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=-6.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,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 8D23BC433E0 for ; Tue, 29 Dec 2020 11:44:42 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (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 D186D207BD for ; Tue, 29 Dec 2020 11:44:41 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D186D207BD Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=ilande.co.uk Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:52062 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kuDQe-0005b7-JM for qemu-devel@archiver.kernel.org; Tue, 29 Dec 2020 06:44:40 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:45128) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kuDQ6-0005CO-T2 for qemu-devel@nongnu.org; Tue, 29 Dec 2020 06:44:06 -0500 Received: from mail.ilande.co.uk ([2001:41c9:1:41f::167]:49576 helo=mail.default.ilande.uk0.bigv.io) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kuDQ4-0005B4-UI for qemu-devel@nongnu.org; Tue, 29 Dec 2020 06:44:06 -0500 Received: from host86-148-34-1.range86-148.btcentralplus.com ([86.148.34.1] helo=[192.168.1.65]) by mail.default.ilande.uk0.bigv.io with esmtpsa (TLS1.3:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.92) (envelope-from ) id 1kuDPy-0006PK-1d; Tue, 29 Dec 2020 11:43:58 +0000 To: BALATON Zoltan References: <8e58807dd2ba46866e7f152244e4541e6425177d.1609107222.git.balaton@eik.bme.hu> From: Mark Cave-Ayland Message-ID: <59564814-9b82-7f9d-7535-201a9ca5189a@ilande.co.uk> Date: Tue, 29 Dec 2020 11:43:52 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.6.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit X-SA-Exim-Connect-IP: 86.148.34.1 X-SA-Exim-Mail-From: mark.cave-ayland@ilande.co.uk Subject: Re: [PATCH v2 2/2] via-ide: Fix fuloong2e support X-SA-Exim-Version: 4.2.1 (built Wed, 08 May 2019 21:11:16 +0000) X-SA-Exim-Scanned: Yes (on mail.default.ilande.uk0.bigv.io) Received-SPF: pass client-ip=2001:41c9:1:41f::167; envelope-from=mark.cave-ayland@ilande.co.uk; helo=mail.default.ilande.uk0.bigv.io X-Spam_score_int: -45 X-Spam_score: -4.6 X-Spam_bar: ---- X-Spam_report: (-4.6 / 5.0 requ) BAYES_00=-1.9, NICE_REPLY_A=-2.698, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Huacai Chen , John Snow , qemu-devel@nongnu.org, Guenter Roeck , f4bug@amsat.org Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 28/12/2020 20:50, BALATON Zoltan via wrote: > I think leaving the legacy ports enabled is a bad idea for at least two reasons: 1) > It may clash with other io ports on other machines, e.g. I'm not sure on PPC where > firmware or OS does not expect to see legacy ISA ports won't map some io BAR of a PCI > card there. 2) If this is left enabled there would be two ports poking the same > registers so if that does not cause a problem by itself, writing to one accidentally > (like when something is mapped over it) could cause corruption of IDE state so I > think it's much better to protect this than later trying to debug such problems. Legacy ioports originate in the x86 world, however all the PCI bus enumeration code I've seen reserves the lower part of the IO address space to prevent such problems with e.g. a BIOS starting up in legacy mode. ATB, Mark.