Public bug reported:
I am seeing a reproducible ~11 second delay when resuming a Lenovo ThinkPad X13
Gen 2 AMD, machine type 20XJ, from s2idle.
After opening the lid, the display remains black for approximately 11 seconds
before the system resumes normally.
The issue disappears completely when booting once with:
amd_iommu=off
With AMD IOMMU disabled, resume is effectively immediate.
The closely related ThinkPad X13 Gen 2 AMD machine type 20XH is currently
present in the AMD PMC firmware bug quirk table, while 20XJ is not. The
existing quirk is documented as working around a platform firmware issue where
an SMI handler during the NVMe D3→D0 transition can cause large resume delays
while IOMMU translation is enabled. This appears consistent with the behavior
observed on this 20XJ system. GitHub
Hardware
System: Lenovo ThinkPad X13 Gen 2 AMD
Machine type: 20XJ
CPU: AMD Ryzen 5 PRO 5650U with Radeon Graphics
RAM: 16 GB
NVMe: Samsung MZVLB512HBJQ-000L7
The system also contains a Quectel EM120R-GL LTE modem, but disabling Wireless
WAN completely in UEFI had no effect on the resume delay.
Firmware
BIOS version: R1NET67W (1.37)
BIOS date: 04/16/2026
Software
Kernel:
7.0.0-34-generic
linux-firmware:
20260319.git217ca6e4.1ubuntu
Suspend mode:
$ cat /sys/power/mem_sleep
[s2idle]
The firmware exposes only s2idle on this system.
Steps to reproduce
1. Boot normally with AMD IOMMU enabled.
2. Log into the desktop.
3. Suspend the laptop normally by closing the lid or invoking suspend.
4. Wait for the system to enter s2idle.
5. Open the lid.
6. Measure the time before the display becomes active.
Actual result
The screen remains black for approximately:
11+ seconds
before the system becomes usable.
The problem is reproducible across repeated suspend/resume cycles.
Expected result
Resume should occur within approximately 1–2 seconds, as it does when AMD IOMMU
is disabled.
Important A/B test
I edited the GRUB kernel command line for one boot only and appended:
amd_iommu=off
No other relevant configuration was changed.
Result:
Normal boot / IOMMU enabled:
~11 seconds black screen after opening lid
amd_iommu=off:
resume immediately / delay disappears
This result is reproducible and strongly suggests that the delay depends on AMD
IOMMU being enabled.
WWAN test
Because this system contains a Quectel EM120R-GL LTE modem using
mhi_pci_generic, I also tested whether the WWAN device was responsible.
Detected device:
04:00.0 Unassigned class [ff00]:
Quectel Wireless Solutions Co., Ltd. EM120R-GL LTE Modem [1eac:1001]
Kernel driver in use: mhi_pci_generic
Kernel modules: mhi_pci_generic
ModemManager detects:
[Quectel] EM120R_GL
I disabled Wireless WAN completely in ThinkPad UEFI:
Security
-> I/O Port Access
-> Wireless WAN: Off
The ~11 second resume delay remained unchanged.
Therefore the WWAN modem does not appear to be responsible for this issue.
Relevant kernel observations
The system logs contain recurring AMD display firmware diagnostics:
amdgpu 0000:05:00.0: [drm] *ERROR*
dc_dmub_srv_log_diagnostic_data:
DMCUB error - collecting diagnostic data
However, once the visible kernel resume sequence begins, the AMD GPU itself
resumes quickly:
amdgpu 0000:05:00.0: SMU is resuming...
amdgpu 0000:05:00.0: SMU is resumed successfully!
and PM: suspend exit follows shortly afterwards.
The logs also show:
nvme nvme0: D3 entry latency set to 8 seconds
I understand that this value is a power-management latency value and is not by
itself evidence of an 8-second measured stall.
The long user-visible delay appears to occur before the normal device resume
sequence becomes visible in the kernel log, which would be consistent with a
firmware/SMI-level delay.
