diff --git a/drivers/scsi/ultrastor.c b/drivers/scsi/ultrastor.c
index 1d3b029..75eca6b 100644
--- a/drivers/scsi/ultrastor.c
+++ b/drivers/scsi/ultrastor.c
@@ -298,9 +298,16 @@
 {
   int rv;
 
-  if (*field == 0) panic("No free mscp");
-  asm("xorl %0,%0\n0:\tbsfw %1,%w0\n\tbtr %0,%1\n\tjnc 0b"
-      : "=&r" (rv), "=m" (*field) : "1" (*field));
+  if (*field == 0)
+    panic("No free mscp");
+
+  asm volatile (
+	"xorl %0,%0\n\t"
+	"0: bsfw %1,%w0\n\t"
+	"btr %0,%1\n\t"
+	"jnc 0b"
+	: "=&r" (rv), "=m" (*field) :);
+
   return rv;
 }