Workaround proposal for monitor layout bug (#9801)

proposed-fix/udev-monitor-layout-workaround.md

@@ -0,0 +1,54 @@
+# Cinnamon monitor layout bug (#9801) — workaround proposal
+
+## Problem
+
+Cinnamon does not remember the monitor layout (e.g. left-of) after a monitor is deactivated and re-enabled. It always defaults to placing the secondary monitor to the right, regardless of previous settings.
+
+## Workaround (functional example using udev and xrandr)
+
+This script and rule automatically re-position the second monitor when it's reconnected or re-enabled:
+
+### 1. Create the shell script
+
+sudo nano /usr/local/bin/cinnamon-monitor-fix.sh
+
+#!/bin/sh
+
+# Re-set the layout if DP-1 (Dell) was just (re)connected
+
+sleep 1        # give Cinnamon a moment to finish its own xrandr call
+export DISPLAY=:0
+export XAUTHORITY=/var/lib/lightdm/.Xauthority   # adjust if you use GDM/SDDM
+USER=$(who | grep '(:0)' | awk '{print $1}')
+XAUTHORITY=/home/$USER/.Xauthority DISPLAY=:0 \
+xrandr --output DisplayPort-1 --left-of DisplayPort-0 --auto
+
+### Make it executable:
+
+sudo chmod +x /usr/local/bin/cinnamon-monitor-fix.sh
+
+### 2. Add a udev rule that fires when the monitor re-appears
+
+sudo nano /etc/udev/rules.d/99-cinnamon-monitor-fix.rules
+
+ACTION=="change", SUBSYSTEM=="drm", ENV{HOTPLUG}=="1", RUN+="/usr/local/bin/cinnamon-monitor-fix.sh"
+
+### Reload rules:
+
+sudo udevadm control --reload-rules
+
+##########################################################################################################
+
+Proposal
+
+This workaround shows that the monitor layout can be reliably restored with simple logic.
+
+Suggested features for Cinnamon:
+
+    Store and restore previous x/y position of known monitors
+
+    Restore layout automatically on re-enable
+
+    Optional: toggle in Display Settings → “Remember monitor layout”
+
+Thank you!