I was able to get the onboard LCD panel working, finally, as follows:
First I extracted the edid file from the LCD panel using get-edid and putting that in /lib/firmware/edid/ncp.bin, and then forcing the kernel to take that using the kernel boot option drm.edid_firmware=edid/ncp.bin. This failed, and dmesg said that the ncp.bin file had a "bad block 0". Possibly that means that nothing within Linux can accept edid version 2.4?
Then I grabbed a generic 1920x1080.bin edid file from edid-generator github and put that one in /lib/firmware/edid/ and used that one with drm.edid_firmware and the display worked for the first time!
I am still unsure why Linux couldn't accept the version 2.4 edid data from the LCD panel.
I was able to get the onboard LCD panel working, finally, as follows:
First I extracted the edid file from the LCD panel using get-edid and putting that in /lib/firmware/ edid/ncp. bin, and then forcing the kernel to take that using the kernel boot option drm.edid_ firmware= edid/ncp. bin. This failed, and dmesg said that the ncp.bin file had a "bad block 0". Possibly that means that nothing within Linux can accept edid version 2.4?
Then I grabbed a generic 1920x1080.bin edid file from edid-generator github and put that one in /lib/firmware/edid/ and used that one with drm.edid_firmware and the display worked for the first time!
I am still unsure why Linux couldn't accept the version 2.4 edid data from the LCD panel.