3.5.7.31 -stable review patch. If anyone has any objections, please let me know.
------------------ From: Yijing Wang <[email protected]> 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] Signed-off-by: Yijing Wang <[email protected]> Signed-off-by: Jiang Liu <[email protected]> Signed-off-by: Bjorn Helgaas <[email protected]> [ luis: backported to 3.5: used Yijing Wang's backport to 3.4 ] Signed-off-by: Luis Henriques <[email protected]> --- drivers/pci/pci.c | 17 ++++++++++------- 1 file changed, 10 insertions(+), 7 deletions(-) diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index fa7c0f0..caeddd4 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -1974,6 +1974,9 @@ void pci_free_cap_save_buffers(struct pci_dev *dev) /** * pci_enable_ari - enable ARI forwarding if hardware support it * @dev: the PCI device + * + * If @dev and its upstream bridge both support ARI, enable ARI in the + * bridge. Otherwise, disable ARI in the bridge. */ void pci_enable_ari(struct pci_dev *dev) { @@ -1985,10 +1988,6 @@ 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; @@ -2007,10 +2006,14 @@ 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; } /** -- 1.9.0 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
