[Bug 219748] Pluggable UD-4VPD dock appears to continually reset with AMD AI 365

bugzilla-daemon
2025-03-07T20:38:13Z

--- Comment #32 from Thomas (lyz27@yahoo.com) ---
>Do those same failures happen in the case that the retimer scan was totally
>commented out?
Yes. Same issues happen when testing the HDMI port of the dock with that patch
applied.

> Do you have CONFIG_USB4_DEBUGFS_MARGINING=y set in your kernel .config?
No, CONFIG_USB4_DEBUGFS_MARGINING doesn't show up in /proc/config.gz

Tried a few more things to see if it would provide clearer details.

In Linux, the monitor connected to the dock detected correctly, which doesn't
happen every time, setting the resolution to below 4k causes the monitor to
display output. Before setting the resolution below 4k, the monitor would
detect HDMI signal over and over without displaying video output.

Booted to Windows and reproduced the issue of the monitor blinking on an off
with the HDMI output on the dock. It did work after unplugging the dock and
plugging it back in though. Didn't check the resolution though. If that is an
important detail, I can get it.

Overall, both the Skip retimer scanning and 0001-thunderbolt patches cause the
dock to be correctly detected.

I'm not sure if I should pursue -- or how to pursue -- the other issues with
video. They seems sporadic. Amdgpu doesn't seem entirely stable. So maybe
video issues are expected.