diff --git a/drivers/ide/pci/serverworks.c b/drivers/ide/pci/serverworks.c
index 49ec0ac..40b0383 100644
--- a/drivers/ide/pci/serverworks.c
+++ b/drivers/ide/pci/serverworks.c
@@ -97,6 +97,7 @@
 			mode = 2;
 
 		switch(mode) {
+		case 3:	 mask = 0x3f; break;
 		case 2:	 mask = 0x1f; break;
 		case 1:	 mask = 0x07; break;
 		default: mask = 0x00; break;