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Re: pxa_camera with one buffer don't work

Guennadi Liakhovetski schrieb:

On Fri, 2 May 2008, Stefan Herbrechtsmeier wrote:


Guennadi Liakhovetski schrieb:

On Fri, 25 Apr 2008, Stefan Herbrechtsmeier wrote:


Hi,

is it normal, that the pxa_camera driver don`t work with one buffer?. The
DQBUF blocks if only one buffer is in the query.

Well, in v4l2-apps/test/capture_example.c we see:

	if (req.count < 2) {
		fprintf (stderr, "Insufficient buffer memory on %s\n",
			 dev_name);
		exit (EXIT_FAILURE);
	}

so, they seem to refuse to run with fewer than 2 buffers. But if I remove
this restriction and enforce 1 buffer, it works. 2.5 times slower, but
works. 
If I do the same thing, I get a select timeout.


With the same capture_example.c?
I used a modified capture_example.c (with the modification you point me some emails ago). If I change the 
req.count to 1 and remove the restriction I get the select timeout.

Can there be a problem with your application? What kernel sources are you
using? Try using the latest v4l-dvb/devel git.

At the moment I use the kernel 2.6.24 and the V4L kernel modules from
mercurial.


How new are the modules?

I have update the modules some hours ago.

After I have port my robot platform to the current kernel, I will test it
again.
What do you mean by latest v4l-dvb/devel git:
   git.kernel.org/pub/scm/linux/kernel/git/mchehab/v4l-dvb.git?


Yes, its "devel" branch.


Thanks
   Stefan

--
Dipl.-Ing. Stefan Herbrechtsmeier

Heinz Nixdorf Institute
University of Paderborn System and Circuit Technology Fürstenallee 11 
D-33102 Paderborn (Germany)

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