drm-[stable|next]-kmod and MAXCPU

[Kevin Oberman]

On Mon, Sep 24, 2018 at 6:24 AM Claude Buisson <clbuisson at orange.fr> wrote:

> Hello,
>
> I tried to switch an amd64 Ivy Bridge system (with STABLE-11 @ r338696),
> from drm2 in base to drm-stable-kmod (and also drm-next-kmod) in ports,
> after rebuilding the custom kernel without any drm/drm2 module.
>
> I installed:
>
> gpu-firmware-kmod-g20180825
> drm-stable-kmod-g20180822
>
> (and also tried:
>
> drm-next-kmod-g20180822
>
> with the same results)
>
> Loading "by hand", by rc.conf, or by loader.conf
>
> i915kms.ko
>
> led to an immediate reboot.
>
> I built a GENERIC kernel (without any drm/drm2 module), and everything
> was OK.
>
> So I tried modifying the GENERIC kernel and came to that conclusion:
>
> the drm-[stable|next]-kmod ports cannot be used with a kernel built with
> MAXCPU (at least not defined as 256)!!
>
> I commented the MAXCPU line in my custom kernel definition, and got back
> a working system.
>
> May be, the assumptions about kernels could be explicited for ports of
> this kind ??
>
> Hoping being useful,
>
> CBu


I am running drm-stable-kmod on a Sandy Bridge system... one generation
older than Ivy with no problems. From your description, I wonder if you
might be doing too much.

First, a GENERIC kernel should be fine. No need to remove anything. You do
need to remove any module loads from /boot/loader.conf. (acpi_video_load is
OK). You must add "kld_list="/boot/modules/i915kms.ko" to /etc/rc.conf.
Nothing else should be required.

When booting, assuming you use the default vt(4) console, the switch from
sc to vt should be much later in the boot process... at or near the end of
the device scan. If you have am xorg.conf file, move it aside. Most of it
is unneeded. I have only a files section for added fonts, a modules section
for freetype (which might be unneeded by now), and a screen section to
enable brightness control. Nothing else. That works flawlessly on my  seven
year old system.
Good luck!
--
Kevin Oberman, Part time kid herder and retired Network Engineer
E-mail: rkoberman at gmail.com
PGP Fingerprint: D03FB98AFA78E3B78C1694B318AB39EF1B055683