[{"id":1739157,"web_url":"http://patchwork.ozlabs.org/comment/1739157/","msgid":"<20170805065754.GA8509@wunner.de>","date":"2017-08-05T06:57:54","subject":"Re: [PATCH 2/3] Split VGA default device handler out of VGA arbiter","submitter":{"id":68499,"url":"http://patchwork.ozlabs.org/api/people/68499/","name":"Lukas Wunner","email":"lukas@wunner.de"},"content":"On Fri, Aug 04, 2017 at 08:20:32PM +1000, Daniel Axtens wrote:\n> A system without PCI legacy resources (e.g. ARM64, powerpc) may\n> find that no default/boot VGA device has been marked, because the\n> VGA arbiter checks for legacy resource decoding before marking a\n> card as default.\n\nWould it be feasible to just sprinkle some \"if (IS_ENABLED(CONFIG_X86))\"\nover the portions of vgaarb.c that deal with legacy resources?\n\nI'm missing some context as to the negative consequences you're\nexperiencing on other arches (the cover letter merely refers to\n\"quirks in ppc and concerns in arm land\" and is missing links to\narchived versions of v1 and v2), but clearly legacy resources are\nx86-specific so any code dealing with them seems superfluous on\nother arches and should be marked as such.\n\nPlease cc dri-devel when proposing changes to vgaarb.c (see\nMAINTAINERS).\n\nThanks,\n\nLukas","headers":{"Return-Path":"","X-Original-To":["patchwork-incoming@ozlabs.org","linuxppc-dev@lists.ozlabs.org"],"Delivered-To":["patchwork-incoming@ozlabs.org","linuxppc-dev@lists.ozlabs.org"],"Received":["from lists.ozlabs.org (lists.ozlabs.org [103.22.144.68])\n\t(using TLSv1.2 with cipher ADH-AES256-GCM-SHA384 (256/256 bits))\n\t(No client certificate requested)\n\tby ozlabs.org (Postfix) with ESMTPS id 3xPZkB5Qz0z9s7g\n\tfor ;\n\tSat, 5 Aug 2017 17:12:34 +1000 (AEST)","from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3])\n\tby lists.ozlabs.org (Postfix) with ESMTP id 3xPZkB4Z3nzDqpS\n\tfor ;\n\tSat, 5 Aug 2017 17:12:34 +1000 (AEST)","from mailout2.hostsharing.net (mailout2.hostsharing.net\n\t[83.223.90.233])\n\t(using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256\n\tbits)) (No client certificate requested)\n\tby lists.ozlabs.org (Postfix) with ESMTPS id 3xPZbP2BlJzDqjF\n\tfor ;\n\tSat, 5 Aug 2017 17:06:41 +1000 (AEST)","from h08.hostsharing.net (h08.hostsharing.net [83.223.95.28])\n\t(using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256\n\tbits)) (No client certificate requested)\n\tby mailout2.hostsharing.net (Postfix) with ESMTPS id CCF1A10167A4B;\n\tSat, 5 Aug 2017 08:57:24 +0200 (CEST)","from localhost (5-38-90-81.adsl.cmo.de [81.90.38.5])\n\t(using TLSv1.2 with cipher ECDHE-RSA-AES128-SHA (128/128 bits))\n\t(No client certificate requested)\n\tby h08.hostsharing.net (Postfix) with ESMTPSA id A5135608BC69;\n\tSat, 5 Aug 2017 08:57:23 +0200 (CEST)"],"X-Greylist":"delayed 549 seconds by postgrey-1.36 at bilbo;\n\tSat, 05 Aug 2017 17:06:41 AEST","Date":"Sat, 5 Aug 2017 08:57:54 +0200","From":"Lukas Wunner ","To":"Daniel Axtens ","Subject":"Re: [PATCH 2/3] Split VGA default device handler out of VGA arbiter","Message-ID":"<20170805065754.GA8509@wunner.de>","References":"<20170804102033.27731-1-dja@axtens.net>\n\t<20170804102033.27731-3-dja@axtens.net>","MIME-Version":"1.0","Content-Type":"text/plain; charset=us-ascii","Content-Disposition":"inline","In-Reply-To":"<20170804102033.27731-3-dja@axtens.net>","User-Agent":"Mutt/1.6.1 (2016-04-27)","X-Mailman-Approved-At":"Sat, 05 Aug 2017 17:11:30 +1000","X-BeenThere":"linuxppc-dev@lists.ozlabs.org","X-Mailman-Version":"2.1.23","Precedence":"list","List-Id":"Linux on PowerPC Developers Mail List\n\t","List-Unsubscribe":",\n\t","List-Archive":"","List-Post":"","List-Help":"","List-Subscribe":",\n\t","Cc":"catalin.marinas@arm.com, gabriele.paoloni@huawei.com, airlied@linux.ie, \n\tlinux-pci@vger.kernel.org, will.deacon@arm.com,\n\tdri-devel@lists.freedesktop.org, z.liuxinliang@hisilicon.com,\n\tbhelgaas@google.com, alex.williamson@redhat.com, zourongrong@gmail.com,\n\tdaniel.vetter@intel.com, linuxppc-dev@lists.ozlabs.org,\n\tlinux-arm-kernel@lists.infradead.org","Errors-To":"linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org","Sender":"\"Linuxppc-dev\"\n\t"}},{"id":1739821,"web_url":"http://patchwork.ozlabs.org/comment/1739821/","msgid":"<87zibcqmt7.fsf@linkitivity.dja.id.au>","date":"2017-08-06T23:49:24","subject":"Re: [PATCH 2/3] Split VGA default device handler out of VGA arbiter","submitter":{"id":65792,"url":"http://patchwork.ozlabs.org/api/people/65792/","name":"Daniel Axtens","email":"dja@axtens.net"},"content":"Hi Lukas,\n\nLet me reply \"back-to-front\":\n\n> Please cc dri-devel when proposing changes to vgaarb.c (see\n> MAINTAINERS).\n\nSorry, will do in future.\n\n> I'm missing some context as to the negative consequences you're\n> experiencing on other arches (the cover letter merely refers to\n> \"quirks in ppc and concerns in arm land\" and is missing links to\n> archived versions of v1 and v2), but clearly legacy resources are\n> x86-specific so any code dealing with them seems superfluous on\n> other arches and should be marked as such.\n\nQuirk/v1: https://www.spinics.net/lists/linux-pci/msg62865.html\nApproach 2: https://www.spinics.net/lists/linux-pci/msg63092.html\n https://www.spinics.net/lists/linux-pci/msg63083.html\n\nThe quirk in powerpc land that I'm referring to is\narch/powerpc/kernel/pci-common.c::fixup_vga() which is a class enable\nhook that marks the first VGA device it comes across as default if the\narbiter has not marked one.\n\nThe arm concerns are ventaliated in the threads I linked - they boil\ndown to \"why do we need the arbiter at all on platforms without legacy\nresources? Can't we do this more simply?\"\n\n> Would it be feasible to just sprinkle some \"if (IS_ENABLED(CONFIG_X86))\"\n> over the portions of vgaarb.c that deal with legacy resources?\n\nYes and no. That would disable the unnecessary chunks of the VGA\narbiter, but we then still have to figure out how to mark devices as\ndefault if not with the arbiter.\n\nRegards,\nDaniel\n\n>\n> Thanks,\n>\n> Lukas","headers":{"Return-Path":"","X-Original-To":["patchwork-incoming@ozlabs.org","linuxppc-dev@lists.ozlabs.org"],"Delivered-To":["patchwork-incoming@ozlabs.org","linuxppc-dev@lists.ozlabs.org"],"Received":["from lists.ozlabs.org (lists.ozlabs.org [103.22.144.68])\n\t(using TLSv1.2 with cipher ADH-AES256-GCM-SHA384 (256/256 bits))\n\t(No client certificate requested)\n\tby ozlabs.org (Postfix) with ESMTPS id 3xQcqk6vkmz9s7C\n\tfor ;\n\tMon, 7 Aug 2017 09:50:58 +1000 (AEST)","from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3])\n\tby lists.ozlabs.org (Postfix) with ESMTP id 3xQcqk5lGzzDqkv\n\tfor ;\n\tMon, 7 Aug 2017 09:50:58 +1000 (AEST)","from mail-pf0-x243.google.com (mail-pf0-x243.google.com\n\t[IPv6:2607:f8b0:400e:c00::243])\n\t(using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128\n\tbits)) (No client certificate requested)\n\tby lists.ozlabs.org (Postfix) with ESMTPS id 3xQcp418WrzDqZy\n\tfor ;\n\tMon, 7 Aug 2017 09:49:30 +1000 (AEST)","by mail-pf0-x243.google.com with SMTP id t86so7412238pfe.1\n\tfor ;\n\tSun, 06 Aug 2017 16:49:30 -0700 (PDT)","from localhost (124-171-162-147.dyn.iinet.net.au.