with dual monitor from display port over HDMI to 2nd Monitor

dummy@example.com (bai4Iej2need) — Tue, 05 May 2026 08:58:09 +0000

Hardware:
Lenovo-r500, with a local display
1 DP to HDMI adapter
1 HDMI Cable of 6 meters
remote is a TV set with 3 HDMI inputs

Xorg -version
X.Org X Server 1.21.1.7
X Protocol Version 11, Revision 0
Current Operating System: Linux lenovo-r500 6.1.0-45-amd64 #1 SMP PREEMPT_DYNAMIC Debian 6.1.170-1 (2026-04-30) x86_64
Kernel command line: BOOT_IMAGE=/boot/vmlinuz-6.1.0-45-amd64 root=UUID=2da904de-743c-4e19-ac3f-5ec79cf96870 ro quiet noapic lsm=none
xorg-server 2:21.1.7-3+deb12u11devuan1 (https://www.devuan.org/os/community)
Current version of pixman: 0.42.2

when running
echo detect > /sys/class/drm/card0-DP-1/status

then the kernel reports the monitor as connected. when opening a console, the console is mirrored on the TV monitor.
However the console disappears after a few 10 or 20 seconds.
The kernel reports then disconnected.
cat /sys/class/drm/*/status
disconnected
disconnected
disconnected
connected
disconnected

Before XRandr is then able to detect the TV Monitor, but not able to create a dual display setting.
How to make the kernel keep the detected used displayport ?

Dev1 Galaxy Forum / with dual monitor from display port over HDMI to 2nd Monitor

with dual monitor from display port over HDMI to 2nd Monitor