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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 04660C32767 for ; Sat, 4 Jan 2020 01:05:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D57E621835 for ; Sat, 4 Jan 2020 01:05:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727218AbgADBF1 (ORCPT ); Fri, 3 Jan 2020 20:05:27 -0500 Received: from mga14.intel.com ([192.55.52.115]:3117 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726968AbgADBF0 (ORCPT ); Fri, 3 Jan 2020 20:05:26 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga002.jf.intel.com ([10.7.209.21]) by fmsmga103.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 03 Jan 2020 17:05:26 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.69,392,1571727600"; d="scan'208";a="232264180" Received: from linux.intel.com ([10.54.29.200]) by orsmga002.jf.intel.com with ESMTP; 03 Jan 2020 17:05:25 -0800 Received: from [10.54.74.33] (skuppusw-desk.jf.intel.com [10.54.74.33]) by linux.intel.com (Postfix) with ESMTP id 00525580569; Fri, 3 Jan 2020 17:05:25 -0800 (PST) Reply-To: sathyanarayanan.kuppuswamy@linux.intel.com Subject: Re: [PATCH v11 1/8] PCI/ERR: Update error status after reset_link() To: Bjorn Helgaas Cc: linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, ashok.raj@intel.com, keith.busch@intel.com References: <20200104003452.GA63827@google.com> From: Kuppuswamy Sathyanarayanan Organization: Intel Message-ID: Date: Fri, 3 Jan 2020 17:03:03 -0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.9.0 MIME-Version: 1.0 In-Reply-To: <20200104003452.GA63827@google.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 1/3/20 4:34 PM, Bjorn Helgaas wrote: > On Thu, Dec 26, 2019 at 04:39:07PM -0800, sathyanarayanan.kuppuswamy@linux.intel.com wrote: >> From: Kuppuswamy Sathyanarayanan >> >> Commit bdb5ac85777d ("PCI/ERR: Handle fatal error recovery") uses >> reset_link() to recover from fatal errors. But, if the reset is >> successful there is no need to continue the rest of the error recovery >> checks. Also, during fatal error recovery, if the initial value of error >> status is PCI_ERS_RESULT_DISCONNECT or PCI_ERS_RESULT_NO_AER_DRIVER then >> even after successful recovery (using reset_link()) pcie_do_recovery() >> will report the recovery result as failure. So update the status of >> error after reset_link(). > I like the part about updating "status" with the result of > reset_link(), and I split that into its own patch because it > seems like a fix that *can* be separated. > > But I'm not convinced that we should skip the ->slot_reset() > callbacks if the reset_link() was successful. If reset_link() call is successful then the result value will be "PCI_ERS_RESULT_RECOVERED". So even if you proceed with rest of the code, slot_reset() will never get called right ? > According to > Documentation/PCI/pci-error-recovery.rst, we should call > ->slot_reset() after completion of the reset. > > For example, rsxx_err_handler implements ->slot_reset(), but > not ->resume(). If we reset the device, we'll claim success and > return, but we won't call rsxx_slot_reset(), which does a bunch > of important-looking recovery stuff. > > If pci-error-recovery.rst is wrong, we should fix that (after > auditing all the drivers to make sure they match). > >> Fixes: bdb5ac85777d ("PCI/ERR: Handle fatal error recovery") >> Cc: Ashok Raj >> Cc: Keith Busch >> Signed-off-by: Kuppuswamy Sathyanarayanan >> Acked-by: Keith Busch >> --- >> drivers/pci/pcie/err.c | 10 +++++++--- >> 1 file changed, 7 insertions(+), 3 deletions(-) >> >> diff --git a/drivers/pci/pcie/err.c b/drivers/pci/pcie/err.c >> index b0e6048a9208..53cd9200ec2c 100644 >> --- a/drivers/pci/pcie/err.c >> +++ b/drivers/pci/pcie/err.c >> @@ -204,9 +204,12 @@ void pcie_do_recovery(struct pci_dev *dev, enum pci_channel_state state, >> else >> pci_walk_bus(bus, report_normal_detected, &status); >> >> - if (state == pci_channel_io_frozen && >> - reset_link(dev, service) != PCI_ERS_RESULT_RECOVERED) >> - goto failed; >> + if (state == pci_channel_io_frozen) { >> + status = reset_link(dev, service); >> + if (status != PCI_ERS_RESULT_RECOVERED) >> + goto failed; >> + goto done; >> + } >> >> if (status == PCI_ERS_RESULT_CAN_RECOVER) { >> status = PCI_ERS_RESULT_RECOVERED; >> @@ -228,6 +231,7 @@ void pcie_do_recovery(struct pci_dev *dev, enum pci_channel_state state, >> if (status != PCI_ERS_RESULT_RECOVERED) >> goto failed; >> >> +done: >> pci_dbg(dev, "broadcast resume message\n"); >> pci_walk_bus(bus, report_resume, &status); >> >> -- >> 2.21.0 >> -- Sathyanarayanan Kuppuswamy Linux kernel developer