svn commit: r205024 - head/sys/net

[Robert N. M. Watson]

On Mar 12, 2010, at 12:18 AM, Qing Li wrote:

>  You definitely have a very good point here.  I was a bit surprised
>  during debugging that the link state is not consistently initialized
>  and by far not enforced across all of the drivers. Admittedly I checked
>  the most commonly deployed devices and they are in good state.
> 
>  I certainly appreciate your patience on this one and will try to get
>  it resolved quickly.

One of the reasons drivers don't do this consistently his that historically, hardware has not consistently supported link state detection. This now does seem to be a standard feature, but I think it would be useful to continue to support some notion of a driver not supporting it, hence my thoughts on a link state capability: only test link state if the driver can implement it. Otherwise, you end up with a link state undefined state, which likely comes to much the same thing, and is presumably what in practice you get today on drivers that don't set it.

Robert