From patchwork Fri May 24 10:57:14 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Siddharth Vadapalli X-Patchwork-Id: 13673081 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id D0EBDC25B74 for ; Fri, 24 May 2024 10:58:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-ID:Date:Subject:CC:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=sMyOCJ/B4lmIGigTye4IxxPe41v6Q8RsEU9OmAveSYo=; b=mhfvDUIWJj+DOz xlfa7I15uwOA1Sjxt5ow9yFdTKsooGv9gbU/nJ7X/tZjQ1kr21XX2iI9au4PmtQNLODU3DUEjLUMv +GEluI8DYU3EBwreMsfH1tN6F/uMK7HLBXX7bGmBf6/uJHPQFHRE7za+1K3/3+kCjIXMahD2Lkkaa /4RTmkav99faQ+Ak46H9UHeU+1zqPMI89k55/6EJ1PE3C5nUX77dZSVKScDKM8JMF8vVXSro6hXW8 Q000d64TkLouY/9s4wr5VC2sVesi2z7+fFnxW6OEXpIuZ8xW7pZ7Cbuwkb612ZnIK6ZY0HuKUK1Yr SBdmXEYaB1GmfurEpCcg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1sAScU-00000008jVd-3iGm; Fri, 24 May 2024 10:57:54 +0000 Received: from lelv0143.ext.ti.com ([198.47.23.248]) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1sAScS-00000008jTW-1cgt for linux-arm-kernel@lists.infradead.org; Fri, 24 May 2024 10:57:53 +0000 Received: from fllv0035.itg.ti.com ([10.64.41.0]) by lelv0143.ext.ti.com (8.15.2/8.15.2) with ESMTP id 44OAvTFY056814; Fri, 24 May 2024 05:57:29 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ti.com; s=ti-com-17Q1; t=1716548249; bh=oAxDy7HRzkzyrAajDGbOIZ7VyO0W++qJINz2lTGFPco=; h=From:To:CC:Subject:Date:In-Reply-To:References; b=A9+BSXlBOhx1TAmOU96P2XHek96O/xk+nOzNEpSNTep++dnl6X1t3n6KatGRqv6bi rloF0zLQxtkSMuCaHh/OCw7gXgJBAk7w8JBzcLpbRf2zn+p7OAlT8QFbZIHisKiPrZ qtZvZwyocV54FIk80sVYPr8Chc+BfAHRDJSzVEQI= Received: from DLEE107.ent.ti.com (dlee107.ent.ti.com [157.170.170.37]) by fllv0035.itg.ti.com (8.15.2/8.15.2) with ESMTPS id 44OAvTVZ037425 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=FAIL); Fri, 24 May 2024 05:57:29 -0500 Received: from DLEE102.ent.ti.com (157.170.170.32) by DLEE107.ent.ti.com (157.170.170.37) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2507.23; Fri, 24 May 2024 05:57:29 -0500 Received: from lelvsmtp5.itg.ti.com (10.180.75.250) by DLEE102.ent.ti.com (157.170.170.32) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2507.23 via Frontend Transport; Fri, 24 May 2024 05:57:29 -0500 Received: from uda0492258.dhcp.ti.com (uda0492258.dhcp.ti.com [172.24.227.9]) by lelvsmtp5.itg.ti.com (8.15.2/8.15.2) with ESMTP id 44OAvFvF049802; Fri, 24 May 2024 05:57:25 -0500 From: Siddharth Vadapalli To: , , , , , , , , , CC: , , , , Subject: [PATCH v2 2/2] PCI: keystone: Add link up check in ks_child_pcie_ops.map_bus() Date: Fri, 24 May 2024 16:27:14 +0530 Message-ID: <20240524105714.191642-3-s-vadapalli@ti.com> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20240524105714.191642-1-s-vadapalli@ti.com> References: <20240524105714.191642-1-s-vadapalli@ti.com> MIME-Version: 1.0 X-EXCLAIMER-MD-CONFIG: e1e8a2fd-e40a-4ac6-ac9b-f7e9cc9ee180 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240524_035752_537372_AA184D6B X-CRM114-Status: GOOD ( 14.84 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org From: Kishon Vijay Abraham I 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 Signed-off-by: Siddharth Vadapalli --- 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 3184546ba3b6..ca476fa584e7 100644 --- a/drivers/pci/controller/dwc/pci-keystone.c +++ b/drivers/pci/controller/dwc/pci-keystone.c @@ -430,6 +430,17 @@ 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))