Mirror mode doesn't work when panel only supports one refresh rate with reduced blanking

[Kai-Heng Feng]

[Impact]
On systems equipped with reduced blanking panel, mirror mode can result to no image on external monitor.
The reason is due to current fallback modes don't have pixelclock for reduced blanking, so inadequate refresh rate is used to mode set, and result with atomic commit failure.

[Fix]
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3449
Add reduced blanking (RB) to fallback modes, so mutter can use RB mode to meet pixelclock requirement in order to pick the right refresh rate.

[Test]
Connect an external monitor to affected system. Use the monitor hotkey to switch to mirror mode or use GNOME control center to choose mirror mode. With the patch included, the issue is no longer observed.

[Where problems could occur]
The modelines of reduced blanking have reversed Hsync and Vsync flags, so if the driver doesn't handle those flags correctly, the atomic modeset/commit may fail.

I haven't observe any issue on Intel/AMD/Nvidia GPU so far.

[Daniel van Vugt (vanvugt)]

Thanks, I was looking for this LP bug a couple of days ago :)

[Daniel van Vugt (vanvugt)]

Sounds like this is one possible cause of bug 1968040, although some users there have issues even with a single monitor.

[Kai-Heng Feng (kaihengfeng)]

The mirror mode issue may be resolved by this one. Issues on single monitor quite likely have different root cause.

[Ubuntu Foundations Team Bug Bot (crichton)]

The attachment "mutter_45.3-1ubuntu2.debdiff" seems to be a debdiff. The ubuntu-sponsors team has been subscribed to the bug report so that they can review and hopefully sponsor the debdiff. If the attachment isn't a patch, please remove the "patch" flag from the attachment, remove the "patch" tag, and if you are member of the ~ubuntu-sponsors, unsubscribe the team.

[This is an automated message performed by a Launchpad user owned by ~brian-murray, for any issue please contact him.]

[Daniel van Vugt (vanvugt)]

I think the preferred place for mutter patches is:
https://salsa.debian.org/gnome-team/mutter/-/merge_requests

[Kai-Heng Feng (kaihengfeng)]

Thanks for the note. Just created merge requests on salsa instead.

[Dan Bungert (dbungert)]

Hi Kai-Heng,

It looks like you're working on this through Salsa. The debdiffs on this bug mean that this shows in the sponsor queue, so I'm removing Ubuntu Sponsors from this bug since there looks like no action to take for Sponsors. Please re-subscribe Sponsors if you feel otherwise. Thanks!

[Kai-Heng Feng (kaihengfeng)]

Noble will get this fix via Mutter 46, still needs this fix lands in Mantic and Jammy.

[Daniel van Vugt (vanvugt)]

I'm merging the fix for bug 2054510 into the same updates so please wait...

[Daniel van Vugt (vanvugt)]

Jammy is awaiting sponsorship in https://bugs.launchpad.net/ubuntu/+source/mutter/+bug/2054510/comments/3

[Daniel van Vugt (vanvugt)]

Mantic is awaiting sponsorship in https://bugs.launchpad.net/ubuntu/+source/mutter/+bug/2054510/comments/4

[Łukasz Zemczak (sil2100)]

Hello Kai-Heng, or anyone else affected,

Accepted mutter into mantic-proposed. The package will build now and be available at https://launchpad.net/ubuntu/+source/mutter/45.2-0ubuntu4 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, what testing has been performed on the package and change the tag from verification-needed-mantic to verification-done-mantic. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed-mantic. 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 for helping!

N.B. The updated package will be released to -updates after the bug(s) fixed by this package have been verified and the package has been in -proposed for a minimum of 7 days.

[Łukasz Zemczak (sil2100)]

Hello Kai-Heng, or anyone else affected,

Accepted mutter into jammy-proposed. The package will build now and be available at https://launchpad.net/ubuntu/+source/mutter/42.9-0ubuntu6 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, what testing has been performed on the package and change the tag from verification-needed-jammy to verification-done-jammy. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed-jammy. 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 for helping!

N.B. The updated package will be released to -updates after the bug(s) fixed by this package have been verified and the package has been in -proposed for a minimum of 7 days.

[Daniel van Vugt (vanvugt)]

Mantic built OK, except on arm64 and armhf due to known flaky tests. We can try rebuilding for those.

Jammy failed to build mostly due to a new bug 2055519 (unrelated to our changes). So we should add a fix for that and roll a new version. amd64 also failed with "fatal error: meta/meta-enum-types.h: No such file or directory", which is bug 2055530.

[Daniel van Vugt (vanvugt)]

Proposed fixes for the Jammy build failures:

https://bugs.launchpad.net/ubuntu/+source/mutter/+bug/2054510/comments/11

No we didn't cause them :)

[Ubuntu SRU Bot (ubuntu-sru-bot)]

All autopkgtests for the newly accepted mutter (45.2-0ubuntu4) for mantic have finished running.
The following regressions have been reported in tests triggered by the package:

mutter/45.2-0ubuntu4 (armhf)

Please visit the excuses page listed below and investigate the failures, proceeding afterwards as per the StableReleaseUpdates policy regarding autopkgtest regressions [1].

https://people.canonical.com/~ubuntu-archive/proposed-migration/mantic/update_excuses.html#mutter

[1] https://wiki.ubuntu.com/StableReleaseUpdates#Autopkgtest_Regressions

Thank you!

