Re: e1000e: I219-V RX CRC errors on ThinkPad P14s Gen6 Intel; disabling K1 restores throughput

[Paul Menzel]

Dear Christoph,


Thank you for your report.

Am 03.10.26 um 16:56 schrieb Christoph Groth:

> I noticed that wired Ethernet throughput from WAN is much lower than
> expected on my new ThinkPad P14s Gen6 Intel.  The culprit seems to be
> CRC errors.  This is with current firmware.  I updated everything one or
> two weeks ago.
>
> Executing ‘ethtool --set-priv-flags enp0s31f6 disable-k1 on’ works
> around the problem.  There could be a relation to commit 578294b8b60d
> that re-enabled K1 by default.
>
> See below for a shell session demonstrating the problem by downloading
> data for 30 seconds.  With K1 enabled, the transfer generated 125 CRC
> errors while receiving 156 MiB; with K1 disabled, the error counter
> remained unchanged while receiving 2547 MiB (i.e. a 16-fold faster
> download).  The following has been recorded using a freshly booted
> current Debian testing live system.
>
> I’ve been observing the same problem with different recent kernel
> versions, different network cables, routers, and networks.  I also had
> the opportunity to reproduce the problem with a second identical
> computer.

[…]

This is a known problem, and patches were sent to net just on October 
1st [1], and accepted. It’d be great if you could take a look, and reply 
there, if these solve the problem for you.


Kind regards,

Paul


[1]: 
https://lore.kernel.org/all/20261001222443.3500206-7-anthony.l.nguyen@xxxxxxxxx/