diff --git a/arch/m32r/kernel/sys_m32r.c b/arch/m32r/kernel/sys_m32r.c
index e0500e1..fe55b28 100644
--- a/arch/m32r/kernel/sys_m32r.c
+++ b/arch/m32r/kernel/sys_m32r.c
@@ -41,7 +41,8 @@
 		return -EFAULT;
 	local_irq_save(flags);
 	oldval = *addr;
-	*addr = 1;
+	if (!oldval)
+		*addr = 1;
 	local_irq_restore(flags);
 	return oldval;
 }
@@ -59,7 +60,8 @@
 
 	_raw_spin_lock(&tas_lock);
 	oldval = *addr;
-	*addr = 1;
+	if (!oldval)
+		*addr = 1;
 	_raw_spin_unlock(&tas_lock);
 
 	return oldval;