From: Vladimir Oltean vladimir.oltean@nxp.com
[ Upstream commit b94cbc909f1d80378a1f541968309e5c1178c98b ]
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: 91da11f870f0 ("net: Distributed Switch Architecture protocol support") Signed-off-by: Vladimir Oltean vladimir.oltean@nxp.com Reviewed-by: Florian Fainelli f.fainelli@gmail.com Reviewed-by: Andrew Lunn andrew@lunn.ch Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- net/dsa/slave.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-)
diff --git a/net/dsa/slave.c b/net/dsa/slave.c index 11f1560de639..b887d9edb9c3 100644 --- a/net/dsa/slave.c +++ b/net/dsa/slave.c @@ -598,13 +598,15 @@ static int dsa_slave_get_sset_count(struct net_device *dev, int sset) struct dsa_switch *ds = dp->ds;
if (sset == ETH_SS_STATS) { - int count; + int count = 0;
- count = 4; - if (ds->ops->get_sset_count) - count += ds->ops->get_sset_count(ds, dp->index, sset); + if (ds->ops->get_sset_count) { + count = ds->ops->get_sset_count(ds, dp->index, sset); + if (count < 0) + return count; + }
- return count; + return count + 4; }
return -EOPNOTSUPP;