net/ethernet: cpsw: Bugfix interrupts before enabling napi

If interrupts happen before napi_enable was called, the driver will not
work as expected. Network transmissions are impossible in this state.
This bug can be reproduced easily by restarting the network interface in
a loop. After some time any network transmissions on the network
interface will fail.

This patch fixes the bug by enabling napi before enabling the network
interface interrupts.
Signed-off-by: NMarkus Pargmann <mpa@pengutronix.de>
Acked-by: NPeter Korsgaard <jacmet@sunsite.dk>
Acked-by: NMugunthan V N <mugunthanvnm@ti.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/ti/cpsw.c

@@ -1169,9 +1169,9 @@ static int cpsw_ndo_open(struct net_device *ndev)
 		}
 	}
 
+	napi_enable(&priv->napi);
 	cpdma_ctlr_start(priv->dma);
 	cpsw_intr_enable(priv);
-	napi_enable(&priv->napi);
 	cpdma_ctlr_eoi(priv->dma, CPDMA_EOI_RX);
 	cpdma_ctlr_eoi(priv->dma, CPDMA_EOI_TX);