Weirds pausing bug. on 3.38 .4-1

Not sure where else to post this as I cannot see it mentioned anywhere else which makes me feel uneasy that is just me, but it is very repeatable so.

The Scenario is this. When starting Gnome in Xorg or Wayland. After the screen saver cuts in I subsequentially get ‘pauses’ of about 1-2 seconds every minute or several. So. It is not perfectly regular but very noticeable. In Xorg the entire screen freezes and all input freezes. The extensions like system-montor and simple-Networkspeed don’t update. This happens for about a second or so and then resumes.

Under Wayland it is slightly different. The input never freezes, but the keyboard seems to buffer key strokes so if I am typing "This is a bug"it will appear as “This issssssssssssssssssssssssssssssssssssssssssssss a bug” or any letter I am typing at the time.

I have combed through dmesg to see if there is anything there but nada. So I thought I would see if the same thing happened with Plasma and Wayland or Plasma and Xorg. No it does not. So I feel it is specific to the Gnome framework but I am unsure about how to go about debugging it.

For the record the system is.

Tuxedo Pulse 15 with AMD Ryzen 7 4800H with Radeon Graphics. 64Gb Memory (3200 Mhz)

Debian 10 (testing)
Linux 5.10.0-4-amd64 #1 SMP Debian 5.10.19-1 (2021-03-02) x86_64 GNU/Linux
gnome-shell 3.38.4-1
libmutter-7-0 3.38.4-1
mutter-common 3.38.4-1

Thoughts anyone? Has anyone else experienced something similar. There’s a lot of stuff in user.log I don’t know way does might the answer be hidden there?

Thanks.

Are you saying that e.g. the mouse cursor never stops when using Wayland, but keyboard “pauses” than repeats the letter you were typing?

If the mouse cursor freezes as well when using Xorg, it makes it seem more like a driver bug that GNOME happens to trigger.

Are you saying that e.g. the mouse cursor never stops when using Wayland, but keyboard “pauses” than repeats the letter you were typing?

Not in Wayland no. In Xorg yes… Everything including the mouse seems to freeze.

The is also another, perhaps related bug. Sometimes when the lock screen is on I can type my password and nothing happens. No error no login. It just clears the password and starts again.

Even going to the GDM screen and logging in again just brings me back to the lock screen and the same situation.

The only way to rectify it is to restart GDM3

UPDATE: So following on from a hunch I disabled the screen blanking and lock. I’ve left it on for over 24 hours and no sign of the bug. Which leads me to postulate whether is it the actual screen locking that is causing it? If Wayland or X call the video card directly to blank the screen is there some sort of bug there?

Just a reminder to everyone I am on AMD Ryzen 7 4800H with [AMD/ATI] Renoir (rev c6) embedded GPU.

Screen blanking should normally come after a slow fade-out though, and I assume you’re not seing that. Not until that is done will any kind of power saving on the GPU level kick in.

Correct and so I turned that off and have not had a problem since. So either the slow fade is the problem or the blanking is. Either way for me, it is reproducible. When I am not so busy with work etc I will try it again from a fresh boot and look for any errors in user.log . But for now I will just have to live without screen lock.

Did the freezes happen during or after the “fade”? Moving the cursor should have discarded the fade.

No it freezes during normal use after a resume from a lock screen etc. So if I leave it for 10 mins or so and the screen has locked and come back within about 5 minutes I notice the problem. Now I have disabled screen locking and it is just ‘on’ all the time it seems ok. I left it overnight and here I am using it again this afternoon, and it is fine.

I’d like to remind people I did not have the problem in Plasma with either Wayland or X , their screensaver or lock screen seemed no affected, so I was using that for a day or two till it started to bug me and came to report this bug to Gnome so I can continue using it.

Like I say I hope to get a clean boot done and fresh user.logs to see if that holds the answers. Just can’t do that right at the moment.