For the Radxa Rock 5B SBC, I use the Radxa Display 8HD. Everything works fine except for the brightness control. The command $ echo 0 > /sys/class/backlight/dsi1-backlight/brightness turns off the backlight. If I vary the PWM value from 1…255 the backlight is switched on but always stays the same brightness. Is it possible that the backlight PWM control is not working. I use the rock-5b-radxa-display-8hd.dtbo overlay.
Thank you.