revision higher than 250508 breaks webcam support

[Jože Zobec]

Sorry, for waiting this long to post this problem, I thought it would be dealt with this week, but since it wasn't better to report it now. I hope this is the right mailing list for this particular problem.

I am running FreeBSD 9.1-STABLE and using Logitech Webcam C525. I it's not listed amongst the supported hardware, but it was working perfectly until the updates that came this Sunday, 2013-05-12.

The problem I'm getting is this: 

I keep getting this error message from the kernel, if I'm using 9.1-STABLE r250707

...
pcm6: detached
ugen7.2: <vendor 0x046d> at asbus7
uaudio0: <vendor 0x046d HD Webcam C525, class 239/2, rev 2.00/0.10, addr 2> on usbus7
uaudio0: No playback.
uaudio0: Record: 48000 Hz, 1 ch, 16-bit S-LE PCM format, 2x8ms buffer.
uaudio0: Record: 32000 Hz, 1 ch, 16-bit S-LE PCM format, 2x8ms buffer.
uaudio0: Record: 24000 Hz, 1 ch, 16-bit S-LE PCM format, 2x8ms buffer.
uaudio0: Record: 16000 Hz, 1 ch, 16-bit S-LE PCM format, 2x8ms buffer.
uaudio: No MIDI squencer.
pcm6: <USB audio> on uaudio0
uaudio0: No HID volume keys found.
ugen7.2: <vendor 0x046d> at usbus7 (disconnected)
uaudio0: at uhub7, port4, addr 2 (disconnected)
pcm6: detached
...

This message is displayed periodically "ad infinitum" or at least until I unplug the webcam. It stays this way, even if I use the GENERIC kernel. In a "healthy" case, revision 250508, kernel message upon plugging the webcam, is

...
ugen7.2: <vendor 0x046d> at usbus7
uaudio0: <vendor 0x046d HD Webcam C525, class 239/2, rev 2.00/1.00, addr2> on usbus7
uaudio: No playback.
uaudio: Record: 48000 Hz, 1 ch, 16 bit S-LE PCM format, 2x8ms buffer.
uaudio: No MIDI sequencer.
pcm6: <USB audio> on uaudio0
uaudio0: No HID volume keys found.

And there it stops, and the webcam works in Skype.