diff options
| author | Chris Wright <chrisw@sous-sol.org> | 2011-07-13 10:14:33 -0700 |
|---|---|---|
| committer | Jesse Barnes <jbarnes@virtuousgeek.org> | 2011-07-22 08:41:51 -0700 |
| commit | 864d296cf948aef0fa32b81407541572583f7572 (patch) | |
| tree | 67d2cee99f6a5f591bcd6a19bb5333f6c4234598 /drivers/pci | |
| parent | a8c7ef3187a266d201af887fd48afbef3598825a (diff) | |
PCI: ARI is a PCIe v2 feature
The function pci_enable_ari() may mistakenly set the downstream port
of a v1 PCIe switch in ARI Forwarding mode. This is a PCIe v2 feature,
and with an SR-IOV device on that switch port believing the switch above
is ARI capable it may attempt to use functions 8-255, translating into
invalid (non-zero) device numbers for that bus. This has been seen
to cause Completion Timeouts and general misbehaviour including hangs
and panics.
Cc: stable@kernel.org
Acked-by: Don Dutile <ddutile@redhat.com>
Tested-by: Don Dutile <ddutile@redhat.com>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Diffstat (limited to 'drivers/pci')
| -rw-r--r-- | drivers/pci/pci.c | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 692671b1166..d549bbc93cd 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -1905,7 +1905,7 @@ void pci_enable_ari(struct pci_dev *dev) { int pos; u32 cap; - u16 ctrl; + u16 flags, ctrl; struct pci_dev *bridge; if (!pci_is_pcie(dev) || dev->devfn) @@ -1923,6 +1923,11 @@ void pci_enable_ari(struct pci_dev *dev) if (!pos) return; + /* ARI is a PCIe v2 feature */ + pci_read_config_word(bridge, pos + PCI_EXP_FLAGS, &flags); + if ((flags & PCI_EXP_FLAGS_VERS) < 2) + return; + pci_read_config_dword(bridge, pos + PCI_EXP_DEVCAP2, &cap); if (!(cap & PCI_EXP_DEVCAP2_ARI)) return; |