diff options
| author | Bharat Kumar Gogada <bharat.kumar.gogada@xilinx.com> | 2018-11-14 20:17:01 +0530 |
|---|---|---|
| committer | Bjorn Helgaas <bhelgaas@google.com> | 2019-02-01 18:12:55 -0600 |
| commit | b4f6dcb9d35688392d668c46e834f72c55900b49 (patch) | |
| tree | d113138b2c518059a07e79d1af7ac8674895056e | |
| parent | 807ffb1e1eabbcdcd46494ee415317aa80ed415c (diff) | |
PCI: Enable SERR# forwarding for all bridges
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.
It seems clear that an ACPI hotplug parameter method (_HPP or _HPX) that
tells us to "enable SERR in the command register" (ACPI v6.2, sec 6.2.8,
6.2.9.1) refers to PCI_COMMAND_SERR, which enables reporting of errors by
the function itself.
For bridges, we also interpreted that to mean we should enable
PCI_BRIDGE_CTL_SERR, which enables *forwarding* of errors by the bridge.
But we didn't enable PCI_BRIDGE_CTL_SERR anywhere else, which means we
never enabled it for non-ACPI systems or ACPI systems that didn't supply
hotplug parameters.
That means errors reported below bridges were often never forwarded up to a
Root Port where they could be signaled via AER.
Enable PCI_BRIDGE_CTL_SERR for all bridges so we can get better error
reporting for downstream devices.
Signed-off-by: Bharat Kumar Gogada <bharat.kumar.gogada@xilinx.com>
[bhelgaas: changelog]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
| -rw-r--r-- | drivers/pci/probe.c | 21 |
1 files changed, 19 insertions, 2 deletions
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index 257b9f6f2ebb..43e6583417ce 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -1856,8 +1856,6 @@ static void program_hpp_type0(struct pci_dev *dev, struct hpp_type0 *hpp) pci_write_config_byte(dev, PCI_SEC_LATENCY_TIMER, hpp->latency_timer); pci_read_config_word(dev, PCI_BRIDGE_CONTROL, &pci_bctl); - if (hpp->enable_serr) - pci_bctl |= PCI_BRIDGE_CTL_SERR; if (hpp->enable_perr) pci_bctl |= PCI_BRIDGE_CTL_PARITY; pci_write_config_word(dev, PCI_BRIDGE_CONTROL, pci_bctl); @@ -2129,6 +2127,24 @@ static void pci_configure_eetlp_prefix(struct pci_dev *dev) #endif } +static void pci_configure_serr(struct pci_dev *dev) +{ + u16 control; + + if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE) { + + /* + * A bridge will not forward ERR_ messages coming from an + * endpoint unless SERR# forwarding is 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); + } + } +} + static void pci_configure_device(struct pci_dev *dev) { struct hotplug_params hpp; @@ -2139,6 +2155,7 @@ static void pci_configure_device(struct pci_dev *dev) pci_configure_relaxed_ordering(dev); pci_configure_ltr(dev); pci_configure_eetlp_prefix(dev); + pci_configure_serr(dev); memset(&hpp, 0, sizeof(hpp)); ret = pci_get_hp_params(dev, &hpp); |