Intermittent screen blinking with 4k external mini display port with 4.4 kernels

[Jamie Strandboge]

When using an external 4K monitor plugged into the mini display port on my Dell XPS 13 9343 using both the laptop screen and the external monitor (external monitor is left and laptop screen right), when using all of the following kernels:
4.4.0-2.16-generic
4.4.0-4.19-generic
4.4.0-6.21-generic
4.4.0-7.22-generic

the external monitor will sometimes blink off for about a second or two, then back on. What is weird is this seems to only happen when typing into a gnome-terminal as opposed to firefox or evolution. Simply changing to a gnome-terminal and typing into it doesn't cause the blinking, but it might happen immediately or it might take several minutes.

4.3.0-7.18-generic worked fine and I can go hours and hours in a gnome-terminal with no issues.

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: linux-image-4.4.0-6-generic 4.4.0-6.21
ProcVersionSignature: Ubuntu 4.4.0-6.21-generic 4.4.1
Uname: Linux 4.4.0-6-generic x86_64
ApportVersion: 2.20-0ubuntu3
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC2: jamie 5882 F.... pulseaudio
 /dev/snd/controlC1: jamie 5882 F.... pulseaudio
 /dev/snd/controlC0: jamie 5882 F.... pulseaudio
CurrentDesktop: Unity
Date: Fri Feb 19 12:09:28 2016
HibernationDevice: RESUME=UUID=27fa6713-c8c2-4eb8-9766-ba6918bc1cfb
InstallationDate: Installed on 2015-06-13 (250 days ago)
InstallationMedia: Ubuntu 15.04 "Vivid Vervet" - Release amd64 (20150422)
MachineType: Dell Inc. XPS 13 9343
ProcFB: 0 inteldrmfb
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.4.0-6-generic.efi.signed root=UUID=7bc4dcd2-0bd8-4e42-b8b7-9f1ed6b8a3e9 ro libata.force=noncq kaslr quiet splash vt.handoff=7
RelatedPackageVersions:
 linux-restricted-modules-4.4.0-6-generic N/A
 linux-backports-modules-4.4.0-6-generic N/A
 linux-firmware 1.156
SourcePackage: linux
UpgradeStatus: Upgraded to xenial on 2016-01-12 (38 days ago)
dmi.bios.date: 11/11/2015
dmi.bios.vendor: Dell Inc.
dmi.bios.version: A07
dmi.board.name: 0310JH
dmi.board.vendor: Dell Inc.
dmi.board.version: A00
dmi.chassis.type: 9
dmi.chassis.vendor: Dell Inc.
dmi.modalias: dmi:bvnDellInc.:bvrA07:bd11/11/2015:svnDellInc.:pnXPS139343:pvr:rvnDellInc.:rn0310JH:rvrA00:cvnDellInc.:ct9:cvr:
dmi.product.name: XPS 13 9343
dmi.sys.vendor: Dell Inc.

[Joseph Salisbury (jsalisbury)]

I'd like to perform a bisect to identify the commit that introduced this regression. To narrow the bisect window, can you test the 4.4.0-1.15 kernel first? It can be downloaded from:

https://launchpad.net/ubuntu/+source/linux/4.4.0-1.15/+build/8880824

[Jamie Strandboge (jdstrand)]

This kernel has the bug:

$ cat /proc/version_signature
Ubuntu 4.4.0-1.15-generic 4.4.0

[Joseph Salisbury (jsalisbury)]

I was unable to bisect between 4.3.0-7.18 and 4.4.0-1.15-generic because the commits are not linear. Due to this, we should test and confirm 4.4.0-0.10 does not have the bug. It shouldn't.

Once we confirm that, I can start a bisect between 4.4.0-0.10 and 4.4.0-1.15-generic.

I built a 4.4.0-0.10 kernel which can be downloaded from:
http://kernel.ubuntu.com/~jsalisbury/lp1547619/

[Jamie Strandboge (jdstrand)]

I have booted into this kernel:

$ cat /proc/version_signature
Ubuntu 4.4.0-0.10Commit3b7e590bf-generic 4.4.0

Since the bug doesn't always show itself right away, I will want to use the kernel for at least several hours. I'll report back as soon as I see the bug or after using the computer throughout the day on Monday.

