[wdmaudiodev] Re: Need some help with passing the General Audio Test
- From: Tim Roberts <timr@xxxxxxxxx>
- To: "wdmaudiodev@xxxxxxxxxxxxx" <wdmaudiodev@xxxxxxxxxxxxx>
- Date: Wed, 2 Apr 2014 10:40:55 -0700
Stephen Pinto wrote:
>
>
> You based your work on MSVAD, which is a Port Class miniport. The Port
> Class model is designed for devices that connect directly to a hardware
> bus (like PCI), and therefore have no latency. So, the model assumes
> that the IDmaChannel methods (like CopyTo and CopyFrom) will all execute
> immediately. Your design requires those methods to delay while you wait
> on action from outside.
>
>
> In our driver we are not performing any major operations
> inside CopyTo. What we do in CopyTo is just copy the data from the DMA
> buffer to some other buffer and return. There is then this another
> thread which performs the task of reading from that buffer and do what
> we need to i.e. perform our operations. So I presume we are not
> halting the CopyTo while we do our operations. Am I still missing out
> on something ?
No, your question is a good one, and it has made me realize that there
is a gap in my knowledge of Port Class. The message you got from the
HCK test says that it submitted an IRP_KS_WRITE_STREAM request while in
KSSTATE_PAUSE, it was expecting the request to be pended, and instead
the request was held in the driver. As far as I know, that kind of
thing is outside the control of a Port Class miniport -- it's handled by
the Port Class driver.
So, I don't know the answer. Someone who is better with Port Class
should probably take over this thread.
--
Tim Roberts, timr@xxxxxxxxx
Providenza & Boekelheide, Inc.
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