From 8113587c2d14d3be2414190845b2e2617c0aa33b Mon Sep 17 00:00:00 2001 From: "Zhao, Yu" <yu.zhao@intel.com> Date: Thu, 23 Oct 2008 13:15:39 +0800 Subject: [PATCH] PCI: fix ARI code to be compatible with mixed ARI/non-ARI systems The original ARI support code has a compatibility problem with non-ARI devices. 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. Tested-by: Suresh Siddha <suresh.b.siddha@intel.com> Signed-off-by: Yu Zhao <yu.zhao@intel.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org> --- drivers/pci/pci.c | 21 +++++++++++++-------- 1 file changed, 13 insertions(+), 8 deletions(-) diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 533aeb5fcbe..21f2ac639ca 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -1309,27 +1309,32 @@ 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 -- 2.41.3