X11 based application does not respond to touch after first touch ( ILI210x Touchscreen)

[Peter Hutterer]

On Wed, Jun 07, 2023 at 01:04:02PM +0530, Vishnu Motghare wrote:
> Hello All,
> 
> X11-based applications like xterm & xinput_calibrator do not respond to
> touch after the first touch.
> 
> We have an ILI210x Touchscreen controller & the kernel version is 5.15,
> touch was working fine with the 5.4 kernel version with Xterm &
> xinput_calibrator
> 
> This is the  Commit
> <https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/drivers/input/touchscreen/ili210x.c?h=v5.10.182&id=3a492e4403ee2e3442397230d68e26e81525af90>
>   added
> in the kernel to report the pressure value & after this, no X11-based
> application works after the first touch
> 
> Do we need to add any setting in xorg.conf to handle the pressure value
> reported by  ILI210x Touchscreen?

Most likely you're using the xf86-input-libinput driver for touchscreens
(unless you explicitly changed it to use the evdev driver). In that case
you can check with `libinput debug-events` to see what libinput produces
- the xorg libinput driver is a fairly thin wrapper and this should give
you a good indication of where things go wrong.

libinput record works either way and shows you the events produced by
the kernel.

also, fwiw libinput does not handle pressure for touch screen events so
this patch shouldn't have made a difference in userspace. So there's
most likely some other event missing, libinput record should show this.
Probably best to file an issue against libinput for that.

Cheers,
  Peter