X broken after upgrade to 9.0

[Jörn Clausen <joernc%googlemail.com@localhost>]

Hi!

I just upgraded my NetBSD desktop machine (ASRock mainboard with
Celeron J1900 CPU) from 8.1/adm64 to 9.0. It ran X11 without any
problems before, but now I have glitches. Lines of pixels are not
updated correctly, as if parts of the screen are constantly XORed.
It's hard to describe...

The onboard graphics seems to be detected correctly:

Mar  3 21:40:51 itix /netbsd: [   7.7395065] i915drmkms0: interrupting
at ioapic0 pin 16 (i915drmkms0)
Mar  3 21:40:51 itix /netbsd: [   7.8195601] intelfb0 at i915drmkms0
Mar  3 21:40:51 itix /netbsd: [   7.8295675] intelfb0: framebuffer at
0xffffa200636dc000, size 1280x1024, depth 32, stride 5120

A little bit later in /var/log/messages, this pops up:

Mar  3 21:39:58 itix /netbsd: [  34.0453419] kern info: [drm] stuck on
blitter ring
Mar  3 21:39:58 itix /netbsd: [  34.0453419] kern info: [drm] GPU
HANG: ecode 7:2:0x96fbfff7, reason: Ring hung, action: reset
Mar  3 21:39:58 itix /netbsd: [  34.0453419] kern error:
[drm:(/usr/src/sys/external/bsd/drm2/dist/drm/i915/i915_gem.c:3196)i915_context_is_banned]
*ERROR* gpu hanging too fast, banning!
Mar  3 21:39:58 itix /netbsd: [  34.0653569] 000125a8 :  00000230
Mar  3 21:39:58 itix /netbsd: [  34.0653569] 000125ac :  00000000
Mar  3 21:39:58 itix /netbsd: [  34.0653569] 000125b0 :  00000220
Mar  3 21:39:58 itix /netbsd: [  34.0653569] 000125b4 :  00000000
Mar  3 21:39:58 itix /netbsd: [  34.0653569] 000125b8 :  0000026e

I also saw something about "i915 GPU crashed, file a bug report" for a
brief moment in the console window of XDM, just before logging in. I
can't find it in any of the files in /var/log/, so I am not even sure
about the full text or who I am supposed to contact.

Any idea how to fix this? Should I give modular X from pkgsrc a try?

-- 
Joern Clausen
https://www.oe-files.de/photography/