[Jamie Strandboge (jdstrand)]

This kernel has the bug:

$ cat /proc/version_signature
Ubuntu 4.4.0-0.10Commit3b7e590bf-generic 4.4.0

[Joseph Salisbury (jsalisbury)]

Thanks for testing, Jamie. This would indicate the bug was introduced somewhere in late 4.3. I'll figure out the best next kernel to test and post it shortly.

[Joseph Salisbury (jsalisbury)]

I built a 4.4.0-0.3 kernel which was based off of upstream 4.4-rc4. This kernel can be downloaded from:

http://kernel.ubuntu.com/~jsalisbury/lp1547619/

Can you see if this kernel has the bug or not?

[Jamie Strandboge (jdstrand)]

I have booted into this kernel:

$ cat /proc/version_signature
Ubuntu 4.4.0-0.3~lp1547619Commit324ae35-generic 4.4.0

Since the bug doesn't always show itself right away, I will want to use the kernel for at least several hours. I'll report back as soon as I see the bug or after using the computer throughout the day.

[Jamie Strandboge (jdstrand)]

This kernel has the bug:

$ cat /proc/version_signature
Ubuntu 4.4.0-0.3~lp1547619Commit324ae35-generic 4.4.0

[Joseph Salisbury (jsalisbury)]

I've been trying to get early Ubuntu 4.4 kernel to build, but not having much luck. Are you unable to test mainline kernels on this system? It would make the bisect much faster.

[Jamie Strandboge (jdstrand)]

It is difficult for me to use a non-Ubuntu kernel since I do a lot of work with apparmor for the distro. I suppose I could try for a little while at a time, but my ability to test will be impeded (ie, I'll need to run mainline only when not doing the other work).

[Joseph Salisbury (jsalisbury)]

Thanks, Jamie. If we can identify which 4.4 release candidate the regression was introduce, we might be able to switch back to Ubuntu kernels for the actual bisect.

Can you test the following upstream kernel to see if it has the bug:

http://kernel.ubuntu.com/~jsalisbury/lp1547619/

[Jamie Strandboge (jdstrand)]

I have booted into this kernel:

$ cat /proc/version
Linux version 4.4.0-040400rc1-generic (jsalisbury@gomeisa) (gcc version 5.3.1 20160222 (Ubuntu 5.3.1-9ubuntu3) ) #201602231809 SMP Tue Feb 23 23:12:04 UTC 2016

Since the bug doesn't always show itself right away, I will want to use the kernel for at least several hours. I'll report back as soon as I see the bug or after using the computer throughout the day.

[Jamie Strandboge (jdstrand)]

This kernel has the bug:

$ cat /proc/version
Linux version 4.4.0-040400rc1-generic (jsalisbury@gomeisa) (gcc version 5.3.1 20160222 (Ubuntu 5.3.1-9ubuntu3) ) #201602231809 SMP Tue Feb 23 23:12:04 UTC 2016

[Joseph Salisbury (jsalisbury)]

I started a kernel bisect between v4.3 final and v4.4-rc1. The kernel bisect will require testing of about 13 test kernels.

I built the first test kernel, up to the following commit:
118c216e16c5ccb028cd03a0dcd56d17a07ff8d7

The test kernel can be downloaded from:
http://kernel.ubuntu.com/~jsalisbury/lp1547619

Can you test that kernel and report back if it has the bug or not? I will build the next test kernel based on your test results.

Thanks in advance

[Jamie Strandboge (jdstrand)]

I saw a new kernel in xenial with intel fixes so I decided to try it.

This kernel has the bug:
$ cat /proc/version_signature
Ubuntu 4.4.0-9.24-generic 4.4.3

I'll try the bisected kernel now.

[Jamie Strandboge (jdstrand)]

The kernels from http://kernel.ubuntu.com/~jsalisbury/lp1547619 are 4.4.0-040400rc1.201602231809 and have the same checksums as the kernels I tested in https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1547619/comments/15.

