I found that after running "echo 128 > /sys/class/backlight/10-0045/brightness", it displays.
The default value of /sys/class/backlight/10-0045/brightness is 255. When it is either 0 or 255, there is no display.
But how to modify the default value then? It doesn't work to run it in init script or udev rule.
And I haven't found where to modify it in the device tree. It is controlled by I2C device 10-0045. There is no node for backlight while there is only the node reg_display in vc4-kms-dsi-7inch overlay.
The default value of /sys/class/backlight/10-0045/brightness is 255. When it is either 0 or 255, there is no display.
But how to modify the default value then? It doesn't work to run it in init script or udev rule.
And I haven't found where to modify it in the device tree. It is controlled by I2C device 10-0045. There is no node for backlight while there is only the node reg_display in vc4-kms-dsi-7inch overlay.
Statistics: Posted by crane — Thu Jul 10, 2025 5:01 am