Message-Id: <8C7BCE85-D027-4C0C-BD46-619FAD0E6AB8@canonical.com>
Date:   Wed, 26 Jun 2019 13:49:13 +0800
From:   Kai Heng Feng <kai.heng.feng@...onical.com>
To:     "Neftin, Sasha" <sasha.neftin@...el.com>
Cc:     jeffrey.t.kirsher@...el.com, intel-wired-lan@...ts.osuosl.org,
        Anthony Wong <anthony.wong@...onical.com>,
        linux-kernel <linux-kernel@...r.kernel.org>
Subject: Re: [Intel-wired-lan] Opportunistic S0ix blocked by e1000e when
 ethernet is in use

at 6:25 PM, Neftin, Sasha <sasha.neftin@...el.com> wrote:

> On 6/24/2019 18:06, Kai-Heng Feng wrote:
>> at 19:56, Neftin, Sasha <sasha.neftin@...el.com> wrote:
[Snipped]
> Current HW have a limitation. Please, try follow workaround on your  
> platform: echo 3 > /sys/kernel/debug/pmc_core/ltr_ignore

Yes, this does the trick.

On 4.15 based kernel I can see the SoC enters PC10 but SLP_S0 is not  
asserted.

On mainline kernel the SoC, PC10 is hit and SLP_S0 is asserted. Once SLP_S0  
is asserted the SSH connection becomes really sluggish.

>> >> S0ix support is under discussion with our architecture. We will try
>>> enable S0ix in our e1000e OOT driver as first step.
>> Is it possible to add Dynamic LTR as an option so users and downstream  
>> distros can still benefit from it?
> As I said before, this is not a stable solution. No guarantee that HW  
> will work as properly.

Can you describe the symptom of "HW will work as properly”? Is this the  
sluggish connection I observed?

Kai-Heng

>> Kai-Heng
>>>> Kai-Heng
>>>>> Kai-Heng
>>>> _______________________________________________
>>>> Intel-wired-lan mailing list
>>>> Intel-wired-lan@...osl.org
>>>> https://lists.osuosl.org/mailman/listinfo/intel-wired-lan
>>>
>>> Thanks
>>> Sasha

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