CONFIG_DMA_ENGINE helptext

[Christian Kujau]

Hello,

I was wondering what CONFIG_DMA_ENGINE is about and the only hint I 
found was this: http://lkml.org/lkml/2006/9/25/285

That's why I was about to send the attached patch. However, from looking 
at the comments in drivers/dma/dmaengine.c, it seems to be about 
non-HW-specific DMA support:

"This code implements the DMA subsystem. It provides a HW-neutral
 interface for other kernel code to use asynchronous memory copy
 capabilities"

Because I don't know anything about the innards of DMA, can someone 
please enlighten me what this knob is for and why one should enable it?

Thanks,
Christian.
--
BOFH excuse #94:

Internet outage--- linux-2.6/drivers/dma/Kconfig	2006-09-22 06:20:16.000000000 +0100
+++ linux-2.6/drivers/dma/Kconfig.edited	2006-10-02 19:04:25.000000000 +0100
@@ -8,7 +8,11 @@ config DMA_ENGINE
 	bool "Support for DMA engines"
 	---help---
 	  DMA engines offload copy operations from the CPU to dedicated
-	  hardware, allowing the copies to happen asynchronously.
+	  hardware, allowing the copies to happen asynchronously. Special
+	  hardware is required for this, currently only the Intel E5000 
+	  chipset is supported, certain RAID controllers might support
+	  this too. Note that this has nothing to do with PCI-DMA in
+	  the first place.
 
 comment "DMA Clients"