\n\t[124.171.162.147]) by smtp.gmail.com with ESMTPSA id\n\th8sm10757175pfe.81.2017.08.06.16.49.27\n\t(version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256);\n\tSun, 06 Aug 2017 16:49:28 -0700 (PDT)"],"Authentication-Results":["ozlabs.org;\n\tdkim=fail reason=\"signature verification failed\" (1024-bit key;\n\tunprotected) header.d=axtens.net header.i=@axtens.net\n\theader.b=\"Y6MYrHUt\"; dkim-atps=neutral","lists.ozlabs.org;\n\tdkim=fail reason=\"signature verification failed\" (1024-bit key;\n\tunprotected) header.d=axtens.net header.i=@axtens.net\n\theader.b=\"Y6MYrHUt\"; dkim-atps=neutral","lists.ozlabs.org; dkim=pass (1024-bit key;\n\tunprotected) header.d=axtens.net header.i=@axtens.net\n\theader.b=\"Y6MYrHUt\"; dkim-atps=neutral"],"DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/relaxed; d=axtens.net; s=google;\n\th=from:to:cc:subject:in-reply-to:references:date:message-id\n\t:mime-version; bh=CQY1gHPTLgn4OvpikaILbPaFqc8tUaXkE/Btb2+jJsM=;\n\tb=Y6MYrHUtDpXn6YV52TPwnBRWHsvbVFzlBo5xDudF3yqgcdeErjV+R/UykYoTbcvrJc\n\tnLuZKvffwCflLSFDPklto5pZFcQx0L+1fRbQ6rpQmmEPEllJ0oGAptZEL8+VmszyA+2M\n\t/a30gUYXSkTlI6QDBmj4TOrUmxsipijN/O56E=","X-Google-DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/relaxed;\n\td=1e100.net; s=20161025;\n\th=x-gm-message-state:from:to:cc:subject:in-reply-to:references:date\n\t:message-id:mime-version;\n\tbh=CQY1gHPTLgn4OvpikaILbPaFqc8tUaXkE/Btb2+jJsM=;\n\tb=HVIKH+oMST1939PiF6pAuHPnG749k8c89jTsbZnHe7Wsrcu+Rmd3NME6LyVDPDVecG\n\t/jlA//3TUSkhb8hFraZ394IJg3awfPNICLzNiDZh7UdiQIXO42V9jCO21xz+ry/yNEcv\n\t1vo4KGIG/SgEmhrFC26BH50p5gWUDcroCZnlmuZrpUYJCjAkA0ykH6+VM26SfrEckAd4\n\tALu+L1aUIZBaB7Yi6Ld9ikSeWR0Sq8OtRmgcbBOX6BZ39Tq1ZlyUX0WHPMd92kiuWw4k\n\t2SobGQtqdKa0mG42/JTCM3qhCYUYVWxTNeWpEqzoLUJm1BtC/FeVCzVfrOgO0P/4rVZE\n\tShlQ==","X-Gm-Message-State":"AHYfb5glz8wXp+ZMnxFhauKyL23c1IW690t6BIiA280PcJ52KfmSQdQ5\n\tOdOoq+Wnr1gl85fl","X-Received":"by 10.84.238.140 with SMTP id v12mr11269425plk.159.1502063368578;\n\tSun, 06 Aug 2017 16:49:28 -0700 (PDT)","From":"Daniel Axtens ","To":"Lukas Wunner ","Subject":"Re: [PATCH 2/3] Split VGA default device handler out of VGA arbiter","In-Reply-To":"<20170805065754.GA8509@wunner.de>","References":"<20170804102033.27731-1-dja@axtens.net>\n\t<20170804102033.27731-3-dja@axtens.net>\n\t<20170805065754.GA8509@wunner.de>","Date":"Mon, 07 Aug 2017 09:49:24 +1000","Message-ID":"<87zibcqmt7.fsf@linkitivity.dja.id.au>","MIME-Version":"1.0","Content-Type":"text/plain","X-BeenThere":"linuxppc-dev@lists.ozlabs.org","X-Mailman-Version":"2.1.23","Precedence":"list","List-Id":"Linux on PowerPC Developers Mail List\n\t","List-Unsubscribe":",\n\t","List-Archive":"","List-Post":"","List-Help":"","List-Subscribe":",\n\t","Cc":"catalin.marinas@arm.com, gabriele.paoloni@huawei.com, airlied@linux.ie, \n\tlinux-pci@vger.kernel.org, will.deacon@arm.com,\n\tdri-devel@lists.freedesktop.org, z.liuxinliang@hisilicon.com,\n\tbhelgaas@google.com, alex.williamson@redhat.com, zourongrong@gmail.com,\n\tdaniel.vetter@intel.com, linuxppc-dev@lists.ozlabs.org,\n\tlinux-arm-kernel@lists.infradead.org","Errors-To":"linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org","Sender":"\"Linuxppc-dev\"\n\t"}}]