After upgrading the system (Slackware-current), I've ran into an issue of Xorg server aborting on power saving event (10 minutes of inactivity, which is the default value I guess).
Screen switches off, but after reactivation I don't get the screen as I left it, but the display manager's login screen is presented instead. In xdm.log there are stack traces pointing to Xorg and its libraries, in Xorg.log there are messages on GPU sort of resetting (?) several times, once per 5 seconds.

The Xorg packages are at 1.20.9. I've tried downgrading back to May 2020 snapshot (Xorg 1.20.8), no luck. The diagnostic is somewhat different, and the issue doesn't come up every time I leave for 10+ minutes, but happens pretty often all the same.

The issue definitely WASN'T there with January 2020 snapshot of Slackware-current, which had Xorg at either 1.20.6 or 1.20.7 versions. I don't have snapshots for dates before May 2020, and so I can't pinpoint the offending modification more precisely.

I'm thinking about submitting a ticket at Xorg bugzilla, is it worth it?

That's what FlyGoat's RyzenAdj tells me:
Detected Raven
CPU Family: Raven
SMU BIOS Interface Version: 7

Well, the issue might have solved itself, after upgrading the kernel part to 5.4.63. Or it has just got more elusive...

That's getting silly.
Now I'm experiencing somewhat similar-looking issue with Xorg switching off the display after somewhat long inactivity and not putting power back on keyboard/mouse events. Virtual consoles work.

Slackware 64 bits, kernel 5.10.35, hardware's the same.

System logs contain strings of the following kind:
May 9 12:41:05 sandys acpid: 1 client rule loaded
May 9 12:41:05 sandys root: ACPI group jack / action lineout is not defined
May 9 12:41:05 sandys root: ACPI group jack / action videoout is not defined

Xorg log contains tons of "probed modes", like those are checked and re-checked.

I've narrowed it down to my Ryzen graphics or monitor or both being unable to come out correctly of 'Off' phase of DPMS.
The stopgap solution which seems to work is to disable 'Off' phase completely:
or put the following file (naming it like 99-ryzen-dpms-off-phase.conf) in /etc/X11/xorg.conf.d/:
UPDATED: This doesn't work reliably every time though, there's some random factor.
At the moment I've had to disable any dpms on the monitor:

And moving to kernel 5.12 brought the old problem back - X won't start.
This time I knew where to look and found fairly quickly that any touching Power Management in xorg.conf/ xorg.conf.d is out. So, previously described 99-ryzen-dpms-off-phase.conf had to go.

try
slackpkg new-config over write old ones.
seems your getting hung up on a runlevel
if you have a proprietary gpu driver this will also cause it.
rebuild the module that is link to the xorg.
I found the 5.13.0 kernel has solved my usb disconnect issues.
and yes I have the latest bios on my x570 board for my 3700X

Thanks.
Like I said, what worked for me this time (on kernel 5.12) was removing any modifications regarding power management from Xorg configuration.