From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp.codeaurora.org ([198.145.29.96]:52030 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725900AbeGMF1f (ORCPT ); Fri, 13 Jul 2018 01:27:35 -0400 MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Date: Fri, 13 Jul 2018 10:44:38 +0530 From: poza@codeaurora.org To: Bharat Kumar Gogada Cc: linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, bhelgaas@google.com, linux-pci-owner@vger.kernel.org Subject: Re: [PATCH] PCI/AER: Enable SERR# forwarding in non ACPI flow In-Reply-To: <1531406719-18606-1-git-send-email-bharat.kumar.gogada@xilinx.com> References: <1531406719-18606-1-git-send-email-bharat.kumar.gogada@xilinx.com> Message-ID: Sender: linux-pci-owner@vger.kernel.org List-ID: On 2018-07-12 20:15, Bharat Kumar Gogada wrote: > Currently PCI_BRIDGE_CTL_SERR is being enabled only in > ACPI flow. > This bit is required for forwarding errors reported > by EP devices to upstream device. > This patch enables SERR# for Type-1 PCI device. > > Signed-off-by: Bharat Kumar Gogada > --- > drivers/pci/pcie/aer.c | 23 +++++++++++++++++++++++ > 1 files changed, 23 insertions(+), 0 deletions(-) > > diff --git a/drivers/pci/pcie/aer.c b/drivers/pci/pcie/aer.c > index a2e8838..943e084 100644 > --- a/drivers/pci/pcie/aer.c > +++ b/drivers/pci/pcie/aer.c > @@ -343,6 +343,19 @@ int pci_enable_pcie_error_reporting(struct pci_dev > *dev) > if (!dev->aer_cap) > return -EIO; > > + if (!IS_ENABLED(CONFIG_ACPI) && > + dev->hdr_type == PCI_HEADER_TYPE_BRIDGE) { > + u16 control; > + > + /* > + * A Type-1 PCI bridge will not forward ERR_ messages coming > + * from an endpoint if SERR# forwarding is not enabled. > + */ > + pci_read_config_word(dev, PCI_BRIDGE_CONTROL, &control); > + control |= PCI_BRIDGE_CTL_SERR; > + pci_write_config_word(dev, PCI_BRIDGE_CONTROL, control); > + } > + > return pcie_capability_set_word(dev, PCI_EXP_DEVCTL, > PCI_EXP_AER_FLAGS); > } > EXPORT_SYMBOL_GPL(pci_enable_pcie_error_reporting); > @@ -352,6 +365,16 @@ int pci_disable_pcie_error_reporting(struct > pci_dev *dev) > if (pcie_aer_get_firmware_first(dev)) > return -EIO; > > + if (!IS_ENABLED(CONFIG_ACPI) && > + dev->hdr_type == PCI_HEADER_TYPE_BRIDGE) { > + u16 control; > + > + /* Clear SERR Forwarding */ > + pci_read_config_word(dev, PCI_BRIDGE_CONTROL, &control); > + control &= ~PCI_BRIDGE_CTL_SERR; > + pci_write_config_word(dev, PCI_BRIDGE_CONTROL, control); > + } > + > return pcie_capability_clear_word(dev, PCI_EXP_DEVCTL, > PCI_EXP_AER_FLAGS); > } Should this configuration no be set by Firmware ? why should Linux dictate it ? Regards, Oza.