Alderlake status? (problem with video on Yoga Book)

From: Milan Obuch <freebsd-x11_at_dino.sk>
Date: Sat, 27 Apr 2024 12:50:25 UTC
Hi,

I am working on Yoga Book, installing X the usual way, and it works
well, or at least partially. It has Alder Lake CPU:

vgapci0@pci0:0:2:0:     class=0x030000 rev=0x00 hdr=0x00 vendor=0x8086 device=0x46d2 subvendor=0x8086 subdevice=0x7270
    vendor     = 'Intel Corporation'
    device     = 'Alder Lake-N [UHD Graphics]'
    class      = display
    subclass   = VGA
    bar   [10] = type Memory, range 64, base 0x6000000000, size 16777216, enabled
    bar   [18] = type Prefetchable Memory, range 64, base 0x4000000000, size 268435456, enabled
    bar   [20] = type I/O Port, range 32, base 0x4000, size 64, enabled

Playing video with vlc basically just works, I am experiencing some
unexpected behaviour, however. Last time, video stopped, and there are
some messages repeatedly logged on console and /var/log/messages:

drmn0: [drm] Resetting rcs0 for CS error
drmn0: [drm] GPU HANG: ecode 12:1:7d05520f, in vlc [109629]

Then some messages like

Fence expiration time out i915-drmn0:vlc[109629]:630f6!

followed with GPU hang messages as above (too numerous to count them),
after some time vlc dies, but GPU hang messages are continuing, just
without mentioning vlc.

Then X fails, but trying to start it anew is not possible, because...

[163977.753] _XSERVTransSocketUNIXCreateListener: ...SocketCreateListener() failed
[163977.753] _XSERVTransMakeAllCOTSServerListeners: server already running
[163977.753] (EE) 
Fatal server error:
[163977.753] (EE) Cannot establish any listening sockets - Make sure an X server isn't already running(EE) 
[163977.753] (EE) 
Please consult the The X.Org Foundation support 
         at http://wiki.x.org
 for help. 
[163977.753] (EE) Please also check the log file at "/var/log/Xorg.0.log" for additional information.
[163977.753] (EE) 
[163977.753] (EE) Server terminated with error (1). Closing log file.

It is necessary to restart it now... and video plays again. There may
be some other problems, I just documented the one as it just occured.

Is anybody working on Alder Lake support? I can test something, I am
currently running 15-CURRENT (maybe a week old), but I don't know much
about video from kernel and firmware perspective...

Regards,
Milan