Question

11

How to get Bus and Device relationship for a /dev/ttyUSB

rated 0 times [ 11] [ 0] / answers: 1 / hits: 60510 / 3 Years ago, tue, june 8, 2021, 2:19:57

I need to write an script for restart USB dongles. I have all tools but I can't link my /dev/ttyUSBx to physical BUS and DEVICE. An issue is that I have three dongles with the same id vendor and id product.

If I do lsusb the output is:

Bus 001 Device 004: ID 12d1:1003 Huawei Technologies Co., Ltd. E220 HSDPA Modem / E270 HSDPA/HSUPA Modem

Bus 001 Device 006: ID 12d1:1003 Huawei Technologies Co., Ltd. E220 HSDPA Modem / E270 HSDPA/HSUPA Modem

Bus 001 Device 007: ID 12d1:1003 Huawei Technologies Co., Ltd. E220 HSDPA Modem / E270 HSDPA/HSUPA Modem

Bus 001 Device 002: ID 80ee:0021

Bus 001 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub

And I have attached it to:

/dev/ttyUSB0

/dev/ttyUSB3

/dev/ttyUSB5

But I want to know which device is related with which Bus Device. By example I need to get the following:

/dev/ttyUSB0 -> Bus 001 Device 006

/dev/ttyUSB3 -> Bus 001 Device 004

/dev/ttyUSB5 -> Bus 001 Device 007

I'm using Ubuntu Server 10.04 and I tested the tools:

lsusb

hal

lsmod

But I can't get the relationship.

Answers

Only authorized users can answer the question. Please sign in first, or register a free account.

fulpu

Add To Favorites

Follow

Total Points: 116

Total Questions: 118

Total Answers: 104

Location: Solomon Islands

Member since Fri, Oct 8, 2021

3 Years ago

fulpu questions

1 How to insert an ascii character in a line position?

Fri, Apr 1, 22, 08:36, 2 Years ago

1 HP Omen 15 - ek0010ca - audio issues

Wed, Mar 16, 22, 15:25, 2 Years ago

1 Suspend not working properly (cannot wake up) on Ubuntu 20.04 with NVIDIA

Sun, Jan 1, 23, 19:04, 1 Year ago

1 How to get Extended Security Maintenance for Ubuntu 16.04

Wed, Aug 24, 22, 22:59, 2 Years ago

1 openmpi installation fails locally and on remote server

Tue, Dec 20, 22, 22:33, 1 Year ago

View All

answered 3 Years ago pipeag · Accepted Answer

Since I don't have your hardware I can't give you an exact answer.

I'd suggest that you go to the device in question, for example:

ls -l /dev/ttyUSB0

and obtain the major and minor node numbers. Let's say they are 116, 7

Then go to:

ls -l /sys/dev/char/116:7

(char, because a tty is a character device, if you were tracing down a disk device you would specify block instead of char)

In the output from the command you will see something a little like:

lrwxrwxrwx 1 root root 0 Sep 6 00:17 116:7 -> ../../devices//sys/devices/pci0000:00/0000:00:13.5/pci0000:00/0000:00:13.5/usb1/1-3/1-3:1.1/sound/card1/pcmC1D0c

The directory /sys/devices/pci0000:00/0000:00:13.5/usb1/1-3/ and its subdirectories have much information on the device. As an example, /sys/devices/pci0000:00/0000:00:13.5/usb1/1-3/busnum and /sys/devices/pci0000:00/0000:00:13.5/usb1/1-3/devnum. On my system these match the bus and device number mentioned in the device hotplug entries in /var/log/syslog.

Something else that works on my system for /dev/video0:

find /sys/dev -lname '*video0' -exec cat {}/device/busnum {}/device/devnum ; 2>/dev/null