There is no specific support in the driver for CH7511. It is supposed to look like either a standard eDP or DP device and do signal and timing adjustments to LVDS invisibly to the system and driver. One thing to keep in mind is that the Ch7511 only converts from eDp/DP to LVDS what is fed it. So if your LVDS panel is 1024 x 768 and the driver outputs 1024 x 768 then it works. If the driver somehow outputs 640 x 480, or 800 x 600, then that is what will be converted to LVDS and sent to the LVDS panel which is unlikely to be able to display that.
So it is critical that you specify in your configuration:
-The EXACT resolution needed in a DTD OR be sure the driver only uses the EDID from the CH7511 set for your panel,
-AND set "fixed timing"
-AND disable "standard timing"
-AND set the correct resolutuion in WEC
-and likely set in the attribute the "eDP on DP" option (makes the driver do all the power management stuff that eDP requires and most DP to LVDS converts need us to do).
This should all help to make the CH7511 work properly. My guess is that somehow the driver is convinced to do a non-native resolution and that is whyt he panel does not work. Keep in mind that a DP monitor handles more resoltuons than just the native resolution (640 x 480 and 800 x 600 are assumes supported per PC specifications and MIcrosoft requirements).
The only other thing we can suggest is to contact Chrontel support as they are able to figure out what might be tripping up their chipsets and if there is a driver issue, they will work with us to correct it.
Hope this helps.