Re: question for soc-camera driver

[Guennadi Liakhovetski <g.liakhovetski@xxxxxx>]

On Fri, 18 Apr 2008, ·ëöÎ wrote:

> 2008/4/18 Guennadi Liakhovetski <g.liakhovetski@xxxxxx>:
> >
> >  How exactly are you counting lost frames? I just tried several
> >  configurations - with different number of buffers, writing in tmpfs and
> >  over nfs, without load and under a ping flood. And I'm counting FIFO
> >  overrun interrupts. At most I'm getting 1-3 overruns with dropped frames
> >  in the beginning, and only if I write over NFS.
> >
> >  If your system is using drivers, that block interrupts for a considerable
> >  amount of time, of course DMA done interrupts will be missed, FIFO will
> >  overflow and frames will be dropped. I don't think you can avoid this
> >  under such conditions. As I suggested before - you can use more buffers,
> >  put the frame read-out in a separate thread. As a test try writing to
> >  RAM-based tmpfs and see if frames get dropped then too.
> 
> I write in tmpfs.But some frame is dropped.If I request more
> buffers,the number of dropped frames is reduced.Now I request 20
> buffers and write 100 frames.the 52,53,56,57 is dropped.

...and you didn't reply how you're counting frames - this could help me 
understand why you're losing them.

Thanks
Guennadi
---
Guennadi Liakhovetski

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