Public bug reported:
Hardware:
- Laptop: Dell Pro Max 16 MC16250, Intel Ultra 7, integrated graphics
lspci shows: 00:02.0 VGA compatible controller: Intel Corporation Arrow
Lake-P [Intel Graphics] (rev 03)
Kernel log: "Found meteorlake (device ID 7d51) integrated display"
- Dock: Dell Thunderbolt 4 Dock SD25TB4
- Monitors: 2x Dell U2415H, connected via DisplayPort/HDMI through the dock
Software:
- Ubuntu 24.04
- Kernel: 6.14.0-37-generic #37~24.04.1-Ubuntu
- Problem occurs already on GDM login screen, independent of Xorg/Wayland user
session.
Symptoms:
- On every cold boot, exactly one of the two external monitors starts
flickering heavily.
- If I turn that monitor off (xrandr --output ... --off), the flickering moves
to the other external monitor.
- After physically re-plugging the dock connection between laptop and dock, the
flickering disappears and stays away until the next reboot or sometimes screen
lock/unlock.
- Internal laptop panel is fine; only the external outputs are affected.
Kernel log excerpts:
- i915 0000:00:02.0: [drm] Selective fetch area calculation failed in pipe B
- i915 0000:00:02.0: [drm] *ERROR* CPU pipe B FIFO underrun
- i915 0000:00:02.0: [drm] *ERROR* Atomic update failure on pipe B (...)
- drm_WARN_ON(psr->paused) at drivers/gpu/drm/i915/display/intel_psr.c:2211
intel_psr_pause()
Workaround:
- Creating /etc/modprobe.d/i915-psr.conf with:
options i915 enable_psr=0
and updating initramfs (update-initramfs -u) completely fixes the flickering.
- After reboot, /sys/module/i915/parameters/enable_psr shows "0" and there is
no flickering anymore and no PSR-related warnings in dmesg.
This looks like a PSR-related bug in the i915 driver on Meteor Lake/Arrow Lake
when using external displays through a Dell Thunderbolt 4 dock.
If needed, I can provide full 'journalctl -b0 -k' output and additional logs.
ProblemType: Bug
DistroRelease: Ubuntu 24.04
Package: linux-image-6.14.0-37-generic 6.14.0-37.37~24.04.1
ProcVersionSignature: Ubuntu 6.14.0-37.37~24.04.1-generic 6.14.11
Uname: Linux 6.14.0-37-generic x86_64
ApportVersion: 2.28.1-0ubuntu3.8
Architecture: amd64
AudioDevicesInUse:
USER PID ACCESS COMMAND
/dev/snd/controlC0: schott 3261 F.... pipewire
schott 3264 F.... wireplumber
/dev/snd/controlC1: schott 3264 F.... wireplumber
/dev/snd/seq: schott 3261 F.... pipewire
CRDA: N/A
CasperMD5CheckResult: pass
CurrentDesktop: ubuntu:GNOME
Date: Thu Feb 12 10:08:58 2026
InstallationDate: Installed on 2025-09-25 (140 days ago)
InstallationMedia: Ubuntu 24.04.2 LTS "Noble Numbat" - Release amd64 (20250215)
MachineType: Dell Inc. Dell Pro Max 16 MC16250
ProcEnviron:
LANG=de_DE.UTF-8
PATH=(custom, no user)
SHELL=/bin/bash
TERM=xterm-256color
XDG_RUNTIME_DIR=<set>
ProcFB: 0 i915drmfb
ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-6.14.0-37-generic
root=/dev/mapper/ubuntu--vg-ubuntu--lv ro quiet splash vt.handoff=7
RelatedPackageVersions:
linux-restricted-modules-6.14.0-37-generic N/A
linux-backports-modules-6.14.0-37-generic N/A
linux-firmware 20240318.git3b128b60-0ubuntu2.23
SourcePackage: linux-hwe-6.14
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 11/06/2025
dmi.bios.release: 1.9
dmi.bios.vendor: Dell Inc.
dmi.bios.version: 1.9.0
dmi.board.name: 0YHD6M
dmi.board.vendor: Dell Inc.
dmi.board.version: A00
dmi.chassis.type: 10
dmi.chassis.vendor: Dell Inc.
dmi.ec.firmware.release: 1.21
dmi.modalias:
dmi:bvnDellInc.:bvr1.9.0:bd11/06/2025:br1.9:efr1.21:svnDellInc.:pnDellProMax16MC16250:pvr:rvnDellInc.:rn0YHD6M:rvrA00:cvnDellInc.:ct10:cvr:sku0CF1:
dmi.product.family: Dell Pro Max Laptops
dmi.product.name: Dell Pro Max 16 MC16250
dmi.product.sku: 0CF1
dmi.sys.vendor: Dell Inc.
** Affects: linux-hwe-6.14 (Ubuntu)
Importance: Undecided
Status: New
** Tags: amd64 apport-bug noble
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https://bugs.launchpad.net/bugs/2141643
Title:
[i915][Meteor Lake/Arrow Lake] External monitors flicker with Dell TB4
dock, PSR warnings, fixed by enable_psr=0
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