svn commit: r205024 - head/sys/net

[Julian Elischer]

Juli Mallett wrote:
> On Thu, Mar 11, 2010 at 15:39, Qing Li <qingli at freebsd.org> wrote:
>> I guess it's a good time to clean things up. The if_link_state code has been
>> around for quite some time, either it be fully utilized or not be there at all.
>> The inconsistency is the root cause.
> 
> Sure.  There is an increasing amount of stuff that network drivers are
> expected to do, but they work without doing them.  It's easy to think
> you have a functioning network driver and that you can get by without
> adding support for media changes and link status reporting, etc.
> 
>> I will try going through these tonight and hopefully the fix all take a
>> common approach.

probably should add a flag that means "we have media state"
and if it is not set, assume it is always on.

> 
> If you can think of a way to add some invariants (warn the first time
> a driver receives a packet without having ever set the link state,
> make sure the media status callback sets the valid flag in the
> request, etc) that would probably be very helpful for people who are
> writing network drivers.  If I hadn't been following the threads about
> your changes, I would have had to spend much longer fixing the Octeon
> port's Ethernet driver, wondering why suddenly it broke and
> instrumenting the routing code.  A printf would go a long way.
> 
> Juli.