From nobody Mon Apr 29 06:55:19 2024 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; spf=pass (zoho.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail(p=none dis=none) header.from=redhat.com ARC-Seal: i=1; a=rsa-sha256; t=1569338197; cv=none; d=zoho.com; s=zohoarc; b=R3gMkGHH0bOw6wPBv+xVRmu2Is5XeECCAsVjip9i5AujEDVtZy7E+DNIUIfBZkH/+sR/n2llMZa6Efgt0X/y9Tym1kfooA7LN4PhA0LRSIjL+A4y8FlMIu6eZzJ6n+GGVUCT0nJccA30hxWmzisXSdmqE95nZZU9pr4sKr27kII= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zoho.com; s=zohoarc; t=1569338197; h=Content-Type:Content-Transfer-Encoding:Cc:Date:From:List-Subscribe:List-Post:List-Id:List-Archive:List-Help:List-Unsubscribe:MIME-Version:Message-ID:Sender:Subject:To:ARC-Authentication-Results; bh=86I1tsrpFkq9PrinBexRunLeXs+0nqltYJUZsUIywuk=; b=VHxuiDFhQX/ZPfiVCY0yqh1STv0FCjU9GLhQUIXH+XTqYT/RJFqFmS42UHVLHszVBve843QtC49+FhjIAMvuDa7mUHgsPgvo6mQqUJY+vBBVaqF9kQtb2rmxrfMbtVQ3cNj7UO1c63ZPIrVnwLh9QBj7Ij66jU87W3G41NF8uw0= ARC-Authentication-Results: i=1; mx.zoho.com; spf=pass (zoho.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail header.from= (p=none dis=none) header.from= Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1569338197724244.69565497619556; Tue, 24 Sep 2019 08:16:37 -0700 (PDT) Received: from localhost ([::1]:46894 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iCmYN-0001rV-Nh for importer@patchew.org; Tue, 24 Sep 2019 11:16:35 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:37970) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iClYd-0008DK-A7 for qemu-devel@nongnu.org; Tue, 24 Sep 2019 10:12:48 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1iClYb-0007py-R3 for qemu-devel@nongnu.org; Tue, 24 Sep 2019 10:12:47 -0400 Received: from mx1.redhat.com ([209.132.183.28]:35338) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1iClYT-0007n6-Pp; Tue, 24 Sep 2019 10:12:38 -0400 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 8471230A7B89; Tue, 24 Sep 2019 14:12:36 +0000 (UTC) Received: from x1w.redhat.com (unknown [10.40.205.15]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 990645C1B2; Tue, 24 Sep 2019 14:12:31 +0000 (UTC) From: =?UTF-8?q?Philippe=20Mathieu-Daud=C3=A9?= To: qemu-devel@nongnu.org Subject: [PATCH] hw/timer/pl031: Add warning "do not use as model to implement a RTC" Date: Tue, 24 Sep 2019 16:12:28 +0200 Message-Id: <20190924141228.25009-1-philmd@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.47]); Tue, 24 Sep 2019 14:12:36 +0000 (UTC) Content-Transfer-Encoding: quoted-printable X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 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: qemu-trivial@nongnu.org, Peter Maydell , qemu-arm@nongnu.org, =?UTF-8?q?Philippe=20Mathieu-Daud=C3=A9?= Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" Content-Type: text/plain; charset="utf-8" Peter said we should "not use the pl031 as a good model of how to do an RTC, it has some definite flaws." Add this information to the PL031 header for other developers. Suggested-by: Peter Maydell Signed-off-by: Philippe Mathieu-Daud=C3=A9 --- hw/timer/pl031.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/hw/timer/pl031.c b/hw/timer/pl031.c index 2b3e261006..da453b5b04 100644 --- a/hw/timer/pl031.c +++ b/hw/timer/pl031.c @@ -1,6 +1,14 @@ /* * ARM AMBA PrimeCell PL031 RTC * + * Note from the maintainer: + * + * Don't use the pl031 code as a good model of how to do an RTC, + * it has some definite flaws. x86 or ppc RTC handling is probably + * a better place to look. + * + * See https://lists.gnu.org/archive/html/qemu-devel/2019-09/msg05399.html + * * Copyright (c) 2007 CodeSourcery * * This file is free software; you can redistribute it and/or modify --=20 2.20.1