Public bug reported:
Summary:
High CPU usage caused by irq/<n>-nxp_nci_i2c after boot on ThinkPad P14s
AMD.
System:
- Ubuntu 24.04.4 LTS
- Kernel: 6.8.0-134-generic
- Lenovo ThinkPad P14s AMD
- Machine Type: 21K6S0E000
- BIOS: R2FET69W (1.49)
- BIOS Date: 2026-03-19
Problem:
After boot, the kernel thread
irq/89-nxp_nci_i2c
consumes approximately 20–30% of one CPU core continuously.
As a consequence:
- CPU temperature increases from ~34°C to ~59°C while idle.
- System fan runs continuously.
- Normal CPU usage reported by htop is only about 3%.
The kernel log contains:
nxp-nci_i2c i2c-NXP1001:00: NFC: Read failed with error -121
Workaround:
Running
sudo modprobe -r nxp_nci_i2c
immediately fixes the problem.
Results after unloading the module:
- irq/89-nxp_nci_i2c disappears completely
- CPU temperature drops to about 34°C
- Fan returns to normal operation
The issue started only recently after a system update (approximately two
weeks ago).
It appears that the NXP NFC I2C driver repeatedly handles interrupts
after the device reports I/O error -121.
Further information:
$ cat /proc/interrupts | grep -i nci
89: 0 0 0 0 0 39985756
0 0 0 0 0 0 0 0
0 0 amd_gpio 84 nxp-nci_i2c
$ sudo dmesg > dmesg-before.txt
$ sudo modprobe -r nxp_nci_i2c
ProblemType: Bug
DistroRelease: Ubuntu 24.04
Package: linux-image-6.8.0-134-generic 6.8.0-134.134
ProcVersionSignature: Ubuntu 6.8.0-134.134-generic 6.8.12
Uname: Linux 6.8.0-134-generic x86_64
ApportVersion: 2.28.2-0ubuntu0.1
Architecture: amd64
CRDA: N/A
CasperMD5CheckResult: pass
CurrentDesktop: ubuntu:GNOME
Date: Tue Jul 14 00:42:13 2026
InstallationDate: Installed on 2024-01-29 (896 days ago)
InstallationMedia: Ubuntu 23.10.1 "Mantic Minotaur" - Release amd64 (20231016.1)
MachineType: LENOVO 21K6S0E000
ProcEnviron:
LANG=de_DE.UTF-8
PATH=(custom, no user)
SHELL=/bin/bash
TERM=xterm-256color
XDG_RUNTIME_DIR=<set>
ProcFB: 0 amdgpudrmfb
ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-6.8.0-134-generic
root=/dev/mapper/ubuntu--vg-ubuntu--lv ro quiet splash vt.handoff=7
RelatedPackageVersions:
linux-restricted-modules-6.8.0-134-generic N/A
linux-backports-modules-6.8.0-134-generic N/A
linux-firmware 20240318.git3b128b60-0ubuntu2.27
SourcePackage: linux
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 03/19/2026
dmi.bios.release: 1.49
dmi.bios.vendor: LENOVO
dmi.bios.version: R2FET69W (1.49 )
dmi.board.asset.tag: Not Available
dmi.board.name: 21K6S0E000
dmi.board.vendor: LENOVO
dmi.board.version: Not Defined
dmi.chassis.asset.tag: No Asset Tag
dmi.chassis.type: 10
dmi.chassis.vendor: LENOVO
dmi.chassis.version: None
dmi.ec.firmware.release: 1.33
dmi.modalias:
dmi:bvnLENOVO:bvrR2FET69W(1.49):bd03/19/2026:br1.49:efr1.33:svnLENOVO:pn21K6S0E000:pvrThinkPadP14sGen4:rvnLENOVO:rn21K6S0E000:rvrNotDefined:cvnLENOVO:ct10:cvrNone:skuLENOVO_MT_21K6_BU_Think_FM_ThinkPadP14sGen4:
dmi.product.family: ThinkPad P14s Gen 4
dmi.product.name: 21K6S0E000
dmi.product.sku: LENOVO_MT_21K6_BU_Think_FM_ThinkPad P14s Gen 4
dmi.product.version: ThinkPad P14s Gen 4
dmi.sys.vendor: LENOVO
** Affects: linux (Ubuntu)
Importance: Undecided
Status: New
** Tags: amd64 apport-bug kernel-daily-bug noble wayland-session
** Attachment added: "dmesg-before.txt"
https://bugs.launchpad.net/bugs/2160571/+attachment/5981674/+files/dmesg-before.txt
--
You received this bug notification because you are a member of Ubuntu
Bugs, which is subscribed to Ubuntu.
https://bugs.launchpad.net/bugs/2160571
Title:
nxp_nci_i2c fails on Thinkpad P14s
To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2160571/+subscriptions
--
ubuntu-bugs mailing list
[email protected]
https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