AMD PMC quirk observation
Current upstream drivers/platform/x86/amd/pmc/pmc-quirks.c contains an entry
for:
X13 Gen2 AMD
DMI_PRODUCT_NAME = "20XH"
using:
quirk_s2idle_spurious_8042
but I do not see a corresponding 20XJ entry. GitHub
The same source describes the relevant workaround as applying to systems where
a firmware SMI handler during the NVMe D3→D0 transition can cause large resume
delays when IOMMU translation is enabled. GitHub
My affected machine is:
ThinkPad X13 Gen 2 AMD
DMI product name: 20XJ
This makes me suspect that 20XJ may require the same quirk currently applied to
20XH.
Additional observation
Searching the boot log for:
Using s2idle quirk
produces no output on this machine.
For example:
sudo journalctl -b -k | grep -i "Using s2idle quirk"
returns nothing.
The AMD PMC driver prints such a message when an applicable s2idle_bug_mmio
quirk is selected. GitHub
Proposed investigation
Could you please confirm whether ThinkPad X13 Gen 2 AMD machine type 20XJ
should use the same AMD PMC firmware workaround as 20XH?
A likely DMI addition would conceptually correspond to the existing X13 Gen 2
AMD entry, but match:
DMI_PRODUCT_NAME, "20XJ"
I have not applied a custom kernel patch yet, so I have not independently
verified the quirk itself on 20XJ.
What I have verified is:
20XJ + normal IOMMU configuration -> ~11 s resume delay
20XJ + WWAN disabled -> ~11 s resume delay
20XJ + amd_iommu=off -> immediate resume
ProblemType: Bug
DistroRelease: Ubuntu 26.04
Package: linux-image-7.0.0-34-generic 7.0.0-34.34
ProcVersionSignature: Ubuntu 7.0.0-34.34-generic 7.0.14
Uname: Linux 7.0.0-34-generic x86_64
ApportVersion: 2.34.1-0ubuntu0.1
Architecture: amd64
CasperMD5CheckResult: pass
CurrentDesktop: ubuntu:GNOME
Date: Tue Sep 29 20:08:18 2026
InstallationDate: Installed on 2026-09-23 (6 days ago)
InstallationMedia: Ubuntu 26.04.1 LTS "Resolute Raccoon" - Release amd64
(20260826)
MachineType: LENOVO 20XJS1XM00
ProcEnviron:
LANG=en_US.UTF-8
PATH=(custom, no user)
SHELL=/bin/bash
TERM=xterm-256color
XDG_RUNTIME_DIR=<set>
ProcFB: 0 amdgpudrmfb
ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-7.0.0-34-generic
root=/dev/mapper/ubuntu--vg-ubuntu--lv ro quiet splash
crashkernel=2G-4G:320M,4G-32G:512M,32G-64G:1024M,64G-128G:2048M,128G-:4096M
SourcePackage: linux
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 04/16/2026
dmi.bios.release: 1.37
dmi.bios.vendor: LENOVO
dmi.bios.version: R1NET67W (1.37)
dmi.board.asset.tag: Not Available
dmi.board.name: 20XJS1XM00
dmi.board.vendor: LENOVO
dmi.board.version: SDK0T76538 WIN
dmi.chassis.asset.tag: No Asset Information
dmi.chassis.type: 10
dmi.chassis.vendor: LENOVO
dmi.chassis.version: None
dmi.ec.firmware.release: 1.37
dmi.modalias:
dmi:bvnLENOVO:bvrR1NET67W(1.37):bd04/16/2026:br1.37:efr1.37:svnLENOVO:pn20XJS1XM00:pvrThinkPadX13Gen2a:rvnLENOVO:rn20XJS1XM00:rvrSDK0T76538WIN:cvnLENOVO:ct10:cvrNone:skuLENOVO_MT_20XJ_BU_Think_FM_ThinkPadX13Gen2a:pfaThinkPadX13Gen2a:
dmi.product.family: ThinkPad X13 Gen 2a
dmi.product.name: 20XJS1XM00
dmi.product.sku: LENOVO_MT_20XJ_BU_Think_FM_ThinkPad X13 Gen 2a
dmi.product.version: ThinkPad X13 Gen 2a
dmi.sys.vendor: LENOVO
** Affects: linux (Ubuntu)
Importance: Undecided
Status: New
** Tags: amd64 apport-bug resolute wayland-session
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https://bugs.launchpad.net/bugs/2168884
Title:
ThinkPad X13 Gen 2 AMD (20XJ): ~11 second s2idle resume delay with AMD
IOMMU enabled; delay disappears with amd_iommu=off
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