08 Gigabyte B550 sleep issue

WHAT FUN I HAD trying to get SLEEP to work on my media server.
I ran through at least 6 Linux Distros before I accepted it was a PC issue.
Then hours of forum searching finally pieced it together:
It was a random, specific issue, with my motherboard playing with Linux.

Steps to fix, on Gigabyte B550m

1. Open new shell:

sudo nano /usr/local/bin/nogpp.sh

2. Copy into new script; save & close:

#!/bin/bash

declare -a devices=(GPP0 GPP8)
for device in "${devices[@]}"; do
    if grep -qw ^$device.*enabled /proc/acpi/wakeup; then
        sudo sh -c "echo $device > /proc/acpi/wakeup"
    fi
done

3. Create new service

sudo nano /etc/systemd/system/nogpp.service

4. Copy into new service; save & close:

[Unit]
Description=No GPP Wake

[Service]
Type=oneshot
ExecStart=/usr/local/bin/nogpp.sh

[Install]
WantedBy=default.target

5. change permissions on both new files:

sudo chmod 744 /usr/local/bin/nogpp.sh

sudo chmod 644 /etc/systemd/system/nogpp.service

6. reload & enable service:

sudo systemctl daemon-reload && systemctl enable nogpp.service

7. Make sure it’s running:

sudo systemctl status nogpp.service

8. Make sure the two “GPP” devices are disabled in list:

nano /proc/acpi/wakeup

So what happened?

In short, motherboard bridge/device had specific conflict with Linux.
These helped during the resolution searching:
I don’t know how, but essentially a day was spent daisy-chaining searching until it came to an answer.

Prints system info if you need to troubleshoot

inxi -F

Command to sleep from terminal

sudo systemctl suspend

Checks sleep command report, look for errors

journalctl -b -u systemd-suspend.service 

Lists sleep inhibitors

systemd-inhibit --list --mode=block

Lists devices that enable wake / prevent sleep

nano /proc/acpi/wakeup