amd64 ACPI poweroff doesn't work on NUC01A: known problem?

[is%netbsd.org@localhost]

Hi,

I noticed that the Intel NUC based box I'm preparing for yet another
workplace I'll need in the next months DOES boot netbsd-7.1 mostly fine,
but 

- complains about GPU crash from time to time (e.g., the initial 
xdm login window caption ("Welcome to...") is often shortened to "W"

drm: GPU HANG: ecode 0:0x0fdf110c, reason: Ring hung, action: reset
drm: GPU hangs can indicate a bug anywhere in the entire gfx stack, including userspace.
drm: GPU crash dump saved to /sys/class/drm/card0/error

(I didn't find that - where's that supposed to be?)

- more annoying:

halt -p (or that part of shutdown -p now or pressing the power button)
gets ACPI errors, not finding the necessary methods, then drops into 
the "system halted\npress any key to reboot" prompt - only : the graphics
are still active, but apparently USB (meaning: the keyboard) is inactive
so this doesn't work. (Works from console=com0, though).

Another press on the power button manages to tell the BIOS to power off.

If this is something new, I'll create a PR. Else please point me to the
known information.

Here are the details - errors/dmesg grabbed by switching to serial console
for a boot period:

Machine is an Shuttle xpc err... nano? (the "0.5l" ones), (NUCA01)

BIOS is 1.09, the lastest available from Shuttle.com

Kernel / OS is:

NetBSD 7.1_STABLE (GENERIC) #10: Wed Jun  7 15:39:58 CEST 2017
        ignatios%random84.cs.uni-bonn.de@localhost:/var/itch/obj/7/Oamd64/sys/arch/amd64/compile/GENERIC

total memory = 8075 MB
avail memory = 7823 MB

cpu0 at mainbus0 apid 0: Intel(R) Celeron(R) 3205U @ 1.50GHz, id 0x306d4
cpu1 at mainbus0 apid 2: Intel(R) Celeron(R) 3205U @ 1.50GHz, id 0x306d4
acpi0 at mainbus0: Intel ACPICA 20131218
ACPI Error: [CPST] Namespace lookup failure, AE_NOT_FOUND (20131218/psargs-393)
ACPI Error: Method parse/execution failed [\_SB_.PCI0.LPCB.EC0_._REG] (Node 0xfffffe824cae35d8), AE_NOT_FOUND (20131218/psparse-553)


atabus0: detached^
acpi0: entering state S5
ACPI Error: No handler for Region [ECMP] (0xfffffe824cada6a8) [EmbeddedControl] (20131218/evregion-181)
ACPI Error: Region EmbeddedControl (ID=3) has no handler (20131218/exfldio-323)
ACPI Error: Method parse/execution failed [\RPTS] (Node 0xfffffe824cae9228), AE_NOT_EXIST (20131218/psparse-553)
ACPI Error: Method parse/execution failed [\_PTS] (Node 0xfffffe824cae6250), AE_NOT_EXIST (20131218/psparse-553)
acpi0: failed to prepare S5: AE_NOT_EXIST

The operating system has halted.
Please press any key to reboot.

Full dmesg of the run is at

http://theory.cs.uni-bonn.de/~ignatios/kalypso.log