RE: [Intel-wired-lan] [REGRESSION] e1000e: RX stops after link down/up on Intel 8086:550a since v6.12.43 (fixed by suspend/resume)

["Wenger Jeremie (EDU)" <jeremie.wenger@edu.ge.ch>]

De : Lifshits, Vitaly <vitaly.lifshits@intel.com>
Envoyé : mardi, 13 janvier 2026 04:05
À : Wenger Jeremie (EDU); netdev@vger.kernel.org
Cc : anthony.l.nguyen@intel.com; przemyslaw.kitszel@intel.com; intel-wired-lan@lists.osuosl.org; linux-kernel@vger.kernel.org
Objet : Re: [Intel-wired-lan] [REGRESSION] e1000e: RX stops after link down/up on Intel 8086:550a since v6.12.43 (fixed by suspend/resume)
    
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On 1/8/2026 4:15 PM, Wenger Jeremie (EDU) via Intel-wired-lan wrote:
> Hello,
>
>
> I would like to report a regression in the e1000e driver affecting an
> Intel integrated Ethernet controller.
>
>
> Hardware:
> Intel Ethernet controller [8086:550a]
> Driver: e1000e
>
>
> Summary:
> RX stops working after an Ethernet link down/up (unplug/replug cable).
> TX still works. A system suspend/resume reliably restores RX.
>
>
> Regression range:
>
>   *
>
>     Working: v6.12.22
>
>   *
>
>     Broken: v6.12.43 .. v6.18.3 (tested on Debian 12 backports, Debian
>     13, Debian sid). v6.18.3 is the most recent kernel tested so far, so
>     the regression is likely still present in newer kernels.
>
> Symptoms:
>
>   *
>
>     Link is detected (1Gbps, full duplex).
>
>   *
>
>     DHCP DISCOVER frames are transmitted (confirmed via external packet
>     capture).
>
>   *
>
>     No packets are received (no DHCP OFFER, RX appears dead).
>
>   *
>
>     Booting with the cable plugged works.
>
>   *
>
>     The issue is triggered only after unplugging and replugging the cable.
>
>   *
>
>     A suspend/resume cycle restores RX immediately.
>
>   *
>
>     Using a USB Ethernet adapter (r8152) on the same network works
>     correctly.
>
> Reproduction steps:
>
>  1.
>
>     Boot with Ethernet cable plugged.
>
>  2.
>
>     Verify network connectivity works.
>
>  3.
>
>     Unplug the Ethernet cable.
>
>  4.
>
>     Plug the Ethernet cable back in.
>
>  5.
>
>     Observe that RX no longer works (no DHCP OFFER).
>
>  6.
>
>     Suspend/resume the system → RX works again.
>
> This suggests that the PHY or RX path is not correctly reinitialized
> on link up after a link down event, while the resume path performs a
> more complete reset.
>
>
> I can provide additional logs, ethtool statistics, or test patches if
> needed.
>
>
>
> Best regards,
>
>
> Jérémie Wenger
>
>

Hi Jérémie,

Your issue sounds very similar to the issues that were addresses in this
commit:
https://github.com/torvalds/linux/commit/3c7bf5af2196087f394f9099b53e37569636b259

Are you able to reproduce it over the latest kernel 6.19?

    

Hi Vitaly,

Yes, I can confirm this.

I tested with Linux 6.19 (6.19~rc4-1~exp1), and the issue is fixed there.
After an Ethernet link down/up, RX now recovers correctly without requiring
a suspend/resume cycle.

So this appears to be resolved by commit:
3c7bf5af2196087f394f9099b53e37569636b259

Do you know if this fix is planned to be backported to stable kernels
(e.g. 6.12.y), or if a backport would be acceptable?

Thanks again for your help.

Best regards,

Jérémie