From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 D4DBD56440 for ; Fri, 30 Aug 2024 12:32:18 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725021139; cv=none; b=oOEKw/aKEMSPNIhfvDL4l8k11PRgzTwFp+Ln8ZIUMqUd0tHRtJ4afbBjyhJP4qvlglkhE2AY3PzNyl/qabAPC2zlC8jSEhQcUtLl3b8E/EL+esJpEb3xcBNJA4lotLfXmiUqpfWKe9p1VZVJsEkf6ozEk6xnQxVV4t/RnLC3u2Q= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725021139; c=relaxed/simple; bh=dTr4R7Y/6pfCQtUaVEHZxYBTMm7UG3cMLTqOe+sWlKM=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=ViNa60IY1NMUipXBBVWbOV03WHX+sZKrkKd94fcOAsgTRoGFxvVQMIAGHJ70N0Jb1n6Q0XUM9UTLOx6hYvW7NSQVv9PogivypL5bRwcqWr6BMGaCW3kCfH/9GBe1FoDTJAzmdOdM+JK2ZWh1T9ZuHrCM9hDNt8asAyeVl/DKA3w= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=a/5dX5XK; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="a/5dX5XK" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2B97EC4CEC7; Fri, 30 Aug 2024 12:32:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1725021138; bh=dTr4R7Y/6pfCQtUaVEHZxYBTMm7UG3cMLTqOe+sWlKM=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=a/5dX5XKFGHFY4KEFElkULkYPqI0F9fd+c10NYy35oCOzQc0qgSQeHrKyK/icD6rM HLpPEmX6yfWRMfwrfASLktQI0/GE9qP44SxCeRplXRZiCqFWh92k01HFhGcw0iilSS oUC0i7pnOkZcF98PfPn965ggXmey6Ik5iRN66Dg0= Date: Fri, 30 Aug 2024 14:32:15 +0200 From: Greg KH To: Eyal Lebedinsky Cc: linux-usb@vger.kernel.org Subject: Re: Understanding 'lsusb -t' Message-ID: <2024083057-charger-lustrous-d434@gregkh> References: <63d4782a-1d83-4252-a0ca-a9b50e6074f0@eyal.emu.id.au> Precedence: bulk X-Mailing-List: linux-usb@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <63d4782a-1d83-4252-a0ca-a9b50e6074f0@eyal.emu.id.au> On Fri, Aug 30, 2024 at 10:14:20PM +1000, Eyal Lebedinsky wrote: > I assume that the generated list is a tree, so each leaf (Device/If) is on only one point. > > I note this output: > > $ lsusb -tv > /: Bus 001.Port 001: Dev 001, Class=root_hub, Driver=xhci_hcd/16p, 480M > ID 1d6b:0002 Linux Foundation 2.0 root hub > [trimmed] > |__ Port 004: Dev 004, If 0, Class=Hub, Driver=hub/4p, 480M > [trimmed] > |__ Port 005: Dev 006, If 0, Class=Hub, Driver=hub/4p, 480M > [trimmed] > |__ Port 006: Dev 019, If 0, Class=Hub, Driver=hub/4p, 480M > ID 2109:2817 VIA Labs, Inc. > /: Bus 002.Port 001: Dev 001, Class=root_hub, Driver=xhci_hcd/10p, 10000M > [trimmed] > |__ Port 006: Dev 006, If 0, Class=Hub, Driver=hub/4p, 5000M > ID 2109:0817 VIA Labs, Inc. > > I removed some content that is not relevant to my question. > > Note the Bus 001.Port 006 and Bus 002.Port 006 entries. > > I verified that both are for the same (one) device. They do not show when I disconnect it. > The device is an external 4-port USB3.0 hub. It is listed once as 480M and once as 5000M. > Nothing is plugged into any of the four ports. > > Is this correct? Why does this device show twice in the list? That's odd, as the same device shouldn't be on multiple busses. Busses are a "root port" on the system (i.e. a new PCI controller device), so are you sure you just don't have multiple devices with the same device/vendor id? What is the diff between running the command before and after removing a single device? thanks, greg k-h