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Re: DMA buffer
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Re: DMA buffer

It is more correct to call prepare() and complete() but a recent version of the kernel allows a new flag called 'kIOMemoryAutoPrepare'. If you use the inkernel withOptions variants to create memory descriptors then this option will allow you to create and automatically prepare an IOMD.

Goodfrey

On Jun 11, , at 23:43, Chris Thomas wrote:


On Jun 11, 2004, at 10:52 AM, Godfrey van der Linden wrote:

You can combine step 1 & 2 by creating an contiguous IOBufferMemoryDescriptor rather than calling IOMallocContiguous directly. I believe the IOBMD also 'auto-prepares' so it will generally just do the right thing.

Really? I've been told repeatedly to call prepare and complete even for IOBufferMemoryDescriptor. Guess I'd better go read the source again...

Chris
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References: 
 >DMA buffer (From: "Lalit Chandivade" <email@hidden>)
 >Re: DMA buffer (From: Godfrey van der Linden <email@hidden>)
 >Re: DMA buffer (From: Chris Thomas <email@hidden>)



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