After I turn on the machine in the morning (probably from S3 sleep), it just blinks the displays for a few moments, than it turns to black for seconds and this is an endless loop

[vinibali]

Hello there!

I have an HP 840 G5, with an external docking station (HP USB-C Dock G4). All the input and output devices are connected to this docking station"
- display on Displayport (x2)
- ethernet
- keyboard
- mouse
After I turn on the machine in the morning (probably from S3 sleep), it just blinks the displays for a few moments, than it turns to black for seconds and this is an endless loop. If I reconnect the docking station I can get back one of the displays to life, but the other one remain in sleep state.
In the meanwhile after each of these problems, the intel_pstate driver seems to fail, all the processors cores are clocked to 3.6GHz.
If I reboot the machine, both the screens are usable again and the intel_pstate driver is able to change the freqency.
Kernel version 5.0.0-23 was not able to lower the frequency at all, I had to use the ondemand scheduler.
I found these lines for about 5 days in a previous dmesg log.
[10443.450243] [drm:intel_mst_enable_dp [i915]] *ERROR* Timed out waiting for ACT sent
[10443.703810] [drm:intel_cpu_fifo_underrun_irq_handler [i915]] *ERROR* CPU pipe B FIFO underrun
[10444.257321] [drm:intel_mst_enable_dp [i915]] *ERROR* Timed out waiting for ACT sent

If I can help in any other way, please let me know!

Regards

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: xorg 1:7.7+19ubuntu7.1
ProcVersionSignature: Ubuntu 5.0.0-31.33~18.04.1-generic 5.0.21
Uname: Linux 5.0.0-31-generic x86_64
ApportVersion: 2.20.9-0ubuntu7.7
Architecture: amd64
BootLog: Error: [Errno 13] Permission denied: '/var/log/boot.log'
CompizPlugins: No value set for `/apps/compiz-1/general/screen0/options/active_plugins'
CompositorRunning: None
CurrentDesktop: XFCE
Date: Tue Oct 15 06:29:14 2019
DistUpgraded: Fresh install
DistroCodename: bionic
DistroVariant: ubuntu
ExtraDebuggingInterest: Yes
GraphicsCard:
 Intel Corporation UHD Graphics 620 [8086:5917] (rev 07) (prog-if 00 [VGA controller])
   Subsystem: Hewlett-Packard Company UHD Graphics 620 [103c:83b2]
InstallationDate: Installed on 2019-10-08 (6 days ago)
InstallationMedia: Ubuntu 18.04.3 LTS "Bionic Beaver" - Release amd64 (20190805)
MachineType: HP HP EliteBook 840 G5
ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-5.0.0-31-generic root=/dev/mapper/elxnoname--vg-root ro audit=0 noquiet nosplash sysrq_always_enabled
SourcePackage: xorg
Symptom: display
Title: Xorg freeze
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 04/17/2019
dmi.bios.vendor: HP
dmi.bios.version: Q78 Ver. 01.07.00
dmi.board.name: 83B2
dmi.board.vendor: HP
dmi.board.version: KBC Version 04.59.00
dmi.chassis.asset.tag: 5CG8322Y91
dmi.chassis.type: 10
dmi.chassis.vendor: HP
dmi.modalias: dmi:bvnHP:bvrQ78Ver.01.07.00:bd04/17/2019:svnHP:pnHPEliteBook840G5:pvr:rvnHP:rn83B2:rvrKBCVersion04.59.00:cvnHP:ct10:cvr:
dmi.product.family: 103C_5336AN HP EliteBook
dmi.product.name: HP EliteBook 840 G5
dmi.product.sku: 3WQ22EC#ABB
dmi.sys.vendor: HP
version.compiz: compiz N/A
version.libdrm2: libdrm2 2.4.97-1ubuntu1~18.04.1
version.libgl1-mesa-dri: libgl1-mesa-dri 19.0.8-0ubuntu0~18.04.2
version.libgl1-mesa-glx: libgl1-mesa-glx 19.0.8-0ubuntu0~18.04.2
version.xserver-xorg-core: xserver-xorg-core N/A
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev N/A
version.xserver-xorg-video-ati: xserver-xorg-video-ati N/A
version.xserver-xorg-video-intel: xserver-xorg-video-intel N/A
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau N/A

[Daniel van Vugt (vanvugt)]

It appears a number of people are reporting the same kernel error or similar with docks in bug 1550779. And one other user also mentions "HP 840" but an older model.

The problems are close enough that I think the best next step is to treat this as a duplicate of bug 1550779 until further progress is made there in teasing out multiple issues as appropriate.

[vinibali (vinibali)]

Thanks Daniel!