From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 76CD9367 for ; Sat, 16 Sep 2023 00:25:03 +0000 (UTC) Received: from mp-relay-01.fibernetics.ca (mp-relay-01.fibernetics.ca [208.85.217.136]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2986D3A86 for ; Fri, 15 Sep 2023 17:21:04 -0700 (PDT) Received: from mailpool-fe-01.fibernetics.ca (mailpool-fe-01.fibernetics.ca [208.85.217.144]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mp-relay-01.fibernetics.ca (Postfix) with ESMTPS id 83840E1883 for ; Sat, 16 Sep 2023 00:16:19 +0000 (UTC) Received: from localhost (mailpool-mx-02.fibernetics.ca [208.85.217.141]) by mailpool-fe-01.fibernetics.ca (Postfix) with ESMTP id 7C06E4414F for ; Sat, 16 Sep 2023 00:16:19 +0000 (UTC) X-Virus-Scanned: Debian amavisd-new at X-Spam-Score: -0.2 X-Spam-Level: X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_BLOCKED,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.6 Received: from mailpool-fe-01.fibernetics.ca ([208.85.217.144]) by localhost (mail-mx-02.fibernetics.ca [208.85.217.141]) (amavisd-new, port 10024) with ESMTP id 1689nPXziuu6 for ; Sat, 16 Sep 2023 00:16:19 +0000 (UTC) Received: from [192.168.48.17] (host-104-157-209-188.dyn.295.ca [104.157.209.188]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: dgilbert@interlog.com) by mail.ca.inter.net (Postfix) with ESMTPSA id 1D98E4414B for ; Sat, 16 Sep 2023 00:16:19 +0000 (UTC) Message-ID: <70c563f1-847c-32a1-cf4d-6bf9802017ab@interlog.com> Date: Fri, 15 Sep 2023 20:16:18 -0400 Precedence: bulk X-Mailing-List: linux-usb@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.15.1 To: "linux-usb@vger.kernel.org" Reply-To: dgilbert@interlog.com Content-Language: en-CA From: Douglas Gilbert Subject: device present in lsusb, disappears in lsusb -t Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net The device in question is this one: Bus 005 Device 015: ID 0483:572b STMicroelectronics STEVAL-USBC2DP Type-C to DisplayPort adapter. It is a USB-C alternate mode device (so tbtadm does not report it). That adapter is connected to a screen (and working) and to a USB-C port on a Lenovo TB3 dock [40AN] which in turn is connected to a Thinkpad X13 Gen3's USB-C port. The Thinkpad is running lk 6.6.0-rc1 with "lsusb (usbutils) 014". The strange thing is that this device is nowhere to be found in the output of "lsusb -t". The lsusb manpage describes the '-t' option as: "Tells lsusb to dump the physical USB device hierarchy as a tree." So is 'physical' a weasel word in this context, or is there a bug in the '-t' option, or is there some other explanation? Doug Gilbert