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I've been running Ubuntu 13.10 on my ThinkPad X1 Carbon for 6 months. A couple of months ago the camera spontaneously stopped working; I'm not sure what the trigger was, but it could have been an update.

Now I see that the Bluetooth is not working either. Neither of the devices seem to be recognized (e.g. there is no /dev/vid*).

Output of lsusb:

Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 001 Device 002: ID 0eef:790a D-WAV Scientific Co., Ltd 
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

The devices work fine in both Windows 8 and the Live USB that I used for the original 13.10 install. Here's the output of lsusb from the Live USB version:

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 003 Device 002: ID 0eef:790a D-WAV Scientific Co., Ltd
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 003 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 004 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 001 Device 003: ID 0951:1666 Kingston Technology
Bus 001 Device 004: ID 147e:2020 Upek
Bus 001 Device 005: ID 0a5c:21e6 Broadcom Corp.
Bus 001 Device 006: ID 5986:0266 Acer, Inc

As you can see, there are many more devices; I believe that the last three lines are the fingerprint reader, the Bluetooth adapter and the camera, respectively. Why do they not appear above? Could they be connected through the "Integrated Rate Matching Hub", which is also missing?

I upgraded to 14.04 beta today hoping that a bug might have been fixed, but the problem persists.

Edit: The Live USB I mentioned is running the kernel from linux-image-3.8.0-19-generic. I just booted that kernel with the installed version of Ubuntu, but the same problem persists, so it's not obvious to me whether or not this is a kernel issue.

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This is a bug that you should report as a regression. In the meantime, boot from the last working kernel. –  Richard Apr 2 at 21:30
    
Thanks for the reply @searchfgold6789. How do we know that it's a bug and not an error with my config somewhere? As I mentioned in the edit, rolling back the kernel doesn't fix the problem. I just want to get the details right if I'm going to submit a bug report... –  Brent Pym Apr 3 at 20:23
    
Have you tried 12.04? –  Braiam Apr 4 at 1:38
    
No, I haven't tried 12.04 yet, @Braiam; for the moment, I'd prefer to keep that as a last resort since it's a production machine and all else is working smoothly. Have you any thoughts on how to diagnose the problem through syslogs, etc? –  Brent Pym Apr 4 at 23:01
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1 Answer 1

up vote 0 down vote accepted

I managed to fix the problem. Looking at the output of lspci, lshw and dmesg, I eventually determined that all of the USB root hubs were being detected, but there was an issue with interrupt requests that was preventing some of them from working. The Bluetooth, camera, etc., were failing because they were connected through one of the hubs that wasn't working.

The solution was to remove all instances of the string acpi=noirq from `/boot/grub/grub.cfg'.

Things probably went wrong when I was editing the grub configuration a couple of months ago trying to fix a separate issue. I didn't notice the problem right away because I don't use the devices in question all that often. Thanks to everyone who took the time to comment.

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