Re: GetScatterGatherList() for bidirectional DMA ?

On 28 Nov 2005 16:22:00 -0800, "icrashedagain"
<icrashedagain@xxxxxxxxxxx> wrote:

>I can not use IoAllocateCommonBuffer() because the buffer must be
>allocated in user mode. I must set up the SGL based on a MDL.
>
>David


Until you hit a platform with a write only memory mode your approach
will work. Also you might have issues on a platform where your DMA
operations are actually mapped (e.g. 32pci device on a 64bit
platform.)

You could of course build two separate sgls and have dma going in both
directions each using the appropriate sematics.

=====================
Mark Roddy DDK MVP
Windows Vista/2003/XP/2000 Consulting
Device and Filesystem Drivers
Hollis Technology Solutions 603-321-1032
www.hollistech.com
.

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