Public bug reported:
Hardware
Lenovo ThinkPad X1 Carbon Gen 14
Model: 21V7CTO1WW
BIOS: N4OET49W (1.12)
EC: N4OHT39W
Software
Ubuntu 26.04 LTS
Kernel: 7.0.0-27-generic
Problem
Intermittently, while the USB-C charger remains connected and the
charging LED is still lit, the laptop stops charging and the battery
begins to drain.
Physically unplugging and reconnecting the USB-C cable immediately
restores charging.
The problem occurs with either USB-C port and with multiple known-good
USB-C chargers/cables.
Observed behaviour while the problem is occurring
AC/online = 1
BAT0/status = Not charging
BAT0/power_now = 0
At the same time, BAT0/energy_now continues to decrease, showing that
the battery is actually discharging despite external power remaining
connected.
After unplugging and reconnecting the charger:
BAT0/status = Charging
BAT0/power_now ≈ 45 W
Charging resumes immediately.
Kernel messages
On boot:
ucsi_acpi USBC000:00: error -ENODEV: PPM init failed
Reloading ucsi_acpi later creates the Type-C ports, but then produces:
Firmware bug: duplicate port altmode SVID 0x17ef
GET_CABLE_PROPERTY failed (-95)
UCSI_GET_PDOS failed (-70)
followed by UBSAN reports:
UBSAN: array-index-out-of-bounds
drivers/usb/typec/ucsi/psy.c
index 7 is out of range for type 'u32 [7]'
The UBSAN trace occurs in:
ucsi_psy_get_prop()
power_supply_changed_work
After UCSI initializes, /sys/class/power_supply/ contains:
ucsi-source-psy-USBC000:001
ucsi-source-psy-USBC000:002
ucsi-source-psy-USBC000:003
During the failure, the active UCSI source reports:
online=1
status=Charging
usb_type=PD
voltage_now=0
voltage_max=0
current_now=3250000
even though the battery is not charging and its stored energy is
decreasing.
Expected behaviour
While AC power remains connected, the battery should continue charging
(or at least power the system) without requiring the USB-C cable to be
unplugged and reconnected.
ProblemType: Bug
DistroRelease: Ubuntu 26.04
Package: linux-image-7.0.0-27-generic 7.0.0-27.27
ProcVersionSignature: Ubuntu 7.0.0-27.27-generic 7.0.6
Uname: Linux 7.0.0-27-generic x86_64
ApportVersion: 2.34.0-0ubuntu2
Architecture: amd64
AudioDevicesInUse:
USER PID ACCESS COMMAND
/dev/snd/controlC0: arcane 5145 F.... pipewire
arcane 5163 F.... wireplumber
/dev/snd/seq: arcane 5145 F.... pipewire
CasperMD5CheckResult: pass
CurrentDesktop: ubuntu:GNOME
Date: Mon Jul 13 10:46:42 2026
InstallationDate: Installed on 2026-07-02 (11 days ago)
InstallationMedia: Ubuntu 26.04 "Resolute Raccoon" - Release amd64 (20260423.1)
MachineType: LENOVO 21V7CTO1WW
ProcEnviron:
LANG=en_US.UTF-8
PATH=(custom, no user)
SHELL=/bin/bash
TERM=xterm-256color
XDG_RUNTIME_DIR=<set>
ProcFB: 0 xedrmfb
ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-7.0.0-27-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: 05/14/2026
dmi.bios.release: 1.12
dmi.bios.vendor: LENOVO
dmi.bios.version: N4OET49W (1.12 )
dmi.board.asset.tag: Not Available
dmi.board.name: 21V7CTO1WW
dmi.board.vendor: LENOVO
dmi.board.version: Not Defined
dmi.chassis.asset.tag: No Asset Information
dmi.chassis.type: 10
dmi.chassis.vendor: LENOVO
dmi.chassis.version: None
dmi.ec.firmware.release: 1.9
dmi.modalias:
dmi:bvnLENOVO:bvrN4OET49W(1.12):bd05/14/2026:br1.12:efr1.9:svnLENOVO:pn21V7CTO1WW:pvrThinkPadX1CarbonGen14:rvnLENOVO:rn21V7CTO1WW:rvrNotDefined:cvnLENOVO:ct10:cvrNone:skuLENOVO_MT_21V7_BU_Think_FM_ThinkPadX1CarbonGen14:pfaThinkPadX1CarbonGen14:
dmi.product.family: ThinkPad X1 Carbon Gen 14
dmi.product.name: 21V7CTO1WW
dmi.product.sku: LENOVO_MT_21V7_BU_Think_FM_ThinkPad X1 Carbon Gen 14
dmi.product.version: ThinkPad X1 Carbon Gen 14
dmi.sys.vendor: LENOVO
** Affects: linux (Ubuntu)
Importance: Undecided
Status: New
** Tags: amd64 apport-bug resolute wayland-session
** Attachment added: "x1c-charge-bug.tgz"
https://bugs.launchpad.net/bugs/2160496/+attachment/5981491/+files/x1c-charge-bug.tgz
--
You received this bug notification because you are a member of Ubuntu
Bugs, which is subscribed to Ubuntu.
https://bugs.launchpad.net/bugs/2160496
Title:
ThinkPad X1 Carbon Gen 14 21V7: charging stops until USB-C reconnect;
ucsi_acpi errors and UBSAN OOB in ucsi_psy_get_prop
To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2160496/+subscriptions
--
ubuntu-bugs mailing list
[email protected]
https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
