Comment 64 for bug 1581088

I'm not sure this is a kernel issue. It appears to be something related to the evdev driver or how the files in xorg.conf.d are interpreted when setting up the evdev driver. the "Evdev Wheel Emulation" is "false" even though my config file xorg.conf.d is trying to set it to "true" - when I manually set it to "true" scrolling works fine.

I have a precise install (3.13.0-112-generic kernel) where the scrolling works. When I look at the output of "xinput --list-props XX" for my trackball, I see that "Evdev Wheel Emulation" is "true". On a Xenial install (4.8.0-41-generic kernel), using the same file in xorg.conf.d for my trackball, it shows Evdev Wheel Emulation as false.

Looking in the syslog, I see a line for:
"/usr/lib/gdm3/gdm-x-session[2042]: (**) Option "EmulateWheel" "true""
but the option isn't being set to true. I believe this is where the problem lies.

Here is a work around:

find the id of the device that won't scroll using "xinput --list", mine is 11

then check whether wheel emulation is true or false usng "xinput --list-props 11"

Here is what I see for list-props when I first boot and log in:

Evdev Wheel Emulation (297): 0

the 0 is false. Change this with the following:

xinput --set-property 11 297 1

where
11 - id of the device
297 - property number (shown in parenthesis from above)
1 is the boolean for true

After doing this, the output from "xinput --list-props 11" shows:
Evdev Wheel Emulation (297): 1

And now the scroll works as it did before I experienced this problem.

Can others check what they find using "xinput --list-props xx" to see if this is repeatable?

Thanks