[Xorg-driver-geode] Memory corruption problem

[Michael]

Hello

I have a strange memory corruption problem.

I use a Geode LX based system running mostly Debian Lenny on kernel 
2.6.31.4. I also use a bttv based video grabber card (Commell MP-878D). The 
system opens and closes the video device several hundred times a day. After 
a couple of days I see clearly memory corruption symptoms, mostly resulting 
in a total crash of the system.

I now use a small testing program:

#!/bin/bash
count=0
while [ 1 == 1 ]
do
        ((count++))
        date; echo "COUNT = " $count
        mplayer -frames 10 -fs -vo xv tv:// -tv norm=pal:input=1 > /dev/null
        sleep 0.1
done

I have done as many different tests as possible, but results are still 
limited. So far I can say that:

- I get memory corruptions and crashes only when using xv as output driver 
for mplayer, not with x11.
- I only seem to get the corruptions when opening the bttv device at the 
same time. That means if I grab the video from /dev/video0 via 'mencoder -
ovc copy' to a local file and then play this via mplayer there seems to be 
no problem so far.
- I also use mplayer -vo xv with many locally stored video files or (for a 
test) with an em28xx based USB video grabber without problems.
- Using a stress-buffer.c program that opens the bttv device, reads a random 
number of bytes and closes it again, there are no problems even after 
100.000 runs.

So the crashes only seem to occur when 1) from the bttv device is streamed 
and 2.) the xvideo hardware acceleration is used at the same time.

I have tried the following things without success:
- updating geode video driver to 2.11.6 (this version needed more video 
memory, 32MB instead of 8MB, and it segfaultet when not providing EDID 
information, but otherwise no difference)
- updating kernel to 2.6.32
- updating mplayer to newest version in debian testing (app. svn30072).
- starting bttv with option no_overlay=1

This is a complicated problem as it seems to involve two drivers at the same 
time. Can anybody hint me at where the problem may lie or what I could try 
to identify the culprit? Or better even to find a solution to the problem?

Thanks 

Michael