Some Logitech web-cams have serious problems all of the last kernel revisions (somewhere since 2.6.26 kernel revision). Sometimes when user starts its Linux OS things with web-cam go bad. Symptoms are "Waiting for sound system to respond" when clicking at the sound icon in system tray and ton of "cannot set freq 16000 to ep 0x86" in your /var/log/kern.log. What solves this problem when this occurs is removing snd-usb-audio kernel module from kernel and plugging it back. Cause of this bug is still unknown, and some say it is a bug in some Logitech webcam firmwares which gets triggered by something in Linux boot process. Lets work around it on Debian, Ubuntu and its derivatives...
Attached to this post there is a script designed to be run at the end of boot process that checks last 30 lines of /var/log/kern.log. If it founds more than 3 occurrences of "cannot set freq 16000 to ep 0x86", snd-usb-audio module is ripped out of kernel and plugged back five seconds latter. Did your webcam made troubles during boot process you can check in your /var/log/messages cause script will write to that log file when it starts and if it found problems or not. Procedure is as follows:
Step 1. - Downloading and extractingYou must download my script by clicking on the link at the end of this article. In tar.bz2 file there is a scrip you must extract before using. Start you terminal program and navigate to a folder where you stored the ubuntu-bug459445-workaround.sh.tar.bz2 file and type:
tar -xjvf ubuntu-bug459445-workaround.sh.tar.bz2
Step 2. - Adding to be run at boot
After you have extracted ubuntu-bug459445-workaround.sh script we must make our script executable and put it to be run at boot by issuing this commands:
chmod +x ubuntu-bug459445-workaround.sh sudo cp ubuntu-bug459445-workaround.sh /etc/init.d/ sudo update-rc.d ubuntu-bug459445-workaround.sh start 99 2 3 4 5 .
Now we have worked around this problem. But still you should go to your distribution bug site and file bug report if report doesn't exists so this problem could be fixed for real. For Ubuntu go to Ubuntu bug #459445 and for Fedora please go to Red Hat bug #544554If you have found problems with this script or you have question please comment here by clicking on the link in upper right corner of this post. Please do the same thing if you find better workaround.
Here is the DOWNLOAD LINK
Now if you want to tweak your webcam settings you can do so by using GUI:Webcam settings control on Ubuntu Linux operating system
You can even use Linux terminal to control your webcam settings. More info in my following article:Webcam settings on Ubuntu and Fedora Linux CLI from terminal