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=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS 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 61E40C433F5 for ; Fri, 10 Sep 2021 09:32:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 417B66105A for ; Fri, 10 Sep 2021 09:32:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231916AbhIJJda (ORCPT ); Fri, 10 Sep 2021 05:33:30 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46964 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231818AbhIJJd3 (ORCPT ); Fri, 10 Sep 2021 05:33:29 -0400 Received: from bombadil.infradead.org (bombadil.infradead.org [IPv6:2607:7c80:54:e::133]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BA189C061574 for ; Fri, 10 Sep 2021 02:32:18 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=MIME-Version:Content-Type:References: In-Reply-To:Date:Cc:To:From:Subject:Message-ID:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=nuSqD2vwifGtH2/hBbiDYPaHSatLdkbMylszZECNmsw=; b=W50Y9QnvBTM8ksbBqLQcrDatwh Ocsjg/LxtjWA9TpkOwo7MtlL5Ju5v+KLgnMmTnqeQ0p8VYzG7Ui1OOH7gayLGtHCpo7Nb+qb0PsHJ Ko9DkCrGBTPOt0BYd1xzAvOVllDVoJBhjeBKN312cprGdQ0B0XTXanNs17QEnlJI1U1zRiTyv5m65 d+5c3NXGo6XISCsdSecHZHhpgq5olPwnZj8Fns0Da1Xv+mle3bLulcFW91we8/UXNaEnZ/L+GwfBm CL98RhVhpdQaSteAitiXSnRvi+rRQH94X1MkaSfZCIUH1KsdLYeEsVInQxUWWr1dkC39pzW/XyRo0 kLpq3q5A==; Received: from [2001:8b0:10b:1::3ae] (helo=u3832b3a9db3152.infradead.org) by bombadil.infradead.org with esmtpsa (Exim 4.94.2 #2 (Red Hat Linux)) id 1mOctM-00CMC0-Il; Fri, 10 Sep 2021 09:32:17 +0000 Message-ID: <0d113858778a53b0a89400a81f2a06bb4474351d.camel@infradead.org> Subject: Re: [PATCH v4 0/3] Improve PCI device post-reset readiness polling From: David Woodhouse To: Stanislav Spassov , linux-pci@vger.kernel.org Cc: Stanislav Spassov , Bjorn Helgaas , Thomas Gleixner , Andrew Morton , "Jan H ." =?ISO-8859-1?Q?Sch=F6nherr?= , Jonathan Corbet , Ashok Raj , Alex Williamson , Sinan Kaya , Rajat Jain Date: Fri, 10 Sep 2021 10:32:12 +0100 In-Reply-To: <8c9c45025b6130719d23c2fe151e2b6d3eef3baf.camel@infradead.org> References: <20200307172044.29645-1-stanspas@amazon.com> <8c9c45025b6130719d23c2fe151e2b6d3eef3baf.camel@infradead.org> Content-Type: multipart/signed; micalg="sha-256"; protocol="application/pkcs7-signature"; boundary="=-MyHSPKApf9fMhhZ77wPA" User-Agent: Evolution 3.36.5-0ubuntu1 MIME-Version: 1.0 X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org --=-MyHSPKApf9fMhhZ77wPA Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Fri, 2021-01-22 at 08:54 +0000, David Woodhouse wrote: > On Sat, 2020-03-07 at 18:20 +0100, Stanislav Spassov wrote: > > From: Stanislav Spassov < > > stanspas@amazon.de > > > > >=20 > > The first version of this patch series can be found here: > > https://lore.kernel.org/linux-pci/20200223122057.6504-1-stanspas@amazon= .com > >=20 > >=20 > > The goal of this patch series is to solve an issue where pci_dev_wait > > can cause system crashes. After a reset, a hung device may keep > > responding with CRS completions indefinitely. If CRS Software Visibilit= y > > is enabled on the Root Port, attempting to read any register other than > > PCI_VENDOR_ID will cause the Root Port to autonomously retry the reques= t > > without reporting back to the CPU core. Unless the number of retries or > > the amount of time spent retrying is limited by platform-specific means= , > > this scenario leads to low-level platform timeouts (such as a TOR > > Timeout), which can easily escalate to a crash. > >=20 > > Feedback on the v1 inspired a lot of additional improvements all around= the > > device reset codepaths and reducing post-reset delays. These improvemen= ts > > were published as part of v2 (v3 is just small build fixes). > >=20 > > It looks like there is immediate demand specifically for the CRS work, > > so I am once again reducing the series to just that. The reset will be > > posted as a separate patch series that will likely require more time an= d > > iterations to stabilize. >=20 > Hm, what happened to this? >=20 > Bjorn? 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