From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Yijing Wang , Jiang Liu , Bjorn Helgaas Subject: [PATCH 3.4 22/30] PCI: Enable ARI if dev and upstream bridge support it; disable otherwise Date: Tue, 11 Feb 2014 11:06:22 -0800 Message-Id: <20140211184647.775796791@linuxfoundation.org> In-Reply-To: <20140211184647.149512538@linuxfoundation.org> References: <20140211184647.149512538@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Yijing Wang 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 Signed-off-by: Jiang Liu Signed-off-by: Bjorn Helgaas Signed-off-by: Greg Kroah-Hartman --- drivers/pci/pci.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) --- 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; } /**