I want to use my ACR122U contact-less smart card reader in Ubuntu 14 smarty. So I installed my required packages and drivers.
Finally when I want to use the reader I receive the following error:
rc@rc-System-Product-Name:~/Desktop/itsme$ sudo nfc-list
[sudo] password for rc:
nfc-list uses libnfc 1.7.0
error libnfc.driver.acr122_usb Unable to claim USB interface (Device or resource busy)
nfc-list: ERROR: Unable to open NFC device: acr122_usb:001:020
rc@rc-System-Product-Name:~/Desktop/itsme$
rc@rc-System-Product-Name:~/Desktop/itsme$ sudo mfoc -O output.txt
error libnfc.driver.acr122_usb Unable to claim USB interface (Device or resource busy)
No NFC device found.
rc@rc-System-Product-Name:~/Desktop/itsme$
It seems that my reader is in use with a kernel tool. I searched a lot. there are a lot of people that had the same issue already, but I couldn't find my answer among them.
Does anybody has any idea how I can resolve this problem? (By reclaiming the device, for example)
If you have kernel version > 3.5, nfs-list and pcscd will report this error due to the automatic load of pn533 driver.
To read the pcscd dameon output you can run it using: pcscd -f -d
- Check which kernel version is installed:
uname -a
Blacklist pn533 and nfc drivers (references: Arch Linux wiki Touchatag RFID Reader, nfc-tools forum):
$ sudo nano /etc/modprobe.d/blacklist-libnfc.conf
Add the following lines:
blacklist pn533
blacklist nfc
Disable kernel modules:
$ modprobe -r pn533 nfc
Restart the pcscd daemon: sudo service pcscd restart
Here you can fine a small program to test your ACR122U reader and a more detailed guide.
sudo modprobe -r pn533_usb
sudo modprobe -r pn533
Works for me.
--------@--------:~$ sudo nfc-list
nfc-list uses libnfc 1.7.1
NFC device: ACS / ACR122U PICC Interface opened
1 ISO14443A passive target(s) found:
ISO/IEC 14443A (106 kbps) target:
ATQA (SENS_RES): 00 04
UID (NFCID1): ab c9 67 00
SAK (SEL_RES): 08
A quick-and-dirty solution:
sudo rmmod pn533 ## unload the driver right now
sudo nfc-list ## now it works...
