[Bug 104054] [SKL][DP] HP Lap Dock external display with DisplayPort over USB Type-C input not properly detected

[bugzilla-daemon at freedesktop.org]

https://bugs.freedesktop.org/show_bug.cgi?id=104054

--- Comment #33 from Jérôme de Bretagne <jerome.debretagne at gmail.com> ---
Hi Rodrigo,

Thanks for your input. Could you expand a bit why you believe "This shouldn't
be related to this alternate mode discussion"? Could you also share which
display with USB Type-C input is working for you, for reference?

For this HP external screen model rebooting, I have two assumptions: 1/ either
a correct modeset is maybe taking too long to happen (compared to an internal
timer), or 2/ an unexpected modeset is triggering a bug in the display itself.

This portable display can work as both a wireless display or a wired display
(with DisplayPort over USB Type-C) and is showing a screen on startup to expose
the 2 modes, waiting for one or the other. After plugging it via USB Type-C, it
is trying to get configured in wired mode, but (assumption 1/) if it takes too
long, maybe it decides to expose the initial screen again to offer the 2
options (wired or wireless), so it reboots. But since it is still plugged in
via USB, it tries to get configured in wired mode again. And again, and again.

I'll try to point the time in the logs when the reboots happen for the next
time I'll share updated logs taken on a more current drm-tip. I'll see if I can
update xserver on that occasion too, but I've never done that yet.

Thanks, Jérôme

-- 
You are receiving this mail because:
You are on the CC list for the bug.
You are the assignee for the bug.
You are the QA Contact for the bug.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.freedesktop.org/archives/intel-gfx-bugs/attachments/20180705/8021a62d/attachment.html>