em(4) on FreeBSD is sometimes annoying

Bob Bishop rb at gid.co.uk
Fri Aug 1 13:27:51 UTC 2008


On 1 Aug 2008, at 13:20, Martin wrote:

> Hello,
> I don't remember anymore when I reported it the first time. I think it
> was around 4.x or something like that. The em(4) bug is still there
> after years.
> Hasn't anyone really noticed yet that em(4) only appears when you boot
> FreeBSD with the interface physically attached to a switch for  
> example?
> If you attach it later, after boot up, the interface won't power up  
> and
> appear in the interface list (ifconfig)?
> Steps to reproduce:
> 1) Switch your PC/laptop off. Really OFF, no reboot.
> 2) Disconnect the em(4) NIC from your switch.
> 3) Boot FreeBSD.
> 4) Plug in the ethernet cable.
> 5) Tataa! All leds at the NIC stay off. You won't be able to use em(4)
> unless you reboot your machine.
> Something is not being initialized properly on em(4) devices, it  
> seems.
> I have had 3 of 3 em(4) NICs so far, where this bug shows up. And it's
> extremely annoying on Thinkpads, when you just want to plug in your
> laptop somewhere.

Well it's not a problem for my TP T41 (just tested with 5.0R and  
7.0R), the NIC probes as: <Intel (R) PRO/1000 Network Connection  
Version - 6.7.3>
and I've never seen it on sundry other boxes with em.

That doesn't mean it can't happen, of course.

> --
> Martin

Bob Bishop          +44 (0)118 940 1243
rb at gid.co.uk    fax +44 (0)118 940 1295
              mobile +44 (0)783 626 4518

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