This is a big clue! I think. I believe it supports my suspicion that the DMA linked list programming might get occasionally clobbered with SMP kernels. In your case you have two physically separate processors so you can remove one. When the kernel boots it will only see one so there is never going to be another processor banging away with an opportunity to collide with whatever goes wrong in DMA transactions. In my case, I have a hyper threading enabled P4 processor which is actually two processor cores on one socket so I can not do this experiment. My only option is to load a plain vanilla non SMP kernel instead. That means I also have to recompile and install many modules which I built for SMP kernel. I am thinking of just building another whole image on a differend HDD. It might be easier!
 
I think what you are seeing when you press "save position" is the pointers being shifted to a new index in the video stream buffer and programming a new DMA transfer starting at the new index thus fixing the corrupt DMA link list. I do not have clue how to go about debugging this myself. I would be happy to load gdb and look at it if someone who knows what they are doing can give some direction.
 
Sounds to me like we just have way more processing power available than the driver can handle! of course it only seems to be a problem when X is running along with mythtv. Like you I would really like to be able to exploit my extra processor but I may just have to downgrade my media center to a single processor till we can get this figured out.
 
Steve
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]On Behalf Of Ricardo Lugo
Sent: Saturday, November 19, 2005 8:24 AM
To: Discussion list for development of the IVTV driver
Subject: Re: [ivtv-devel] ivtv framebuffer is broken with PVR350

I have the same problem as Steve with my dual-processor & PVR350 TV-out setup.
I usually get freezes within the first 10 minutes of playback.

When I remove one of my processors (same vanilla 2.6.14 kernel w/ SMP & PREEMPT) this doesn't happen.

Curiously, when it freezes during playback in myth, if I press "save position," it saves the position, displays some stuff on the OSD, and then unfreezes & continues playback 10 minutes downstream (hopefully this means something to someone).

John, I tried your tests (an hour each) and here are the results:

1) Decoder-only: no crashes
2) Decoder & Encoder: no crashes
3) Decoder & FB updates: no crashes
4) Decoder & Encoder & FB: no crashes

So, inconclusive...
If there's any other tests you would like for me to run, I offer up my time to help diagnose.

-Rick

On Nov 12, 2005, at 2:34 PM, Steve & Laurie Sanders wrote:

I have been posting about freezing playback and ivtv-osd warnings, and ivtv DEC warnings in the ivtv-users list sinsce I am using 0.4.0 stable. I tried to provide enough detail to solicit some help but nobody has responded. I think I have done enough debugging to narrow the problem down to the ivtv driver and based on that have filed abug report (#53) in the Trac system.

Ticket URL: http://ivtvdriver.org/trac/ticket/53

You can find my previous posts to ivtv-users here:

&
If I need to post somewhere else, let me know where. If you need more infomation "". Yesterday I went so far as to disable tvout, and not load ivtv-fb and just playback directly to my monitor without using framebuffer or xdriver. When I did this I was able to playback a two hour movie without any freezes. This to me indicates the problem is somewhere in either the framebuffer or xdriver interface.
I would like to do whatever I can to support the development of this project, I am willing and able to capture any kind of debug information that might be requested. Are there any develpers out there that have any interest in this failure? It may be specific to smp cores, I don't know how many are developing systems with smp processors.

Regards,
Steve

Regards,
Steve

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