Re: [PATCH] 8139cp: reject invalid MTU values

From: Paolo Bonzini <pbonzini@redhat.com>
Date: Fri, 17 Feb 2012 13:33:15 +0100

The 8139cp driver has a change_mtu function that has not been
enabled since the dawn of the git repository.  However, the
generic eth_change_mtu is not used in its place, so that
invalid MTU values can be set on the interface.

This patch salvages the broken code for the single case of
setting the MTU while the interface is down, which is safe
and also includes the range check.

Well, now you can't change the MTU while the device is up
which to me is a worse problem than MTU validation because
this breaks valid things that potentially worked previously.

Also you didn't bother to give your patch a proper signoff.

You're going to have to fix cp_change_mtu() so that it does the
correct HW reset sequence when the MTU changes, otherwise I am not
going to apply this patch.