This is where Yocto can be totally different from Raspberry Pi OS.
The systemd-backlight service saves the backlight brightness on shutdown and restores it on restart. I've never noticed an issue of the backlight not coming on, but it may be due to that always running.
The backlight is attached to the relevant panel driver via device tree, so drm_panel_[enable|disable] should automatically turn it on/off. The brightness property defaults to max as well, although REG_PWM is written as 0 initially.
The systemd-backlight service saves the backlight brightness on shutdown and restores it on restart. I've never noticed an issue of the backlight not coming on, but it may be due to that always running.
The backlight is attached to the relevant panel driver via device tree, so drm_panel_[enable|disable] should automatically turn it on/off. The brightness property defaults to max as well, although REG_PWM is written as 0 initially.
Statistics: Posted by 6by9 — Fri Jul 11, 2025 10:28 am