From patchwork Sun Sep 27 03:28:28 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Zhao, Haifeng" X-Patchwork-Id: 11801747 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id C83306CA for ; Sun, 27 Sep 2020 03:30:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BA27C2100A for ; Sun, 27 Sep 2020 03:30:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730251AbgI0DaN (ORCPT ); Sat, 26 Sep 2020 23:30:13 -0400 Received: from mga12.intel.com ([192.55.52.136]:65386 "EHLO mga12.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730250AbgI0DaN (ORCPT ); Sat, 26 Sep 2020 23:30:13 -0400 IronPort-SDR: NxTuNn9+vb+x2PaDySmV0JOT6jJbvwlVXQwCIZ+WjPmm4qi24g3gT6PxcNqwH3mdMK8qgqLIf7 l9UM12bnhMXA== X-IronPort-AV: E=McAfee;i="6000,8403,9756"; a="141242670" X-IronPort-AV: E=Sophos;i="5.77,308,1596524400"; d="scan'208";a="141242670" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga004.fm.intel.com ([10.253.24.48]) by fmsmga106.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 26 Sep 2020 20:30:12 -0700 IronPort-SDR: k7kuHZOWuM6IQrSnGRUR3zYbRDGCMufzqKZhok+pDtbmKePH/qNPUOJY5HucATi1ycN9zgk3KE 870H3MnH+aJw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.77,308,1596524400"; d="scan'208";a="337697538" Received: from shskylake.sh.intel.com ([10.239.48.137]) by fmsmga004.fm.intel.com with ESMTP; 26 Sep 2020 20:30:09 -0700 From: Ethan Zhao To: bhelgaas@google.com, oohall@gmail.com, ruscur@russell.cc, lukas@wunner.de, andriy.shevchenko@linux.intel.com, stuart.w.hayes@gmail.com, mr.nuke.me@gmail.com, mika.westerberg@linux.intel.com Cc: linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, pei.p.jia@intel.com, ashok.raj@linux.intel.com, sathyanarayanan.kuppuswamy@intel.com, Ethan Zhao Subject: [PATCH 4/5 V2] PCI: only return true when dev io state is really changed Date: Sat, 26 Sep 2020 23:28:28 -0400 Message-Id: <20200927032829.11321-5-haifeng.zhao@intel.com> X-Mailer: git-send-email 2.18.4 In-Reply-To: <20200927032829.11321-1-haifeng.zhao@intel.com> References: <20200927032829.11321-1-haifeng.zhao@intel.com> Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org When uncorrectable error happens, AER driver and DPC driver interrupt handlers likely call pcie_do_recovery() ->pci_walk_bus() ->report_frozen_detected() with pci_channel_io_frozen the same time. If pci_dev_set_io_state() return true even if the original state is pci_channel_io_frozen, that will cause AER or DPC handler re-enter the error detecting and recovery procedure one after another. The result is the recovery flow mixed between AER and DPC. So simplify the pci_dev_set_io_state() function to only return true when dev->error_state is changed. Signed-off-by: Ethan Zhao Tested-by: Wen Jin Tested-by: Shanshan Zhang Reviewed-by: Andy Shevchenko Reviewed-by: Alexandru Gagniuc --- Changes: V2: revise doc and code flow according to Andy's suggestion. drivers/pci/pci.h | 34 +++++----------------------------- 1 file changed, 5 insertions(+), 29 deletions(-) diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h index fa12f7cbc1a0..387f891ce6a1 100644 --- a/drivers/pci/pci.h +++ b/drivers/pci/pci.h @@ -362,35 +362,11 @@ static inline bool pci_dev_set_io_state(struct pci_dev *dev, bool changed = false; device_lock_assert(&dev->dev); - switch (new) { - case pci_channel_io_perm_failure: - switch (dev->error_state) { - case pci_channel_io_frozen: - case pci_channel_io_normal: - case pci_channel_io_perm_failure: - changed = true; - break; - } - break; - case pci_channel_io_frozen: - switch (dev->error_state) { - case pci_channel_io_frozen: - case pci_channel_io_normal: - changed = true; - break; - } - break; - case pci_channel_io_normal: - switch (dev->error_state) { - case pci_channel_io_frozen: - case pci_channel_io_normal: - changed = true; - break; - } - break; - } - if (changed) - dev->error_state = new; + if (dev->error_state == new) + return changed; + + dev->error_state = new; + changed = true; return changed; }