Comment # 35 on bug 954532 from Andr�s Barrantes Silman

Interestingly, my Acer Aspire 5 (A515-43-R19L) had the touchpad working
inconsistently across reboots (sometimes it got detected and sometimes it
didn't).

Same problem, it wasn't listed at all in /proc/bus/input/devices when it wasn't
working, and when it worked it did get listed.

Adding i8042.nopnp to kernel options did fix the behavior, which I am posting
here just in case somebody comes across the same issue. I'm not sure but it
seems like the touchpad driver was freezing Leap 15.2 on some reboots so I
jumped into Tumbleweed since the hardware is fairly new, and it worked fine.
I'm not sure why would this kernel parameter fix it, and I didn't check dmesg,
but ok!