Re: [PATCH net-next v2 3/9] ethtool: add a new command for reading standard stats

On Fri, Apr 16, 2021 at 12:27:39PM -0700, Jakub Kicinski wrote:

+static int stats_prepare_data(const struct ethnl_req_info *req_base,
+			      struct ethnl_reply_data *reply_base,
+			      struct genl_info *info)
+{
+	const struct stats_req_info *req_info = STATS_REQINFO(req_base);
+	struct stats_reply_data *data = STATS_REPDATA(reply_base);
+	struct net_device *dev = reply_base->dev;
+	int ret;
+
+	ret = ethnl_ops_begin(dev);
+	if (ret < 0)
+		return ret;
+

Nit: A comment here would be nice. Something like:

Mark all stats as unset (see ETHTOOL_STAT_NOT_SET) to prevent them from
being reported to user space in case driver did not set them.

+	memset(&data->phy_stats, 0xff, sizeof(data->phy_stats));
+
+	if (test_bit(ETHTOOL_STATS_ETH_PHY, req_info->stat_mask) &&
+	    dev->ethtool_ops->get_eth_phy_stats)
+		dev->ethtool_ops->get_eth_phy_stats(dev, &data->phy_stats);
+
+	ethnl_ops_complete(dev);
+	return 0;
+}