On Tue, 22 Jun 2010 12:44:40 +0100
Ben Hutchings [off-list ref] wrote:

On Tue, 2010-06-22 at 04:50 -0400, Amerigo Wang wrote:

quoted

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.

[...]

quoted

+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;

Should lro_enable=0 really prevent enabling it later?  This seems
unusual.

We are doing this in bnx2x. Current Amerigo patch change to the
same behavior mlx4. For me that have sense - if you want to disallow
LRO - use module option.

In this case however lro_enable variable looks obsolete from times
where there was no ethtool possibility to dynamic set/unset LRO.
Perhaps it should be removed at all, but maybe not as part
of that patch.

Stanislaw