====== Monitors ======

DisplayPort acts as plug&play (pnp) devices, so when display is powered off, the device will disappear. This will cause issues in multi-monitor and MST (DP Daisy-Chain) configurations.

Due to the device disappearing and reappearing, the display ID will change and settings like rotations and positions will not point to the correct display any longer.

Options:

  * Disable DCC/CI in the monitor settings. This will disable bidirectional communication between the monitor and the pc.
  * Enabling or disabling DisplayPort 1.2 settings in monitor may help (required for MST though)
  * Disabling screensaver/power saving options to switch off the monitor can act as a workaround

These linux commands to turn monitors off and on in case they do not come back from sleep:
<code>
env DISPLAY=:0 xset dpms force off
env DISPLAY=:0 xset dpms force on
</code>

Removing kernel parameters like the ones below from grub bootloader for the graphics driver may help:
<code - /etc/default/grub>
#GRUB_CMDLINE_LINUX="amdgpu.dcdebugmask=0x10 amdgpu.dc=0"
</code>
<code>
sudo update-grub
</code>

If using lightdm or similar and a specific monitor configuration is set, remove or alter it to avoid not being able to see the login screen:
<code>
sudo vi /etc/lightdm/lightdm.conf.d/70-linuxmint.conf
</code>

Some Sources:
https://superuser.com/questions/630555/turning-displayport-monitor-off-disables-monitor-completely

https://unix.stackexchange.com/questions/584088/how-can-i-get-stable-video-output-names


The autorandr package is able to save and restore the settings based on the monitor edid, thus bypassing the issue of the monitors getting re-arranged:
https://github.com/phillipberndt/autorandr
https://packages.debian.org/sid/all/autorandr/download
<code>
wget http://ftp.de.debian.org/debian/pool/main/a/autorandr/autorandr_1.15-1_all.deb
sudo dpkg -i autorandr_1.15-1_all.deb
rm autorandr_1.15-1_all.deb
autorandr --match-edid --save user
</code>

https://askubuntu.com/questions/1333688/how-to-get-external-monitor-to-reconnect-after-sleep-or-power-off


https://wiki.archlinux.org/title/AMDGPU