Bug 341763 - Plugging in a second monitor turns both black
Summary: Plugging in a second monitor turns both black
Status: RESOLVED FIXED
Alias: None
Product: KScreen
Classification: Plasma
Component: common (show other bugs)
Version: unspecified
Platform: Ubuntu Linux
: NOR grave
Target Milestone: ---
Assignee: Alex Fiestas
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2014-12-11 01:05 UTC by john
Modified: 2014-12-21 05:07 UTC (History)
2 users (show)

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Description john 2014-12-11 01:05:48 UTC 
I use my laptop at with a second monitor plugged in. After today's update (mostly nvidia I guess, see /var/log/apt/history.log below), both monitors go black as soon as I login to KDE (the second does not get any input signal and shuts down). Login manager is displayed without problems, as are tty1-tty6. I've tried to use the Fn key to switch displays, without any effect.

Reproducible: Always

Steps to Reproduce:
1. Boot with second screen connected. Login window is displayed on both monitors.
2. Login to KDE. Both screens go black (the secondary one does not get any signal and shuts down).
3. Switch to any of tty1-tty6. They are correctly displayed on both monitors.
4. Switching back to tty7 turns everything black again.
5. Unplug display. Laptop screen remains black.
6. Switch to one of tty1-tty6, then back to tty7. Now KDE is displayed correctly, but sometimes the touchpad is disabled.
7. Reconnecting the second display repeatedly reproduces the same result.

Alternatively, when starting with the second display disconnected, login to KDE works fine, but as soon as I plug in, all turns black again.

Actual Results:  
Stuff turns black.

Expected Results:  
It shouldn't, KDE should be displayed on both screens.

Here's today's entry in /var/log/apt/history.log

Start-Date: 2014-12-10  17:33:22
Install: screen-resolution-extra:amd64 (0.17.1, automatic), lib32gcc1:amd64 (4.9.1-0ubuntu1, automatic), nvidia-opencl-icd-331-updates:amd64 (331.113-0ubuntu0.0.4, automatic), dkms:amd64 (2.2.0.3-1.1ubuntu5.14.04, automatic), nvidia-settings:amd64 (331.20-0ubuntu8, automatic), nvidia-331-updates-uvm:amd64 (331.113-0ubuntu0.0.4, automatic), libcuda1-331-updates:amd64 (331.113-0ubuntu0.0.4, automatic), bbswitch-dkms:amd64 (0.7-2ubuntu1, automatic), nvidia-prime:amd64 (0.6.2, automatic), nvidia-331-updates:amd64 (331.113-0ubuntu0.0.4, automatic)
Upgrade: nvidia-libopencl1-331-updates:amd64 (331.38-0ubuntu7.1, 331.113-0ubuntu0.0.4)
End-Date: 2014-12-10  17:34:54
Comment 1 john 2014-12-12 22:29:56 UTC 
additional information from /var/log/syslog:
12/12/14 05:27:31 PM	laptop	colord	Device added: xrandr-Hewlett Packard-HP ZR2440w-CNT21450J3
12/12/14 05:27:43 PM	laptop	acpid	client 1750[0:0] has disconnected
12/12/14 05:27:43 PM	laptop	kernel	[  480.677253] HDMI: ELD buf size is 0, force 128
12/12/14 05:27:43 PM	laptop	kernel	[  480.677267] HDMI: invalid ELD data byte 0
12/12/14 05:27:43 PM	laptop	kernel	[  480.677313] HDMI: ELD buf size is 0, force 128
12/12/14 05:27:43 PM	laptop	kernel	[  480.677336] HDMI: invalid ELD data byte 0
12/12/14 05:27:43 PM	laptop	acpid	client connected from 1750[0:0]
12/12/14 05:27:43 PM	laptop	acpid	1 client rule loaded
12/12/14 05:27:44 PM	laptop	colord	device removed: xrandr-Hewlett Packard-HP ZR2440w-CNT21450J3
Comment 2 john 2014-12-21 05:05:50 UTC 
The latest update solved this, back to normal again:

Start-Date: 2014-12-20  16:40:25
Install: ocl-icd-libopencl1:amd64 (2.1.3-4)
Remove: nvidia-libopencl1-331-updates:amd64 (331.113-0ubuntu0.0.4)
End-Date: 2014-12-20  16:40:29

Start-Date: 2014-12-20  16:40:46
Upgrade: libhwloc-plugins:amd64 (1.8-1ubuntu1, 1.8-1ubuntu1.14.04.1)
End-Date: 2014-12-20  16:40:47