pci_enable_ari will set the pci bridge ARI Forwarding Enable bit in Device
Control 2 Register when a ARI pcie device connected found. But the bridge ARI
Forwarding Enable bit will never be cleared when the ARI device hot removed.
As PCIe Spec 2.0(6.13/441) recommends:
"Following a hot-plug event below a Downstream Port, it is strongly recommended
that software Clear the ARI Forwarding Enable bit in the Downstream Port until
software determines that a newly added component is in fact an ARI Device"
This patch rework pci_enable_ari to support disable ARI Forwarding whenever found
the new pci device is a non-ari device.
Signed-off-by: Yijing Wang <wangyijing@xxxxxxxxxx>
Signed-off-by: Jiang Liu <jiang.liu@xxxxxxxxxx>
---
drivers/pci/pci.c | 16 ++++++++++------
1 files changed, 10 insertions(+), 6 deletions(-)
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 5cb5820..a17129f 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -2078,9 +2078,6 @@ void pci_enable_ari(struct pci_dev *dev)
if (pcie_ari_disabled || !pci_is_pcie(dev) || dev->devfn)
return;
- if (!pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ARI))
- return;
-
bridge = dev->bus->self;
if (!bridge)
return;
@@ -2088,9 +2085,16 @@ void pci_enable_ari(struct pci_dev *dev)
pcie_capability_read_dword(bridge, PCI_EXP_DEVCAP2, &cap);
if (!(cap & PCI_EXP_DEVCAP2_ARI))
return;
-
- pcie_capability_set_word(bridge, PCI_EXP_DEVCTL2, PCI_EXP_DEVCTL2_ARI);
- bridge->ari_enabled = 1;
+
+ if (pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ARI)) {
+ pcie_capability_set_word(bridge, PCI_EXP_DEVCTL2,
+ PCI_EXP_DEVCTL2_ARI);
+ bridge->ari_enabled = 1;
+ } else {
+ pcie_capability_clear_word(bridge, PCI_EXP_DEVCTL2,
+ PCI_EXP_DEVCTL2_ARI);
+ bridge->ari_enabled = 0;
+ }
}
/**
--
1.7.1
--
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