My device: RNUC12WSKi50000
My system: -current 6.6.7 & limine UEFI bootloader

I can suspend the device just fine. To wake it up, I have to press the power button twice. When I press the power button (to wake it up) the first time, it acts like it goes out of sleep: keyboard and monitor backlight light. But then it immediately goes back to sleep.

I suspend on live booted Linux Mint, everything works fine there.

I have a intel NUC . They are persnickety buggers.

You have a swap file or a swap partition? How big?

2GiB.

I'd increase it to at least 4 gig. See if it changes anything. Have you looked into running zram in Slackware?

https://slackbuilds.org/repository/1...em/swapinzram/

I have 16 GiB of RAM, what would I need that for? I still have a 2 GiB swap partition just for the sake of the old days.
Suspend does not rely on disk space, swap is useless for that.

1st I heard of this.

I am backing out and letting a slackware user deal with this.

Is there a way to find out what "event" causes suspend?

What sort of suspend : suspend to ram or suspend to disk (hibernate) ?

Answers above naturally though it was suspend to disk. In this case, the state of the RAM is put in the SWAP. So you need some swap...

Swap is not only for lack of RAM. It can be use for hibernate or for reserve virtual memory in processes which won't be ever physically used. 64 bits systems can reserve huge amounts of virtual memory. But the system try with some parameters which can be tuned to verify that the virtual memory won't be converted into physical overheaded memory. And those parameters depends on the size of swaps.

Try something more equivalent. Mint (Ubuntu) is using a 5.15 kernel. Perhaps test Slackware 15.0 that also uses 5.15. That might provide some clues.

Another angle is use WoL to awaken the system and see what happens. If the device remains powered on that would indicate something in the way the power switch is handled. If not then likely something in the ACPI handling.

I have no idea if swap is playing a role.

I am talking about suspend to RAM, not hibernate to disk.

My New Year's resolution is to not try to debug suspend issues as they are always hardware dependent.

When I trigger suspend to RAM with
my system suspends.
Hitting any key on the keyboard successfully initiates resume.