[v4 Patch 1/2] s2io: add dynamic LRO disable support

[Amerigo Wang <amwang@redhat.com>]

This patch adds dynamic LRO diable support for s2io net driver.

(I don't have s2io card, so only did compiling test. Anyone who wants
to test this is more than welcome.)

This is based on Neil's initial work, and heavily modified
based on Ramkrishna's suggestions.

Signed-off-by: WANG Cong <amwang@redhat.com>
Signed-off-by: Neil Horman <nhorman@redhat.com>
Acked-by: Neil Horman <nhorman@redhat.com>
Reviewed-by: Stanislaw Gruszka <sgruszka@redhat.com>
Cc: Ramkrishna Vepa <Ramkrishna.Vepa@exar.com>

---

diff --git a/drivers/net/s2io.c b/drivers/net/s2io.c
index 668327c..2e6e3b3 100644
--- a/drivers/net/s2io.c
+++ b/drivers/net/s2io.c
@@ -795,7 +795,6 @@ static int init_shared_mem(struct s2io_nic *nic)
 		ring->rx_curr_put_info.ring_len = rx_cfg->num_rxd - 1;
 		ring->nic = nic;
 		ring->ring_no = i;
-		ring->lro = lro_enable;
 
 		blk_cnt = rx_cfg->num_rxd / (rxd_count[nic->rxd_mode] + 1);
 		/*  Allocating all the Rx blocks */
@@ -6684,6 +6683,41 @@ static int s2io_ethtool_op_set_tso(struct net_device *dev, u32 data)
 
 	return 0;
 }
+static int s2io_ethtool_set_flags(struct net_device *dev, u32 data)
+{
+	struct s2io_nic *sp = netdev_priv(dev);
+	int rc = 0;
+	int changed = 0;
+
+	if (data & ~ETH_FLAG_LRO)
+		return -EOPNOTSUPP;
+
+	if (data & ETH_FLAG_LRO) {
+		if (lro_enable) {
+			if (!(dev->features & NETIF_F_LRO)) {
+				dev->features |= NETIF_F_LRO;
+				changed = 1;
+			}
+		} else
+			rc = -EOPNOTSUPP;
+	} else if (dev->features & NETIF_F_LRO) {
+		dev->features &= ~NETIF_F_LRO;
+		changed = 1;
+	}
+
+	if (changed && netif_running(dev)) {
+		s2io_stop_all_tx_queue(sp);
+		s2io_card_down(sp);
+		sp->lro = dev->features & NETIF_F_LRO;
+		rc = s2io_card_up(sp);
+		if (rc)
+			s2io_reset(sp);
+		else
+			s2io_start_all_tx_queue(sp);
+	}
+
+	return rc;
+}
 
 static const struct ethtool_ops netdev_ethtool_ops = {
 	.get_settings = s2io_ethtool_gset,
@@ -6701,6 +6735,8 @@ static const struct ethtool_ops netdev_ethtool_ops = {
 	.get_rx_csum = s2io_ethtool_get_rx_csum,
 	.set_rx_csum = s2io_ethtool_set_rx_csum,
 	.set_tx_csum = s2io_ethtool_op_set_tx_csum,
+	.set_flags = s2io_ethtool_set_flags,
+	.get_flags = ethtool_op_get_flags,
 	.set_sg = ethtool_op_set_sg,
 	.get_tso = s2io_ethtool_op_get_tso,
 	.set_tso = s2io_ethtool_op_set_tso,
@@ -7229,6 +7265,7 @@ static int s2io_card_up(struct s2io_nic *sp)
 		struct ring_info *ring = &mac_control->rings[i];
 
 		ring->mtu = dev->mtu;
+		ring->lro = sp->lro;
 		ret = fill_rx_buffers(sp, ring, 1);
 		if (ret) {
 			DBG_PRINT(ERR_DBG, "%s: Out of memory in Open\n",