diff -rU2 linux-2.6.24-rc6/Documentation/kernel-parameters.txt linux-2.6.24-rc6-mine/Documentation/kernel-parameters.txt
--- linux-2.6.24-rc6/Documentation/kernel-parameters.txt	2008-01-06 15:58:54.000000000 +0100
+++ linux-2.6.24-rc6-mine/Documentation/kernel-parameters.txt	2008-01-06 16:11:20.000000000 +0100
@@ -883,4 +883,11 @@
 			C2 power state.
 
+	libata.dma=	[LIBATA] DMA control
+			libata.dma=0	  Disable all PATA DMA like old IDE
+			libata.dma=1	  Disk DMA only
+			libata.dma=2	  ATAPI DMA only
+			libata.dma=3	  CF DMA only 
+			libata.dma=0,1,3  Combinations also work.
+
 	libata.noacpi	[LIBATA] Disables use of ACPI in libata suspend/resume
 			when set.