12.1-STABLE crash after upgrade to r360192

[Wolfgang Zenker]

Hi,

I went from 12.1-STABLE r359345 to r360192 on an Acer C720 Notebook.
The system now crashes on loading /boot/modules/i915kms.ko
I build and install graphics/drm-kmod and graphics/drm-fbsd12.0-kmod
together with the kernel.

If i915kms.ko is loaded via kld_list in /etc/rc.conf at boot, the screen
goes blank upon loading the module and does not react any more, powercycle
is required. If I load the the module manually after a successful boot,
the screen goes blank and the system reboots after a while; on reboot
a dump is found and written to /var/crash.

Kernel config is GENERIC with added options WITNESS and WITNESS_SKIPSPIN
CPU is a Celeron 2955U (Haswell class) and the graphics controller
identifies as 'Haswell-ULT Integrated Graphics Controller' in pciconf.

Any suggestions how to proceed from here? Any usefull information that
I could extract from the crashdump?

Wolfgang