[Intel-wired-lan] e1000e driver stuck at 10Mbps after reconnection

[Camille Bordignon <camille.bordignon@easymile.com>]

Le mardi 11 sept. 2018 ? 17:31:47 (+0900), Benjamin Poirier a ?crit :
> On 2018/09/07 08:28, Camille Bordignon wrote:
> > Le mercredi 08 ao?t 2018 ? 18:00:28 (+0300), Neftin, Sasha a ?crit :
> > > On 8/8/2018 17:24, Neftin, Sasha wrote:
> > > > On 8/7/2018 09:42, Camille Bordignon wrote:
> > > > > Le lundi 06 ao?t 2018 ? 15:45:29 (-0700), Alexander Duyck a ?crit :
> > > > > > On Mon, Aug 6, 2018 at 4:59 AM, Camille Bordignon
> > > > > > <camille.bordignon@easymile.com> wrote:
> > > > > > > Hello,
> > > > > > > 
> > > > > > > Recently we experienced some issues with intel NIC (I219-LM
> > > > > > > and I219-V).
> > > > > > > It seems that after a wire reconnection, auto-negotation "fails" and
> > > > > > > link speed drips to 10 Mbps.
> > > > > > > 
> [...]
> > 
> > I recently figured out that neither the previous patch nor commit
> > 0b76aae741abb9d16d2c0e67f8b1e766576f897d fix this issue.
> > 
> > In these cases, after reproducing the issue, when ethernet wire is connected
> > kernel logs mention full speed (1000 Mbps) but actually it seems it is not.
> > The problem persists.
> > 
> 
> Hmm, so the newer (post 4110e02eb45e) kernels are actually "better", in
> that they accurately report that link speed is 10Mb/s.
> 
Exactly.

> In the end, do you know of a kernel version that doesn't exhibit the
> problem of slower actual link speed?
> 
No. I've tried older version but at some point API has changed and
it fails to compile.
> I had a look at the code and I tried to reproduce the problem on the
> hardware that I have (I217) but could not.
> 
> Also, out of curiosity, have you tried playing with the speed, autoneg
> and advertise settings via ethtool -s to force the link to 1000Mb/s?
Forcing the speed fixes the issue in any case (I mean even when speed is
wronly reported to 1000Mb/s).

Done this way:

#ethtool -s enp0s31f6 speed 1000 duplex full autoneg off

Thanks.