Purple line appears on the external monitor after it is turned off and back on

[Karolis]

I have an external LED monitor connected to my laptop via HDMI. When I first log in everything seems to be fine, but when the monitor turns off due to inactivity and then turns back on, I see 2 pixel wide purple line on the left side (photo attached).

I got the same issue when I tried upgrading kernel to 3.2 in Ubuntu 11.10

The same happens in Unity 2D and 3D, so I don't think it's a Unity problem. It's probably either kernel or intel driver.

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: linux-image-3.2.0-23-generic 3.2.0-23.36
ProcVersionSignature: Ubuntu 3.2.0-23.36-generic 3.2.14
Uname: Linux 3.2.0-23-generic x86_64
NonfreeKernelModules: wl
AlsaVersion: Advanced Linux Sound Architecture Driver Version 1.0.24.
ApportVersion: 2.0.1-0ubuntu5
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: karolis 14155 F.... pulseaudio
 /dev/snd/controlC1: karolis 14155 F.... pulseaudio
CRDA: Error: command ['iw', 'reg', 'get'] failed with exit code 1: nl80211 not found.
Card0.Amixer.info:
 Card hw:0 'Intel'/'HDA Intel at 0xf6dfc000 irq 46'
   Mixer name : 'Silicon Image SiI1392 HDMI'
   Components : 'HDA:83847616,1028020a,00100201 HDA:10951392,1028020a,00100000'
   Controls : 33
   Simple ctrls : 19
Card1.Amixer.info:
 Card hw:1 'Headset'/'Logitech Logitech USB Headset at usb-0000:00:1d.7-1.4, full speed'
   Mixer name : 'USB Mixer'
   Components : 'USB046d:0a0b'
   Controls : 6
   Simple ctrls : 2
Date: Fri Apr 20 00:19:10 2012
HibernationDevice: RESUME=UUID=4626d6a9-26ae-4151-9855-e85315830484
InstallationMedia: Ubuntu 11.10 "Oneiric Ocelot" - Release amd64 (20111012)
MachineType: Dell Inc. XPS M1330
ProcFB: 0 inteldrmfb
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.2.0-23-generic root=UUID=e2c1bf72-7985-458c-af54-83144d4687d0 ro quiet splash vt.handoff=7
RelatedPackageVersions:
 linux-restricted-modules-3.2.0-23-generic N/A
 linux-backports-modules-3.2.0-23-generic N/A
 linux-firmware 1.79
SourcePackage: linux
UpgradeStatus: Upgraded to precise on 2012-04-13 (6 days ago)
dmi.bios.date: 12/26/2008
dmi.bios.vendor: Dell Inc.
dmi.bios.version: A15
dmi.board.name: 0N6705
dmi.board.vendor: Dell Inc.
dmi.chassis.type: 8
dmi.chassis.vendor: Dell Inc.
dmi.modalias: dmi:bvnDellInc.:bvrA15:bd12/26/2008:svnDellInc.:pnXPSM1330:pvr:rvnDellInc.:rn0N6705:rvr:cvnDellInc.:ct8:cvr:
dmi.product.name: XPS M1330
dmi.sys.vendor: Dell Inc.

[Joseph Salisbury (jsalisbury)]

Would it be possible for you to test the latest upstream kernel? Refer to https://wiki.ubuntu.com/KernelMainlineBuilds . Please test the latest v3.4kernel[1] (Not a kernel in the daily directory). Once you've tested the upstream kernel, please remove the 'needs-upstream-testing' tag(Only that one tag, please leave the other tags). This can be done by clicking on the yellow pencil icon next to the tag located at the bottom of the bug description and deleting the 'needs-upstream-testing' text.

If this bug is fixed in the mainline kernel, please add the following tag 'kernel-fixed-upstream'.

If the mainline kernel does not fix this bug, please add the tag: 'kernel-bug-exists-upstream'.

If you are unable to test the mainline kernel, for example it will not boot, please add the tag: 'kernel-unable-to-test-upstream'.
Once testing of the upstream kernel is complete, please mark this bug as "Confirmed".

Thanks in advance.

http://kernel.ubuntu.com/~kernel-ppa/mainline/v3.4-rc3-precise/

[Karolis (karolis)]

I have tested this with 3.4.0-rc3 kernel and the problem is still present.

It might be worth noting that purple line first appears during splash sequence, then disappears at login screen and is not there after logging in until the monitor is turned off and back on (I use 'xset dpms force off' for testing).

[Joseph Salisbury (jsalisbury)]

This issue appears to be an upstream bug, since you tested the latest upstream kernel. Would it be possible for you to open an upstream bug report at bugzilla.kernel.org [1]? That will allow the upstream Developers to examine the issue, and may provide a quicker resolution to the bug.

If you are comfortable with opening a bug upstream, It would be great if you can report back the upstream bug number in this bug report. That will allow us to link this bug to the upstream report.

[1] https://wiki.ubuntu.com/Bugs/Upstream/kernel

[Karolis (karolis)]

I have raised the same issue at bugzilla.kernel.org and linked it to this report.

[Karolis (karolis)]

This issue has been resolved in 3.8 kernel.

[penalvch (penalvch)]

Karolis, when you updated to the Precise enablement stack 12.04.3, is this issue resolved for you?

[Karolis (karolis)]

To be honest, I never used 12.04.3, but I can grab the live CD and test it, if you'd like.

[penalvch (penalvch)]

Karolis, getting back to your comment https://bugs.launchpad.net/ubuntu/+source/linux/+bug/985949/comments/8 :
"This issue has been resolved in 3.8 kernel."

Were you in Raring?

[Karolis (karolis)]

I've upgraded the kernel manually from http://kernel.ubuntu.com/~kernel-ppa/mainline/

[penalvch (penalvch)]

Karolis, ok. Could you please update your Precise install to 12.04.3 enablement stack and advise on if this is still reproducible?

[Karolis (karolis)]

I do not use Precise any longer and can't really install it at the moment. Would testing LiveCD be sufficient?

[penalvch (penalvch)]

Karolis, if the problem was reproducible in a live environment, then yes.