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From: "Rafael J. Wysocki" <firstname.lastname@example.org>
To: Joseph Salisbury <email@example.com>
Cc: "Rafael J. Wysocki" <firstname.lastname@example.org>,
"Rafael J. Wysocki" <email@example.com>,
Len Brown <firstname.lastname@example.org>, Bjorn Helgaas <email@example.com>,
ACPI Devel Maling List <firstname.lastname@example.org>,
Linux PCI <email@example.com>,
Mika Westerberg <firstname.lastname@example.org>
Subject: Re: [Regression] PCI / PM: Simplify device wakeup settings code
Date: Tue, 1 May 2018 10:34:29 +0200 [thread overview]
Message-ID: <CAJZ5v0iPsoxCLxsq156RvyZ1cWtM9jNMLUPMnE3cqi5r1jk8jg@mail.gmail.com> (raw)
On Mon, Apr 30, 2018 at 4:22 PM, Joseph Salisbury
> On 04/16/2018 11:58 AM, Rafael J. Wysocki wrote:
>> On Mon, Apr 16, 2018 at 5:31 PM, Joseph Salisbury
>> <email@example.com> wrote:
>>> On 04/13/2018 05:34 PM, Rafael J. Wysocki wrote:
>>>> On Fri, Apr 13, 2018 at 7:56 PM, Joseph Salisbury
>>>> <firstname.lastname@example.org> wrote:
>>>>> Hi Rafael,
>>>>> A kernel bug report was opened against Ubuntu . After a kernel
>>>>> bisect, it was found that reverting the following two commits resolved
>>>>> this bug:
>>>>> 0ce3fcaff929 ("PCI / PM: Restore PME Enable after config space restoration")
>>>>> 0847684cfc5f("PCI / PM: Simplify device wakeup settings code")
>>>>> This is a regression introduced in v4.13-rc1 and still exists in
>>>>> mainline. The bug causes the battery to drain when the system is
>>>>> powered down and unplugged, which does not happed prior to these two
>>>> What system and what do you mean by "powered down"? How much time
>>>> does it take for the battery to drain now?
>>> By powered down, the bug reporter is saying physically powered off and
>>> unplugged. The system is a HP laptop:
>>> dmi.chassis.vendor: HP
>>> dmi.product.family: 103C_5335KV HP Notebook
>>> dmi.product.name: HP Notebook
>>> vendor_id : GenuineIntel
>>> cpu family : 6
>>>>> The bisect actually pointed to commit de3ef1e, but reverting
>>>>> these two commits fixes the issue.
>>>>> I was hoping to get your feedback, since you are the patch author. Do
>>>>> you think gathering any additional data will help diagnose this issue,
>>>>> or would it be best to submit a revert request?
>>>> First, reverting these is not an option or you will break systems
>>>> relying on them now. 4.13 is three releases back at this point.
>>>> Second, your issue appears to be related to the suspend/shutdown path
>>>> whereas commit 0ce3fcaff929 is mostly about resume, so presumably the
>>>> change in pci_enable_wake() causes the problem to happen. Can you try
>>>> to revert this one alone and see if that helps?
>>> A test kernel with commits 0ce3fcaff929 and de3ef1eb1cd0 reverted was
>>> tested. However, the test kernel still exhibited the bug.
>> So essentially the bisection result cannot be trusted.
> We performed some more testing and confirmed just a revert of the
> following commit resolves the bug:
> 0847684cfc5f0 ("PCI / PM: Simplify device wakeup settings code")
Thanks for confirming this!
> Can you think of any suggestions to help debug further?
The root cause of the regression is likely the change in
pci_enable_wake() removing the device_may_wakeup() check from it.
Probably, one of the drivers in the platform calls pci_enable_wake()
directly from its ->shutdown() callback and that causes the device to
be set up for system wakeup which in turn causes the power draw while
the system is off to increase.
I would look at the PCI drivers used on that platform to find which of
them call pci_enable_wake() directly from ->shutdown() and I would
make these calls conditional on device_may_wakeup().
next prev parent reply other threads:[~2018-05-01 8:34 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-04-13 17:56 Joseph Salisbury
2018-04-13 21:34 ` Rafael J. Wysocki
2018-04-16 15:31 ` Joseph Salisbury
2018-04-16 15:58 ` Rafael J. Wysocki
2018-04-16 16:48 ` Joseph Salisbury
2018-04-30 14:22 ` Joseph Salisbury
2018-05-01 8:34 ` Rafael J. Wysocki [this message]
2018-05-01 19:55 ` Bjorn Helgaas
2018-05-02 8:21 ` Rafael J. Wysocki
2018-05-02 10:41 ` Rafael J. Wysocki
2018-05-02 11:12 ` Joseph Salisbury
2018-05-03 18:29 ` Joseph Salisbury
2018-05-03 19:11 ` Bjorn Helgaas
2018-05-03 21:29 ` Rafael J. Wysocki
2018-05-04 11:14 ` Rafael J. Wysocki
2018-05-07 16:15 ` Joseph Salisbury
2018-05-08 22:13 ` Rafael J. Wysocki
2018-05-08 22:18 ` [PATCH] PCI / PM: Check device_may_wakeup() in pci_enable_wake() Rafael J. Wysocki
2018-05-09 22:34 ` Rafael J. Wysocki
2018-05-10 13:03 ` Bjorn Helgaas
2018-05-10 14:49 ` Rafael J. Wysocki
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