Re: [PATCH net-next 2/2] bgmac: Add support for ethtool statistics

On 06/03/2016 10:57 AM, Ben Hutchings wrote:

On Fri, 2016-06-03 at 10:07 -0700, Florian Fainelli wrote:
[...]

quoted

+static void bgmac_get_strings(struct net_device *dev, u32 stringset,
+			      u8 *data)
+{
+	int i;
+
+	if (stringset != ETH_SS_STATS)
+		return;
+
+	for (i = 0; i < BGMAC_STATS_LEN; i++)
+		memcpy(data + i * ETH_GSTRING_LEN,
+		       bgmac_get_strings_stats[i].name,
+		       ETH_GSTRING_LEN);

These strings are null-terminated, not padded to ETH_GSTRING_LEN.  So
here you should be using strlcpy() instead of memcpy().

quoted

+}
+
+static void bgmac_get_ethtool_stats(struct net_device *dev,
+				    struct ethtool_stats *ss, uint64_t *data)
+{
+	struct bgmac *bgmac = netdev_priv(dev);
+	const struct bgmac_stat *s;
+	unsigned int i;
+	u64 val;
+
+	if (!netif_running(dev))
+		return;
+
+	for (i = 0; i < BGMAC_STATS_LEN; i++) {
+		s = &bgmac_get_strings_stats[i];
+		val = 0;
+		if (s->size == 8)
+			val = (u64)bgmac_read(bgmac, s->offset + 4);

Isn't this missing a << 32?

It is, guess I should have made sure there was 4GB+ worth of traffic to
make sure this seemed reasonable.

Does reading the high 32 bits latch the value of the low 32 bits?  If
not, you need to read the high bits again after the low bits and retry
if they changed.

Yes these registers are latched.

quoted

+		val |= bgmac_read(bgmac, s->offset);
+		data[i] = (u64)val;

Redundant cast.

Indeed, thanks.
-- 
Florian