[Joseph Salisbury (jsalisbury)]

I rebuilt the first test kernel and copied it to:

http://kernel.ubuntu.com/~jsalisbury/lp1547619

[Gronor (tonut)]

Hi, just to add some info to this really annoying bug.
I am using external monitors connected through a display port hub which in turn connects to my laptop mini display port.
What I noticed is that this only happens when my monitors are at the 1920 x 1080 resolution. If I switch to 1280 x 1024, this never ever happens.

[Jamie Strandboge (jdstrand)]

I have booted into this kernel:

$ cat /proc/version
Linux version 4.3.0-040300-generic (jsalisbury@gomeisa) (gcc version 5.3.1 20160225 (Ubuntu 5.3.1-10ubuntu2) ) #201603030935 SMP Thu Mar 3 14:39:41 UTC 2016

Since the bug doesn't always show itself right away, I will want to use the kernel for at least several hours. I'll report back as soon as I see the bug or after using the computer throughout the day.

I saw a new xenial kernel 4.4.0-10.25 come in. All try that one too after this one.

[Gronor (tonut)]

People reported 4.5.0-040500rc6 fixes the bug for them.

You can see https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1488719 for reference

I am on 4.5.0 RC6 myself and for me it is not fixed. It is a lot better, screen blinking is reduced a lot but it still happens from time to time.

[Jamie Strandboge (jdstrand)]

While I can't be 100% sure cause the issue is intermittent, it seems that this kernel does not have the bug:

$ cat /proc/version
Linux version 4.3.0-040300-generic (jsalisbury@gomeisa) (gcc version 5.3.1 20160225 (Ubuntu 5.3.1-10ubuntu2) ) #201603030935 SMP Thu Mar 3 14:39:41 UTC 2016

$ uptime
 08:44:12 up 3 days, 19 min, 3 users, load average: 1.43, 0.68, 0.57

[Joseph Salisbury (jsalisbury)]

I built the next test kernel, up to the following commit:
e6604ecb70d4b1dbc0372c6518b51c25c4b135a1

The test kernel can be downloaded from:
http://kernel.ubuntu.com/~jsalisbury/lp1547619

Can you test that kernel and report back if it has the bug or not? I will build the next test kernel based on your test results.

Thanks in advance

[Jamie Strandboge (jdstrand)]

I have booted into this kernel:

$ cat /proc/version
Linux version 4.3.0-040300-generic (jsalisbury@gomeisa) (gcc version 5.3.1 20160225 (Ubuntu 5.3.1-10ubuntu2) ) #201603101009 SMP Thu Mar 10 15:13:56 UTC 2016

Since the bug doesn't always show itself right away, I will want to use the kernel for at least several hours. I'll report back as soon as I see the bug or after using the computer throughout the day.

[Jamie Strandboge (jdstrand)]

FYI, I needed overlayfs and so had to interrupt my 4.3.0-040300-generic (#201603101009) testing and booted into 4.4.0-12.28. 4.4.0-12.28 has the bug.

I am back in 4.3.0-040300-generic (#201603101009) now.

[Joseph Salisbury (jsalisbury)]

I built the next test kernel, up to the following commit:
2f4bf528eca5b2d9eef12b6d323c040254f8f67c

The test kernel can be downloaded from:
http://kernel.ubuntu.com/~jsalisbury/lp1547619

Can you test that kernel and report back if it has the bug or not? I will build the next test kernel based on your test results.

Thanks in advance

[Jamie Strandboge (jdstrand)]

While I can't be 100% sure cause the issue is intermittent, it seems that this kernel does not have the bug:

$ cat /proc/version
Linux version 4.3.0-040300-generic (jsalisbury@gomeisa) (gcc version 5.3.1 20160225 (Ubuntu 5.3.1-10ubuntu2) ) #201603101009 SMP Thu Mar 10 15:13:56 UTC 2016

$ uptime
 14:16:39 up 1 day, 5:18, 2 users, load average: 1.72, 1.29, 1.20

[Joseph Salisbury (jsalisbury)]

I built the next test kernel, up to the following commit:
b44a3d2a85c64208a57362a1728efb58a6556cd6

The test kernel can be downloaded from:
http://kernel.ubuntu.com/~jsalisbury/lp1547619

Can you test that kernel and report back if it has the bug or not? I will build the next test kernel based on your test results.

