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=-16.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham 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 E8F80C433B4 for ; Sat, 10 Apr 2021 15:21:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9B594611CA for ; Sat, 10 Apr 2021 15:21:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234680AbhDJPVU (ORCPT ); Sat, 10 Apr 2021 11:21:20 -0400 Received: from mail.kernel.org ([198.145.29.99]:39012 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234392AbhDJPVU (ORCPT ); Sat, 10 Apr 2021 11:21:20 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 1DB57611C2; Sat, 10 Apr 2021 15:21:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1618068065; bh=+Qmc8k9G7vMTnKZ+bWVMEMwIV3SSxAOpo2eWKe1OI34=; h=Date:From:To:Cc:Subject:In-Reply-To:From; b=UYd9OmxHnb7appWRQ8iQL3leCzRl37H7nnLSzWqLc5ErqDRhZq1iza6dr8VUk4IxC n8SObzrC7tABlMkRHQBHuF2DKuEn7EbZZgscLt17p3s9nXzo6gUd0dBvNSuV95/33K 081+K+wmtAAb7RiAG6pIp9heu5SnLsbyrTZbC7xYMPHxFXEfBMHURIQoZTygoN8doh MWVWSC5PqA2Gp5ydRke/4DD00qyO7BaQhkr4Ou/hOrFiLhKr+rCf0WH0QTkRYHL58a m6ffahp4Jxp5Iitd8kL/aWFyXlXqlxYmhIuhAFOEc28o/9vTlR610h1pWAILDsxnSw Ral1EREVDwCpw== Date: Sat, 10 Apr 2021 10:21:03 -0500 From: Bjorn Helgaas To: Yicong Yang Cc: linux-pci@vger.kernel.org, sathyanarayanan.kuppuswamy@linux.intel.com, kbusch@kernel.org, sean.v.kelley@intel.com, qiuxu.zhuo@intel.com, prime.zeng@huawei.com, linuxarm@openeuler.org Subject: Re: [PATCH] PCI/DPC: Disable ERR_COR explicitly for native dpc service Message-ID: <20210410152103.GA2043340@bjorn-Precision-5520> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1612356795-32505-2-git-send-email-yangyicong@hisilicon.com> Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org On Wed, Feb 03, 2021 at 08:53:15PM +0800, Yicong Yang wrote: > Per Downstream Port Containment Related Enhancements ECN[1], > Table 4-6 Interpretation of _OSC Control Field Returned Value, > for bit 7 of _OSC control return value: > > "If firmware allows the OS control of this feature, then, > in the context of the _OSC method the OS must ensure that > Downstream Port Containment ERR_COR signaling is disabled > as described in the PCI Express Base Specification." > > and PCI Express Base Specification Revision 4.0 Version 1.0 > section 6.2.10.2, Use of DPC ERR_COR Signaling: > > "...DPC ERR_COR signaling is primarily intended for use by > platform firmware..." > > Currently we don't set DPC ERR_COR enable bit, but explicitly > clear the bit to ensure it's disabled. > > [1] Downstream Port Containment Related Enhancements ECN, > Jan 28, 2019, affecting PCI Firmware Specification, Rev. 3.2 > https://members.pcisig.com/wg/PCI-SIG/document/12888 > > Signed-off-by: Yicong Yang Anybody want to chime in and review this? Sometimes I feel like a one-man band :) > --- > drivers/pci/pcie/dpc.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/pci/pcie/dpc.c b/drivers/pci/pcie/dpc.c > index e05aba8..5cc8ef3 100644 > --- a/drivers/pci/pcie/dpc.c > +++ b/drivers/pci/pcie/dpc.c > @@ -302,7 +302,7 @@ static int dpc_probe(struct pcie_device *dev) > pci_read_config_word(pdev, pdev->dpc_cap + PCI_EXP_DPC_CAP, &cap); > pci_read_config_word(pdev, pdev->dpc_cap + PCI_EXP_DPC_CTL, &ctl); > > - ctl = (ctl & 0xfff4) | PCI_EXP_DPC_CTL_EN_FATAL | PCI_EXP_DPC_CTL_INT_EN; > + ctl = (ctl & 0xffe4) | PCI_EXP_DPC_CTL_EN_FATAL | PCI_EXP_DPC_CTL_INT_EN; > pci_write_config_word(pdev, pdev->dpc_cap + PCI_EXP_DPC_CTL, ctl); > pci_info(pdev, "enabled with IRQ %d\n", dev->irq); > > -- > 2.8.1 >