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authorZhao, Yu <yu.zhao@intel.com>2008-10-23 07:15:39 +0200
committerJesse Barnes <jbarnes@virtuousgeek.org>2008-10-23 23:42:13 +0200
commit8113587c2d14d3be2414190845b2e2617c0aa33b (patch)
tree8fd7355ae2d677342a6dd2c2f7afb6e0e9db98f8 /drivers/pci/pci.c
parentPCI hotplug: cpqphp: fix kernel NULL pointer dereference (diff)
downloadlinux-8113587c2d14d3be2414190845b2e2617c0aa33b.tar.xz
linux-8113587c2d14d3be2414190845b2e2617c0aa33b.zip
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>
Diffstat (limited to 'drivers/pci/pci.c')
-rw-r--r--drivers/pci/pci.c21
1 files changed, 13 insertions, 8 deletions
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 533aeb5fcbe4..21f2ac639cab 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