Hello,
I'm running NetBSD 7.99.2 (snapshot from 5th December) on a Samsung laptop (amd64).
Now when resuming from ACPI's S3 sleep, I'm getting a kernel panic followed by an immediate reboot.
To get most far I needed to disable vga resetting with BIOS with
hw.acpi.sleep.vbios=0
hw.acpi.acpivga0.bios_switch=0
hw.drm2.i915drm.reset=0
and at resume I can see the console from where the suspend was invoked, however it won't result in a return to a prompt but system restart after a few seconds.
If I enable ddb instead of restart debugging prompt appears however ignores any input, no keyboard response, no acpi power button reaction - hard reset or turn off is required.
The strangest thing that is my 2nd installation from the same image and I previously somehow managed to tweak settings so S3 suspend/resume cycle worked repeatedly, even usb mass storeage could be mounted reliably after.
I played with disabling various devices in /boot.cfg (userconf=disable devname*) but cann't rememember which combination did the job.