net: fec: only clear a queue's work bit if the queue was emptied

In the receive path a queue's work bit was cleared unconditionally even
if fec_enet_rx_queue only read out a part of the available packets from
the hardware. This resulted in not reading any packets in the next napi
turn and so packets were delayed or lost.

The obvious fix is to only clear a queue's bit when the queue was
emptied.

Fixes: 4d494cdc92b3 ("net: fec: change data structure to support multiqueue")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Lucas Stach <l.stach@pengutronix.de>
Tested-by: Fugang Duan <fugang.duan@nxp.com>
Acked-by: Fugang Duan <fugang.duan@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c
index 08243c2ff4b4ae3d201c95c0bbc9caa5a7bd776c..2a03857cca18e55adfd5139b3c33755b19b7e3c5 100644 (file)
--- a/drivers/net/ethernet/freescale/fec_main.c
+++ b/drivers/net/ethernet/freescale/fec_main.c
@@ -1521,9 +1521,15 @@ fec_enet_rx(struct net_device *ndev, int budget)
        struct fec_enet_private *fep = netdev_priv(ndev);
 
        for_each_set_bit(queue_id, &fep->work_rx, FEC_ENET_MAX_RX_QS) {
-               clear_bit(queue_id, &fep->work_rx);
-               pkt_received += fec_enet_rx_queue(ndev,
+               int ret;
+
+               ret = fec_enet_rx_queue(ndev,
                                        budget - pkt_received, queue_id);
+
+               if (ret < budget - pkt_received)
+                       clear_bit(queue_id, &fep->work_rx);
+
+               pkt_received += ret;
        }
        return pkt_received;
 }