[systemd-devel] Alienware graphics amplifier scancodes

[Mario Limonciello]

Hi,

Some Alienware notebooks and desktops support an external graphics
housing called the "Alienware Graphics Amplifier". It allows the usage
of a larger or more modern graphics card than your gaming PC would
already support.  In order to provide a good experience, systems that
support it can provide notification to the OS via the scancodes on the
the keyboard controller of events related to the cable.

The following 4 events are supported (and the presumed OS response):
* Cable plugged in (An app on the existing display or terminal would
tell the user to reboot the system to activate)
* Undock cable pressed (An app would let the user know to reboot the
system to complete undock process; also when supported by GFX driver,
driver can clean up and work without a reboot)
* Undock hotkey pressed (Same result as undock cable expected)
* Surprise removal of cable (System immediately reboots).

The first three events I think it would make sense to assign to a
keycode that a userspace application in X land can pickup and recognize,
but I'm at a loss what makes most sense (prog1, prog2, prog3 maybe?).
This userspace application hasn't yet been made or decided, I just want
to pave the path for it first.

The fourth event I'm submitting a kernel patch
(https://lkml.org/lkml/2015/5/27/817) so that the kernel would issue a
reboot when this was detected, so I believe it would  make sense to mark
it 'unknown' in systemd.

Also, these don't show up in xev output, but they do show up in evtest.

Can I get some advice on these?  I'll gladly submit a bug with a patch
afterward.

Thanks,

-- *Mario Limonciello* *Dell*| EUC SW Dev Engineering