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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS autolearn=ham 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 1F6B0C10F14 for ; Mon, 22 Apr 2019 01:13:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E87BA2075A for ; Mon, 22 Apr 2019 01:13:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726272AbfDVBNc (ORCPT ); Sun, 21 Apr 2019 21:13:32 -0400 Received: from mail5.windriver.com ([192.103.53.11]:47964 "EHLO mail5.wrs.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725908AbfDVBNc (ORCPT ); Sun, 21 Apr 2019 21:13:32 -0400 Received: from ALA-HCA.corp.ad.wrs.com (ala-hca.corp.ad.wrs.com [147.11.189.40]) by mail5.wrs.com (8.15.2/8.15.2) with ESMTPS id x3M1CPDa012152 (version=TLSv1 cipher=AES128-SHA bits=128 verify=FAIL); Sun, 21 Apr 2019 18:12:51 -0700 Received: from [128.224.162.188] (128.224.162.188) by ALA-HCA.corp.ad.wrs.com (147.11.189.50) with Microsoft SMTP Server (TLS) id 14.3.439.0; Sun, 21 Apr 2019 18:12:41 -0700 Subject: Re: Bug report: A commit about serial8250 cause the output disorderly at the phase of startup To: , linux-rt-users , , References: <5f1398dd-d505-dd8a-0ea1-8186618d56d3@windriver.com> From: "Hongzhi, Song" Message-ID: <82793501-9ddf-11ec-3f91-73872bf3bd54@windriver.com> Date: Mon, 22 Apr 2019 09:12:38 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 MIME-Version: 1.0 In-Reply-To: <5f1398dd-d505-dd8a-0ea1-8186618d56d3@windriver.com> Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: 8bit Content-Language: en-US X-Originating-IP: [128.224.162.188] Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi all, Anyone notice this issue? --Hongzhi On 4/19/19 10:24 AM, Hongzhi, Song wrote: > 1. Issue description: > > Boot kernel( >= linux-rt-devel-v5.0.3 ) with qemu. > Then qemu will print following disorderly messages. > > At the beginning, the messages are disorderly. But then it becomes > normally from printing "[    0.000000] 000: Linux version..." > > -------------------------------------------------- > [    0.019000] 000: tsc: Unable to calibrate against PIT > [    0.002583] 000: 6199.83 BogoMIPS (lpj=3099918) > [    0.521247] 000: Intel(R) Core(TM)2 Duo CPU     T7700  @ 2.40GHz > [    0.521247] 000:  (family: 0x6, model: 0xf > [    0.521247] 000: , stepping: 0xb) > [    0.533126] 000: unsupported p6 CPU model 15 > [    0.533318] 000: no PMU driver, software events only. > [    0.765082] 000: 1 ACPI AML tables successfully acquired and loaded > [    0.765274] 000: > [    0.785903] 000: Enabled 2 GPEs in block 00 to 0F > [    0.786128] 000: > [    0.835675] 000: acpi PNP0A03:00: fail to add MMCONFIG information, > can't access extended PCI configuration space under this bridge. > [    0.892056] 000:  5 > [    0.892289] 000:  *10 > [    0.892416] 000:  11 > [    0.892527] 000: ) > [    0.892661] 000: > > /* skip some repeated contents */ > > [    5.052149] 000: , 512kB Cache > [    0.000000] 000: Linux version 5.0.3-yocto-preempt-rt+ > (hsong@pek-lpggp1) (gcc version 8.3.0 (GCC)) #24 SMP PREEMPT Thu Apr > 18 03:29:58 EDT 2019 > [    0.000000] 000: Command line: root=/dev/vda rw highres=off > console=ttyS0 mem=256M ip=192.168.7.4::192.168.7.3:255.255.255.0 vga=0 > uvesafb.mode_opti0 > [    0.000000] 000: x86/fpu: x87 FPU will use FXSAVE > [    0.000000] 000: BIOS-provided physical RAM map: > [    0.000000] 000: BIOS-e820: [mem > 0x0000000000000000-0x000000000009fbff] > [    0.000000] 000: BIOS-e820: [mem > 0x000000000009fc00-0x000000000009ffff] > [    0.000000] 000: BIOS-e820: [mem > 0x00000000000f0000-0x00000000000fffff] > [    0.000000] 000: BIOS-e820: [mem > 0x0000000000100000-0x000000000ffdbfff] > > -------------------------------------------------- > > 2. Reproduce: > (1)build kernel: (Attachment is my .config) > make ARCH=x86_64 > CROSS_COMPILE=[path-to-my-cross-toolchain]/x86_64-wrs-linux- > > (2)boot kernel with qemu: > > qemu-system-x86_64 \ > -drive file=qemux86-64.rootfs.ext4,if=virtio,format=raw \ > -nographic \ > -kernel arch/x86/boot/bzImage \ > -append 'root=/dev/vda rw highres=off  console=ttyS0 mem=256M ip=dhcp' > > 3. Analysis: > I find the following commit from >=linux-rt-devel-v5.0.3. cause the > issue. > > b9d460e serial: 8250: implement write_atomic >