Display changes lead to weird Xorg behaviour

[3hhh]

How to file a helpful issue

Qubes OS release

4.2

Brief summary

Switching to a different display leads to areas of the new display becoming unusable. Clicking on certain areas leads to clicks on other areas of the screen.

Steps to reproduce

1. I use my T530 without dock (Qubes OS booted, some VMs started, some windows open).
2. Attach it to the dock.
3. Attempt to work on the non-laptop display with the attached keyboard & mouse.

Expected behavior

Mouse clicks happen where the mouse is pointed at.

Actual behavior

Mouse clicks happen elswhere.

Notes

• This worked ~2-3 months ago, i.e. this is a regression.
• Restarting the dom0 display manager (awesomeWM in my case) doesn't help.
• Restarting the VMs with the unusable windows appears to help. It's however sometimes painful to do that (e.g. for sys-net to re-gain access to the tray icon functionality).

[0spinboson]

See the top of this guide -> https://www.qubes-os.org/doc/gui-troubleshooting/

[3hhh]

On 10/13/24 12:12, Foppe wrote: See the top of this guide -> https://www.qubes-os.org/doc/gui-troubleshooting/

Hm, interesting. I had never needed that, but it was working ~2-3 months ago. Anyway I just tried it with (2560*1440 + 1920*1080)*4/1024 = 22500 as I have a 2k and a FHD monitor, but it unfortunately did not resolve the issue.

[marmarek]

I just tried it with (25601440 + 19201080)*4/1024 = 22500 as I have a 2k and a FHD monitor

That's not enough, it's about rectangle covering them all. See the xrandr output (or the long xrandr command in the doc) to get the accurate number easily.

[3hhh]

I just tried it with (2560_1440 + 1920_1080)*4/1024 = 22500 as I have a 2k and a FHD monitor

That's not enough, it's about rectangle covering them all. See the xrandr output (or the long xrandr command in the doc) to get the accurate number easily.

The xrandr command returns 14400, i.e. even less.

xrandr output (without --verbose as it was too long) with both displays connected:

Screen 0: minimum 320 x 200, current 2560 x 1440, maximum 16384 x 16384
LVDS-1 connected 1920x1080+0+0 (normal left inverted right x axis y axis) 344mm x 193mm
   1920x1080     60.02*+  60.01    59.97    59.96    50.03    59.93  
   1680x1050     59.95    59.88  
   1400x1050     59.98  
   1600x900      59.99    59.94    59.95    59.82  
   1280x1024     60.02  
   1400x900      59.96    59.88  
   1280x960      60.00  
   1440x810      60.00    59.97  
   1368x768      59.88    59.85  
   1280x800      59.99    59.97    59.81    59.91  
   1280x720      60.00    59.99    59.86    59.74  
   1024x768      60.04    60.00  
   960x720       60.00  
   928x696       60.05  
   896x672       60.01  
   1024x576      59.95    59.96    59.90    59.82  
   960x600       59.93    60.00  
   960x540       59.96    59.99    59.63    59.82  
   800x600       60.00    60.32    56.25  
   840x525       60.01    59.88  
   864x486       59.92    59.57  
   700x525       59.98  
   800x450       59.95    59.82  
   640x512       60.02  
   700x450       59.96    59.88  
   640x480       60.00    59.94  
   720x405       59.51    58.99  
   684x384       59.88    59.85  
   640x400       59.88    59.98  
   640x360       59.86    59.83    59.84    59.32  
   512x384       60.00  
   512x288       60.00    59.92  
   480x270       59.63    59.82  
   400x300       60.32    56.34  
   432x243       59.92    59.57  
   320x240       60.05  
   360x202       59.51    59.13  
   320x180       59.84    59.32  
VGA-1 disconnected (normal left inverted right x axis y axis)
HDMI-1 disconnected (normal left inverted right x axis y axis)
DP-1 disconnected (normal left inverted right x axis y axis)
HDMI-2 disconnected (normal left inverted right x axis y axis)
HDMI-3 disconnected (normal left inverted right x axis y axis)
DP-2 connected primary 2560x1440+0+0 (normal left inverted right x axis y axis) 553mm x 311mm
   2560x1440     59.95*+
   2048x1152     60.00  
   1920x1200     59.88  
   1920x1080     60.00    50.00    59.94    30.00    25.00    24.00    29.97    23.98  
   1920x1080i    60.00    50.00    59.94  
   1600x1200     60.00  
   1680x1050     59.95  
   1280x1024     75.02    60.02  
   1200x960      59.99  
   1152x864      75.00  
   1280x720      60.00    50.00    59.94  
   1024x768      75.03    60.00  
   800x600       75.00    60.32  
   720x576       50.00  
   720x480       60.00    59.94  
   640x480       75.00    60.00    59.94  
   720x400       70.08  
DP-3 disconnected (normal left inverted right x axis y axis)

But ok, I'll try the rectangle covering it all, i.e. (2560 + 1920)*1440*4/1024 = 25200...

[3hhh]

But ok, I'll try the rectangle covering it all, i.e. (2560 + 1920)*1440*4/1024 = 25200...

No, that still didn't fix the issue. :(

[3hhh]

Btw I mirror the displays (and the larger one is sometimes disconnected) instead of extending them, i.e. 14400 is probably indeed the correct value.

Nonetheless that value doesn't work either:
I can correctly click on the upper left area of the larger screen, but not on the lower right area.