When using 2D and 3D accelerated graphics I get corruption like missing/blinking characters in fonts, broken transparency and torn rectangles on screen, black with dark blue dots that sometimes move/blink, which sometimes also show up in textures.
Every half an hour or so of especially intensive use, such as switching workspaces a lot or running games/flightgear, I see the screen freeze for a minute, during which everything non-graphics related keeps going -- then most of the time it recovers, but if one hang happens more hangs are likely to occur soon, and sometimes they either start happening without a pause, or perf degrades so bad I have to kill X or reboot the computer.
During that minute I can not do anything at all:
- switching to console does not work;
- if I suspend to reset the video, the whole machine hangs.
So I either have to reboot it -- or just wait a whole minute.
Might be related to https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=194766 but I don't see the same stream of errors, only the "error: [drm:pid12:i915_hangcheck_elapsed] *ERROR* Hangcheck timer elapsed... GPU hung" and something else.
Is there a way to at least make this hangcheck run more often, say, every 10 seconds, so I don't have to just sit there?
Created attachment 192939 [details]
Verbose boot dmesg
That corruption I described happens _sometimes_, once in a few hours.
I'm using a Intel Sandy Bridge GPU and I suffered/had the same issue that you have reported.
intel(4) driver is old and buggy so I installed graphics/drm-next-kmod following the instructions of pkg-message
# For drm-next-kmod
Deinstall x11-drivers/xf86-video-intel and remove /etc/X11/xorg.conf
Finally check that your user is member of the 'video' group.
But I get the corruption with modeset driver AND drm-next-kmod! No hangs so far, but lots of corruption!
Eh sorry about shouting. I had written about this in the other bug, not here.
Have you taken a look at their bug database?
If you report the issue there, maybe they can shed some light on the artifacts/misrendering that you are seeing.