[wdmaudiodev] Re: Specifying KSPIN_FLAG_DISPATCH_LEVEL_PROCESSING on audio render pin

  • From: Tim Roberts <timr@xxxxxxxxx>
  • To: "wdmaudiodev@xxxxxxxxxxxxx" <wdmaudiodev@xxxxxxxxxxxxx>
  • Date: Tue, 6 Dec 2011 09:47:09 -0800

Jeff Claar wrote:
>
> I ran into this once too…in the docs for AvStrMiniPinProcess, it
> states this:
>
>  
>
> “The process dispatch is either made at the default IRQL =
> PASSIVE_LEVEL, or possibly at DISPATCH_LEVEL if the minidriver has
> specified KSPIN_FLAG_DISPATCH_LEVEL_PROCESSING in the relevant
> *KSPIN_DESCRIPTOR_EX*
> <http://technet.microsoft.com/es-es/query/ff563534>.”
>
>  
>
> So, I finally concluded that KSPIN_FLAG_DISPATCH_LEVEL_PROCESSING does
> not mean that the processing WILL happen at DISPATCH_LEVEL, just that
> it may. If you don’t specify the flag, you’re guaranteed that the
> processing will occur at PASSIVE_LEVEL.
>

That's the interpretation I had in my brain as well.  The flag says "it
is OK to call me at DISPATCH_LEVEL", not "you MUST call me at
DISPATCH_LEVEL".  I started to say that in reply to the original thread,
but I couldn't find the reference to back up my interpretation.

-- 
Tim Roberts, timr@xxxxxxxxx
Providenza & Boekelheide, Inc.

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