Commit b94cbc90 authored by Vladimir Oltean's avatar Vladimir Oltean Committed by David S. Miller

net: dsa: fix error code getting shifted with 4 in dsa_slave_get_sset_count

DSA implements a bunch of 'standardized' ethtool statistics counters,
namely tx_packets, tx_bytes, rx_packets, rx_bytes. So whatever the
hardware driver returns in .get_sset_count(), we need to add 4 to that.

That is ok, except that .get_sset_count() can return a negative error
code, for example:

b53_get_sset_count
-> phy_ethtool_get_sset_count
   -> return -EIO

-EIO is -5, and with 4 added to it, it becomes -1, aka -EPERM. One can
imagine that certain error codes may even become positive, although
based on code inspection I did not see instances of that.

Check the error code first, if it is negative return it as-is.

Based on a similar patch for dsa_master_get_strings from Dan Carpenter:
https://patchwork.kernel.org/project/netdevbpf/patch/YJaSe3RPgn7gKxZv@mwanda/

Fixes: 91da11f8 ("net: Distributed Switch Architecture protocol support")
Signed-off-by: default avatarVladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: default avatarFlorian Fainelli <f.fainelli@gmail.com>
Reviewed-by: default avatarAndrew Lunn <andrew@lunn.ch>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent db825fee
...@@ -776,13 +776,15 @@ static int dsa_slave_get_sset_count(struct net_device *dev, int sset) ...@@ -776,13 +776,15 @@ static int dsa_slave_get_sset_count(struct net_device *dev, int sset)
struct dsa_switch *ds = dp->ds; struct dsa_switch *ds = dp->ds;
if (sset == ETH_SS_STATS) { if (sset == ETH_SS_STATS) {
int count; int count = 0;
count = 4; if (ds->ops->get_sset_count) {
if (ds->ops->get_sset_count) count = ds->ops->get_sset_count(ds, dp->index, sset);
count += ds->ops->get_sset_count(ds, dp->index, sset); if (count < 0)
return count;
}
return count; return count + 4;
} else if (sset == ETH_SS_TEST) { } else if (sset == ETH_SS_TEST) {
return net_selftest_get_count(); return net_selftest_get_count();
} }
......
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