kern/133756: [bce] bce commit r190582 breaks lagg in 7.2-PRERELASE

[Pete French]

This is just a quick update about some further investigations on
this. I tested out the patch that Niki Denev kindly sent me which
apparently fixes a length issue when zero copy sockets are not
in use. This did not, however, solve the problem, but as part of
this I ran tcpdump on the bce0 and bce1 interfaces for the
working and non working kernels. On the kernel which does not
work I never see any packets being received, though LACP packets
are being transmitted.

The switch to which the devices are connected is (I believe) configured
in a mode where it will only send LACP packets back when it has received
some. So the lack of incomming pa ckets in tcpdump does not necessarily
mean that the recive side is failing, as it may be that the transmitted
packets are not making it out of the interface. On identical hardware
with no LACP in place the bce interfaces work fine. What I have yet
to try is runnign a simple lagg bundle on this machine, to see if the
problem is specific to LACP.

I also rolled the system back to 7.1 and tested a patch from Doug Ambrisko
which adds the support for the 5709 but contains none of the other
changes. This did work, so that has excluded those changes from the cause
of the problems.

-pete.