Problem Report: i915 driver most probably causing freezes on FreeBSD 13.1-RELEASE

Hello,

I'm having an issue with the i915kms driver on a fresh FreeBSD 
13.1-RELEASE install. The system boots and shows the Display Manager 
(LightDM) without any problem, but after logging in, X crashes leaving a 
black screen and a dead keyboard. The crash occurs always about 3 
seconds after user login, no matter there was any user activity. I need 
to shutdown the system remotely from my laptop through ssh.

Loading the xf86-video-intel driver from xorg.conf.d/ instead of the 
modesetting driver leads to the same result. Forcing DRI3 from 
configuration file in xorg.conf.d/ doesn't help, nor does changing the 
acceleration options. As of DRM, I have tried drm-kmod and drm-510-kmod, 
both installed from packages and ports.

I'm pretty sure that it is NOT a desktop environment issue because I 
have the same behavior with LXDE and XFCE (the later installed just for 
testing purposes), and also because everything works as expected when 
the default xf86-video-vesa driver is used (but then the system is too 
slow and just unusable for everyday work).

A very similar issue has been discussed for FreeBSD 13.0 here 
[https://forums.freebsd.org/threads/i915-driver-causing-freezes-on-freebsd-13-0.80016/], 
and I have added some details about my own experience with FreeBSD 13.1 
here 
[https://forums.freebsd.org/threads/i915-driver-causing-freezes-on-freebsd-13-0.80016/post-582154].

I attach hereafter the output of several commands, as suggested in this 
page: https://wiki.freebsd.org/Graphics#Issues_.2F_Bugs . I can give 
more details if needed. Not sure whether this is the right place and/or 
way for reporting, so please be indulgent if I'm wrong. Thanks.

Any advise or help will be welcomed, as I'm just clueless at this point 
after having tried every different configuration I can think of. Big 
thanks.

Regards.