[wdmaudiodev] Re: StartDevice Empty Resource List?

  • From: Tim Roberts <timr@xxxxxxxxx>
  • To: "wdmaudiodev@xxxxxxxxxxxxx" <wdmaudiodev@xxxxxxxxxxxxx>
  • Date: Mon, 10 Jun 2013 10:33:49 -0700

Max K wrote:
> Over the last days, I have made huge progress in understanding KS and
> especially PortCls. I still can't however create a MIDI port that can
> be found using midiInGetDevCaps. I am probably missing something very
> important in correct startup of the driver.

Can you see and instantiate the device in graphedt or ksstudio?

> Apparently, you don't necessarily need to have interfaces defined in
> your inf files. I looked at a couple of inf files of my midi keyboards
> here and none of them defines any interfaces (except one driver, which
> specifies his topology interface).

That's true.  KsInitializeDriver and KsCreateFilterFactory will both
register the interfaces for you, based on the information you provide in

> I wonder, when a Midi Stream in the miniport is supposed to be created
> and by who. Will the OS call the newStream function when the driver is
> completely loaded or when a client connects to the midi port? Or do I
> need to create it in some kind of ISR?

The system will do this when some client opens a MIDI port.

> I haven't worried too much about the Interrupts as it wasn't well
> documented in the audio section (the only thing I found there was how
> to notify the Port that a hardware interrupt was triggered) and the
> sample didn't seem to do very much in the ISRs.

You are a virtual driver.  There is no hardware.  You will never see
interrupts, and you will not implement an ISR.

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

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