Take the 2-minute tour ×
Ask Ubuntu is a question and answer site for Ubuntu users and developers. It's 100% free, no registration required.

I am getting a very strange problem as regards the USB3 port of my laptop under ubuntu 12.04 (My laptop is a Dell Inspiron n14z). The laptop has two USB3 ports and one USB2 port.

In order to get any usb mobile broadband stick(s) to work, I have to plug them in the USB2 port. They are immediately recognised and I can connect. If I plug them in one of the two usb3 ports, they are not recognized.

I even get different results from lsusb. I have tried this with four different USB sticks. One of O2, one of vodaphone, one of WindHellas, and one of CosmoteHellas. Three of them are Huawei and one of them is a K3570-Z.

As an example of a huawei e173:

lsusb result when plugged in USB2:

Bus 002 Device 005: ID 12d1:1436 Huawei Technologies Co., Ltd.

lsusb result when plugged in USB3:

Bus 003 Device 003: ID 12d1:1446 Huawei Technologies Co., Ltd. E1552/E1800 (HSPA modem)

I don't think that this problem has anything to do with the laptop brand or the mobile broadband usb sticks. The reason for that is that on the same laptop the usb sticks work just fine on all usb ports when I am running windows 7 or ubuntu 11.04. So this must be somekind of a bug relating to ubuntu 12.04. Is anyone else experiencing the same problem? I thank you very much in advance for any of your thoughts/ideas/assistance.

share|improve this question
    
I experienced it with other deivice. :( See the product ID got changed. You may write an usb_modeswitch rule to handle that. Possibly some firmware bug. –  Web-E Jul 13 '12 at 11:44
    
This problem doesn't make sence. It would make more sence if I couldn't connect in any USB port (2or3) and I had to prepare a usb_modeswitch rule. But why is the firmware recognized correclty on USB2 port and not on USB3...? Pretty strange, eh? With what kind of device did you experience the same problem? (thank you for your reply! :) –  Madvinegar Jul 13 '12 at 12:48
add comment

1 Answer 1

This makes sense. Each USB device type gives a unique ID to the computer so the computer can load the correct driver. If you use a different ID for USB3 then you end up confusing a driver which has a list of ids which this new id isn't in.

To fix the issue permanently, the driver must be modified to include the new IDs. This is a problem with Linux (kernel) and should be reported as a bug.

To get it working for yourself, you can follow this guide for adding an id to your driver: http://www.ha19.no/usb/ Attempt this only if you're comfortable running the commands.

share|improve this answer
add comment

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.