drivers: net: xgene: Fix redundant prefetch buffer cleanup

BugLink: http://bugs.launchpad.net/bugs/1693673

Prefetch buffer cleanup code was called twice, causing EDAC to
report errors during reboot.

[ 1130.972475] xgene-edac 78800000.edac: IOB bridge agent (BA) transaction
error
[ 1130.979584] xgene-edac 78800000.edac: IOB BA write response error
[ 1130.985648] xgene-edac 78800000.edac: IOB BA write access at 0x00.00000000
()
[ 1130.993612] xgene-edac 78800000.edac: IOB BA requestor ID 0x00002400
[ 1131.000242] xgene-edac 78800000.edac: IOB bridge agent (BA) transaction
error
...

This patch fixes the errors by,

- removing the redundant prefetch buffer cleanup from port_ops->shutdown()
- moving port_ops->shutdown() after delete_rings()
Signed-off-by: Iyappan Subramanian <isubramanian@apm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
(back ported from commit 8aba8474)
Signed-off-by: Joseph Salisbury <joseph.salisbury@canonical.com>
Acked-by: Stefan Bader <stefan.bader@canonical.com>
Acked-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>

drivers/net/ethernet/apm/xgene/xgene_enet_hw.c

@@ -681,27 +681,6 @@ static void xgene_enet_clear(struct xgene_enet_pdata *pdata,
 static void xgene_gport_shutdown(struct xgene_enet_pdata *pdata)
 {
 	struct device *dev = &pdata->pdev->dev;
-	struct xgene_enet_desc_ring *ring;
-	u32 pb, val;
-	int i;
-
-	pb = 0;
-	for (i = 0; i < pdata->rxq_cnt; i++) {
-		ring = pdata->rx_ring[i]->buf_pool;
-
-		val = xgene_enet_ring_bufnum(ring->id);
-		pb |= BIT(val - 0x20);
-	}
-	xgene_enet_wr_ring_if(pdata, ENET_CFGSSQMIFPRESET_ADDR, pb);
-
-	pb = 0;
-	for (i = 0; i < pdata->txq_cnt; i++) {
-		ring = pdata->tx_ring[i];
-
-		val = xgene_enet_ring_bufnum(ring->id);
-		pb |= BIT(val);
-	}
-	xgene_enet_wr_ring_if(pdata, ENET_CFGSSQMIWQRESET_ADDR, pb);
 
 	if (dev->of_node) {
 		if (!IS_ERR(pdata->clk))

drivers/net/ethernet/apm/xgene/xgene_enet_main.c

@@ -1706,8 +1706,8 @@ static int xgene_enet_remove(struct platform_device *pdev)
 		xgene_enet_mdio_remove(pdata);
 
 	unregister_netdev(ndev);
-	pdata->port_ops->shutdown(pdata);
 	xgene_enet_delete_desc_rings(pdata);
+	pdata->port_ops->shutdown(pdata);
 	free_netdev(ndev);
 
 	return 0;

drivers/net/ethernet/apm/xgene/xgene_enet_sgmac.c

@@ -527,27 +527,6 @@ static void xgene_enet_clear(struct xgene_enet_pdata *pdata,
 static void xgene_enet_shutdown(struct xgene_enet_pdata *p)
 {
 	struct device *dev = &p->pdev->dev;
-	struct xgene_enet_desc_ring *ring;
-	u32 pb, val;
-	int i;
-
-	pb = 0;
-	for (i = 0; i < p->rxq_cnt; i++) {
-		ring = p->rx_ring[i]->buf_pool;
-
-		val = xgene_enet_ring_bufnum(ring->id);
-		pb |= BIT(val - 0x20);
-	}
-	xgene_enet_wr_ring_if(p, ENET_CFGSSQMIFPRESET_ADDR, pb);
-
-	pb = 0;
-	for (i = 0; i < p->txq_cnt; i++) {
-		ring = p->tx_ring[i];
-
-		val = xgene_enet_ring_bufnum(ring->id);
-		pb |= BIT(val);
-	}
-	xgene_enet_wr_ring_if(p, ENET_CFGSSQMIWQRESET_ADDR, pb);
 
 	if (dev->of_node) {
 		if (!IS_ERR(p->clk))

drivers/net/ethernet/apm/xgene/xgene_enet_xgmac.c

@@ -309,27 +309,6 @@ static void xgene_enet_xgcle_bypass(struct xgene_enet_pdata *pdata,
 static void xgene_enet_shutdown(struct xgene_enet_pdata *pdata)
 {
 	struct device *dev = &pdata->pdev->dev;
-	struct xgene_enet_desc_ring *ring;
-	u32 pb, val;
-	int i;
-
-	pb = 0;
-	for (i = 0; i < pdata->rxq_cnt; i++) {
-		ring = pdata->rx_ring[i]->buf_pool;
-
-		val = xgene_enet_ring_bufnum(ring->id);
-		pb |= BIT(val - 0x20);
-	}
-	xgene_enet_wr_ring_if(pdata, ENET_CFGSSQMIFPRESET_ADDR, pb);
-
-	pb = 0;
-	for (i = 0; i < pdata->txq_cnt; i++) {
-		ring = pdata->tx_ring[i];
-
-		val = xgene_enet_ring_bufnum(ring->id);
-		pb |= BIT(val);
-	}
-	xgene_enet_wr_ring_if(pdata, ENET_CFGSSQMIWQRESET_ADDR, pb);
 
 	if (dev->of_node) {
 		if (!IS_ERR(pdata->clk))