Regression/crash in i915 for 4.15.0-44.47

[Mikael Ståldal]

I have a Lenovo T470s laptop with a Thinkpad Ultra dock.

After upgrading kernel to 4.15.0-44, the system freeze and has to be hard reset (hold power button for 7 seconds) when booting, unlocking or changing display configuration when in dock.

I downgraded the kernel to 4.15.0-43 and the problem went away.

(The system information is collected after downgraded the kernel to 4.15.0-43 and removing 4.15.0-44.)

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: linux-image-4.15.0-44-generic (not installed)
ProcVersionSignature: Ubuntu 4.15.0-43.46-generic 4.15.18
Uname: Linux 4.15.0-43-generic x86_64
ApportVersion: 2.20.9-0ubuntu7.5
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: mikaelstaldal 2219 F.... pulseaudio
CurrentDesktop: Unity:Unity7:ubuntu
Date: Tue Jan 29 13:20:45 2019
HibernationDevice: RESUME=UUID=3c08f9f9-c1a9-43fa-97c9-5dc4873f87d9
InstallationDate: Installed on 2018-10-12 (108 days ago)
InstallationMedia: Ubuntu 18.04.1 LTS "Bionic Beaver" - Release amd64 (20180725)
MachineType: LENOVO 20HF004UMX
ProcFB: 0 inteldrmfb
ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-4.15.0-43-generic root=/dev/mapper/ubuntu--vg-root ro quiet splash vt.handoff=1
RelatedPackageVersions:
 linux-restricted-modules-4.15.0-43-generic N/A
 linux-backports-modules-4.15.0-43-generic N/A
 linux-firmware 1.173.3
SourcePackage: linux
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 12/27/2016
dmi.bios.vendor: LENOVO
dmi.bios.version: N1WET25W (1.04 )
dmi.board.asset.tag: Not Available
dmi.board.name: 20HF004UMX
dmi.board.vendor: LENOVO
dmi.board.version: SDK0J40697 WIN
dmi.chassis.asset.tag: No Asset Information
dmi.chassis.type: 10
dmi.chassis.vendor: LENOVO
dmi.chassis.version: None
dmi.modalias: dmi:bvnLENOVO:bvrN1WET25W(1.04):bd12/27/2016:svnLENOVO:pn20HF004UMX:pvrThinkPadT470s:rvnLENOVO:rn20HF004UMX:rvrSDK0J40697WIN:cvnLENOVO:ct10:cvrNone:
dmi.product.family: ThinkPad T470s
dmi.product.name: 20HF004UMX
dmi.product.version: ThinkPad T470s
dmi.sys.vendor: LENOVO

[Launchpad Janitor (janitor)]

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

[Juraj Korcek (korcek-juraj)]

Experienced the same problem as the OP. Downgrading to 4.15.0-43 worked for as well. The only difference is that my laptop is Dell E7450.

To be more specific, With dock and an external screen the system freezes when I close the laptop lid. When booting with the laptop lid is closed, the system does not even get to login screen. With laptop lid open everything works. With laptop not in dock everything works.

[Tomas Jonsson (tomas-jonsson)]

Same for me as well, but running Dell XPS 13 with a Dell WD15 docking station.
The scenarios for me have been:

1, When changing the screen resolution on my laptop, both screens turns blank and I have to reboot the computer

2, If power saving for the screens kicks in. I have to reboot the computer.

After downgrading to 4.15.0-43-generic the problem disappears.

The computer is still responding to ping when pinging from another machine tough.

[TJ (tj)]

Initial summary of the changes affecting i915 specifically:

gitlog Ubuntu-4.15.0-43.46..Ubuntu-4.15.0-44.47 -- drivers/gpu/drm/i915
d2da7cbf2ae0 2019-01-14 09:28:55 +0000 N Ville Syrjälä drm/i915: Fix PIPESTAT irq ack on i965/g4x
e417085e7913 2019-01-14 09:28:55 +0000 N Lyude Paul drm/i915/dp: Send DPCD ON for MST before phy_up
0f5eea60a4f8 2019-01-14 09:28:55 +0000 N Kenneth Graunke drm/i915: Enable provoking vertex fix on Gen9 systems.

[TJ (tj)]

From an initial reading of the commit history I suspect the issue may be caused by e417085e79136d9f955 "drm/i915/dp: Send DPCD ON for MST before phy_up" which deals with power transitions during monitor connect/disconnect.

[TJ (tj)]

The 4.15.0-44 kernel in in the bionic-proposed pocket. Looks like we need to pull it due to this regression until this is resolved.

[TJ (tj)]

Marking this as a duplicate of bug #1813745 since that already has a test kernel build available which you should try, and if it solves the issue, confirm on that bug.