GPD Win Max eDP display not properly detected

The GPD Win Max is a small laptop using an i5-1035G7.

It seems the EDID can't be read from the display connected on eDP-1. As a result, the screen boots with the wrong resolution (as soon as i915 kms starts), and (mostly) unreadable. Everyone using this device on Linux uses an EDID extracted from Windows and passes it as an argument to drm.edid_firmware= on the kernel command line. I don't know if the issue is with the eDP link probing or the lack of EDID.

Here is the dmesg from a boot on drm-tip today, (HEAD at ca1f02fd329bec1a62fc515647b1fd2ecc6b7aac): dmesg-drm-tip-0x1e-bad-default.txt. Sorry, it's noisy because I plug an HDMI screen for convenience.

And here is a boot using this EDID extracted from windows:

dmesg-drm-tip-0x1e-good-edid.txt

Note that it works out-of the box on Windows since stock installs do detect the screen properly (albeit with the wrong orientation, but this should be a trivial fix).