# Webcam refuses audio/oss, kernel panics...



## jozze (Jun 10, 2013)

Hello!

I have a bit of a problem. So far I have been using oss that came with the kernel (modules sound.ko and snd_hda.ko). I managed to use it for listening to music and for usage with my webcam.

I wasn't impressed by the sound quality of the base oss, however, so I have been trying to make a switch (it was constantly giving me that scratchy sound where it should be crystal clear). I have decided to go for audio/oss. So far, I have been very pleased with result. In order to use it, I had to disable aforementioned modules, in order to enable osscore.ko and oss_hdaudio.ko that come with it.

However, as the name indicates, when I plug in my USB webcam, the kernel associates it with my old oss from the base system. Not knowing how to proceed (because the modules conflict), the kernel begins to panic.

Does anyone here have similar experience, and knows how to force multimedia/webcamd to associate my webcam with audio/oss? Does multimedia/webcamd even support anything else, besides the base system oss?

My webcam is Logitech Webcam C525, I am running FreeBSD 9.1-STABLE #3 r251600.


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## jozze (Jun 10, 2013)

I don't see the entire error, but what I see is


```
(ada0:ata5:0:0:0): Error 5, Retries exahusted
(ada0:ata5:0:0:0): Synchronize cache failed
(ada1:ata5:0:1:0): FLUSHCACHE48. ACB: ea 00 00 00 00 40 00 00 00 00 00 00
(ada1:ata5:0:1:0): CAM status: CCB request is in progress
(ada1:ata5:0:1:0): Error 5, Retries exhausted
(ada1:ata5:0:1:0): Synchronize cache failed
Dumping 320 out of 3052 MB:kernel trap 12 with interrupts disabled


Fatal trap 12: page fault while in kernel mode
cpuid = 7; apic id = 07
fault virtual address   = 0x0
fault code              = supervisor read data, page not present
instruction pointer     = 0x20:0xffffffff8028020c
stack pointer           = 0x28:0xffffff80db5de890
frame pointer           = 0x28:0xffffff80db5de940
code segment            = base 0x0, limit 0xfffff, type 0x1b
                        = DPL 0, pres 1, long 1, def32 0, gran 1
processor eflags        = resume, IOPL = 0
current process         = 1526 (kldload)
trap number             = 12
panic: page fault
cpuid = 7
Uptime: 50s
```

This happened after I booted the computer and afterwards plugged in the webcam. The situation is different if I plug in first, and then power up the computer. In this case it just gives me notification, that osscore.ko could not be loaded (because of sound.ko which was automatically chosen when the kernel recognized my webcam.

I use audio/oss with audio/musicpd, to devices provided by audio/oss are busy, and modules cannot be simply unloaded.


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## jozze (Jun 11, 2013)

According to `# make -C /usr/ports/audio/oss maintainer`, the "maintainer" is ports@FreeBSD.org -- so the port is no longer maintained. Judging from freshports, the last update was made at 2007, and I shouldn't be surprised that it doesn't work properly with multimedia/mplayer either.

People at freebsd-usb@freebsd.org were unable to help me either. I'll just mark this thread [SOLVED].


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