i915kms load locks up Haswell 4.16.g20191120 STABLE_12

[Niclas Zeising]

On 2019-12-25 08:10, grarpamp wrote:
> Christian Weisgerber <naddy at mips.inka.de> wrote:
>>> grarpamp <grarpamp at gmail.com> wrote:
>>> 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.
> 
> "For haswell based systems, if the drm-kmod port does not work"
> 
> This implies that it is supposed to work. Same with table on...
> wiki/Graphics/Intel-GPU-Matrix
> 
> There are some lists here that can help users identify...
> https://en.wikipedia.org/wiki/List_of_Intel_graphics_processing_units
> https://en.wikipedia.org/wiki/Intel_Graphics_Technology
> https://en.wikipedia.org/wiki/Haswell_(microarchitecture)
> 
>>> 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,
>>> FreeBSD-12.1-STABLE-amd64-20191219-r355880
> 
> 
>> Maybe you ran afoul of the API change 12.0->12.1 issue that
>> has caused numerous reports here...?
> 
> Btw, no blurb is in src or ports UPDATING, relnotes, or errata.
> 
> Though yes now I see a downrev buldbox issue that maybe
> you are refer to (they seem to panic, not lock)...
> 
> https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=241101
> https://github.com/FreeBSDDesktop/kms-drm/issues/183
> 
> If this is the case, adding some logic to the [meta] pkg,
> and making a 12.1 pkg would seem to solve.
> That way none of the release train and progress are held back.
> It might be possible to bundle and autoselect based on base
> rev from multiple module KBI/ABI/API revs in one package.
> Or to point with logic to another pkg repo that is building
> just kern mods from a set of light VMs. Or some combination.
> Maybe even put some checks or logic in kld mechanism.
> Should also see if other kernel modules in ports have this
> compatibility problem scheme, so to solve all uniformly.
> NO_PACKAGE seems questionable if the result is that hardware
> that does work, doesn't, requiring beginner users to build.

This is a FAQ, and it's in the errata for FreeBSD 12.1.  You need to 
compile drm-kmod locally on FreeBSD 12.1.

It is not possible to create a separate 12.1 package, since all packages 
for 12 are built on 12.0 until 12.0 is EOL.  The drm-fbsd12.0-kmod is 
compatible with 12.1 in that it builds and works on 12.1, it just has to 
be built on a 12.1 system (same goes for stable).

Haswell is supported by the new drm-kmod (it is also the last one that's 
supported by drm-legacy-kmod, if memory serves).

Regards
-- 
Niclas