Same problem on a Dell Vostro 5480 with reader 138a:0011 Validity Sensors, Inc. VFS5011

But the problem does not occur on fprint_demo. I posted a message to fingerprint-gui about this:

http://home.ullrich-online.cc/fingerprint/Forum/topic.php?TopicId=519&Posts=0

Here's a copy of I what I observed and posted to the fingerprint-gui forum

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Hi, I just got a Dell Vostro 5480 with a fresh Ubuntu 14.04 pre-installed by Dell. Tried to use Fingerprint-GUI, but cannot enroll. First enroll works, and all the others fail. My reader is: 

Bus 002 Device 014: ID 138a:0011 Validity Sensors, Inc. VFS5011 Fingerprint Reader 


I searched the Internet and found 5 or 6 similar posts on several forums, all with no solution. 

Here's the details: 

Install: 

sudo add-apt-repository ppa:fingerprint/fingerprint-gui 
apt-get update 
apt-get upgrade 
sudo apt-get install libbsapi policykit-1-fingerprint-gui fingerprint-gui 

Logged off and logged in 

From a terminal, I tried: 

fingerprint-gui 

or 

fingerprint-gui debug 

The reader is detect, and I can select the finger. When I go to the Scan/Verify tab, it says "Please swipe Your Right Index"  

I swipe the finger and it shows OK with a green check and asks for a second scan, but no more scans work. 

auth.log shows: 

Feb  6 14:45:31 vostro fingerprint-gui[20691]: Need 1 stages. 
Feb  6 14:45:31 vostro fingerprint-gui[20691]: Please Swipe Your Right Index. 
Feb  6 14:45:31 vostro fingerprint-gui[20691]: Swipe finger at vfs5011. 
Feb  6 14:45:31 vostro fingerprint-gui[20691]: Thread started. 
Feb  6 14:45:31 vostro fingerprint-gui[20691]: Starting acquire. 
Feb  6 14:45:32 vostro fingerprint-gui[20691]: Need 1 stages. 
Feb  6 14:45:32 vostro fingerprint-gui[20691]: Acquire stage 0 waiting... 
Feb  6 14:45:37 vostro fingerprint-gui[20691]: Acquire: have image. 
Feb  6 14:45:37 vostro fingerprint-gui[20691]: Acquire result 3. 
Feb  6 14:45:37 vostro fingerprint-gui[20691]: FP_ENROLL_PASS. 
Feb  6 14:45:37 vostro fingerprint-gui[20691]: Acquire stage 0 OK. 
Feb  6 14:45:37 vostro fingerprint-gui[20691]: Need 2 stages. 
Feb  6 14:45:37 vostro fingerprint-gui[20691]: Acquire stage 1 waiting... 
Feb  6 14:45:38 vostro fingerprint-gui[20691]: Acquire failed with error -22. 
Feb  6 14:45:38 vostro fingerprint-gui[20691]: Acquire stage 0 waiting... 
Feb  6 14:45:40 vostro fingerprint-gui[20691]: Acquire failed with error -22. 
Feb  6 14:45:40 vostro fingerprint-gui[20691]: Acquire stage 0 waiting... 

syslog shows: 

Feb  6 14:45:31 vostro kernel: [ 8713.848752] usb 2-4: reset full-speed USB device number 16 using xhci_hcd 
Feb  6 14:45:31 vostro kernel: [ 8713.865597] xhci_hcd 0000:00:14.0: xHCI xhci_drop_endpoint called with disabled ep ffff880010258500 
Feb  6 14:45:31 vostro kernel: [ 8713.865603] xhci_hcd 0000:00:14.0: xHCI xhci_drop_endpoint called with disabled ep ffff880010258540 
Feb  6 14:45:31 vostro kernel: [ 8713.865605] xhci_hcd 0000:00:14.0: xHCI xhci_drop_endpoint called with disabled ep ffff880010258580 
Feb  6 14:45:31 vostro kernel: [ 8713.865606] xhci_hcd 0000:00:14.0: xHCI xhci_drop_endpoint called with disabled ep ffff8800102585c0 
Feb  6 14:45:33 vostro kernel: [ 8715.417185] xhci_hcd 0000:00:14.0: WARN Event TRB for slot 15 ep 4 with no TDs queued? 
Feb  6 14:45:37 vostro kernel: [ 8719.555654] xhci_hcd 0000:00:14.0: WARN Event TRB for slot 15 ep 4 with no TDs queued? 


Seems like after each scan on fingerprint-gui, the reader resets! 

BUT, if I test with fprint-demo (version 0.4): 

$ sudo apt-get install fprint-demo 
$ fprint_demo 

It works perfectly! I can enroll several fingers, identify, scan, etc. 

There is an open bug at launchpad saying that the problem is on libfprint, but all works on fprint_demo. Maybe libfprint is called differently on fprint_demo and on fingerprint-gui? 

https://bugs.launchpad.net/ubuntu/+source/libfprint/+bug/1415348 

Any ideas? 

thanks! 

Rafael

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thanks!

Rafael