From patchwork Wed Mar 24 12:19:01 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kishon Vijay Abraham I X-Patchwork-Id: 12160901 X-Patchwork-Delegate: lorenzo.pieralisi@arm.com 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=-19.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT 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 91960C433C1 for ; Wed, 24 Mar 2021 12:20:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 66ED96192B for ; Wed, 24 Mar 2021 12:20:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233911AbhCXMT4 (ORCPT ); Wed, 24 Mar 2021 08:19:56 -0400 Received: from fllv0015.ext.ti.com ([198.47.19.141]:55160 "EHLO fllv0015.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233676AbhCXMTX (ORCPT ); Wed, 24 Mar 2021 08:19:23 -0400 Received: from lelv0266.itg.ti.com ([10.180.67.225]) by fllv0015.ext.ti.com (8.15.2/8.15.2) with ESMTP id 12OCJDSJ012494; Wed, 24 Mar 2021 07:19:13 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ti.com; s=ti-com-17Q1; t=1616588353; bh=cowBO1dcfWlhVDX9uRu8VrJ6Mb2a92ZE4IRbCBJpBKo=; h=From:To:CC:Subject:Date:In-Reply-To:References; b=sTbKL1tlWI5F8XPGpDfHYCsupd8u88PTi3MsGp7tw4V+6AXZr6KaLvLo2zBnpFJ+k X+N4uz9xmk7ncs4UCM8Bmwi8ze/945mX3mGzgvYmiz4GOGLBosucAjLr1PQcpFfd6M v7O/AjvFq0P8QAgv8QnLt56wu+UEGNEphMciw1W8= Received: from DFLE106.ent.ti.com (dfle106.ent.ti.com [10.64.6.27]) by lelv0266.itg.ti.com (8.15.2/8.15.2) with ESMTPS id 12OCJD1V021542 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=FAIL); Wed, 24 Mar 2021 07:19:13 -0500 Received: from DFLE104.ent.ti.com (10.64.6.25) by DFLE106.ent.ti.com (10.64.6.27) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2176.2; Wed, 24 Mar 2021 07:19:12 -0500 Received: from lelv0327.itg.ti.com (10.180.67.183) by DFLE104.ent.ti.com (10.64.6.25) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2176.2 via Frontend Transport; Wed, 24 Mar 2021 07:19:13 -0500 Received: from a0393678-ssd.dhcp.ti.com (ileax41-snat.itg.ti.com [10.172.224.153]) by lelv0327.itg.ti.com (8.15.2/8.15.2) with ESMTP id 12OCJ1Ci121061; Wed, 24 Mar 2021 07:19:09 -0500 From: Kishon Vijay Abraham I To: Kishon Vijay Abraham I , Lorenzo Pieralisi , Rob Herring , Bjorn Helgaas CC: , , , Lokesh Vutla Subject: [PATCH 2/2] PCI: keystone: Add link up check in ks_child_pcie_ops.map_bus() Date: Wed, 24 Mar 2021 17:49:01 +0530 Message-ID: <20210324121901.1856-3-kishon@ti.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20210324121901.1856-1-kishon@ti.com> References: <20210324121901.1856-1-kishon@ti.com> MIME-Version: 1.0 X-EXCLAIMER-MD-CONFIG: e1e8a2fd-e40a-4ac6-ac9b-f7e9cc9ee180 Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org K2G forwardS the error triggered by a link-down state (e.g., no connected endpoint device) on the system bus for PCI configuration transactions; these errors are reported as an SError at system level, which is fatal and hangs the system. So fix it similar to how it was done in designware core driver commit 15b23906347c ("PCI: dwc: Add link up check in dw_child_pcie_ops.map_bus()"). Fixes: 10a797c6e54a ("PCI: dwc: keystone: Use pci_ops for config space accessors") Signed-off-by: Kishon Vijay Abraham I Cc: # v5.10 --- drivers/pci/controller/dwc/pci-keystone.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/drivers/pci/controller/dwc/pci-keystone.c b/drivers/pci/controller/dwc/pci-keystone.c index 7171ea70da49..4de8c8e5e3f2 100644 --- a/drivers/pci/controller/dwc/pci-keystone.c +++ b/drivers/pci/controller/dwc/pci-keystone.c @@ -432,6 +432,17 @@ static void __iomem *ks_pcie_other_map_bus(struct pci_bus *bus, struct keystone_pcie *ks_pcie = to_keystone_pcie(pci); u32 reg; + /* + * Checking whether the link is up here is a last line of defense + * against platforms that forward errors on the system bus as + * SError upon PCI configuration transactions issued when the link + * is down. This check is racy by definition and does not stop + * the system from triggering an SError if the link goes down + * after this check is performed. + */ + if (!dw_pcie_link_up(pci)) + return NULL; + reg = CFG_BUS(bus->number) | CFG_DEVICE(PCI_SLOT(devfn)) | CFG_FUNC(PCI_FUNC(devfn)); if (!pci_is_root_bus(bus->parent))