Finding which USB port does what: low-, high-, and full-speed

[Paddy Landau]

While booting my USB into Recovery Mode, I noticed some text skipping past. There were mentions of three different USB speeds for my four USB ports:


usb 1-1.5: new high-speed USB device number 3 using ehci_hcd
usb 1-1.6: new full-speed USB device number 4 using ehci_hcd
usb 2-1.3: new low-speed USB device number 3 using ehci_hcd
usb 2-1.8: new high-speed USB device number 4 using ehci_hcdDoes this mean that one of my USB ports is low speed (1½Mbit/s), one is full-speed (12Mbit/s) and two are high speed (480Mbit/s)?

If so, how do I tell which USB port is which?

I would like to plug my keyboard and mouse into the low-speed port, my ancient device into the full-speed one, and my modern devices into the two high-speed ones.

Extra information

lsusb gives the following information.

Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 001 Device 002: ID 8087:0024 Intel Corp. Integrated Rate Matching Hub
Bus 002 Device 002: ID 8087:0024 Intel Corp. Integrated Rate Matching Hub
Bus 001 Device 003: ID 04f2:b28b Chicony Electronics Co., Ltd
Bus 001 Device 004: ID 0408:3003 Quanta Computer, Inc.
Bus 002 Device 003: ID 046d:c517 Logitech, Inc. LX710 Cordless Desktop Laser
Bus 002 Device 004: ID 0bda:8172 Realtek Semiconductor Corp. RTL8191SU 802.11n WLAN Adapter
Bus 001 Device 005: ID 04e8:1323 Samsung Electronics Co., Ltd lsusb -t gives the following information.

/: Bus 02.Port 1: Dev 1, Class=root_hub, Driver=ehci_hcd/2p, 480M
|__ Port 1: Dev 2, If 0, Class=hub, Driver=hub/8p, 480M
|__ Port 3: Dev 3, If 0, Class=HID, Driver=usbhid, 1.5M
|__ Port 3: Dev 3, If 1, Class=HID, Driver=usbhid, 1.5M
|__ Port 8: Dev 4, If 0, Class=vend., Driver=r8712u, 480M
/: Bus 01.Port 1: Dev 1, Class=root_hub, Driver=ehci_hcd/2p, 480M
|__ Port 1: Dev 2, If 0, Class=hub, Driver=hub/6p, 480M
|__ Port 1: Dev 5, If 0, Class=stor., Driver=usb-storage, 480M
|__ Port 5: Dev 3, If 0, Class='bInterfaceClass 0x0e not yet handled', Driver=uvcvideo, 480M
|__ Port 5: Dev 3, If 1, Class='bInterfaceClass 0x0e not yet handled', Driver=uvcvideo, 480M
|__ Port 5: Dev 3, If 2, Class=audio, Driver=snd-usb-audio, 480M
|__ Port 5: Dev 3, If 3, Class=audio, Driver=snd-usb-audio, 480M
|__ Port 6: Dev 4, If 0, Class=HID, Driver=usbhid, 12M

[Rebelli0us]

There is/was an app in Synaptic called "device manager" that shows all devices in treeview-like format. There you can see which devices are plugged in the various USBs. The app title is a misnomer, it's a device-viewer as it doesn't manage anything. It's handy for setting resume from S3 via keyboard.

[Paddy Landau]

Hmm, I don't find anything like that in Synaptic or in Ubuntu Software Centre.

You have a point, though; there must be a way to find out what is plugged into what. That would give the answer.

But I don't know how to find out this information.

[haqking]

Hmm, I don't find anything like that in Synaptic or in Ubuntu Software Centre.

You have a point, though; there must be a way to find out what is plugged into what. That would give the answer.

But I don't know how to find out this information.

Am i missing something ?

Your Wireless is plugged into a High Speed.
Your keyboard is already plugged into a low speed

etc

The lsusb-t tells you whats in what

[Paddy Landau]

Am i missing something ?
No… it is I who is missing something! I speak from ignorance :(


Your Wireless is plugged into a High Speed.
Your keyboard is already plugged into a low speed
Please explain how you know. I've looked and frowned at the output that I posted, but I can't put 2 and 2 together. I'm sure it's quite obvious if you know what you are looking at, but I can't figure it out.

[haqking]

No… it is I who is missing something! I speak from ignorance :(


Please explain how you know. I've looked and frowned at the output that I posted, but I can't put 2 and 2 together. I'm sure it's quite obvious if you know what you are looking at, but I can't figure it out.

OK for example:

Port 8: Dev 4, If 0, Class=vend., Driver=r8712u, 480M

Shows you your wireless device is plugged into a High Speed Device

[westie457]

As usual when someone posts a normal command with an option I have never heard of, I try it out.

As far as I can work things out the lsusb -t command with nothing connected to USB ports will return the default speed capabilities of the ports and with something connected - eg a mouse - the speed returned will be the speed of the device.

Of course I could be wrong.

[Paddy Landau]

Thank you for your responses.

From what you have said, it looks to me that:


I must have more than four USB ports, but some of them are hidden from me; for example, the wireless seems to be plugged in to a USB port.



All of the ports probably have the same capability, but they just appear to be different because of what is plugged into them at that particular time.

Does that seem right? If so, I don't need to bother myself.

[haqking]

Thank you for your responses.

From what you have said, it looks to me that:


I must have more than four USB ports, but some of them are hidden from me; for example, the wireless seems to be plugged in to a USB port.



All of the ports probably have the same capability, but they just appear to be different because of what is plugged into them at that particular time.

Does that seem right? If so, I don't need to bother myself.

the speeds are listed in /sys/bus/usb/devices/

So if you cat /sys/bus/usb/devices/usb1/speed

It will show you the speed for the the usb1 port. or use "usb?" to list all ports.

such as on mine the output is as follows:

480
480
480
5000
480
5000


Which means port 1,2,3 are high speed, 4 and 6 are USB 3 so 5Gb etc.

But your first ouptut shows you devices connected, your ports are likely to all be at least USB 2.0 I imagine, so the speed shown will be the device, you dont get high speeds keyboards for example

hid means human interface device by the way so refers usually to a keyboard/mouse etc. You can also do a verbose output with your lsusb for more information. (lsusb -v)

[Paddy Landau]

Thank you; that is most informative.

I think I can mark this thread as solved.