PCI: Enable ARI if dev and upstream bridge support it; disable otherwise
authorYijing Wang <wangyijing@huawei.com>
Tue, 15 Jan 2013 03:12:16 +0000 (11:12 +0800)
committerBjorn Helgaas <bhelgaas@google.com>
Thu, 24 Jan 2013 18:42:14 +0000 (11:42 -0700)
commitb0cc6020e1cc62f1253215f189611b34be4a83c7
treefd798c95fe1ebe506dc2a3d2e7576777393408e6
parentd1c3ed669a2d452cacfb48c2d171a1f364dae2ed
PCI: Enable ARI if dev and upstream bridge support it; disable otherwise

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 <wangyijing@huawei.com>
Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
drivers/pci/pci.c