ath(4) randomly changes MTU to 2290 after explicitly set to 1500

[Chris Buechler]

Chris Buechler wrote:
> <snip>
> somehow it ends up switching MTU to 2290 when we never configure it as 
> such. This breaks bridging to an Ethernet interface because if_bridge 
> requires the MTU to be the same on both interfaces.
<snip>

For the sake of the archives and anyone who finds this thread in the 
future, the problem was resolved by Jim Thompson and Sam Leffler. This 
is the change:
http://svn.freebsd.org/changeset/base/193524

Thanks Jim and Sam!