[bug report] adlp_tc_phy_connect [i915] floods logs with drm_WARN_ON(tc->mode == TC_PORT_LEGACY) call traces

[Francesco Poli]

Hi all,
on a laptop where I installed Debian testing some 6 months ago,
I noticed that the logs are continuously flooded with call traces
like the attached snippet (taken from /var/log/kern.log ).

It seems to me that it also used to happen with previous versions
of the Linux kernel, but I am under the impression that, with Linux
kernel 6.9.7, it got worse. I have recently upgraded to Linux kernel
version 6.9.8 (provided by the distro, Debian testing, as I said), but
the bug is still reproducible:

  $ uname -srvmo
  Linux 6.9.8-amd64 #1 SMP PREEMPT_DYNAMIC Debian 6.9.8-1 (2024-07-07) x86_64 GNU/Linux

I see at least 12 of these call traces just after boot, before even
starting X (with 'startx').
More of these call traces are sent to the logs after starting X, or
after invoking 'xrandr', or after locking the X session (with
XScreenSaver), ...
I always see these call traces (I mean the bug is always reproducible:
each time I boot, each time I call xrandr, ...).

They seem to correspond to no actual issue, as far as I can tell,
but they are flooding the logs with a significant flow of text...
which is worrying by itself.


What's wrong?
How can I stop this log-filling flood?
Should I black-list some module, for instance?


The outputs of

  # lspci -vnn -d :*:0300

and of

  # dmidecode

are attached.
Also, I booted with kernel parameters
'drm.debug=0xe log_buf_len=4M ignore_loglevel' and
logged in as root right after the boot.
The output of

  # dmesg

is attached.

Some additional information may be found on the [Debian bug] report I had previously filed.

[Debian bug]: <https://bugs.debian.org/1075770>


N.B.:
Please Cc me and the Debian bug address <1075770 at bugs.debian.org>
on replies, so that the interested parties (including me!) are kept
in the loop.
Thanks a lot for your time and for any help you may provide!


-- 
 http://www.inventati.org/frx/
 There's not a second to spare! To the laboratory!
..................................................... Francesco Poli .
 GnuPG key fpr == CA01 1147 9CD2 EFDF FB82  3925 3E1C 27E1 1F69 BFFE
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