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=-7.5 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,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 A68F2C433E1 for ; Wed, 26 Aug 2020 11:15:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7DB0C206E3 for ; Wed, 26 Aug 2020 11:15:41 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=ibm.com header.i=@ibm.com header.b="NQSsqa27" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728805AbgHZLPW (ORCPT ); Wed, 26 Aug 2020 07:15:22 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:22308 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728668AbgHZLOb (ORCPT ); Wed, 26 Aug 2020 07:14:31 -0400 Received: from pps.filterd (m0098409.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 07QB3IIM112212; Wed, 26 Aug 2020 07:14:19 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=subject : to : cc : references : from : message-id : date : mime-version : in-reply-to : content-type : content-transfer-encoding; s=pp1; bh=TusebNyuzSZj6zQ1qcq5fCJU7Qk0mlvSif7um9HzO9I=; b=NQSsqa27uQfGSHl+6tFWbHyHia+PmDtjkmPoXRg20wlXf3gMnRaye48i44VnECKaaFZL mXSObA0Lh9jhK0js2Xx07hKPtRrC/qtisDnye3DjV+qH71/t82w88RyYed1+GH6rbyXm +HdbdyPyLa2wFBXk3LHHHv5zZ6DtIh6qbh55+PEId0zzVtrxkM4BDhKAPYznqv1lKhBh 1uYNNtWNMFHS1xTNEPrBM8e+6V16NHUzbD7eHnZ2ggEL2txwFmvVYMuj1gGqFRRWmOOo xWP4sm75+C0e5H0EDSJpu0A7Y85PFazG9ectbhoQu3xVfNr4zHE1rHZR3fbqp1to16wf VQ== Received: from ppma04ams.nl.ibm.com (63.31.33a9.ip4.static.sl-reverse.com [169.51.49.99]) by mx0a-001b2d01.pphosted.com with ESMTP id 335pfn8cxn-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 26 Aug 2020 07:14:19 -0400 Received: from pps.filterd (ppma04ams.nl.ibm.com [127.0.0.1]) by ppma04ams.nl.ibm.com (8.16.0.42/8.16.0.42) with SMTP id 07QBBZ28000618; Wed, 26 Aug 2020 11:14:16 GMT Received: from b06avi18878370.portsmouth.uk.ibm.com (b06avi18878370.portsmouth.uk.ibm.com [9.149.26.194]) by ppma04ams.nl.ibm.com with ESMTP id 33498uadc4-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 26 Aug 2020 11:14:16 +0000 Received: from b06wcsmtp001.portsmouth.uk.ibm.com (b06wcsmtp001.portsmouth.uk.ibm.com [9.149.105.160]) by b06avi18878370.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 07QBEEE349545564 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 26 Aug 2020 11:14:14 GMT Received: from b06wcsmtp001.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 82C98A405F; Wed, 26 Aug 2020 11:14:14 +0000 (GMT) Received: from b06wcsmtp001.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 6D56CA405B; Wed, 26 Aug 2020 11:14:13 +0000 (GMT) Received: from [9.199.33.201] (unknown [9.199.33.201]) by b06wcsmtp001.portsmouth.uk.ibm.com (Postfix) with ESMTP; Wed, 26 Aug 2020 11:14:13 +0000 (GMT) Subject: Re: [PATCH 4.19 65/71] powerpc/pseries: Do not initiate shutdown when system is running on UPS To: Pavel Machek , Greg Kroah-Hartman Cc: linux-kernel@vger.kernel.org, stable@vger.kernel.org, Michael Ellerman References: <20200824082355.848475917@linuxfoundation.org> <20200824082359.202438041@linuxfoundation.org> <20200825195620.GB27453@duo.ucw.cz> From: Vasant Hegde Message-ID: <268a861f-59ac-679c-7507-d685d059a2ab@linux.vnet.ibm.com> Date: Wed, 26 Aug 2020 16:44:12 +0530 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.8.0 MIME-Version: 1.0 In-Reply-To: <20200825195620.GB27453@duo.ucw.cz> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-TM-AS-GCONF: 00 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.235,18.0.687 definitions=2020-08-26_08:2020-08-26,2020-08-26 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 clxscore=1011 impostorscore=0 mlxlogscore=999 lowpriorityscore=0 priorityscore=1501 mlxscore=0 malwarescore=0 adultscore=0 bulkscore=0 phishscore=0 suspectscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2006250000 definitions=main-2008260089 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 8/26/20 1:26 AM, Pavel Machek wrote: > Hi! > Hi Pavel, >> We have a user space tool (rtas_errd) on LPAR to monitor for >> EPOW_SHUTDOWN_ON_UPS. Once it gets an event it initiates shutdown >> after predefined time. It also starts monitoring for any new EPOW > > Yeah, so there's userspace tool, and currently systems _with_ that > tool work poorly with UPS. > > So you have fixed that, and now, systems _without_ that tool will work > poorly. User space tool exists for long long time (more than decade) and its default tool on pseries system. Also user space tool behavior is not changed for long time. The original design was to forward UPS event to userspace and let user space wait for predefined time and then initiate shutdown. Previous fix accidentally initiated shutdown as soon as system switch to UPS power. > > That's not a fix for serious bug, that's behaviour change. You are > fixing one set of systems and breaking another. Without fix, as soon as system switches to UPS power supply, kernel will start shutdown process. which is not correct. Its actually impacting customers running Linux on pseries LPAR mode. Hence I have requested this fix for stable tree. Hope this clarifies your concern. -Vasant > > I don't believe it is suitable for stable. > > Pavel > >> @@ -118,7 +118,6 @@ static void handle_system_shutdown(char >> case EPOW_SHUTDOWN_ON_UPS: >> pr_emerg("Loss of system power detected. System is running on" >> " UPS/battery. Check RTAS error log for details\n"); >> - orderly_poweroff(true); >> break; >> >> case EPOW_SHUTDOWN_LOSS_OF_CRITICAL_FUNCTIONS: >> >