Lenovo T480s touchpad and buttons randomly fail

[Peter Hutterer]

On Wed, Oct 17, 2018 at 08:35:56PM +0800, Kai Hendry wrote:
> Updated Archlinux user here.
> Through 4.18.9-arch1-1-ARCH to 4.18.14-arch1-1-ARCH
> 
> Some times when I boot, my touch pad doesn't work at all. Or it might work
> and suddenly stop working. Unreproducible.

has it ever worked before? This page here has the list of things needed:
https://wayland.freedesktop.org/libinput/doc/latest/reporting-bugs.html
but see below, it appears to be a kernel (hw?) bug.

> Any ideas?
> 
> https://s.natalian.org/2018-09-24/touchpad.txt

there's no touchpad in that list which usually has only one of two reasons:
- the kernel doesn't detect it (likely)
- the udev setup is broken and ID_INPUT + ID_INPUT_TOUCHPAD isn't assigned
  (unlikely unless you manually messed with udev rules)

right now, my bet is on a kernel bug.

> https://www.youtube.com/watch?v=PVPmcg0oxrY

can you sum this up please? making everyone watch a youtube video is likely
to reduce the number of people who can reply with suggestions.

> Workaround is using the external USB mouse. Which wouldn't be so bad if my
> USB port on the left didn't work. Could it simply be a hardware issue?

probably a bios issue, google for it. there's some weird issues with them
being working for some devices but not others depending on the charge option
in the bios (depends on the model number, but my T440s here has similar
issues with some devices only working on a specific port).

Cheers,
   Peter