From Rockchip open source Document
Whether eDP display card has been registered successfully
If the eDP display card has been created, it would create a sysfs debug directory.
$ ls /sys/class/drm/card0-eDP-1</code>
So you just need to check that directory. If that directory is missing in your machine board, please check:
- Whether eDP & eDP-PHY have been enabled in DTS files.
- Whether eDP panel have been registered successfully.
- Whether you have available VOP module for eDP.
- Check the kernel log for more detail (dmesg | grep dp)
Check eDP display card status: status, enabled, modes
$ cd /sys/class/drm/card0-eDP-1 $ cat status # should printed connected or disconnected $ cat enabled # should printed enabled or disabled $ cat modes # should printed the available mode list, like 1536x2048
If you still have no picture on eDP panel, please check bellow information:
- Check the eDP panel power supply.
- Check the panel datasheet, ensure you have configured the timing and power sequence rightly.
- Check the hardware connected status, or test the panel on workable board.