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=-11.5 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_2 autolearn=unavailable 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 90919C433E4 for ; Mon, 27 Jul 2020 11:18:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 72A542078A for ; Mon, 27 Jul 2020 11:18:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726475AbgG0LSv (ORCPT ); Mon, 27 Jul 2020 07:18:51 -0400 Received: from lhrrgout.huawei.com ([185.176.76.210]:2533 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726269AbgG0LSv (ORCPT ); Mon, 27 Jul 2020 07:18:51 -0400 Received: from lhreml710-chm.china.huawei.com (unknown [172.18.7.107]) by Forcepoint Email with ESMTP id 0D70944B09787BEA11F6; Mon, 27 Jul 2020 12:18:50 +0100 (IST) Received: from localhost (10.52.121.176) by lhreml710-chm.china.huawei.com (10.201.108.61) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256) id 15.1.1913.5; Mon, 27 Jul 2020 12:18:49 +0100 Date: Mon, 27 Jul 2020 12:17:26 +0100 From: Jonathan Cameron To: Sean V Kelley CC: , , , , , , , Qiuxu Zhuo Subject: Re: [RFC PATCH 5/9] PCI/AER: Apply function level reset to RCiEP on fatal error Message-ID: <20200727121726.000072a8@Huawei.com> In-Reply-To: <20200724172223.145608-6-sean.v.kelley@intel.com> References: <20200724172223.145608-1-sean.v.kelley@intel.com> <20200724172223.145608-6-sean.v.kelley@intel.com> Organization: Huawei Technologies Research and Development (UK) Ltd. X-Mailer: Claws Mail 3.17.4 (GTK+ 2.24.32; i686-w64-mingw32) MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.52.121.176] X-ClientProxiedBy: lhreml704-chm.china.huawei.com (10.201.108.53) To lhreml710-chm.china.huawei.com (10.201.108.61) X-CFilter-Loop: Reflected Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org On Fri, 24 Jul 2020 10:22:19 -0700 Sean V Kelley wrote: > From: Qiuxu Zhuo > > Attempt to do function level reset for an RCiEP associated with an > RCEC device on fatal error. I'd like to understand more on your reasoning for flr here. Is it simply that it is all we can do, or is there some basis in a spec somewhere? > > Signed-off-by: Qiuxu Zhuo > --- > drivers/pci/pcie/err.c | 31 ++++++++++++++++++++++--------- > 1 file changed, 22 insertions(+), 9 deletions(-) > > diff --git a/drivers/pci/pcie/err.c b/drivers/pci/pcie/err.c > index 044df004f20b..9b3ec94bdf1d 100644 > --- a/drivers/pci/pcie/err.c > +++ b/drivers/pci/pcie/err.c > @@ -170,6 +170,17 @@ static void pci_walk_dev_affected(struct pci_dev *dev, int (*cb)(struct pci_dev > } > } > > +static enum pci_channel_state flr_on_rciep(struct pci_dev *dev) > +{ > + if (!pcie_has_flr(dev)) > + return PCI_ERS_RESULT_NONE; > + > + if (pcie_flr(dev)) > + return PCI_ERS_RESULT_DISCONNECT; > + > + return PCI_ERS_RESULT_RECOVERED; > +} > + > pci_ers_result_t pcie_do_recovery(struct pci_dev *dev, > enum pci_channel_state state, > pci_ers_result_t (*reset_link)(struct pci_dev *pdev)) > @@ -191,15 +202,17 @@ pci_ers_result_t pcie_do_recovery(struct pci_dev *dev, > if (state == pci_channel_io_frozen) { > pci_walk_dev_affected(dev, report_frozen_detected, &status); > if (pci_pcie_type(dev) == PCI_EXP_TYPE_RC_END) { > - pci_warn(dev, "link reset not possible for RCiEP\n"); > - status = PCI_ERS_RESULT_NONE; > - goto failed; > - } > - > - status = reset_link(dev); > - if (status != PCI_ERS_RESULT_RECOVERED) { > - pci_warn(dev, "link reset failed\n"); > - goto failed; > + status = flr_on_rciep(dev); > + if (status != PCI_ERS_RESULT_RECOVERED) { > + pci_warn(dev, "function level reset failed\n"); > + goto failed; > + } > + } else { > + status = reset_link(dev); > + if (status != PCI_ERS_RESULT_RECOVERED) { > + pci_warn(dev, "link reset failed\n"); > + goto failed; > + } > } > } else { > pci_walk_dev_affected(dev, report_normal_detected, &status);