Following this issue: Error when updating to 8.9 - #33 by giuliomagnifico I also found that in DietPI 8.9 I’ve always used this command to turn off/on the display (Pimoroni HyperPixel but is the same for other displays) echo 1 > /sys/class/backlight/rpi_backlight/bl_power but now I get this error:
root@Pi-Hole:~# echo 1 > /sys/class/backlight/rpi_backlight/bl_power
-bash: /sys/class/backlight/rpi_backlight/bl_power: No such file or directory
meanwhile I wait for the fix, but is there another way to turn on/off the display and save some watts and display wear?
Thanks