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Subject: Re: [External] Re: [PATCH 3/3] Revert "e1000e: Add handshake with the
 CSME to support S0ix"
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To:     Sasha Neftin <sasha.neftin@intel.com>,
        Kai-Heng Feng <kai.heng.feng@canonical.com>,
        <jesse.brandeburg@intel.com>, <anthony.l.nguyen@intel.com>
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        <intel-wired-lan@lists.osuosl.org>, <netdev@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>,
        "Ruinskiy, Dima" <dima.ruinskiy@intel.com>,
        "Lifshits, Vitaly" <vitaly.lifshits@intel.com>,
        "Avivi, Amir" <amir.avivi@intel.com>
References: <20211122161927.874291-1-kai.heng.feng@canonical.com>
 <20211122161927.874291-3-kai.heng.feng@canonical.com>
 <0ba36a30-95d3-a5f4-93c2-443cf2259756@intel.com>
From:   Mark Pearson <markpearson@lenovo.com>
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Hi Sasha

On 2021-11-28 08:23, Sasha Neftin wrote:
> On 11/22/2021 18:19, Kai-Heng Feng wrote:
>> This reverts commit 3e55d231716ea361b1520b801c6778c4c48de102.
>>
>> Bugzilla:
>> https://bugzilla.kernel.org/show_bug.cgi?id=214821>>>
>> Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
>> ---
<snip>
>>
> Hello Kai-Heng,
> I believe it is the wrong approach. Reverting this patch will put
> corporate systems in an unpredictable state. SW will perform s0ix flow
> independent to CSME. (The CSME firmware will continue run
> independently.) LAN controller could be in an unknown state.
> Please, afford us to continue to debug the problem (it is could be
> incredible complexity)
> 
> You always can skip the s0ix flow on problematic corporate systems by
> using privilege flag: ethtool --set-priv-flags enp0s31f6 s0ix-enabled off
> 
> Also, there is no impact on consumer systems.
> Sasha

I know we've discussed this offline, and your team are working on the
correct fix but I wanted to check based on your comments above that "it
was complex". I thought, and maybe misunderstood, that it was going to
be relatively simple to disable the change for older CPUs - which is the
biggest problem caused by the patch.

Right now it's breaking networking for folk who happen to have a vPro
Tigerlake (and I believe even potentially Cometlake or older) system. I
think the impact of that could potentially be quite severe.

I understand not wanting to revert the change for the ADL platforms I
believe this is targeting and to fix this instead - but your comment
made me nervous that Linux users on older Intel based platforms are in
for a long and painful wait - it is likely a lot of users....

Can you or Dima confirm the fix for older platforms will be available
soon? I appreciate the ADL platform might take a bit more work and time
to get right.

Thanks
Mark