--- /n/sources/plan9/sys/src/9/pc/sdata.c	Wed Feb 13 21:05:25 2013
+++ /sys/src/9/pc/sdata.c	Wed Aug 13 00:00:00 2014
@@ -577,6 +577,7 @@
 		drive->dma = (dma>>8) & dma;
 		if(drive->dma)
 			drive->dma |= 'U'<<16;
+		drive->dmactl = drive->dma;
 	}
 
 	return dma;