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authorZhao, Yu <yu.zhao@intel.com>2008-10-23 13:15:39 +0800
committerJesse Barnes <jbarnes@virtuousgeek.org>2008-10-23 14:42:13 -0700
commit8113587c2d14d3be2414190845b2e2617c0aa33b (patch)
tree8fd7355ae2d677342a6dd2c2f7afb6e0e9db98f8
parentd2174c3c07adad88dd9ba37a731e0b00b746822a (diff)
downloadlinux-linaro-8113587c2d14d3be2414190845b2e2617c0aa33b.tar.gz
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>
-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 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