On 2018-08-09 20:27, Bharat Kumar Gogada wrote:
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@xxxxxxxxxx>
---
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);
}
Hi Bjorn,
I made some comments on patchv1., same I am putting it across here.
what about hot-plug case ?
should not aer_init() call pci_enable_pcie_error_reporting() for all
the downstream pci_dev ?
and remove all the calls from drivers..
aer_init will be called for each device (pci_dev) while pciehp does
re-enumeration.
so probable we might want to call pci_enable_pcie_error_reporting()
but that dictates the design where AER framework is taking decision to
enable error reporting on behalf of drivers as well.
but thats fine I think, if drivers do not want to participate then they
have to call pci_disable_pcie_error_reporting explicitly.
does this make sense ?
