Finger print sensor stops working

REPRODUCIBILITY (% or how often): 100%
BUILD ID = OS VERSION (Settings > About product): 4.4.0 Vanha Rauma
HARDWARE (XA2, X10, X10 II, …): X10 II
REGRESSION: (compared to previous public release: Yes, No, ?): ?


Sensor works for a while; then stops working.
Reboot fixes the issue, until it stops again.


Have a fingerprint stored on-device


  1. Enable fingerprint sensor
  2. Use during the day


The finger print sensor keeps on working.


Currently it works for a while. Then stops, at which point a reboot is necessary.


(Please ALWAYS attach relevant data such as logs, screenshots, etc…)

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Same here on my X10 II. On XA2+ is working without problems.

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I think there are several threads about the issue. See for example Fingerprint record lost randomly which is reported already on Sailfish 4.1

Im not sure this is the same reason. As stated, rebooting for me makes the sensor work again, for a while. It seems like it could be more on the service / driver side…

This issue of fingerprints lost can sure cause similar symptoms. Could you maybe next time when the sensor is not working, take a look at the settings and see if there are any fingerprints shown? Personally, I haven’t stumbled upon the issue on Sailfish 4.4, but I’m thinking it’s just matter of time :smiley:

As pointed in the linked post, the following commands should fix the fingerprint daemon, and the fingerprints should be visible on the settings again.


Just to confirm that I’ve had similar issues on my Xperia 10ii both when first upgrading to 4.4 and previously. Existing fingerprints “disappear” but when you try to add new ones you sometimes get a message that you can’t because of memory problems. (Insufficient memory) which isn’t the actual case. (There is sufficient memory it seems).

I’m wondering if there is some link to how the fingerprint service runs and memory usage that causes this to fail over time?

I encounter also this problem from time to time on the Xperia 10ii.

My understanding is that it is not a problem of memory, but access to the fingerprints. There are only 5 slots for saving fingerprints.

When the fingerprint authentication stops working, your fingerprints are still stored but not displayed in the lock settings and not recognized by the sensor.

When you add a new fingerprint, it’s taken into account right away. But you can only do that if there are already less than 5 fingerprints stored. Otherwise you get the error message about a lack of memory…


Other related threads:

To delete stored FP and start all fingerprint thing over again, one useful sequence is, as root (devel-su + password):

systemctl stop sailfish-fpd
/usr/libexec/sailfish-fpd/fpslave --remove-all
/usr/libexec/sailfish-fpd/fpslave --flush-cache
systemctl start sailfish-fpd

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Im sorry I might be nitpicking here;
as stated, this bug report is not about missing fingerprints, but about the fact that the sensor stops working. In fact, after a reboot, everything is fine. No fingerprint is lost.

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This bug exists since the X10 II is supported. Is this something that can be fixed or do we have to live with it?

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Id assume this to be one of those bugs that should be fixed before official release? @Jolla?

I don’t mean to nitpick either, but I don’t see how you have provided that the sensor stops working as you stated. Do you have some logs like journal or anything how you have deduced it’s about the sensor? I’m asking since I really think that the underlying issue is the same or most likely at least very related to the fingerprints lost issue. There are already a few threads about those, and adding another won’t get the issue fixed any sooner. On the other hand, if you can provide more information about the sensor not working, then it can also help this specific issue to get fixed.

To clarify the fingerprints lost issue, it surely causes similar symptoms as the “sensor” is not working either since there are no fingerprints on the system for some reason. Reboot also gets the fingerprints back thus makes the “sensor” work again. At least to me, this behaviour seems very much the same as the issue you have described on this bug report. However, it might be that I’m just seeing what I want to see :smiley:

I’d still suggest that you take a look at the settings when the sensor stops working and see if you have any fingerprints shown there at the moment. If there are, the issue you provided might very likely be something different than the other issues linked here as well. In my opinion, this is also crucial since otherwise this issue might be too vague, and people can mix it up with the other similar issues and so on. So instead of just stating that something is not working, would it be possible to get some more information or how to reproduce the issue?

Independently from the word plays around “sensor” (In fact, if there are “no fingerprints” on the system anymore, how can the system “get them back”?) ; I dont see my finger prints going “missing” either (as stated, a reboot fixes the problem temporary for me).
Keep in mind, see it from the perspective of a user, not a developer - I have no idea how the stack looks like, or how it works.
SFOS is a black box for me; so I dont have any notion of logs or such either :).
Perhaps instructions can help.

@amha thanks for clarifying.

@Moppa5 thank you very much! You just helped me very much with my Xperia 10 III ,


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On my Xperia 10 III, a reboot did not help after the finger print sensor stopped working. Restarting the service with systemctl did. Strange.

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Oh… And finally I have found the button in System Utilities. :rofl: