Cursor corruption on ALL displays (not just evdi) when DisplayLink monitor is used alongside native NVIDIA output through a KVM

[Newspaper8459]

Environment:

• OS: Ubuntu 24.04
• Kernel: 6.11.0-29-generic
• evdi version: 1.15.0
• NVIDIA driver: 595.71.05 (proprietary)
• GPU: RTX A6000
• Session: X11
• KVM switch: TESmart 2-Way Dual Monitor KVM

Symptom:
Screen corruption/artifacts near mouse cursor occurring on ALL connected displays (not just the evdi virtual display) when a DisplayLink monitor is connected simultaneously with a native GPU output (DP/HDMI),WITH a KVM switch in between. Corruption appears both on evdi-driven and natively-driven outputs at the same time.

Steps to reproduce:

1. Connect a native display via DP/HDMI through a KVM switch
2. Connect a DisplayLink USB monitor (with or without KVM switch, either is fine)
3. Move the mouse cursor
4. Cursor-area artifacts appear on both displays

Confirmed reproduction conditions:

• DisplayLink monitor: reproduces regardless of whether it's connected via a KVM switch or directly
• Native DP/HDMI monitor: reproduction confirmed when connected via a KVM switch (TESmart Dual Monitor KVM). Direct connection without KVM does not reproduce the symptom.

Workaround found:
Setting the evdi module parameter enable_cursor_blending=0 (/etc/modprobe.d/evdi-cursor.conf: options evdi enable_cursor_blending=0) resolves the issue completely.