Display can't reconnect after turning it if off during lockscreen

User Support
1

Recently reinstalled Qubes.
Now every time I lock the screen and press the power-off button on my display it can’t wake up again ( after a certain amount of time, no signal or just black screen)

I have no idea why it isn’t working.

In the xfce settings I set that it should connect to newly plugged in displays.
I also tried to mask every sleep target with systemd and also disabled sleep in xfce settings.

I have an NVIDIA gpu (1070)

I am using display-port and reconnecting the cable also doesn’t help.

it worked correctly before my reinstall.

Would this help ?

# xset s off
# xset dpms 0 0 0
# xset -dpms s off

Advice would be greatly appreciated.

2

Maybe the system is trying to enter the suspend mode after some inactive timeout but failing to do so and can’t resume from it.
Check if you disabled the suspend in the Power Manager for both “On battery” and “Plugged In” modes.

3

I disabled suspend.

Also I had syncthing running in the background while the display wasn’t working and other devices connected just fine to the pc.

I also upgraded my UEFI and changed some settings. Are there any that might cause this behavior?

4

Also I discovered new weird behaviors. This might not be an Qubes issue after all.

When I change from DP to HDMI during UEFI password prompt and change back I get the no signal error.

Also when I try to plug in a new display while Qubes is unlocked and running that also gets no display output.

Like I said I installed a M.2 ssd and upgraded the UEFI the issues started from there …

5

Then maybe it’s crashing when it’s trying to switch off display after timeout.
Try to disable display power management in the Power Manager → Display tab.

No idea.

6

I have that disabled. Only thing still enabled is that after 30min the display gets black( can’t disabled this under the screensaver settings)

7

Yup something is weird. No new displays get recognized at all whether HDMI or DP. Also a lot of settings are missing under the display settings for the current display ( can’t rotate it, can’t change the resolution or refresh rate.)

I installed qubes with the grub option nomodeset, might this have anything to do with it ?
Do I have to do anything after installing with this option. Otherwise are there some drivers that might help?

I already spent a lot of time trying settings in the UEFI but that also did not help…

8

Yes, nomodeset provides just the basic graphics support.
You should fix your problem with GPU driver so you won’t need nomodeset anymore.

9

Holy I thought I checked /etc/default/grub for nomodeset and it wasn’t there.

So I thought… But apparently I missed it.

This post might be really silly after all…

10

If you’re using NVIDIA GPU:

Then you need to either use kernel 6.6.42 or build the kernel with this patch:

Or wait for kernel with this patch to be available for dom0.

1 Like
11

So do you have nomodeset or not?
Check the current kernel command line options:

cat /proc/cmdline
1 Like
12

Yup I have it. (removed it now)

Also I don’t have kernerl-lates installed but I still have these 2 kernels:

kernel.x86_64                                     1000:6.6.48-1.qubes.fc37          @anaconda         
kernel.x86_64                                     1000:6.6.54-1.qubes.fc37          @qubes-dom0-cached

Is the patch included in those?

13

No, the kernel with this patch is still not available for dom0.
The kernels 6.6.48 and 6.6.54 won’t work for you with NVIDIA GPU, you need to install kernel-6.6.42 package in dom0 and boot with kernel 6.6.42 until the patched kernel will be available.

14

Okay yeah I think that was the old version I was using before will install it. Hope this will solve my issues.

15

I installed the kernel with

sudo qubes-dom0-update kernel-6.6.42

And now it appears to work again. Will still have to test if the display wakes up again but I am confident.

I feel really stupid.

Anyway thanks for you patience and time.