IVTV DMA Issue

[harrijay]

I just noticed I am having some weird issue and I am not sure what to account it to. I was watching TV on an MVP the other day when for no apparent reason the video froze and if I tried to change the channel I get no signal. However if I go to another one of my IVTV tuners I am able to watch video again without any problem. I ran "dmesg" and the last line in there is "ivtv1: DMA TIMEOUT 00000001 0" I am currently running Ubuntu 7.10 and I have a PVR500 and a PVR150. has anyone seen anything like this? any ideas on what might be causing it?

[jpwegas]

Originally Posted by harrijay

I just noticed I am having some weird issue and I am not sure what to account it to. I was watching TV on an MVP the other day when for no apparent reason the video froze and if I tried to change the channel I get no signal. However if I go to another one of my IVTV tuners I am able to watch video again without any problem. I ran "dmesg" and the last line in there is "ivtv1: DMA TIMEOUT 00000001 0" I am currently running Ubuntu 7.10 and I have a PVR500 and a PVR150. has anyone seen anything like this? any ideas on what might be causing it?

I looked through all my log files (going back to June) and didn't see any messages like this. (My setup: 2 PVR-500 cards running on Ubuntu 7.04.)

What version of ivtv is installed?

If it's before 0.10.5 you probably want to upgrade - see this announcement that mentions the same DMA error.

Also the ivtv 0.10.6 release notes have this entry related to DMA issues:

- It turns out that the cx23415/6 DMA engine cannot do scatter/gather
DMA reliably. Every so often depending on the phase of the moon and
your hardware configuration the cx2341x DMA engine simply chokes on
it and you have to reboot to get it working again.

This change replaced the scatter/gather DMA by single transfers at a
time, where the driver is now responsible for DMA-ing each buffer.

Many thanks to Mark Bryars <mark.bryars@etvinteractive.com> for
discovering the link between scatter/gather and the DMA timeouts.

Not sure which one is hitting you, but it's probably one of these two bugs.

--John