Comment # 15 on bug 954532 from Robin Roevens

I tried your suggestions. To summarize the results:

- In TW: Booting with 4.3 and acpi=off results in touchpad working. evtest show
events when touching the pad. Xorg however fails to start.

- In TW: Booting with 4.3, acpi enabled and i8042.nopnp results in device
existing but touchpad NOT working. evtest doesn't show events when touching the
pad.  Xorg does start correctly with accelerated VGA.

- In TW: Booting with 4.3, normal boot without extra parameters results in
device not being detected (AUX port disabled warning). Xorg does start
correctly with accelerated VGA. 

- In TW: Booting with 4.1, acpi enabled and nomodeset the screen indeed does
not turn black during boot. However, it seems now also using this kernel, the
touchpad is also NOT detected. (warning about AUX being disabled in dmesg).
Xorg fails to start.

- In Leap: Booting with acpi=off resulted in Xorg starting up using
unaccelerated framebuffer graphics. Touchpad working. 

.. So it seems to be ACPI related.

I also noticed, as it may be related in some way: (just giving you this
information, in case it could be useful. I don't really require investigation
on these things)
- Whenever i boot with acpi enabled there is no graphical splash screen
displayed during boot. Instead I get a text splash with 3 strange characters in
the middle instead of the 3 little squares.
- When I boot with acpi=off I always get a graphical splash screen.
- Strange however: When I boot a read-only snapshot with acpi enabled I DO get
a graphical splash screen.

- Also note: first try of Leap was using Legacy BIOS instead of UEFI: In Legacy
mode Grub was displayed in low resolution, was really ugly and very very slow
(characters where displayed one by one). Also booting Leap was in low
resolution. ACPI enabled resulted in black screen. But also with ACPI disabled
Xorg fails to start while that does work when booted in UEFI with ACPI
disabled.