[PATCH 4.19 013/116] net: mvneta: Fix the case where the last poll did not process all rx

[Greg Kroah-Hartman]

From: Jisheng Zhang <Jisheng.Zhang@xxxxxxxxxxxxx>

[ Upstream commit 065fd83e1be2e1ba0d446a257fd86a3cc7bddb51 ]

For the case where the last mvneta_poll did not process all
RX packets, we need to xor the pp->cause_rx_tx or port->cause_rx_tx
before claculating the rx_queue.

Fixes: 2dcf75e2793c ("net: mvneta: Associate RX queues with each CPU")
Signed-off-by: Jisheng Zhang <Jisheng.Zhang@xxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/net/ethernet/marvell/mvneta.c |    3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

--- a/drivers/net/ethernet/marvell/mvneta.c
+++ b/drivers/net/ethernet/marvell/mvneta.c
@@ -2801,11 +2801,10 @@ static int mvneta_poll(struct napi_struc
 	/* For the case where the last mvneta_poll did not process all
 	 * RX packets
 	 */
-	rx_queue = fls(((cause_rx_tx >> 8) & 0xff));
-
 	cause_rx_tx |= pp->neta_armada3700 ? pp->cause_rx_tx :
 		port->cause_rx_tx;
 
+	rx_queue = fls(((cause_rx_tx >> 8) & 0xff));
 	if (rx_queue) {
 		rx_queue = rx_queue - 1;
 		if (pp->bm_priv)