[wdmaudiodev] Re: Default Format

  • From: Tim Roberts <timr@xxxxxxxxx>
  • To: wdmaudiodev@xxxxxxxxxxxxx
  • Date: Thu, 29 Oct 2009 10:57:08 -0700

NCH Obble Smith wrote:
> I believe I am catching out the way out.  Do I have to
> MmProbeAndLockPages the Irp->UserBuffer???

You shouldn't have to; all of this should take place in the calling
process context.  This is just a data structure request.  No I/O is
required.  You should see a KSMULTIPLE_ITEM as the first thing in
UserBuffer, followed by a number of data ranges, as given by the
KSMULTIPLE_ITEM.

Is there an error code in the IRP?  The caller might have to issue this
once with a short buffer, to find out how much data there will be, then
issue it again with the real buffer.

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

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