Bug#851952: linux-image-3.16.0-4-amd64: Intel X540 10G NIC interfaces can end up with 'Speed: unknown' as members of a 802.3ad bond

[Alexandros Afentoulis <alexaf@noc.grnet.gr>]

Package: src:linux
Version: 3.16.39-1
Severity: important

Dear Maintainer,

Please consider backporting upstream commit 0e4d422f5f72 [1], fixing
ixgbe link speed detection on LACP bond members.

When changing an ixgbe NIC link status on 3.16 either from the server
side (ip link set dev ens2f0 down ; ip link set dev ens2f0 up) or the
switch side can sometimes result in 'Speed: Uknown' for a particular
bond member, as seen in 'cat /proc/net/bonding/bond0', causing the
member to be eventually dropped from the bond and thus reducing the
network's availability. Backporting the said commit on top of 3.16.39
fixes the issue for us.

More information can be provided if needed,
Thanks

[1] 
https://github.com/torvalds/linux/commit/0e4d422f5f7249324ac8d1b8e12772e530787a66