False alarms raised in bionic because 4.15 kernel needs "pm_debug_messages" to be enabled

[Pierre Equoy]

== SRU justfication, BIONIC (and XENIAL too) ==

[ update - doing the SRU for XENIAL too, Fri, 10th Aug 2018 ]

While performing Hibernate stress tests on a device with 18.04 server installed, we got some failures with FWTS and reported them in lp:1769809.

Even though some of these original failures are due to a bug in Checkbox, some others are due to the fact that the Bionic kernel 4.15 has a parameter "pm_debug_messages" that needs to be enabled.

If you run the stress tests on this device, you will end up with 4 PASS and 2 FAIL. But if you run this command before running the stress tests:

 $ echo 1 | sudo tee -a /sys/power/pm_debug_messages

then all tests are marked as PASSED.

(see comment #9 in the bug above for more information)

It looks like this is something that should be taked into account by FWTS. (but I might be wrong!)

Thanks!

== Fix ==

Upstream commits:

lib: fwts_set: fix API for fwts_set, add fwts_set_int
lib: add small helpers top get/set
acpi: s3: force enable /sys/power/pm_debug_messages (LP: #1772563)
acpi: s4: also check for file based swap files
acpi: s4: force enable /sys/power/pm_debug_messages (LP: #1772563)
acpi: s3power: force enable /sys/power/pm_debug_messages (LP: #1772563)

== Regression Potential ==

Minimal, this fix enables a setting in /sys/power/pm_debug_messages and then returns it back to the initial saved value. At most this could leave debug on if fwts aborts during the test, but this will not affect the behavior of a running system.

[Alex Hung (alexhung)]

@colin,

Do you think this should be fixed in fwts or in bionic kernel?

[Colin Ian King (colin-king)]

I think we should make fwts enable this setting at run time rather than change the kernel's behaviour

[Colin Ian King (colin-king)]

Fixes sent to fwts-devel for review:

https://lists.ubuntu.com/archives/fwts-devel/2018-June/010469.html

[Alex Hung (alexhung)]

Thanks Colin for fixing this.

[Brian Murray (brian-murray)]

Hello Pierre, or anyone else affected,

Accepted fwts into bionic-proposed. The package will build now and be available at https://launchpad.net/ubuntu/+source/fwts/18.03.00-0ubuntu2 in a few hours, and then in the -proposed repository.

Please help us by testing this new package. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation on how to enable and use -proposed.Your feedback will aid us getting this update out to other Ubuntu users.

If this package fixes the bug for you, please add a comment to this bug, mentioning the version of the package you tested and change the tag from verification-needed-bionic to verification-done-bionic. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed-bionic. In either case, without details of your testing we will not be able to proceed.

Further information regarding the verification process can be found at https://wiki.ubuntu.com/QATeam/PerformingSRUVerification . Thank you in advance!

[Colin Ian King (colin-king)]

Tested fwts 18.03.00-0ubuntu2 and this enables the pm kernel debug over a S3/S4 cycle. Marking as verified.

[Launchpad Janitor (janitor)]

This bug was fixed in the package fwts - 18.03.00-0ubuntu2

---------------
fwts (18.03.00-0ubuntu2) bionic; urgency=medium

  * enable PM debug messages for S3 + S4 (LP: #1772563)
    - kernels may have pm debug disabled, so force this on during S3/S4
      tests. Patches from upstream fwts

 -- Colin Ian King <email address hidden> Tue, 12 Jun 2018 14:20:11 +0100

[Łukasz Zemczak (sil2100)]

The verification of the Stable Release Update for fwts has completed successfully and the package has now been released to -updates. Subsequently, the Ubuntu Stable Release Updates Team is being unsubscribed and will not receive messages about this bug report. In the event that you encounter a regression using the package from -updates please report a new bug using ubuntu-bug and tag the bug report regression-update so we can easily find any regressions.

[Colin Ian King (colin-king)]

I've just uploaded the backport fixes for xenial for this bug. Will re-rescribe the SRU team on this

[Colin Ian King (colin-king)]

Can somebody from the SRU team handle the Xenial SRU of this bug? I've got the fix ready for -proposed. Ta

[Brian Murray (brian-murray)]

Hello Pierre, or anyone else affected,

Accepted fwts into xenial-proposed. The package will build now and be available at https://launchpad.net/ubuntu/+source/fwts/16.03.00-0ubuntu1.2 in a few hours, and then in the -proposed repository.

Please help us by testing this new package. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation on how to enable and use -proposed.Your feedback will aid us getting this update out to other Ubuntu users.

If this package fixes the bug for you, please add a comment to this bug, mentioning the version of the package you tested and change the tag from verification-needed-xenial to verification-done-xenial. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed-xenial. In either case, without details of your testing we will not be able to proceed.

Further information regarding the verification process can be found at https://wiki.ubuntu.com/QATeam/PerformingSRUVerification . Thank you in advance!

[Colin Ian King (colin-king)]

Tested -proposed fwts on Xenial with 4.15 kernel; works OK. Ran using strace and I can observe /sys/power/pm_debug_messages is being set and restored to enable this to work fine.

[Launchpad Janitor (janitor)]

This bug was fixed in the package fwts - 16.03.00-0ubuntu1.2

---------------
fwts (16.03.00-0ubuntu1.2) xenial; urgency=low

  * enable PM debug messages for S3 + S4 (LP: #1772563)
   - kernels may have pm debug disabled, so force this on during S3/S4
     tests. Patches from upstream fwts

 -- Colin King <email address hidden> Fri, 10 Aug 2018 10:06:12 +0100