From: Bharat Kumar Gogada <bharat.kumar.gogada@xilinx.com>
To: <linux-pci@vger.kernel.org>, <linux-kernel@vger.kernel.org>
Cc: <bhelgaas@google.com>, <rgummal@xilinx.com>,
Bharat Kumar Gogada <bharat.kumar.gogada@xilinx.com>
Subject: [PATCH v2] PCI/AER: Enable SERR# forwarding in non ACPI flow
Date: Thu, 9 Aug 2018 20:27:37 +0530 [thread overview]
Message-ID: <1533826657-24552-1-git-send-email-bharat.kumar.gogada@xilinx.com> (raw)
As per Figure 6-3 in PCIe r4.0, sec 6.2.6, ERR_ messages
will be forwarded from the secondary interface to the primary interface,
if the SERR# Enable bit in the Bridge Control register is set.
Currently PCI_BRIDGE_CTL_SERR is being enabled only in
ACPI flow.
This patch enables PCI_BRIDGE_CTL_SERR for Type-1 PCI device.
Signed-off-by: Bharat Kumar Gogada <bharat.kumar.gogada@xilinx.com>
---
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..4fb0d24 100644
--- a/drivers/pci/pcie/aer.c
+++ b/drivers/pci/pcie/aer.c
@@ -343,6 +343,20 @@ int pci_enable_pcie_error_reporting(struct pci_dev *dev)
if (!dev->aer_cap)
return -EIO;
+ if (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);
+ if (!(control & PCI_BRIDGE_CTL_SERR)) {
+ 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 +366,15 @@ int pci_disable_pcie_error_reporting(struct pci_dev *dev)
if (pcie_aer_get_firmware_first(dev))
return -EIO;
+ if (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);
}
--
1.7.1
next reply other threads:[~2018-08-09 15:03 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-08-09 14:57 Bharat Kumar Gogada [this message]
2018-08-09 15:11 ` [PATCH v2] PCI/AER: Enable SERR# forwarding in non ACPI flow poza
2018-08-24 12:13 ` Bharat Kumar Gogada
2018-09-05 20:10 ` Bjorn Helgaas
2018-09-10 6:10 ` poza
2018-09-05 20:04 ` Bjorn Helgaas
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