Debian – How to Interpret the Output of ‘lsusb’?

debianusb

I recently found out about the lsusb command while troubleshooting a headset issue..

My laptop runs debian and doesn't have anything plugged into USB currently, but when I run the "lsusb" command, I still get quite a bit of output:

root@t500:~# lsusb
Bus 008 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 007 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 006 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 005 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 004 Device 003: ID 0a5c:2145 Broadcom Corp. Bluetooth with Enhanced Data Rate II
Bus 004 Device 002: ID 08ff:2810 AuthenTec, Inc. AES2810
Bus 004 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 003 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 002 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 001 Device 002: ID 0781:b6d0 SanDisk Corp. 
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

Could someone break down what this means in more detail?

The SanDisk card is connected via PCMCIA, not USB. Are both PC cards and USB devices listed in lsusb?

I don't have any external bluetooth connected, why would this display?

Why are some root hubs 1.1, and some 2.0? Does that mean some of my USB ports are 2.0 and others aren't?

What is a root hub exactly, just an empty USB port?

Best Answer

A USB hub is a device that has one cord that plugs into one USB port, but provides multiple USB ports for you to plug devices into. It's essentially a USB multiplexer.

A root hub, AFAIK, is a USB hub that's internal. For example, there might ony be one USB slot in your motherboard, but there are multiple external ports because there's an internal root hub plugged into the motherboard. (This is simplified, of course. I'm not an expert in hardware.)

The Bluetooth device is the chip inside your computer that actually broadcasts Bluetooth radio traffic. Probably, it's wired through a USB port inside the computer's case.

With regards to the display of "Linux Foundation", my guess is that that's where the drivers come from. But I'm not sure.

lsof

The only way I can think to gain access to a mount such as this would be to mount it as you did before using Nautilus or whatever file browser, and then using a tool such as lsof to see what files/devices are opened by Nautilus.

$ lsof -p $(pgrep nautilus)

But if you're having to connect to your phone via gphoto2 then you're likely not mounting the device a a mass storage device but rather a PTP - Picture Transfer Protocol. There's a Linux FUSE implementation for PTP too.

gvfs?

I would also look in your $HOME directory for a sub-directory called .gvfs. Usually when GNOME or Nautilus are doing the mounting this directory is created as a convenience.

In newer versions of GNOME (3+) this directory has moved and is now here, /run/user/$UID/gvfs.

Example

$ ls -l /run/user/$UID/gvfs/smb-share\:server\=tank\,share\=t 
total 2
drwx------. 1 saml saml    0 Oct 31 09:16 Development
drwx------. 1 saml saml    0 Nov 18 14:52 home
drwx------. 1 saml saml    0 May 14  2013 incoming
...

NOTE: That's a environment variable $UID that is often set in Bash on most modern systems. If it isn't set you can find your user's ID like so:

$ id
uid=1000(saml) gid=1000(saml) groups=1000(saml),10(wheel) context=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023

Debian NetworkManager – Network Connection on Kali

We reached to the conclusion that uncommenting the wlan0 and adding a directive to run the wpa_supplicant, worked. Please note that having dhcp in the interface already makes the dhclient invocation.

auto wlan0
iface wlan0 inet dhcp
    wpa-conf /etc/wpa_supplicant.conf

Best Answer

Related Solutions

How to mount a filesystem from a given USB bus:device

lsof

gvfs?

Example

Debian NetworkManager – Network Connection on Kali

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