Finger print intermittently stops working

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1

It started this week, Gnome version 41. Fingerprint suddenly stops working and disappears from the preferences. This happens when it is asleep or right when it is running.
systemctl status fprintd then shows it is inactive, but starting the daemon doesn’t help. I would assume it is hardware, but after rebooting the laptop the sensor always comes back to life.
Could find fprintd[2145]: Device responded with error: 789 retry: 1 only once, usually it is just

Starting fprintd.service - Fingerprint Authentication Daemon...
Started fprintd.service - Fingerprint Authentication Daemon.
fprintd.service: Deactivated successfully.

Please help me at least localize the problem if it is a software or complex problem, started using linux just couple months back.

2

Hello and welcome @kaimedy!

Could you provide some information on the computer you are using and/or if it’s an integrated fingerprint reader or an external device.

The output from the first few sections (system, machine, etc.) of the inxi -Fzxx command would help as well. Thanks!

3

Thank you @theqlp for reply.

Embedded fingerprint reader combined with power button

System:
  Kernel: 6.13.5-200.fc41.x86_64 arch: x86_64 bits: 64 compiler: gcc v: 14.2.1
  Desktop: GNOME v: 47.4 tk: GTK v: 3.24.43 wm: gnome-shell dm: GDM
    Distro: Fedora Linux 41 (Workstation Edition)
Machine:
  Type: Laptop System: LENOVO product: 21FVCTO1WW v: ThinkPad P1 Gen 6
    serial: <superuser required> Chassis: type: 10 serial: <superuser required>
  Mobo: LENOVO model: 21FVCTO1WW v: NO DPK serial: <superuser required>
    part-nu: LENOVO_MT_21FV_BU_Think_FM_ThinkPad P1 Gen 6 UEFI: LENOVO
    v: N3ZET47W (1.34 ) date: 01/02/2025
5

Do you have any crashes in coredumpctl?

I’m aware of this bug which is probably easy to fix.

6

Thanks @catanzaro, I’m not sure how to verify if it is my case but coredumpctl returns bunch of rows many of them are SIGSEGV but no one references to fprint and the last one seems have timestamp before my problem started.

fprint survived the night just fine but as I started working on laptop… it is gone. Seems after last successful fprintd.service: Deactivated successfully
the following lines containing fprint repeatedly appear in journal

CRED_REFR pid=81956 uid=1000 auid=1000 ses=3 subj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 msg='op=PAM:setcred grantors=pam_env,pam_fprintd acct="root" exe="/usr/bin/sudo" hostname=? addr=? terminal=/dev/pts/1 res=success'
CRED_DISP pid=81956 uid=1000 auid=1000 ses=3 subj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 msg='op=PAM:setcred grantors=pam_env,pam_fprintd acct="root" exe="/usr/bin/sudo" hostname=? addr=? terminal=/dev/pts/1 res=success'

I’m starting thinking that this issue appears when machine gets warmer. If so then no reason to look for why it crashes. But still interesting why it’s not repaired after I start the service and service actually becomes active.