| Message ID | 20201126011816.711106-2-helgaas@kernel.org (mailing list archive) |
|---|---|
| State | New, archived |
| Delegated to: | Bjorn Helgaas |
| Headers | show |
| Series | Simplify PCIe native ownership | expand |
On 11/25/20 5:18 PM, Bjorn Helgaas wrote: > From: Bjorn Helgaas <bhelgaas@google.com> > > 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@google.com> > Cc: Olof Johansson <olof@lixom.net> > --- > 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; > >
On Wed, Nov 25, 2020 at 06:01:57PM -0800, Kuppuswamy, Sathyanarayanan wrote: > On 11/25/20 5:18 PM, Bjorn Helgaas wrote: > > From: Bjorn Helgaas <bhelgaas@google.com> > > > > 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@google.com> > > Cc: Olof Johansson <olof@lixom.net> > > --- > > 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? I don't think that's always true. If I'm reading this right, we have this: get_port_device_capability(...) { #ifdef CONFIG_PCIEAER if (dev->aer_cap && ...) services |= PCIE_PORT_SERVICE_AER; #endif if (pci_find_ext_capability(dev, PCI_EXT_CAP_ID_DPC) && pci_aer_available() && (pcie_ports_dpc_native || (services & PCIE_PORT_SERVICE_AER))) services |= PCIE_PORT_SERVICE_DPC; } and in the case where: - CONFIG_PCIEAER=y - booted with "pcie_ports=dpc-native" (pcie_ports_dpc_native is true) - "dev" has no AER capability - "dev" has DPC capability I think we do enable PCIE_PORT_SERVICE_DPC. > 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
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; + if (!pcie_aer_is_native(pdev) && !pcie_ports_dpc_native) return -ENOTSUPP;