If a device doesn't support ARI, turning on ARI forwarding on its upper level bridge will cause undefined behavior. This fix turns on ARI forwarding only when the subordinate devices support it. Signed-off-by: Yu Zhao <yu.zhao@xxxxxxxxx> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 10a43b2..914a307 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -1307,27 +1307,32 @@ void pci_enable_ari(struct pci_dev *dev) int pos; u32 cap; u16 ctrl; + struct pci_dev *bridge; - if (!dev->is_pcie) + if (!dev->is_pcie || dev->devfn) return; - if (dev->pcie_type != PCI_EXP_TYPE_ROOT_PORT && - dev->pcie_type != PCI_EXP_TYPE_DOWNSTREAM) + pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ARI); + if (!pos) return; - pos = pci_find_capability(dev, PCI_CAP_ID_EXP); + bridge = dev->bus->self; + if (!bridge || !bridge->is_pcie) + return; + + pos = pci_find_capability(bridge, PCI_CAP_ID_EXP); if (!pos) return; - pci_read_config_dword(dev, pos + PCI_EXP_DEVCAP2, &cap); + pci_read_config_dword(bridge, pos + PCI_EXP_DEVCAP2, &cap); if (!(cap & PCI_EXP_DEVCAP2_ARI)) return; - pci_read_config_word(dev, pos + PCI_EXP_DEVCTL2, &ctrl); + pci_read_config_word(bridge, pos + PCI_EXP_DEVCTL2, &ctrl); ctrl |= PCI_EXP_DEVCTL2_ARI; - pci_write_config_word(dev, pos + PCI_EXP_DEVCTL2, ctrl); + pci_write_config_word(bridge, pos + PCI_EXP_DEVCTL2, ctrl); - dev->ari_enabled = 1; + bridge->ari_enabled = 1; } int -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
