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=-20.2 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, 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 1E168C43217 for ; Mon, 20 Sep 2021 18:05:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0724A613C8 for ; Mon, 20 Sep 2021 18:05:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1358392AbhITSG1 (ORCPT ); Mon, 20 Sep 2021 14:06:27 -0400 Received: from mail.kernel.org ([198.145.29.99]:58468 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1356677AbhITSBA (ORCPT ); Mon, 20 Sep 2021 14:01:00 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 5B4F663228; Mon, 20 Sep 2021 17:16:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1632158160; bh=TW5rtwmRc2wqjiX0cxMWR+rBc+hAXEozJAFhx8BFfR4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=pnGbEWup+ncuaY1Frt1/YwDD9Afd7Dr9JdVIDI8JBZTw8a6IAqVuRRYc3ncnp8CZ+ j9EjvjwL1hcLT+/5LdpmCbFQFWWIJ8+g6WiN2wqf46gmTcdkq6W9YoPwR8avJdL3aW am2hGsqOb+WBPJn9vmzUrZTgQxLNWOshpEPk00sg= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Stuart Hayes , Bjorn Helgaas , Lukas Wunner Subject: [PATCH 5.4 029/260] PCI/portdrv: Enable Bandwidth Notification only if port supports it Date: Mon, 20 Sep 2021 18:40:47 +0200 Message-Id: <20210920163932.112595011@linuxfoundation.org> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20210920163931.123590023@linuxfoundation.org> References: <20210920163931.123590023@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Stuart Hayes commit 00823dcbdd415c868390feaca16f0265101efab4 upstream. Previously we assumed that all Root Ports and Switch Downstream Ports supported Link Bandwidth Notification. Per spec, this is only required for Ports supporting Links wider than x1 and/or multiple Link speeds (PCIe r5.0, sec 7.5.3.6). Because we assumed all Ports supported it, we tried to set up a Bandwidth Notification IRQ, which failed for devices that don't support IRQs at all, which meant pcieport didn't attach to the Port at all. Check the Link Bandwidth Notification Capability bit and enable the service only when the Port supports it. [bhelgaas: commit log] Fixes: e8303bb7a75c ("PCI/LINK: Report degraded links via link bandwidth notification") Link: https://lore.kernel.org/r/20210512213314.7778-1-stuart.w.hayes@gmail.com Signed-off-by: Stuart Hayes Signed-off-by: Bjorn Helgaas Reviewed-by: Lukas Wunner Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman --- drivers/pci/pcie/portdrv_core.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) --- a/drivers/pci/pcie/portdrv_core.c +++ b/drivers/pci/pcie/portdrv_core.c @@ -255,8 +255,13 @@ static int get_port_device_capability(st services |= PCIE_PORT_SERVICE_DPC; if (pci_pcie_type(dev) == PCI_EXP_TYPE_DOWNSTREAM || - pci_pcie_type(dev) == PCI_EXP_TYPE_ROOT_PORT) - services |= PCIE_PORT_SERVICE_BWNOTIF; + pci_pcie_type(dev) == PCI_EXP_TYPE_ROOT_PORT) { + u32 linkcap; + + pcie_capability_read_dword(dev, PCI_EXP_LNKCAP, &linkcap); + if (linkcap & PCI_EXP_LNKCAP_LBNC) + services |= PCIE_PORT_SERVICE_BWNOTIF; + } return services; }