bugs on the Midway in the past. The mixture of decent I/O and 8GB of DRAM seemed to be unique enough to spot bugs that didn't easily show on other systems. Most were on KVM, but some were generic, and I remember at least one LPAE related. And some bugs only showed under stress, because you can actually run something useful on that machine before it goes on its knees. >> I don't particularly care about the more optional parts like EDAC, cpuidle, or cpufreq, but I wonder if keeping in at least the rather small SATA and XGMAC drivers and basic platform support is feasible. > > At what point are you better off just running under QEMU/virtualization? For many things we are looking at that's not really an option. If it would be very involved or painful to keep the support alive (as in the KVM/arm32 case), I would see your point, but just some isolated drivers (really a few and mostly quite small) don't justify a removal, IMHO. I think we have far worse and older code in the kernel to worry about. >> If YAML DT bindings are used as an excuse, I am more than happy to convert those over. >> >> And if anyone has any particular gripes with some code, maybe there is a way to fix that instead of removing it? I was always wondering if we could get rid of the mach-highbank directory, for instance. I think most of it is Highbank (Cortex-A9) related. > > Again, how do you fix it if nobody has signed up for maintaining and > keeping it working? Doing blind changes that might or might not work > is not a way to keep a platform supported. > > Just because code is removed, it doesn't mean it can't be reintroduced > when someone comes along and wants to do that. Look at some of the > recent additions of old OLPC hardware support, for example. But > there's a difference between this and keeping the code around hoping > that someone will care about it. It's not lost, and it's easy to bring > back. OK, maybe I should have been more explicit: If Rob does not want to maintain it anymore, I am happy to throw my hat in the ring. I have a working Midway system under my desk, with at least four working nodes, two of them have an SSD connected and are running some off-the-shelf Ubuntu 18.04 or Debian userland. I mostly run mainline kernels, but try the distro kernels as well from time to time. Routinely I test at least every -rc1 for regressions. I also have updates to the A-15 firmware parts (U-Boot and PSCI runtime, including PSCI 1.0 support and a Spectre V2 workaround), and have a working setup to either chainload or actually update the firmware on the flash. Happy to share that if someone is interested. For U-Boot I wanted to send updates anyway. I also have an old Highbank system lying around, but haven't turned that on in years. So would just a patch to MAINTAINERS be a solution? Cheers, Andre _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel