Reproducing this:
$ xrandr -d :0.0 --output HDMI-A-0 --left-of eDP $ xrandr -d :0.0 --output HDMI-A-0 --right-of eDP
No problem with:
$ xrandr -d :0.0 --output HDMI-A-0 --above eDP $ xrandr -d :0.0 --output HDMI-A-0 --below eDP
The affected and unaffected laptops each have identical kernel log entries about IRQ 7 and SADs count so I don't think those are related to this.
Reproducing this:
$ xrandr -d :0.0 --output HDMI-A-0 --left-of eDP
$ xrandr -d :0.0 --output HDMI-A-0 --right-of eDP
No problem with:
$ xrandr -d :0.0 --output HDMI-A-0 --above eDP
$ xrandr -d :0.0 --output HDMI-A-0 --below eDP
The affected and unaffected laptops each have identical kernel log entries about IRQ 7 and SADs count so I don't think those are related to this.