[Daniel van Vugt (vanvugt)]

That failing test case:

  1180s # FAIL: mutter-13/minimized.test (Child process exited with code 133)

is known to be flaky. I've seen it fail on unrelated changes upstream. And it is indeed unrelated to these changes.

The rebuild has now succeeded:

  https://launchpad.net/ubuntu/+source/mutter/45.2-0ubuntu4

[Daniel van Vugt (vanvugt)]

Kai-Heng Feng, please remember to verify mantic.

[Kai-Heng Feng (kaihengfeng)]

Verification steps:
1) Enable proposed
2) sudo apt install mutter=45.2-0ubuntu4 (and other mutter binary packages)
3) Reboot
4) Connect external monitor to the affected system
5) Switch display modes to mirror mode
6) Observe the mirror mode can be set successfully. So the issue is resolved.

[Robie Basak (racb)]

Hello Kai-Heng, or anyone else affected,

Accepted mutter into jammy-proposed. The package will build now and be available at https://launchpad.net/ubuntu/+source/mutter/42.9-0ubuntu7 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, what testing has been performed on the package and change the tag from verification-needed-jammy to verification-done-jammy. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed-jammy. 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 for helping!

N.B. The updated package will be released to -updates after the bug(s) fixed by this package have been verified and the package has been in -proposed for a minimum of 7 days.

[Max Lee (max-lee)]

verify fixed with mutter 42.9-0ubuntu7 in jammy-proposed.
SEV16_DVT1_C4 202309-32111

1. enable proposed
2. sudo apt update
3. sudo apt dist-upgrade
4. sudo reboot -i
5. sudo dpkg -l | grep mutter (make sure all mutter related were ugpraded to 42.9ubuntu7)
6. Connect external monitor to the affected system
7. Switch display modes to mirror mode
8. Observe the mirror mode can be set successfully. So the issue is resolved.

[Andreas Hasenack (ahasenack)]

There is an armhf DEP8 failure that I just retriggered, let's see if it passes in the next run.

[Andreas Hasenack (ahasenack)]

The test failure on armhf persists:

939s # Running test: mutter-13/fullscreen-maximize.test
940s # Executing: mutter-13/fullscreen-maximize.test
941s # FAIL: mutter-13/fullscreen-maximize.test (Child process exited with code 1)
941s not ok - mutter-13/fullscreen-maximize.test

[Kai-Heng Feng (kaihengfeng)]

May I know where can I find the test result?

Everything looks fine at [0].

[0] https://launchpad.net/ubuntu/+source/mutter/42.9-0ubuntu7/+build/27912046

[Daniel van Vugt (vanvugt)]

Ignore the fullscreen-maximize failure...
https://bugs.launchpad.net/ubuntu/+source/mutter/+bug/2054510/comments/18

[Launchpad Janitor (janitor)]

This bug was fixed in the package mutter - 45.2-0ubuntu4

---------------
mutter (45.2-0ubuntu4) mantic; urgency=medium

  [ Kai-Heng Feng ]
  * Fix mirror mode on reduced blanking panel. (LP: #2051074)

  [ Daniel van Vugt ]
  * Add compositor-x11-Sync-again-at-the-end-of-before_paint.patch
    to fix incomplete redraws in X11 virtual machines (LP: #2054510)

 -- Daniel van Vugt <email address hidden> Thu, 22 Feb 2024 16:32:33 +0800

[Timo Aaltonen (tjaalton)]

The verification of the Stable Release Update for mutter has completed successfully and the package is now being 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.

[Launchpad Janitor (janitor)]

This bug was fixed in the package mutter - 42.9-0ubuntu7

---------------
mutter (42.9-0ubuntu7) jammy; urgency=medium

  * Add build-Set-built-headers-as-libmutter_dep-sources.patch to prevent
    occasional build failures depending on parallelism (LP: #2055530)
  * Add cogl-gl-framebuffer-Fix-inverted-test-in-ensure_bits_init.patch to
    fix test failures in mutter:cogl+cogl/conform / framebuffer-get-bits
    when Mesa >= 23.1.1 (LP: #2055519)

mutter (42.9-0ubuntu6) jammy; urgency=medium

  [ Kai-Heng Feng ]
  * Fix mirror mode on reduced blanking panel. (LP: #2051074)

  [ Daniel van Vugt ]
  * Add compositor-x11-Sync-again-at-the-end-of-before_paint.patch
    to fix incomplete redraws in X11 virtual machines (LP: #2054510)
  * debian/control.in: Stop automatically reverting to the old uploaders.

 -- Daniel van Vugt <email address hidden> Fri, 01 Mar 2024 17:47:40 +0800