Suspend not working: Ubuntu 20.04 (does not work at all) / 21.10(in battery mode does not work )

Question

I have IdeaPad 5 Pro 14ACN6 with installed Ubuntu 21.10. Suspend work fine when the laptop is powered, when on battery mode suspending it causes reboot. I have tried working around this issue by playing with

/etc/systemd/logind.conf

and setting

HandleLidSwich=hibernate
HandleLidSwichExternalPower=suspend

but it takes long from closing lid to hibernation -- it does nothing for more than 5-10 minutes and then hopefully hibernates. All those issues are not present if the laptop is plugged.

I went back to 20.04 LTS and there is still an issue with suspension (it is even worse). It is able to suspend but it reboots instead of resuming. It does not work no matter if it is plugged in or not.

I am aware I am not the first one with that problem, it looks almost exactly like this one: suspend doesn't work on battery mode (but it does while charging)

However:

1. Different OS,
2. BIOS update is not an option in my case, it is only available on Windows. I took a look at the description of the update, does not look like it could solve the issue.

Answer 1

I managed to solve it thanks to those answers: Reddit AskUbuntu

There is a hidden BIOS menu:

I found a hidden BIOS menu with an option to enable S3 directly, but then I ran into another issue. Perhaps it will work for you, and might be worth a try. First, in the regular BIOS, disable OneKeyBattery (saving the setting) and then shut down the machine.

Then, while shut down, type this 15-key sequence (the pattern will become clear when you do it): F4 4 R F V F5 5 T G B F6 6 Y H N.

Then start up directly into BIOS (via the F2 key)

In AMD PBS find S3/Modern Standby Support and disable it. According to the Reddit thread newer kernel is necessary so it might not work on Ubuntu older than 21.10.