On 11/25/20 5:18 PM, Bjorn Helgaas wrote:
From: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
Downstream Ports may support DPC regardless of whether they support AER
(see PCIe r5.0, sec 6.2.10.2). Previously, if the user booted with
"pcie_ports=dpc-native", it was possible for dpc_probe() to succeed even if
the device had no AER Capability, but dpc_get_aer_uncorrect_severity()
depends on the AER Capability.
dpc_probe() previously failed if:
!pcie_aer_is_native(pdev) && !pcie_ports_dpc_native
!(pcie_aer_is_native() || pcie_ports_dpc_native) # by De Morgan's law
so it succeeded if:
pcie_aer_is_native() || pcie_ports_dpc_native
Fail dpc_probe() if the device has no AER Capability.
Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
Cc: Olof Johansson <olof@xxxxxxxxx>
---
drivers/pci/pcie/dpc.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/pci/pcie/dpc.c b/drivers/pci/pcie/dpc.c
index e05aba86a317..ed0dbc43d018 100644
--- a/drivers/pci/pcie/dpc.c
+++ b/drivers/pci/pcie/dpc.c
@@ -287,6 +287,9 @@ static int dpc_probe(struct pcie_device *dev)
int status;
u16 ctl, cap;
+ if (!pdev->aer_cap)
+ return -ENOTSUPP;
Don't we check aer_cap support in drivers/pci/pcie/portdrv_core.c ?
We don't enable DPC service, if AER service is not enabled. And AER
service is only enabled if AER capability is supported.
So dpc_probe() should not happen if AER capability is not supported?
206 static int get_port_device_capability(struct pci_dev *dev)
...
...
251 if (pci_find_ext_capability(dev, PCI_EXT_CAP_ID_DPC) &&
252 host->native_dpc &&
253 (host->native_dpc || (services & PCIE_PORT_SERVICE_AER)))
254 services |= PCIE_PORT_SERVICE_DPC;
255
+
if (!pcie_aer_is_native(pdev) && !pcie_ports_dpc_native)
return -ENOTSUPP;
--
Sathyanarayanan Kuppuswamy
Linux Kernel Developer
