Re: r8169 auto speed down issue

[Francois Romieu]

hayeswang <hayeswang@xxxxxxxxxxx> :
[...]
> Sorry for my unclear descriptor. I just think a case that the nic suspends or
> shutdowns without cable plugging. Then, the cable is plugged again. If the nic
> speed down to 10M and the link partner force 100M, the issue appears again. If
> the nic doesn't speed down for normal link partner, it requires more power
> when the linking recovers.

Yes. The nic can not guess what the user values most: power saving in a
stable link layer configuration vs ability to detect and adapt to a yet
unseen configuration.

It could be a reason why EEE exists.

> Finally, I determine to set the speed to 10M when the link partner supports
> 10M. And for the other case, setting the speed to 100M. This avoids the giga
> nic to keep the speed to 1000M, and could fix this issue.
> However, I wonder if there is a switch which forces the speed to giga.

We can check if the partner supports 100M too. It's almost free and it will
avoid this problem.

-- 
Ueimor
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/