[solved] Hibernate from LightDM resumes into a black screen

amity88 · 2021-10-21 08:05:01

When I hibernate from the lock screen in LightDM, the pc hibernates fine, it resumes fine. However, on resuming the screen is blank but not frozen as I can move the mouse around.

Any pointers to solve this is much appreciated.

Last edited by amity88 (2021-10-21 14:57:33)

seth · 2021-10-21 11:17:27

Check your journal, the greeter likely crashed?
You might just require https://wiki.archlinux.org/title/Kernel … _KMS_start

amity88 · 2021-10-21 11:32:21

I went through the logs and tested lightdm in debug mode. Looks like the issue is with the webkit greeter. I switched over to the gtk greeter and it works fine.

seth · 2021-10-21 11:46:07

Do you have error messages for inspection?
(If you want to keep using the webkit greeter - plus it might reveal other issues that you're now glossing over and that will come back to bite you)

amity88 · 2021-10-21 13:16:35

Thanks (for both assisting and motivating me to debug further). As you said, root causing this is useful in multiple ways even though we have a work around.

Questions:
1. How do I increase log verbosity for the greeter? (the log has minimal information)

Observations:
1. This impacts resume (can be from hibernate or from suspend to ram)
2. The screen would be black with a functioning mouse pointer. Inference is that it's likely not a graphics issue.
3. Resuming after suspend/hibernate from within the session (instead of lightdm) works reliably. Implies that the issue is likely with lightdm / greeter.
4. Resume works when using the gtk-greeter. Implies that we need to focus debug on the webkit greeter (sorry to repeat, just summarizing)
5. The greeter reports an error (consolekit) but even the working one (gtk greeter) had this. Do I need consolekit when polkit and systemd are already there?

logs:

lightdm log : https://pastebin.com/2WPjexjJ
greeter log : https://pastebin.com/bUrYjvNM

Last edited by amity88 (2021-10-21 13:19:25)

seth · 2021-10-21 13:26:58

https://github.com/antergos/web-greeter wrote:

a debug console if you set debug_mode to true inside /etc/lightdm/web-greeter.yml

The posted lightdm log shows the greeter coming up and you logging in after ~2½ seconds - it doesn't seem to cover a failed run after resuming from hibernation (or even a logout of the original session)?

console-kit isn't relevant, but do you have an nvidia GPU?

amity88 · 2021-10-21 13:35:59

Oh right, I restarted the gui to post this. Might have overwritten the previous log. Here is a fresh log taken right after the issue. I locked my session, initiated a suspend to disk from lightdm and resumed. The issue was present, so went out of the GUI to both kill lightdm and get the logs

https://pastebin.com/mZTAreQh

I don't use an Nvidia card, do they have issues?

seth · 2021-10-21 13:52:15

VRAM decay causing invalid GL texures, but affects rather S3 than S4.
You're not logging out to lightdm, but use lightdm as screen-locker, are you?

Does it help to switch VTs around (ctrl+alt+f1,2,3,4…)?

amity88 · 2021-10-21 14:04:51

Ah, you're talking about a issue with the nvidia card (The VRAM decay).

Back to the issue, why would it affect the webkit greeter but not the gtk one if it's a hardware issue?

Just to be clear, the issue is present in both suspend to disk as well as suspend to ram. It's quicker to reproduce it in the latter.

Yes, I'm not logging out to lightdm but rather using it like a screen-locker

Swithing the VTs do not help resolve the issue but they let me jump into a terminal to debug and also to restart lightdm. Restarting lightdm will resolve the issue till next sleep but I'll lose my session.

Last edited by amity88 (2021-10-21 14:06:17)

seth · 2021-10-21 14:07:24

I'm curious how you narrowed it to the VRAM decay being the cause.

I didn't - it's a common issue w/ the nvidia driver, you asked but you don't actually have an nvidia chip.
Edit: yes

Do you face the same problem when logging out of the session and initiate the hibernation from the actual DM?

Last edited by seth (2021-10-21 14:07:45)

amity88 · 2021-10-21 14:11:34

(hehe I ninja edited my response after realizing what you said)

Just checked, the same problem is there when repeating the test while being logged out. As usual, the mouse pointer works, but the rest of it is fubared.

/edit1 : Also tested the deepin greeter, it works fine too. This might be an issue affecting only the webkit based greeter (maybe some js issue? )

Last edited by amity88 (2021-10-21 14:32:22)

seth · 2021-10-21 14:28:50

So it's the greeter alone and not the greeter vs. something.
Did you
a) configure the system for early kms
b) enable debug_mode in /etc/lightdm/web-greeter.yml

amity88 · 2021-10-21 14:54:56

The issue was root caused and solved! The default user_image path in the greeter config was invalid. My guess is that it's used on resume and the js code hangs. Changing it to a valid image, fixed the issue.

vi /etc/lightdm/lightdm-webkit2-greeter.conf

[branding]
background_images = /usr/share/backgrounds
logo = /usr/share/pixmaps/archlinux-logo.svg
user_image = /usr/share/pixmaps/archlinux.svg

Last edited by amity88 (2021-10-21 14:56:24)

Arch Linux

#1 2021-10-21 08:05:01

[solved] Hibernate from LightDM resumes into a black screen

#2 2021-10-21 11:17:27

Re: [solved] Hibernate from LightDM resumes into a black screen

#3 2021-10-21 11:32:21

Re: [solved] Hibernate from LightDM resumes into a black screen

#4 2021-10-21 11:46:07

Re: [solved] Hibernate from LightDM resumes into a black screen

#5 2021-10-21 13:16:35

Re: [solved] Hibernate from LightDM resumes into a black screen

#6 2021-10-21 13:26:58

Re: [solved] Hibernate from LightDM resumes into a black screen

#7 2021-10-21 13:35:59

Re: [solved] Hibernate from LightDM resumes into a black screen

#8 2021-10-21 13:52:15

Re: [solved] Hibernate from LightDM resumes into a black screen

#9 2021-10-21 14:04:51

Re: [solved] Hibernate from LightDM resumes into a black screen

#10 2021-10-21 14:07:24

Re: [solved] Hibernate from LightDM resumes into a black screen

#11 2021-10-21 14:11:34

Re: [solved] Hibernate from LightDM resumes into a black screen

#12 2021-10-21 14:28:50

Re: [solved] Hibernate from LightDM resumes into a black screen

#13 2021-10-21 14:54:56

Re: [solved] Hibernate from LightDM resumes into a black screen

Board footer