Public bug reported:
From dmesg:
[10454.147767] i915 0000:00:02.0: [drm] *ERROR* Failed to get ACT after 3000
ms, last status: 04
[10457.158936] i915 0000:00:02.0: [drm] *ERROR* Failed to get ACT after 3000
ms, last status: 04
[10460.172158] i915 0000:00:02.0: [drm] *ERROR* Failed to get ACT after 3000
ms, last status: 04
[18309.299685] i915 0000:00:02.0: [drm] *ERROR* Atomic update failure on pipe A
(start=289524 end=289525) time 224 us, min 1185, max 1200, scanline start 1169,
end 1203
[38305.421320] i915 0000:00:02.0: [drm] *ERROR* Step 2 of creating MST payload
for 00000000ad626958 failed: -5
[38313.491121] i915 0000:00:02.0: [drm] *ERROR* Step 2 of creating MST payload
for 00000000cb1cd95e failed: -5
[38321.558378] i915 0000:00:02.0: [drm] *ERROR* Step 2 of creating MST payload
for 00000000c4d033d3 failed: -5
[38325.217357] i915 0000:00:02.0: [drm] *ERROR* Failed to get ACT after 3000
ms, last status: 00
[38332.612309] i915 0000:00:02.0: [drm] *ERROR* Failed to get ACT after 3000
ms, last status: 00
[38344.073298] i915 0000:00:02.0: [drm] *ERROR* Failed to get ACT after 3000
ms, last status: 00
[38497.811619] i915 0000:00:02.0: [drm] *ERROR* Step 2 of creating MST payload
for 00000000cb1cd95e failed: -5
[38505.883761] i915 0000:00:02.0: [drm] *ERROR* Step 2 of creating MST payload
for 00000000c4d033d3 failed: -5
[38510.687095] i915 0000:00:02.0: [drm] *ERROR* Step 2 of creating MST payload
for 00000000ad626958 failed: -5
[38657.889814] i915 0000:00:02.0: [drm] *ERROR* Failed to get ACT after 3000
ms, last status: 04
[38660.899610] i915 0000:00:02.0: [drm] *ERROR* Failed to get ACT after 3000
ms, last status: 04
[38663.901960] i915 0000:00:02.0: [drm] *ERROR* Failed to get ACT after 3000
ms, last status: 04
Pattern from the logs (repeats 3 times):
ACT timeout × 5–6 (every 3 seconds) ← the dock loses the MST link
↓
fec_enable mismatch (pipes C and D) ← driver bug during retrain
↓
verify_crtc_state WARNING ← the driver detects a desynchronization
↓
"Sending link address failed: -5" ← MST topology was not restored
↓
GuC firmware reload (GPU reset) ← the kernel resets the GPU
t=38305 — a new error type:
Step 2 of creating MST payload failed: -5 ← -EIO, physical disconnect
Failed to get ACT, status: 00 ← the hub does not respond at all
This is no longer just a glitch — it is a complete Thunderbolt link drop.
Root cause: during DP link retraining (intel_dp_retrain_link), the
driver clears FEC in its software state, while the hardware still keeps
FEC enabled. verify_crtc_state detects the mismatch → WARNING → an
atomic commit attempt with incorrect state → GPU reset.
ProblemType: Bug
DistroRelease: Ubuntu 24.04
Package: linux-image-6.17.0-1020-oem 6.17.0-1020.20
ProcVersionSignature: Ubuntu 6.17.0-1020.20-oem 6.17.13
Uname: Linux 6.17.0-1020-oem x86_64
ApportVersion: 2.28.1-0ubuntu3.8
Architecture: amd64
AudioDevicesInUse:
USER PID ACCESS COMMAND
/dev/snd/controlC0: olepro 499737 F.... pipewire
olepro 499740 F.... wireplumber
/dev/snd/seq: olepro 499737 F.... pipewire
CRDA: N/A
CasperMD5CheckMismatches: ./casper/initrd
./casper/minimal.standard.live.hotfix.manifest
./casper/minimal.standard.live.hotfix.size ./casper/minimal.standard.live.size
./casper/minimal.manifest ./casper/minimal.standard.manifest
./casper/minimal.standard.size ./casper/minimal.hotfix.size
./casper/minimal.standard.live.hotfix.squashfs
./casper/minimal.standard.hotfix.squashfs ./casper/minimal.standard.hotfix.size
./casper/minimal.hotfix.squashfs ./casper/minimal.standard.live.manifest
./casper/minimal.size ./boot/grub/grub.cfg
CasperMD5CheckResult: fail
CurrentDesktop: ubuntu:GNOME
Date: Tue May 12 07:45:17 2026
DistributionChannelDescriptor:
# This is the distribution channel descriptor for Ubuntu 24.04 for Dell
# For more information see http://wiki.ubuntu.com/DistributionChannelDescriptor
canonical-oem-somerville-noble-oem-24.04c-20251113-97
InstallationDate: Installed on 2026-04-21 (21 days ago)
InstallationMedia: Ubuntu OEM 24.04.3 LTS "Noble Numbat" - Release amd64
(20251111)
IwConfig:
lo no wireless extensions.
wlp0s20f3 no wireless extensions.
enp5s0 no wireless extensions.
MachineType: Dell Inc. Dell Pro Max 16 Premium MA16250
ProcFB: 0 i915drmfb
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-6.17.0-1020-oem
root=UUID=36e0ecee-d9d5-40f4-a14c-bc8ddc9ecbae ro quiet splash vt.handoff=7
RebootRequiredPkgs: Error: path contained symlinks.
RelatedPackageVersions:
linux-restricted-modules-6.17.0-1020-oem N/A
linux-backports-modules-6.17.0-1020-oem N/A
linux-firmware 20240318.git3b128b60-0ubuntu2.27
SourcePackage: linux-oem-6.17
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 03/10/2026
dmi.bios.release: 1.8
dmi.bios.vendor: Dell Inc.
dmi.bios.version: 1.8.1
dmi.board.name: 0KKK22
dmi.board.vendor: Dell Inc.
dmi.board.version: A00
dmi.chassis.asset.tag: 26D23876
dmi.chassis.type: 10
dmi.chassis.vendor: Dell Inc.
dmi.ec.firmware.release: 1.7
dmi.modalias:
dmi:bvnDellInc.:bvr1.8.1:bd03/10/2026:br1.8:efr1.7:svnDellInc.:pnDellProMax16PremiumMA16250:pvr:rvnDellInc.:rn0KKK22:rvrA00:cvnDellInc.:ct10:cvr:sku0D33:
dmi.product.family: Dell Pro Max Laptops
dmi.product.name: Dell Pro Max 16 Premium MA16250
dmi.product.sku: 0D33
dmi.sys.vendor: Dell Inc.
** Affects: linux-oem-6.17 (Ubuntu)
Importance: Undecided
Status: New
** Tags: amd64 apport-bug noble wayland-session
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https://bugs.launchpad.net/bugs/2152225
Title:
bug in i915 + MST + FEC
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