Disable kalman filter Jolla C/AquaFish

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A simple patch to improve touchscreen responsiveness by disabling kalman filter on Jolla C/AquaFish

This works only on Jolla C/AquaFish. Jolla tablet and Jolla 1 don't use kalman filter.

For the Inoi R7 version go to https://openrepos.net/content/toxip/disable-kalman-filter-inoi-r7


This tampers with a critical file droid-hal-device.conf. If something goes wrong the device might not boot. There should be no risk in using the patch but I make no guarantees. Should the device fail to boot, restore droid-hal-device.conf under /var/lib/environment/compositor to its original state in recovery mode.

Use at your own risk!

Source https://github.com/topiasv/disable-kalman-filter

Donations always welcome!

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Application versions: 
disable-kalman-filter-0.1-1.noarch.rpm3.47 KB03/10/2017 - 16:17
disable-kalman-filter-0.1-2.noarch.rpm3.59 KB03/10/2017 - 20:44

- Updated information to reflect that this works on Aqua Fish too.


gedeon's picture

Hi, can you make it also for Xperia X? Or is this working on the X maybe? I think there is calman filter working on it, terrible to use it yet unfortunately...

(I afraid to try it before I know it is gonna work for sure because of your cauction)

Ingvix's picture

Does Aqua Fish use Kalman filter? Mine has been JollaC'fied. What does the filter do in the first place?

toxip's picture

The filter is supposed to improve touchinput accuracy by predicting touch input but since it doesn't work properly due to reasons unknown it makes the input less accurate instead. If you can get me the contents of a file you can find in /var/lib/environment/compositor/ I can check whether it uses the kalman filter and if this patch is compatible. I would also like to know how Jolla C'fication affects this file so if anyone has a regular AquaFish, please get me that file.

Ingvix's picture

# Config for Nexus4 on CM-10.1
# Tell hybris to use hwcomposer to allow eglfs for Qt to use hwcomposernativewindow
# and Qt to use hwcomposer (note this needs a qpa hwcomposer plugin (qt5-qpa-hwcomposer-plugin))
# which looks like this on the mako
LIPSTICK_OPTIONS=-plugin evdevtouch:/dev/touchscreen:filtered:prediction=16 -plugin evdevkeyboard:keymap=/usr/share/qt5/keymaps/droid.qmap
# PRE_USER_SESSION_DISPLAY_OPTIONS=-displayX 187 -displayY -187 -displayRotation -9

toxip's picture

Okay, it is exactly the same, I will update the information on this page and the package!