Red Hat Bugzilla – Bug 833519
uvcvideo issue with kernel 3.5.0-rc2 and rc3
Last modified: 2013-07-04 18:59:43 EDT
Created attachment 592999 [details]
Description of problem:
My logitech webcam c270 (046d:0825) fails to work with these kernels. In Fedora 17 it functions okay. It looks like a regression in the usb-code or uvc-driver 
When I remove the webcam the kernel crashes with the following message:
"khubd/21 is trying to acquire lock". See further /var/log/messages.
Version-Release number of selected component (if applicable):
Steps to Reproduce:
1. boot system --> see messages in dmesg
2. run kamoso (KDE) or Cheese (Gnome) -> no webcam
3. see dmesg -> probe of webcam fails
light webcam turns on, kamoso/cheese shows image
In /var/log/message you'll see that systemd-udevd taints the kernel. In the output it seems to be related to the sound system e.g card1. That's the microphone of the webcam.
Note: I'v added messages from the crash and the current running/latest kernel in one messages file. dmesg is from the latest kernel.
Created attachment 593000 [details]
Which F17 kernels work? Specifically, do the F17 3.4 kernel updates function correctly?
All kernels - now running 3.4.2-4.fc17.x86_64 - have been working fine. No errors in /var/log/messages and dmesg.
I've checked some older /var/log/messages - /var/log/messages-20120610 - and saw that the first kernel that showed the issues is 3.5.0-0.rc0.git9.2.fc18.x86_64. This kernel was the first one that was installed after upgrading the stable Fedora 17 KDE-liveCD. 3.5.0-0.rc2.git0.1 is the oldest kernel that is currently installed.
Hope this helps.
FYI: Upstream bugreport  comment #6 speaks of a discussion on the alsa-devel list. A fix would land in mainstream soon.
Pressed somewhat too quick on Save Changes :-)
From  comment #54 it seems that kernel v3.5-rc7 contains a fix. As soon this kernel lands in rawhide I'll let you know if it works for me.
Kernel-3.5.0-0.rc7.git0.1.fc18.x86_64 indeed solved this issue. This report can be closed.
Thank you for letting us know. Your persistence in the bug is appreciated.