Touchscreen troubles

Petr Štetiar ynezz at
Sun Dec 13 09:43:10 PST 2009

Tias <tias at> [2009-12-13 18:05:23]:

> Thanks for the patches. Normally the calibrator checks if you have an 
> EvDev driver (in CalibratorEvdev::check_driver) and already prints those 
> things. It's kind of strange that it did not detect you were using 
> evdev. It checks for the same properties as the command line xinput 
> set-int-prop settings, so I don't understand what goes wrong ?

Ok, I'll check this.

> >> It calibrates the Xorg driver (and the values that the X server 
> >> receives). You report calibrating from the values of the kernel, maybe 
> >> using a user-space tool will solve your problem ?

Yes, but I just use this kernel values to get min/max values for both axes.
For nothing else. And I got similar values from evtouch_calibrate, BTW.

> Make sure you set xinput set-int-prop "..." "Evdev Axis Calibration" 32 
> 0 before calibrating (as it does not correctly detect your current 
> calibration values).

You mean ... "Evdev Axis Calibration" 32 0 0 0 0 - four zeros, with one zero I
got error from xinput. Althought I do this, I can now press only top-left
circle, then the mouse pointer moves to 0,0 coordinates on the screen, and I'm
unable to touch another circle in top-right corner, and in Xorg log i see:

Divide by Zero in xf86ScaleAxisDivide by Zero in xf86ScaleAxis(II)

and I see my debug msg "touchscreen: num_valuators: 2 x: 0 y: 0", means both
valuators are 0.

> > What do you mean by user-space tool?
> Not calibrating the kernel values (by doing printk), but calibrating the 
> Xorg driver (as you are currently doing).

Ah, you maybe misunderstood me here, I used those values which kernel driver
outputs when usermode read()s from /dev/input/device to get just min/max axis
values and I use it for Xorg calibration, it's not possible to calibrate this
kind of touchscreen anyway.

> Looking at your original email, I see you are using Xorg server 1.6.0 
> with evdev 2.3.2 manually compiled. It might just be a version thing of 
> course. I would definitely try it on a recent system with a standard 
> setup too.

It was the same with standard setup, so that's why I'm trying first with lates
evdev driver...

-- ynezz

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