Xbox Live Camera on Linux (Part 4)

The promised instructions on rebuilding the kernel UVC kernel module. Here’s what I did on my Ubuntu 11.10 Aspire 1. If you substitute in your own kernel version number then you should be ok if you’re running other releases. I may experiment with something RedHat-ish later to find out how to do it there. Because I’m lazy, and because I’ve spent many years working as a sysadmin, I do this all whilst logged in as root. I’ve reconstructed the sequence of commands from my shell history, so it should be correct, but let me know if you have problems.

# apt-get install linux-source-3.0.0 kernel-package linux-headers-`uname -r`
# cd /usr/src
# tar jxvf linux-source-3.0.0.tar.bz2
# cd linux-source-3.0.0
# ln -s /boot/config-`uname -r` .config
# ln -s /usr/src/linux-headers-`uname -r`/Module.symvers .

At this point you can patch the UVC driver, and assuming that went well, continue:

# make modules_prepare
# make M=drivers/media/video/uvc

And you should now have a re-built driver. To load it manually you can just do:

# insmod drivers/media/video/uvc/uvcvideo.ko ctrltimeout=10000 timeout=10000

But to get it loaded into the kernel automagically a little more work is required:

# mkdir -p /lib/modules/`uname -r`/updates
# cp drivers/media/video/uvc/uvcvideo.ko /lib/modules/`uname -r`/updates
# depmod -a
# echo "options uvcvideo ctrltimeout=10000 timeout=10000" > /etc/modprobe.d/uvcvideo.conf

The patched module should now be loaded when your camera is hooked up. To check that the settings have been changed you can see their current values using:

$ cat /sys/module/uvcvideo/parameters/ctrltimeout
$ cat /sys/module/uvcvideo/parameters/timeout

Or if you want to reload the module manually:

# modprobe -r uvcvideo
# modprobe -v uvcvideo