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=-4.0 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED 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 3CC02C07E95 for ; Sat, 10 Jul 2021 04:32:10 +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 E7AC6613DC for ; Sat, 10 Jul 2021 04:32:09 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E7AC6613DC Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=bugs.launchpad.net Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:58308 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1m24eu-0005YS-Vv for qemu-devel@archiver.kernel.org; Sat, 10 Jul 2021 00:32:09 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:48526) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1m24ZP-0000CX-TG for qemu-devel@nongnu.org; Sat, 10 Jul 2021 00:26:27 -0400 Received: from indium.canonical.com ([91.189.90.7]:45708) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1m24ZO-0000bs-A3 for qemu-devel@nongnu.org; Sat, 10 Jul 2021 00:26:27 -0400 Received: from loganberry.canonical.com ([91.189.90.37]) by indium.canonical.com with esmtp (Exim 4.93 #5 (Debian)) id 1m24Z9-0003gS-UY for ; Sat, 10 Jul 2021 04:26:12 +0000 Received: from loganberry.canonical.com (localhost [127.0.0.1]) by loganberry.canonical.com (Postfix) with ESMTP id 04F4D2E826F for ; Sat, 10 Jul 2021 04:26:04 +0000 (UTC) MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Date: Sat, 10 Jul 2021 04:17:20 -0000 From: Launchpad Bug Tracker <1905297@bugs.launchpad.net> To: qemu-devel@nongnu.org X-Launchpad-Notification-Type: bug X-Launchpad-Bug: product=qemu; status=Expired; importance=Undecided; assignee=None; X-Launchpad-Bug-Information-Type: Public X-Launchpad-Bug-Private: no X-Launchpad-Bug-Security-Vulnerability: no X-Launchpad-Bug-Commenters: janitor michaelpeter philmd th-huth X-Launchpad-Bug-Reporter: Michael Peter (michaelpeter) X-Launchpad-Bug-Modifier: Launchpad Janitor (janitor) References: <160614967524.17013.9714069541645314856.malonedeb@wampee.canonical.com> Message-Id: <162589064019.5654.15245040083649718287.malone@loganberry.canonical.com> Subject: [Bug 1905297] Re: Zynq7000 UART clock reset initialization X-Launchpad-Message-Rationale: Subscriber (QEMU) @qemu-devel-ml X-Launchpad-Message-For: qemu-devel-ml Precedence: bulk X-Generated-By: Launchpad (canonical.com); Revision="1b66c075b8638845e61f40eb9036fabeaa01f591"; Instance="production" X-Launchpad-Hash: bf8cfead19f58f01b49a178aeab016a1c4a42bfb Received-SPF: none client-ip=91.189.90.7; envelope-from=bounces@canonical.com; helo=indium.canonical.com X-Spam_score_int: -68 X-Spam_score: -6.9 X-Spam_bar: ------ X-Spam_report: (-6.9 / 5.0 requ) BAYES_00=-1.9, HEADER_FROM_DIFFERENT_DOMAINS=0.001, RCVD_IN_DNSWL_HI=-5, RCVD_IN_MSPIKE_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_NONE=0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Bug 1905297 <1905297@bugs.launchpad.net> Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" [Expired for QEMU because there has been no activity for 60 days.] ** Changed in: qemu Status: Incomplete =3D> Expired -- = You received this bug notification because you are a member of qemu- devel-ml, which is subscribed to QEMU. https://bugs.launchpad.net/bugs/1905297 Title: Zynq7000 UART clock reset initialization Status in QEMU: Expired Bug description: Hello, we have come across a strange behavior in the Zynq7000 model of Qemu that seems to have been introduced between 5.0.0 and 5.1.0. = The reset values of the SLCR register, in particular those for UART_CLK_C= TRL, are such that the UARTs should find functional clocks. Up to 5.0.0 this was also the be= havior that was implemented in QEMU. Starting in 5.1.0, we found that - despite correct reset values [1] - the= UARTs are non-functional upon reset. Some investigation revealed that the cause for that is that t= he corresponding clocks are not properly initialized. Between 5.0.0 and 5.1.0, there are three commits that touch the Zynq UART clocks [2]. The last of them [3] triggers the faulty behavior. Attached is a patch that applies 5.2.0-rc2 and yields a functional UART. = We surmise that the underlying device release issue runs much deeper, so it is only meant to = identify the issue. [1] hw/misc/zynq_slcr.c static void zynq_slcr_reset_init(Object *obj, ResetType type) s->regs[R_UART_CLK_CTRL] =3D 0x00003F03; [2] 38867cb7ec90..5b49a34c6800 [3] commit 5b49a34c6800d0cb917f959d8e75e5775f0fac3f (refs/bisect/bad) Author: Damien Hedde Date: Mon Apr 6 15:52:50 2020 +0200 To manage notifications about this bug go to: https://bugs.launchpad.net/qemu/+bug/1905297/+subscriptions