External monitors receive no signal over DisplayPort

[David Overcash]

Upon running updates ( which included many related to systemd - so that's my best guess as to the right package - feel free to reclassify ) I can't get an external monitor to actually receive a signal from my laptop anymore. I've tried both displayport and HDMI with no luck. You can flip the switch to turn the monitor "on", but it doesn't actually send any data to the monitor ( it reports "No signal" ).

ProblemType: Bug
DistroRelease: Ubuntu 15.04
Package: systemd 219-5ubuntu1
ProcVersionSignature: Ubuntu 3.19.0-10.10-generic 3.19.2
Uname: Linux 3.19.0-10-generic x86_64
ApportVersion: 2.16.2-0ubuntu5
Architecture: amd64
CurrentDesktop: GNOME
Date: Mon Mar 30 10:55:00 2015
InstallationDate: Installed on 2015-03-11 (19 days ago)
InstallationMedia: Ubuntu-GNOME 15.04 "Vivid Vervet" - Alpha amd64 (20150306)
MachineType: System76, Inc. Galago UltraPro
ProcEnviron:
 TERM=xterm
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_US.UTF-8
 SHELL=/bin/bash
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.19.0-10-generic root=UUID=44e9ad95-1beb-46e2-abaf-8960ae76bcff ro quiet splash vt.handoff=7
SourcePackage: systemd
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 12/12/2013
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: 4.6.5
dmi.board.asset.tag: Tag 12345
dmi.board.name: W740SU
dmi.board.vendor: Notebook
dmi.board.version: Not Applicable
dmi.chassis.asset.tag: No Asset Tag
dmi.chassis.type: 9
dmi.chassis.vendor: Notebook
dmi.chassis.version: N/A
dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvr4.6.5:bd12/12/2013:svnSystem76,Inc.:pnGalagoUltraPro:pvrgalu1:rvnNotebook:rnW740SU:rvrNotApplicable:cvnNotebook:ct9:cvrN/A:
dmi.product.name: Galago UltraPro
dmi.product.version: galu1
dmi.sys.vendor: System76, Inc.

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Martin Pitt (pitti)]

Your dmesg contains that:

[ 8849.688210] [drm:intel_dp_complete_link_train [i915]] *ERROR* failed to train DP, aborting
[ 9438.466017] [drm:intel_dp_complete_link_train [i915]] *ERROR* failed to train DP, aborting
[ 9464.436928] [drm:intel_dp_complete_link_train [i915]] *ERROR* failed to train DP, aborting

Did you file the bug report right after this failure, i. e. is this current information?

Can you reproduce this with "sudo apt-get install --reinstall systemd"? If so, that's most probably fallout from bug 1431200; this is just about the only (indirect) way how systemd touches graphics, so if that doesn't reproduce it, this is a kernel bug. Thanks!

[David Overcash (funnylookinhat)]

Yes, the bug was filed right after the failure. I plugged in the monitor cable and ran ubuntu-bug after nothing had happened ( with the cable still plugged in ).

I just tried running "sudo apt-get install --reinstall systemd" and rebooting and the issue is still there.

I would be very surprised if a kernel introduced this issue this late in the cycle - but I suppose it's possible. :)

Are there any other packages that I should consider filing this against instead of systemd to get it corrected? We can replicate it on several different models and different monitors ( using both HDMI and DisplayPort ).

[David Overcash (funnylookinhat)]

I should add that I've been running on vivid for about a month now - so there could be some weirdness happening with all of the updates ( including the initial move to systemd ). I'm going to try a clean installation and see if I can still reproduce this to make sure that I'm not wasting anyone's time. :)

[David Overcash (funnylookinhat)]

OK - On a completely clean installation of Vivid with up-to-date packages the issue still persists.

[David Overcash (funnylookinhat)]

However - it appears that HDMI is now working - only the display port is not.

[Martin Pitt (pitti)]

Oh wait -- you are saying that the external monitor does not receive a signal at any point in time? I thought the external monitor would stop working *during/after* running dist-upgrade, and start working again after a reboot.

That sounds like a kernel/video driver/X.org regression then, reassigning.

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Martin Pitt (pitti)]

It's worth testing this with earlier kernels; do you have one where this was known to work still? You shold still have some older kernels in the grub boot menu, under "Advanced options".

[David Overcash (funnylookinhat)]

Ugh - really funky hardware issue. Sorry for the inconvenience.