Qubes display issue after dom0 update

Hi all,

I have recently installed Qubes on a Dell Inspirion 3793 laptop after a fair bit of fuss. I was originally getting a black screen on the laptop monitor, but if I connected a second monitor, I was able to then view and interact with the desktop. I installed kernel-latest and that seemed to then fix the laptop issue. This is with LTS 4.0.3.

So, then last week, I clicked on the option at the bottom of the update screen to enable updates that weren’t referenced. (I can’t remember the exact wording.) I then clicked on all of the different host options in the window, including dom0 and following the updates, very odd display behavior began to occur with the laptop monitor.

Here is what happens:

–When the laptop first starts up, it shows the normal Qubes prompt for the disk encryption. I can interact with it fine on the laptop monitor.
–Then the screen goes back except for the mouse pointer. I can move the mouse pointer around the screen and when I mouse over where the password prompt would be, the mouse pointer changes from an arrow to the text bar, just as though the GUI is displayed. Like, the GUI loaded, but for some reason is just not displaying on the screen.
–At this point, if I hit the power button, the GUI will flash on the screen for just a bit and then the laptop will power down. (I have the power button set to shut the computer down when pressed)
–As it is powering down, the Qubes logo and process bar displays just fine on the bottom of the laptop monitor. The weird display problems only occur when the GUI itself should be up.
–If instead, I plug a second monitor in, whatever the current state of the GUI is will display as a static image on the laptop screen, and the same will show on the second monitor, though on the second monitor, I can interact with it normally. Regardless of what I do on the second monitor, the original static GUI image will continue to display unchanged on the laptop monitor.

I have searched for other people having this problem and haven’t found any reference to such an issue as this. Any help would be much appreciated.

I would really like to use this in production, but, as of yet, on this laptop at least, this has not proven to be stable enough for production use.



Hi @kmfreder1,

I have exactly the same problem. Though I can’t trace it to a specific event, I can confirm this issue did not exist at some point in the past. To me it looks as if the system would think the external monitor system is the actual native display, and treats the actual laptop display as the secondary one.

I have attempted using the Display GUI to disable the external display before disconnecting it and managed to get the expected results: All display working on Laptop screen only. However, once I reboot the laptop everything goes back to what you already described.

This issue makes the laptop unusable when an External Display is not around.

It would be nice to learn of a way to troubleshoot this, as I have no idea which modules/packages/configurations are involved other than the Display GUI.

Some details:

Intel integrated GPU
qubes 4.0.4
tested on dom0 kernels 5.8.x and 5.10.13-1

@kmfreder1 ,

Not sure if you already figured this out, but if anyone reads this, it seems to be related to this:

Reverting dom0 from kernel-latest to current kernel version (currently 5.4.X) works around the issue.

I attempted that post’s apparent alternative workaround without success:

Then I attempted to add TripleBuffer=true and TearFree=true as options in dom0’s /boot/efi/EFI/qubes/xen.cfg but this resulted in failure to boot (bootloop to the BIOS screen).

Therefore, downgrade is the workaround I am sticking with for now.

Hey, thanks @some.user7882. I appreciate your tips. I was hoping for some tips on diagnosing the issue, like how to get to whatever logs would be relevant, etc. just as you asked for in your original response.

I will try the workarounds you mentioned.

I had to step away from the Qubes project for a bit as I was just spinning my wheels. I hope to get back into it in the next couple of weeks.

I’m not sure I am ready to commit to using this in production as my main OS with the seeming instability and the ever possible sudden hardware incompatibility issues that I had to work around to get it going to begin with and then that cropped up after a quick update. And, you are the only person who has responded at all to my request for assistance. I was hoping for a more active community here, as I have seen in other open source projects. Maybe I am just missing something about how best to interact with this open source community.

Nonetheless, thanks for your responses. I’ll report back once I try these things out.