[Xorg-driver-geode] Memory corruption problem

[Michael]

Hello

O.k. I have now run the small test program on an intel atom based system. 
The OS and everything else is identical, except that the intel video driver 
is used and that the system has 1GB RAM instead of 256MB. After more than 
300.000 runs there is no memory corruption visible.

This indicates strongly that, although it is necessary to use the bttv 
driver to get memory corruption, it only happens with the geode driver and 
xv acceleration.

As I guess this is an awful bug to find and as Martin said the driver is in 
awful shape, I am considering to switch the hardware plattform to an intel 
based one.

Thanks for all the help and I wish you all the best for the Geode plattform.

Michael

Michael wrote:

> 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