Re: question for soc-camera driver

["冯鑫" <fengxin215@xxxxxxxxx>]

2008/4/18 Guennadi Liakhovetski <g.liakhovetski@xxxxxx>:
> On Thu, 17 Apr 2008, ·ëöÎ wrote:
>
>  > 2008/4/14 Guennadi Liakhovetski <g.liakhovetski@xxxxxx>:
>  > >>  I found the problem with reversed frame order. The same problem led to
>  > >>  corrupted frames. Please try the patch below on the top of the previous
>  > >>  one. With it I have no more problems with the test application with any
>  > >>  number of buffers.
>  >
>  > 2008/4/14 ·ëöÎ <fengxin215@xxxxxxxxx>:
>
> > >  I test it and It is good.But some frames is dropped,like
>  > >  1,2,3,4,5,8,9,10,11,14,15,16,17,18,21,22.The frame 6,7,12,13,19,20 is
>  > >  dropped.I request 4 buffers now.
>  >
>  > Will you improve soc-camera driver for the lost frames?
>
>  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.

Thanks fengxin

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