Xorg server segmentation fault when monitor is not connected.

[Chung-Yeol Lee]

On Sat, Jan 19, 2019 at 8:12 PM Jan Beich <jbeich at freebsd.org> wrote:

> Chung-Yeol Lee <chungyeol.lee at gmail.com> writes:
>
> >> > Is this a known issue?
> >>
> >> Not enough details. The crash fingerprint is obscured by lack of
> symbols,
> >> so it's not possible to search if anyone reported a similar issue
> upstream.
> >>
> >
> > Sorry for the lack of context. I hoped this is known issue or something
> > obvious from its symptom.
> > here's better stack trace with debug symbol:
> > #0  memcpy () at /usr/src/lib/libc/amd64/string/memmove.S:306
> > #1  0x0000000802834af8 in r600_create_vertex_fetch_shader
> (ctx=0x8010fa340,
> > count=2, elements=0x7fffffffd8c0) at r600_asm.c:2783
> > #2  0x0000000802690636 in util_blitter_create (pipe=0x8010fa340) at
> > util/u_blitter.c:302
> > #3  0x000000080283cd5f in r600_create_context (screen=0x806674100,
> > priv=0x0, flags=0) at r600_pipe.c:231
> [...]
>
> Looks similar to
> https://lists.freedesktop.org/archives/amd-gfx/2018-May/022218.html
> fixed by https://github.com/FreeBSDDesktop/kms-drm/commit/1d67729d7c5f
> which is part of drm-fbsd12.0-kmod >= 4.16.g20181210.
>

I have been using drm-fbsd12.0-kmod 4.16.g20181215.
After some recompiling / testing, somehow it was stuck and crashing even
when I connected monitor.
In fact, it could not detect the monitor according to Xorg.0.log.

I confirmed this is resolved by rolling back drm-kmod
to drm-fbsd12.0-kmod-4.11.g20181027_1
I also tried 4.16.g20181210, but it had the same issue.