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authorYijing Wang <wangyijing@huawei.com>2013-01-15 11:12:16 +0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2014-02-13 11:51:17 -0800
commitd7c16d1e0a33ea79d9dc33e3f13f41b4f5caa756 (patch)
tree94fe2dad06b41712c6f25992271551d474cf1ba8
parent27fb12b9e08a7f5bb8d8faa65002b9f76ee285b6 (diff)
PCI: Enable ARI if dev and upstream bridge support it; disable otherwise
commit b0cc6020e1cc62f1253215f189611b34be4a83c7 upstream. Currently, we enable ARI in a device's upstream bridge if the bridge and the device support it. But we never disable ARI, even if the device is removed and replaced with a device that doesn't support ARI. This means that if we hot-remove an ARI device and replace it with a non-ARI multi-function device, we find only function 0 of the new device because the upstream bridge still has ARI enabled, and next_ari_fn() only returns function 0 for the new non-ARI device. This patch disables ARI in the upstream bridge if the device doesn't support ARI. See the PCIe spec, r3.0, sec 6.13. [bhelgaas: changelog, function comment] [yijing: replace PCIe Cap accessor with legacy PCI accessor] Signed-off-by: Yijing Wang <wangyijing@huawei.com> Signed-off-by: Jiang Liu <jiang.liu@huawei.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/pci/pci.c14
1 files changed, 7 insertions, 7 deletions
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index d08c0d8ec22e..a7f6dcea0d76 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -1984,10 +1984,6 @@ void pci_enable_ari(struct pci_dev *dev)
if (pcie_ari_disabled || !pci_is_pcie(dev) || dev->devfn)
return;
- pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ARI);
- if (!pos)
- return;
-
bridge = dev->bus->self;
if (!bridge || !pci_is_pcie(bridge))
return;
@@ -2006,10 +2002,14 @@ void pci_enable_ari(struct pci_dev *dev)
return;
pci_read_config_word(bridge, pos + PCI_EXP_DEVCTL2, &ctrl);
- ctrl |= PCI_EXP_DEVCTL2_ARI;
+ if (pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ARI)) {
+ ctrl |= PCI_EXP_DEVCTL2_ARI;
+ bridge->ari_enabled = 1;
+ } else {
+ ctrl &= ~PCI_EXP_DEVCTL2_ARI;
+ bridge->ari_enabled = 0;
+ }
pci_write_config_word(bridge, pos + PCI_EXP_DEVCTL2, ctrl);
-
- bridge->ari_enabled = 1;
}
/**