diff --git a/arch/parisc/kernel/syscall.S b/arch/parisc/kernel/syscall.S
index 41e60a9c7db2..e775f80ae28c 100644
--- a/arch/parisc/kernel/syscall.S
+++ b/arch/parisc/kernel/syscall.S
@@ -690,15 +690,15 @@ cas_action:
 	/* ELF32 Process entry path */
 lws_compare_and_swap_2:
 #ifdef CONFIG_64BIT
-	/* Clip the input registers */
+	/* Clip the input registers. We don't need to clip %r23 as we
+	   only use it for word operations */
 	depdi	0, 31, 32, %r26
 	depdi	0, 31, 32, %r25
 	depdi	0, 31, 32, %r24
-	depdi	0, 31, 32, %r23
 #endif
 
 	/* Check the validity of the size pointer */
-	subi,>>= 4, %r23, %r0
+	subi,>>= 3, %r23, %r0
 	b,n	lws_exit_nosys
 
 	/* Jump to the functions which will load the old and new values into