Android - Completely disable the fingerprint sensor

On Linux (and Android) it is possible to disconnect a device from its driver[1]. The fingerprint driver (denoted as fpc) on my LG G5 has the name fpc1020. Searching in the /sys path gave me the folder /sys/bus/spi/drivers/fpc1020/. This folder has four files: bind, unbind, uevent AND spi8.1. What we do is to unbind the device spi8.1 from the driver fpc1020.

Now how to disable the sensor:

  1. we need to find the driver name:
    Try this command: find /sys/bus -name 'fpc*'
    For me it's: /sys/bus/spi/drivers/fpc1020/

  2. we need to find the device name:
    The device name is the fourth file in this folder.
    ls /sys/bus/spi/drivers/fpc1020/ (depends on your result from 1.)
    For me it's: spi8.1

  3. unbind this device:
    echo spi8.1 > /sys/bus/spi/drivers/fpc1020/unbind (depends on your result from 1. & 2.)
    Now you are not able to use the fingerprint sensor until the next restart.

  4. unbind on every system boot:
    We want/need to execute this command on every boot. Currently I'm not sure what's the best way to do it.

Requirements:

  • Root Access
  • Terminal App (or adb shell from PC)

References:
1. https://lwn.net/Articles/143397/

Tags:

Recent Posts