Thanks in advance

[Onno Steenbergen (osteenbergen)]

Having this issue as well. Blinking happens on mini displayport not on mini HDMI (running on Intel NUC with dual monitor setup). Some applications trigger the blinking more often than others. Blinking occurs every few minutes when working in a terminal, but it can happen multiple times in a row. Switching to (or away from) the terminal triggers the bug more often than just working in the terminal.

$ cat /proc/version_signature
Ubuntu 4.4.0-21.37-generic 4.4.6

[Gronor (tonut)]

Hi Onno. Do you have the blinking with all resolutions?

[Gronor (tonut)]

Hi Joseph, any news on this?

[Joseph Salisbury (jsalisbury)]

@Gronor, we were performing a kernel bisect. However, we are still waiting on test results for the kernel in comment #29. WOuld it be possible for you to test that kernel?

[Gronor (tonut)]

Unfortunately I won't be able to do that. In the meantime I have switched away from Ubuntu and cannot test the kernel you build

[Jamie Strandboge (jdstrand)]

Apologies for the delay-- I needed our Ubuntu kernel for a number of weeks and had to pause this bisection.

I have booted into this kernel:

$ cat /proc/version
Linux version 4.3.0-040300-generic (jsalisbury@gomeisa) (gcc version 5.3.1 20160311 (Ubuntu 5.3.1-11ubuntu1) ) #201603151533 SMP Tue Mar 15 19:37:15 UTC 2016

Since the bug doesn't always show itself right away, I will want to use the kernel for at least several hours. I'll report back as soon as I see the bug or after using the computer throughout the day.

[Jamie Strandboge (jdstrand)]

Ah, that was fast. This kernel has the bug:

$ cat /proc/version
Linux version 4.3.0-040300-generic (jsalisbury@gomeisa) (gcc version 5.3.1 20160311 (Ubuntu 5.3.1-11ubuntu1) ) #201603151533 SMP Tue Mar 15 19:37:15 UTC 2016

[Joseph Salisbury (jsalisbury)]

There is a similar bug that is now reported fixed in 4.4.9. When you have a chance, could you test that kernel? It can be downloaded from:
http://kernel.ubuntu.com/~kernel-ppa/mainline/v4.4.9-xenial/

[Jamie Strandboge (jdstrand)]

I have booted into this kernel:

$ cat /proc/version
Linux version 4.4.9-040409-generic (kernel@gomeisa) (gcc version 5.3.1 20160413 (Ubuntu 5.3.1-14ubuntu2) ) #201605041832 SMP Wed May 4 22:34:16 UTC 2016

Since the bug doesn't always show itself right away, I will want to use the kernel for at least several hours. I'll report back as soon as I see the bug or after using the computer throughout the day.

[Jamie Strandboge (jdstrand)]

This kernel has the bug:

$ cat /proc/version
Linux version 4.4.9-040409-generic (kernel@gomeisa) (gcc version 5.3.1 20160413 (Ubuntu 5.3.1-14ubuntu2) ) #201605041832 SMP Wed May 4 22:34:16 UTC 2016

[Joseph Salisbury (jsalisbury)]

I built the next test kernel, up to the following commit:
c0f3f90cf454dd845dcc443afa4f0e312a8eaee0

The test kernel can be downloaded from:
http://kernel.ubuntu.com/~jsalisbury/lp1547619

Can you test that kernel and report back if it has the bug or not? I will build the next test kernel based on your test results.

Thanks in advance

[Jamie Strandboge (jdstrand)]

I have booted into this kernel:

$ cat /proc/version
Linux version 4.3.0-040300rc5-generic (jsalisbury@gomeisa) (gcc version 5.2.1 20151010 (Ubuntu 5.2.1-22ubuntu2) ) #201605111621 SMP Wed May 11 20:26:24 UTC 2016

Since the bug doesn't always show itself right away, I will want to use the kernel for at least several hours. I'll report back as soon as I see the bug or after using the computer throughout the day.

