Re: 5.14-rc failure to resume

[Jens Axboe <axboe@kernel.dk>]

On 7/24/21 2:28 PM, Jens Axboe wrote:
> On 7/24/21 1:49 PM, Andy Shevchenko wrote:
>> On Sat, Jul 24, 2021 at 8:56 PM Jens Axboe <axboe@kernel.dk> wrote:
>>> On 7/24/21 9:57 AM, Jens Axboe wrote:
>>
>>>> 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@linux-foundation.org>
>>>> 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:
>>
>> Thanks for the report!
>>
>>> 71f6428332844f38c7cb10461d9f29e9c9b983a0 is the first bad commit
>>> commit 71f6428332844f38c7cb10461d9f29e9c9b983a0
>>> Author: Andy Shevchenko <andy.shevchenko@gmail.com>
>>> 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 commit touches two parts (and API) EFI for Apple devices (seems
>> not your case) and CIO2 bridge (Camera device on Intel Sky Lake and
>> Kaby Lake machines). The EFI code runs at boot time AFAIU and CIO2
>> code runs at device's ->probe() time. I'm a bit puzzled as to why it
>> affects resume parts... Daniel, any ideas?
> 
> That does match my camera type at least, but apart from that, no
> ideas. Does seem to be very reliable, as per the one-liner test I just
> made. Unfortunately I don't have a way to log a crash, since it's just
> a laptop...
> 
> Rebuilding with the revert again, should be solid (I'll retest, since
> you never know with issues like this).

Works fine again with the revert. It really does seem to be that commit
that is problematic.

-- 
Jens Axboe