[Intel-wired-lan] [Regression] "e1000e: Add support for S0ix" breaks s2idle on Lenovo X1 Carbon 7th

[Kai-Heng Feng]

Hi Sasha,

> On Mar 18, 2020, at 15:32, Neftin, Sasha <sasha.neftin at intel.com> wrote:
> 
> On 3/18/2020 05:12, Kai-Heng Feng wrote:
>> Hi Vitaly,
>>> On Mar 17, 2020, at 22:39, Vitaly Lifshits <vitaly.lifshits at intel.com> wrote:
>>> 
>>> On 3/17/2020 16:04, Kai-Heng Feng wrote:
>>>>> On Mar 17, 2020, at 21:56, Neftin, Sasha <sasha.neftin at intel.com> wrote:
>>>>> 
>>>>> On 3/17/2020 15:34, Kai-Heng Feng wrote:
>>>>>> Hi,
>>>>>> Users reported that X1 Carbon 7th can only suspend once due of "e1000e 0000:00:1f.6 enp0s31f6: Hardware Error" [1] [2].
>>>>>> I managed to get one at hand and I can confirm the issue is 100% reproducible.
>>>>>> The error occurs at the first e1e_rphy() in e1000_copper_link_setup_82577() [3].
>>>>>> Reverting "e1000e: Add support for S0ix" makes suspend work again.
>>>>>> I also tried commit e1738282f6c6 "e1000e: fix S0ix flows for cable connected case" however the issue persists.
>>>>>> Kai-Heng
>>>>>> [1] https://bugs.launchpad.net/bugs/1865570
>>>>>> [2] https://bugs.launchpad.net/bugs/1866170
>>>>>> [3] https://git.kernel.org/pub/scm/linux/kernel/git/jkirsher/next-queue.git/tree/drivers/net/ethernet/intel/e1000e/phy.c?h=dev-queue&id=e1738282f6c6ad0ec56a15c4d5a3b657d90e4435#n630
>>>>> please, check of ME enabled on this system. try disable ME and re-run
>>>> I disabled "Intel AMT", issue is still reproducible.
>>>> Kai-Heng
>>> Hi Kai,
>>> 
>>> Do you work with cable connected?
>> No, ethernet cable is not plugged.
>>> If so, please try to run this command:
>>> sudo echo 3 > /sys/kernel/debug/pmc_core/ltr_ignore
>> Same issue after doing that.
>> Though unlikely, can this be caused by the special design of X1 Carbon?
>> To keep the laptop thin, it doesn't have a RJ45 port. Instead it has a special connecter which requires a RJ45 dongle to support ethernet.
>> Maybe that's why the PHY part isn't working after suspend?
> Hello Kai-Heng,
> Thanks for your response. I would like clarify/understand Lenovo X1 Carbon setup:
> How laptop connected to the docking station?

There's no docking station involved. Just a regular e1000e device connects to root complex.

> Thunderbolt or Lenovo proprietary connection?

No thunderbolt involved.

I'd say it's proprietary:
https://www.lenovo.com/us/en/accessories-and-monitors/cables-and-adapters/adapters/CABLE-BO-Ethernet-Extension-Adapter-2/p/4X90Q84427

The ethernet port is next to thunderbolt, but it's not thunderbolt:
https://images.idgesg.net/images/article/2018/08/left-ports-100769115-orig.jpg

> Where is LAN located (physically) in a laptop or dock?
> PHY located in docking, right?

This I don't know. I'll raise the issue to Lenovo hardware team.

> 
> And last question: does this system supported Sx or S0ix (do you know)?

Sx you mean S3?

I think the system supports S3 but it defaults to S0ix.

> The reason I ask it due from my understanding dock always connected to the power and system should be Sx supported.

There's no dock.
For this issue, _nothing_ connects to the ethernet port.

> 
> Therefore may be we need introduce difference behavior between Sx and S0ix support. (if I understand correctly, such systems as Lenovo Carbon X1 should be Sx support, we need ignore S0ix entry/exit in such cases - ACPI interface should provide us with this info)

For this case S0ix is used.

Kai-Heng

> 
>> Kai-Heng
> Sasha