Re: 5.14-rc failure to resume

From: Jens Axboe
Date: Sat Jul 24 2021 - 13:56:43 EST

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://
> 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.

Jens Axboe