linux-kernel - Re: [PATCH] PCI / ACPI: Don't clear pme_poll on device that has unreliable ACPI wake

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Date:   Sun, 3 Feb 2019 01:46:50 +0800
From:   Kai Heng Feng <kai.heng.feng@...onical.com>
To:     Bjorn Helgaas <helgaas@...nel.org>
Cc:     "Rafael J. Wysocki" <rjw@...ysocki.net>,
        Len Brown <lenb@...nel.org>, jeffrey.t.kirsher@...el.com,
        intel-wired-lan@...ts.osuosl.org, netdev@...r.kernel.org,
        linux-acpi@...r.kernel.org, linux-pci@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH] PCI / ACPI: Don't clear pme_poll on device that has
 unreliable ACPI wake

Hi Bjorn,

> On Jan 28, 2019, at 3:51 PM, Kai Heng Feng <kai.heng.feng@...onical.com> wrote:
[snipped]

>> If I understand correctly, the bugzilla lspci
>> (https://bugzilla.kernel.org/attachment.cgi?id=280691) was collected
>> at point 8, and it shows PME_Status=1 when it should be 0.
>> 
>> If we write a 1 to PME_Status to clear it, and it remains set, that's
>> obviously a hardware defect, and Intel should document that in an
>> erratum, and a quirk would be the appropriate way to work around it.
>> But I doubt that's what's happening.
> 
> I’ll ask them if they can provide an erratum.

Got confirmed with e1000e folks, I219 (the device in question) doesn’t really support runtime D3.
I also checked the behavior of the device under Windows, and it stays at D0 all the time even when it’s not in use.

So I sent a patch [1] to disable it.

[1] https://lkml.org/lkml/2019/2/2/200

Kai-Heng