Fishing: Any problems with bktr and amd64 v 6.0? I get page faults

Robert Krten root at parse.com
Wed Apr 12 19:26:12 UTC 2006


Jacob Meuser sez...
[snip]
> On Thu, Apr 06, 2006 at 01:59:46PM -0400, Robert Krten wrote:
> > Jacob Meuser sez...
> > > On Wed, Apr 05, 2006 at 10:20:32AM -0400, Robert Krten wrote:
> > > > I'm investigating a problem I'm having (two kernel page faults so
> > > > far an AMD64 on v6.0 release), possibly related to the bktr driver.
> > > 
> > > do you actually get good results with METEOR_CAP_SINGLE?  I often
> > > just get gibberish.  IIRC, this is because the bt8x8 chip "needs a
> > > moment to settle down".  I don't recall the details, but I believe I
> > > read this in a comment in one of the original bktr sample programs
> > > which uses METEOR_CAP_SINGLE.  according to
> > > http://telepresence.dmem.strath.ac.uk/bt848/ the sample programs are
> > > at ftp://telepresence.dmem.strath.ac.uk/pub/bt848/examples
> > > but I can't seem to connect to that now :(

I've been playing with it for a few days now, and found that after tuning,
I put in a 50ms delay and everything is fine.  CAP_SINGLE gives me a clean
image.

> > What should I be using?  The ring-buffer one, and just fish out the samples
> > as I need them?  Any hints on synchronizing with tuning?
> 
> I'm pretty sure the ringbuffer is not actually usable.  if you figure
> out how to use it, please let me know!

I tried to check out the OpenBSD version of the source that you pointed
me to, but alas some helpful individual(s) made copious gratuitous source
changes in the Open and/or Free source tree.  Thus there were 3500+ lines
of source code changes to wade through (even with various diff options).

I gave up :-(

However, I did "fix" (more accurately, "work around") the problems
that I had -- capturing with YUV_PLANAR mode does not crash my system,
so I am now happy and consider the problem "solved" (until I get to
the next crash) :-)

Cheers,
-RK

--
Robert Krten, PARSE Software Devices
Realtime Systems Architecture, Consulting, Books and Training at www.parse.com
Looking for Digital Equipment Corp. PDP-1 through PDP-15 minicomputers!


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