--- /sys/src/9k/386/sdata.c
+++ /sys/src/9k/386/sdata.c
@@ -578,6 +578,7 @@ atadmamode(Drive* drive)
 		drive->dma = (dma>>8) & dma;
 		if(drive->dma)
 			drive->dma |= 'U'<<16;
+		drive->dmactl = drive->dma;
 	}
 
 	return dma;