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From: Stefan Hoffmeister <stefan.hoffmeister@gmail.com>
To: linux-usb@vger.kernel.org
Subject: Thunderbolt: One missing DisplayPort?
Date: Fri, 20 May 2022 12:22:50 +0200	[thread overview]
Message-ID: <CALhB_QNhzHkf4Yw6TqZAbCisMK6TBy8ecw0M_Sq=EQXPN728fg@mail.gmail.com> (raw)

I am trying to diagnose a problem where I get video output on
Thunderbolt on one DisplayPort, but no output on the second
DisplayPort.

I would love to turn on all the (kernel-level) logging output that
there is, but do not know how to do that.

Basically, on a Dell Inspiron 16 Plus (7610) laptop with Thunderbolt
4, I am running Fedora Linux 36 with kernel 5.17+.

Connecting that laptop to a Thunderbolt docking station (Intel
Thunderbolt 3 chip inside),
with two screens attached via DisplayPort, I get only one screen up and running.

I'd like to discover more about this apparent error mode, because
attaching a different TB3
setup works fine. I am looking for some means to enable logging or to
get debugging insight.

Generally speaking, I suspect that this specific Dell laptop
(configuration) has some challenges
in the BIOS, and with Thunderbolt in general, but am totally blind to
what is going on.

This system offers potential for fun, this being a hybrid PRIME
configuration, with an Intel iGPU passing through to an Nvidia dGPU
which seems to be the only wired-up way to get DisplayPort output.

             reply	other threads:[~2022-05-20 10:23 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-05-20 10:22 Stefan Hoffmeister [this message]
2022-05-24 10:55 ` Thunderbolt: One missing DisplayPort? Heikki Krogerus
2022-05-24 11:04   ` Mika Westerberg
2022-05-27  6:24     ` Stefan Hoffmeister
2022-05-27  9:10       ` Mika Westerberg
2022-05-28 14:29         ` Stefan Hoffmeister
2022-05-29 19:51         ` Stefan Hoffmeister
2022-05-30  8:33           ` Tomasz Moń
2022-05-30  9:54             ` Mika Westerberg
2022-05-30 18:57               ` Stefan Hoffmeister
2022-05-31  9:36                 ` Mika Westerberg
2022-05-31 19:45                   ` Stefan Hoffmeister
2022-06-01 10:51                     ` Mika Westerberg
2022-06-02 19:34               ` Tomasz Moń
2022-06-03  5:04                 ` Mika Westerberg
2022-06-08 14:27                   ` Tomasz Moń
2022-06-11 16:29                     ` Tomasz Moń
2022-06-07 17:28                 ` Stefan Hoffmeister
2022-05-30 18:02             ` Stefan Hoffmeister

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