[Jamie Strandboge (jdstrand)]

This kernel does not seem to have the bug after using the system all day:

$ cat /proc/version
Linux version 4.3.0-040300rc5-generic (jsalisbury@gomeisa) (gcc version 5.2.1 20151010 (Ubuntu 5.2.1-22ubuntu2) ) #201605111621 SMP Wed May 11 20:26:24 UTC 2016

[Joseph Salisbury (jsalisbury)]

I built the next test kernel, up to the following commit:
42d4ebb42a17754d2e8344dc1aa486119671d0eb

The test kernel can be downloaded from:
http://kernel.ubuntu.com/~jsalisbury/lp1547619

Can you test that kernel and report back if it has the bug or not? I will build the next test kernel based on your test results.

Thanks in advance

[Jamie Strandboge (jdstrand)]

I have booted into this kernel:

$ cat /proc/version
Linux version 4.3.0-040300-generic (jsalisbury@gomeisa) (gcc version 5.3.1 20160413 (Ubuntu 5.3.1-14ubuntu2) ) #201605181045 SMP Wed May 18 14:50:13 UTC 2016

Since the bug doesn't always show itself right away, I will want to use the kernel for at least several hours. I'll report back as soon as I see the bug or after using the computer throughout the day.

[Jamie Strandboge (jdstrand)]

This kernel has the bug:

$ cat /proc/version
Linux version 4.3.0-040300-generic (jsalisbury@gomeisa) (gcc version 5.3.1 20160413 (Ubuntu 5.3.1-14ubuntu2) ) #201605181045 SMP Wed May 18 14:50:13 UTC 2016

[Joseph Salisbury (jsalisbury)]

I built the next test kernel, up to the following commit:
816d2206f0f9953ca854e4ff1a2749a5cbd62715

The test kernel can be downloaded from:
http://kernel.ubuntu.com/~jsalisbury/lp1547619

Can you test that kernel and report back if it has the bug or not? I will build the next test kernel based on your test results.

Thanks in advance

[Jamie Strandboge (jdstrand)]

I have booted into this kernel:

$ cat /proc/version
Linux version 4.3.0-040300rc5-generic (jsalisbury@gomeisa) (gcc version 5.2.1 20151010 (Ubuntu 5.2.1-22ubuntu2) ) #201605201447 SMP Fri May 20 18:50:00 UTC 2016

Since the bug doesn't always show itself right away, I will want to use the kernel for at least several hours. I'll report back as soon as I see the bug or after using the computer throughout the day.

[Jamie Strandboge (jdstrand)]

This kernel has the bug:

$ cat /proc/version
Linux version 4.3.0-040300rc5-generic (jsalisbury@gomeisa) (gcc version 5.2.1 20151010 (Ubuntu 5.2.1-22ubuntu2) ) #201605201447 SMP Fri May 20 18:50:00 UTC 2016

[Joseph Salisbury (jsalisbury)]

I built the next test kernel, up to the following commit:
1c431cb4615334fb81c0d1c0ede21aa4354c1187

The test kernel can be downloaded from:
http://kernel.ubuntu.com/~jsalisbury/lp1547619

Can you test that kernel and report back if it has the bug or not? I will build the next test kernel based on your test results.

Thanks in advance

[Jamie Strandboge (jdstrand)]

I have booted into this kernel:

$ cat /proc/version
Linux version 4.3.0-040300rc5-generic (jsalisbury@gomeisa) (gcc version 5.2.1 20151010 (Ubuntu 5.2.1-22ubuntu2) ) #201605241152 SMP Tue May 24 16:01:12 UTC 2016

Since the bug doesn't always show itself right away, I will want to use the kernel for at least several hours. I'll report back as soon as I see the bug or after using the computer throughout the day.

[Jamie Strandboge (jdstrand)]

This kernel has the bug:

$ cat /proc/version
Linux version 4.3.0-040300rc5-generic (jsalisbury@gomeisa) (gcc version 5.2.1 20151010 (Ubuntu 5.2.1-22ubuntu2) ) #201605241152 SMP Tue May 24 16:01:12 UTC 2016

[Joseph Salisbury (jsalisbury)]

I built the next test kernel, up to the following commit:
a2736b07df1f17c24c8890eb7b2dac529d9725d3

The test kernel can be downloaded from:
http://kernel.ubuntu.com/~jsalisbury/lp1547619

Can you test that kernel and report back if it has the bug or not? I will build the next test kernel based on your test results.

Thanks in advance