This is a note to let you know that I've just added the patch titled
PCI: Enable ARI if dev and upstream bridge support it; disable otherwise
to the 3.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
pci-enable-ari-if-dev-and-upstream-bridge-support-it-disable-otherwise.patch
and it can be found in the queue-3.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From b0cc6020e1cc62f1253215f189611b34be4a83c7 Mon Sep 17 00:00:00 2001
From: Yijing Wang <wangyijing@xxxxxxxxxx>
Date: Tue, 15 Jan 2013 11:12:16 +0800
Subject: PCI: Enable ARI if dev and upstream bridge support it; disable otherwise
From: Yijing Wang <wangyijing@xxxxxxxxxx>
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@xxxxxxxxxx>
Signed-off-by: Jiang Liu <jiang.liu@xxxxxxxxxx>
Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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;
}
/**
Patches currently in stable-queue which might be from wangyijing@xxxxxxxxxx are
queue-3.4/pci-enable-ari-if-dev-and-upstream-bridge-support-it-disable-otherwise.patch
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