Re: 5.14-rc failure to resume

From: Jens Axboe
Date: Sat Jul 24 2021 - 16:26:41 EST


On 7/24/21 2:05 PM, Andy Shevchenko wrote:
> On Sat, Jul 24, 2021 at 10:43 PM Jens Axboe <axboe@xxxxxxxxx> wrote:
>> On 7/24/21 11:56 AM, Jens Axboe wrote:
>>> On 7/24/21 9:57 AM, Jens Axboe wrote:
>>>> Hi,
>>>>
>>>> I ran into this when doing the last bit of testing on pending changes
>>>> for this release on the laptop. Outside of running testing on these
>>>> changes, I always build and boot current -git and my changes on my
>>>> laptop as well.
>>>>
>>>> 5.14-rc1 + changes works fine, current -git and changes fail to resume
>>>> every single time. I just get a black screen. Tip of tree before merging
>>>> fixes is:
>>>>
>>>> commit 704f4cba43d4ed31ef4beb422313f1263d87bc55 (origin/master, origin/HEAD, master)
>>>> Merge: 05daae0fb033 0077a5008272
>>>> Author: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
>>>> Date: Fri Jul 23 11:30:12 2021 -0700
>>>>
>>>> Merge tag 'ceph-for-5.14-rc3' of git://github.com/ceph/ceph-client
>>>>
>>>> Since bisection takes forever on the laptop (gen7 x1 carbon), I
>>>> opportunistically reverted some of the most recent git pulls:
>>>>
>>>> - ec6badfbe1cde0eb2bec4a0b8f6e738171156b5b (acpi changes)
>>>> - 1d597682d3e669ec7021aa33d088ed3d136a5149 (driver-core changes)
>>>> - 74738c556db6c7f780a8b98340937e55b72c896a (usb changes)
>>>> - e7562a00c1f54116f5a058e7e3ddd500188f60b2 (sound changes)
>>>> - 8baef6386baaefb776bdd09b5c7630cf057c51c6 (drm changes)
>>>>
>>>> as they could potentially be involved, but even with all of those
>>>> reverted it still won't resume.
>>>>
>>>> Sending this out in case someone has already reported this and I just
>>>> couldn't find it. If this is a new/unknown issues, I'll go ahead and
>>>> bisect it.
>>>
>>> Ran a bisect, and it pinpoints:
>>>
>>> 71f6428332844f38c7cb10461d9f29e9c9b983a0 is the first bad commit
>>> commit 71f6428332844f38c7cb10461d9f29e9c9b983a0
>>> Author: Andy Shevchenko <andy.shevchenko@xxxxxxxxx>
>>> Date: Mon Jul 12 21:21:21 2021 +0300
>>>
>>> ACPI: utils: Fix reference counting in for_each_acpi_dev_match()
>>>
>>> which seems odd, as it worked for me with the acpi changes reverted. It
>>> could be that it _sometimes_ works with that commit, not sure. Adding
>>> relevant folks to the CC.
>>>
>>> I'm going to revert this on top of current master and run with that
>>> and see if it does 10 successful resumes.
>>
>> This does appear to be the culprit. With it reverted on top of current
>> master (and with the block and io_uring changes pulled in too), the
>> kernel survives many resumes without issue.
>
> If I read correctly it seems at one of the local rebase I might have
> missed something.
>
> Can you replace sensor->adev with adev here
>
> https://elixir.bootlin.com/linux/v5.14-rc2/source/drivers/media/pci/intel/ipu3/cio2-bridge.c#L231
>
> and retest?

Tried that, doesn't work unfortunately. Hung on first resume, just like
current -git with that single line edit.

--
Jens Axboe