[fprint] fprint problems

[Albert Schimpf]

Hello everyone.

I'm trying to get the fingerprint reader to work on my HP g7 435 laptop, 
5.13.4-arch1-1 kernel.
The fingerprint reader from Synaptics (06cb:00df) seems to be supported 
since last year.
I fiddled around a lot but can't get it to work.

I first cleared the fingerprints in the BIOS.
I updated the firmware (Prometheus) via fwupdmgr.
I configured the policy kit correctly.
fprintd service is running.

When trying the `fprintd-enroll` command, this is the output:

Using device /net/reactivated/Fprint/Device/0
Enrolling right-index-finger finger.
Enroll result: enroll-stage-passed
Enroll result: enroll-unknown-error

The password is requested by the policy kit agent and then it aborts.

The service log reports:

Device reported an error during enroll: Enrollment failed (104)

There were some suggestions to downgrade fprint to 1.90, but that didn't 
work.
Then I removed the packaged versions and compiled fprintd and libfprint 
from source today and the error stays the same.

Is there something I'm missing? Is there any way to enable more debug 
messages?

Best,
Albert