[wdmaudiodev] Re: Problem about GetMapping() / ReleaseMapping() in WavePCI

  • From: "pritesh gajjar" <gajjar.pritesh@xxxxxxxxx>
  • To: wdmaudiodev@xxxxxxxxxxxxx
  • Date: Fri, 24 Oct 2008 16:59:18 +0530

Hi All,
    Thank you so much for your valuable information.

I installed AC'97 sample and tested it on real hardware. In GetNewMappings()
function, they are writing head of mapping table in some register
WriteControlRegister(), which is read by DMA . Then DMA does some processing
on it. In ReleaseUsedMapping () we again read the value which is updated by
DMA. So my observation is that, here DMA updates this value when it
processes obtained mapping. Once mapping is processed it moves to next
index. So that  values gets updated to plus 1.
     Now, I am using fake DMA, so what does actual these processing done by
DMA mean ? that I need to simulate,  Which could be causing problems.
Because I think my destination stream(Capture) is not getting data which it
is supposed to get, and since I only obtain and release unprocessed mapping,
without any processing on it. Just obtaining and releasing won't help.
Because of which my destination stream is not getting correctly mapped data.
So if you have any suggestions about it, please reply.


Thanks and regards

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