i915kms load locks up Haswell 4.16.g20191120 RELENG_12

[grarpamp]

Is i915kms supposed to work on this plaform?

Intel Haswell HD Graphics "Gen7" GT2 [P]4x00
drm-fbsd12.0-kmod-4.16.g20191120-88dc2c4884.txz

I think wiki/Graphics said yes, but the wiki is down.

These load fine in top to bottom order...

linuxkpi.ko
linuxkpi_gplv2.ko
debugfs.ko
drm.ko

Then attempting to load i915kms locks the system, does
not print anything to the console, and requires a hard reset.

Straight from the tarball, thus no version conflicts...
kern.module_path=''
kldload -v $(pwd)/<module>.ko

Both of the below load fine...

- drm-legacy-kmod-g20191217-913dabbc41.txz
- the set in /boot/kernel of the latest snapshot