[Bug 236838] Commit r340224 prevents loading the kernel for some Intel Xeon hardware

[Bruce Evans]

On Thu, 4 Apr 2019 a bug that dpesnt want replies at freebsd.org wrote:

> https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=236838
>
> --- Comment #5 from longwitz at incore.de ---
> Created attachment 203384
>  --> https://bugs.freebsd.org/bugzilla/attachment.cgi?id=203384&action=edit
> Output serial console of full verbose boot
>
> I use amd64, the commit r340224 (r339979) does only affect amd64. Removing the
> line with 'case 0x3590' helps, kernel now boots fine. With the patch
>
> --- pci_cfgreg.c.orig   2018-11-26 16:43:04.706033000 +0100
> +++ pci_cfgreg.c        2019-04-04 11:30:51.847357000 +0200
> @@ -90,13 +90,15 @@
>         * This also implies that it can do PCIe extended config cycles.
>         */
>
> +       printf("pci_cfgregopen called\n");
> ...

> together with a 'printf(Calling pci_early_quirks())' in machdep.c and setting
> "debug.late_console=0" in loader.conf I got the attached output on the serial
> console.

I checked that vt still crashes with debug.late_console=0.  So configuring
vt breaks early console use even for console drivers that work early.

Bruce