Monitor Sleeps If Switching to Console

glenjo · 2021-07-27 09:27:27

I am using XFCE with lightdm as the display manager on an up to date version of Archlinux. Lately, if I press Ctrl-Alt-F2 to switch to a virtual console, the monitor almost immediately goes to sleep, and nothing is displayed. If I then press Ctrl-Alt-F7, the monitor wakes up, and I see my X session back. When I check the processes, I can see that agetty was started at tty2 so that seems to be working right, except that the monitor has gone to sleep. I'm using a BenQ SW270C monitor, and I can also see all the USB devices in (and connected to) the monitor depower and repower in the kernel ring buffer when checking with dmesg and in Xorg.log.

I haven't seen this behavior before, any help would be appreciated!

TIA

seth · 2021-07-27 10:49:37

Do you have mulitple outputs?
Do you see sth. before lightdm starts (boot messages)?
Does the monitor activate if you switch to tty1? From tty2 or tty7 directly?
Do you use a specific console video mode? https://raw.githubusercontent.com/torva … modedb.rst

glenjo · 2021-07-27 11:19:52

I only have a single monitor.
I do see the boot messages - I rebooted to check, and I remembered I remove quiet from the kernel parameters.
And I can see tty1, tty2 and so on after booting! I think the sleeping behavior starts once the monitor has gone to sleep and I have to wake it up. After that - no consoles. I'll do more testing on that.
I have a GTX 1050 card and am using the nvidia driver with nvidia-drm.modeset=1 as a kernel parameter.

So maybe this has more to do with sleep event?

Last edited by glenjo (2021-07-27 11:26:54)

seth · 2021-07-27 11:45:48

HDMI?
What if you re-attach it once the problem starts?

glenjo · 2021-07-27 12:06:25

I'm using DP.

I will try the re-attach and let you know the results.

Thanks for your help!

glenjo · 2021-07-27 18:04:35

Hm, now I cannot reproduce the error. I'm not sure what happened before, and/or what I did to fix it.

glenjo · 2021-07-29 06:15:15

So after some experimenting here is what I found:

If while the PC is starting up I press the Del key (to get the UEFI Bios to display), and then wait, I see GRUB, and then can watch the console boot messages. After that everything works the way I expect, with all the VTs working.

If while the PC is starting and I press no keys, the next thing I see is the lightdm login display, and after that none of the VTs will work.

That's sorta weird.

seth · 2021-07-29 08:04:55

What if you pass "fbcon=nodefer" to the kernel commandline?
https://wiki.archlinux.org/title/Silent … d_takeover

Arch Linux

#1 2021-07-27 09:27:27

Monitor Sleeps If Switching to Console

#2 2021-07-27 10:49:37

Re: Monitor Sleeps If Switching to Console

#3 2021-07-27 11:19:52

Re: Monitor Sleeps If Switching to Console

#4 2021-07-27 11:45:48

Re: Monitor Sleeps If Switching to Console

#5 2021-07-27 12:06:25

Re: Monitor Sleeps If Switching to Console

#6 2021-07-27 18:04:35

Re: Monitor Sleeps If Switching to Console

#7 2021-07-29 06:15:15

Re: Monitor Sleeps If Switching to Console

#8 2021-07-29 08:04:55

Re: Monitor Sleeps If Switching to Console

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