Rebooting problems with /dev/cxm0

[Erin E Conn]

R. B. Riddick wrote:
> 
> Hmm... Does that mean, that the "dd" command can run for hours now?
> 
> If yes, I would do a "dd if=/dev/cxm0 of=/path/to/huge/filesystem/movie.mpg
> bs=1m" for some hours (if the resolution is 720x576 it produces 4GB/h)...

After some rebuilding and reinstalling of ports, I was able to cat 
/dev/cxm0 to a file in my home directory for about half an hour with no 
dma errors or lockups. I then stopped the cat and tried 'mplayer -cache 
4096 /dev/cxm0', and my machine locked up after about 2 minutes. The 
display continues to update; my dockapps in fluxbox are still 
functioning and updating, but the machine does not respond to any 
network traffic or input devices and the video and audio from /dev/cxm0 
have halted. Nothing is being logged to /var/log/messages at the time. I 
tried it again while keeping an eye on the console in case there are dma 
problems preventing anything being written to the log:

cxm0:encoder dma status 0xb
# MACHINE STOPPED RESPONDING HERE
cmx0:encoder dma status 0xb
ad0: TIMEOUT - WRITE_DMA retrying (1 retry left) LBA=22069947
ad0: TIMEOUT - WRITE_DMA retrying (0 retries left) LBA=22069947
dc0: watchdog timeout
dc0: failed to force tx and rx to idle state
ad0: FAILURE - WRITE_DMA timed out LBA=22069947
ad0: FAILURE - READ_DMA timed out LBA=20487259

The above messages continue to be output to the console and I have to 
manually restart the computer.