diff --git a/drivers/staging/et131x/et1310_rx.c b/drivers/staging/et131x/et1310_rx.c
index 3ddc9b1..81c1a74 100644
--- a/drivers/staging/et131x/et1310_rx.c
+++ b/drivers/staging/et131x/et1310_rx.c
@@ -831,10 +831,10 @@
 
 	/* Indicate that we have used this PSR entry. */
 	/* FIXME wrap 12 */
-	rx_local->local_psr_full = (rx_local->local_psr_full + 1) & 0xFFF;
-	if (rx_local->local_psr_full  > rx_local->PsrNumEntries - 1) {
+	add_12bit(&rx_local->local_psr_full, 1);
+	if ((rx_local->local_psr_full & 0xFFF)  > rx_local->PsrNumEntries - 1) {
 		/* Clear psr full and toggle the wrap bit */
-		rx_local->local_psr_full &=  0xFFF;
+		rx_local->local_psr_full &=  ~0xFFF;
 		rx_local->local_psr_full ^= 0x1000;
 	}