Bug 372837

Summary:	Unplug HDMI cable in sleep mode won't remove external monitor
Product:	[Plasma] KScreen	Reporter:	Guo Yunhe <i>
Component:	kded	Assignee:	Sebastian Kügler <sebas>
Status:	RESOLVED UPSTREAM
Severity:	grave	CC:	chris, idekel.santana, michal.dybczak, nate, robertkasperczyk, swuensch
Priority:	VHI
Version First Reported In:	5.10.5
Target Milestone:	---
Platform:	openSUSE
OS:	Linux
URL:	https://bugzilla.kernel.org/show_bug.cgi?id=202579
See Also:	https://bugs.kde.org/show_bug.cgi?id=413174
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:

Description Guo Yunhe 2016-11-23 14:22:57 UTC

When I connected to external monitor or projector with HDMI cable, sleep the computer, unplug HDMI cable, and wake it up. Even if the cable is not connected, KDE still output to external screen, and I can see the HDMI monitor device in KCM.

1. Connect to external monitor or projector with HDMI cable.
2. Sleep system / close the laptop lid.
3. Unplug HDMI cable.
4. Wake up system.
5. Check desktop output area and KCM, see if the HDMI device is still here.

Since the HDMI device is not connected, windows on it becomes invisible. Users might lose some working data.

Comment 1 Guo Yunhe 2016-11-23 14:24:51 UTC

I tested with both VGA and HDMI cables. VGA cables seem on having this issue.

Comment 2 Guo Yunhe 2017-09-03 22:55:44 UTC

Any news about this bug? Can any developers confirm this?

Comment 3 Sebastian Kügler 2017-09-05 11:00:15 UTC

No news, sorry. I haven't been able to reproduce this issue.

Comment 4 Guo Yunhe 2017-09-06 06:23:01 UTC

I can understand. Hardware related issues are harder to reproduce. I will try with other computers/cables/monitors. If I have new findings, I will update this report.

Comment 5 Nicolas Fella 2019-10-16 21:55:47 UTC

*** Bug 390283 has been marked as a duplicate of this bug. ***

Comment 6 Nate Graham 2019-10-16 21:57:24 UTC

*** Bug 412317 has been marked as a duplicate of this bug. ***

Comment 7 Nate Graham 2019-10-16 21:57:27 UTC

*** Bug 409330 has been marked as a duplicate of this bug. ***

Comment 8 Nate Graham 2019-10-16 21:57:30 UTC

*** Bug 403962 has been marked as a duplicate of this bug. ***

Comment 9 Guo Yunhe 2019-10-17 07:14:12 UTC

I found a related kernel bug report: https://bugzilla.kernel.org/show_bug.cgi?id=202579

Comment 10 Guo Yunhe 2019-11-10 13:57:03 UTC

Closing it because it is not specific to KDE but all GNU/Linux systems. The bug should be fixed in either Kernel or X11. Unluckily, here isn't any ongoing effort to fix it. So it will probably last for several more years.

Comment 11 Nate Graham 2019-11-10 21:24:03 UTC

*** Bug 413174 has been marked as a duplicate of this bug. ***

Comment 12 Michał Dybczak 2019-11-12 22:11:15 UTC

I have kernel 5.3.10 and just upgraded to Plasma 5.17.3. Unplugging secondary monitor don't trigger any reaction. So the issue is still there  for me :(

Comment 13 Nate Graham 2019-11-12 22:21:52 UTC

I guess that makes sense since the Kernel bug (https://bugzilla.kernel.org/show_bug.cgi?id=202579) is still open.

Comment 14 Chris Raven 2019-11-12 22:45:42 UTC

Thanks for the updates everyone. Glad we confirmes this is not a bug in KDE but in the kernel. It's not a major problem but is more annoying. I hope the upstream peoples can fix this as multi monitor is a basic requirement that even Windows XP was able to do right. I never know where the faults lie so thanks for steering us in the right direction.

Thanks Mate for the upstream bug link.

Comment 15 Michał Dybczak 2019-12-05 17:17:05 UTC

The Latest kernel updates fixed it.

Now when I plug and unplug the secondary monitor Plasma recognizes it correctly :). All is well in multimonitor world minus plenty small other bugs, but that's a story for other threads ;D.

Comment 16 Nate Graham 2019-12-05 17:31:40 UTC

Phew! Thanks for closing the loop on this.