Subject: Re: where is ifp->if_baudrate used?
To: Izumi Tsutsui <tsutsui@ceres.dti.ne.jp>
From: Steven M. Bellovin <smb@cs.columbia.edu>
List: tech-net
Date: 03/18/2007 01:34:18
On Sun, 18 Mar 2007 11:41:12 +0900
Izumi Tsutsui <tsutsui@ceres.dti.ne.jp> wrote:

> Hi,
> 
> struct ifnet has if_baudrate (which is actually if_data.ifi_baudrate),
> member, but where is the member used?

It may be intended for use by SNMP agents.
> 
> Should it be initilized to proper values in attachments of each
> driver? Or is it initialized in the MII layer later?
> 
> Currently only a few drivers have it, and if it isn't initialized
> in the driver attacments, it will be set to default 10Mbps in
> sys/net/if_ethersubr.c:ether_ifattach().
> I wonder if we should set it to proper speed manually or not.

A lot of device drivers know the link speed; it's even reportable via
ifconfig.  It would be nice if they could set it.


		--Steve Bellovin, http://www.cs.columbia.edu/~smb