confused with if_baudrate

[Juli Mallett]

On Thu, Nov 17, 2011 at 13:12, Maksim Yevmenkin
<maksim.yevmenkin at gmail.com> wrote:
> hello,
>
> i'm a little bit confused about if_baudrate. from system headers
>
> #define if_baudrate     if_data.ifi_baudrate
>
> and
>
> u_long  ifi_baudrate;           /* linespeed */
>
> so, i'm taking this as if_baudrate really should be an interface line
> speed in megabits per second. am i correct? if so, then it appears
> that at least some drivers lie about true line speed. for example from
> ixgbe(4)
>
>        ifp->if_baudrate = 1000000000;
>
> it looks like its order of magnitude lower (i.e. 1 gigabit per second
> instead of 10 gigabits per second). am i missing something here or its
> just a typo?

ixgbe's developer is excessively concerned about overflow on 32-bit
hosts (and unwilling to correct it under a preprocessor conditional),
unlike several of the other 10GbE driver developers, although I think
one 10GbE driver opts to omit if_baudrate entirely.

Thanks,
Juli.